2409 in number 6 Shop ©2005, Trevor Heath
In addition to organising and working on the restoration of 2409 and chasing elephants round Tsavo Game park, not to mention helping maintain the Museum's other two operating locomotives in running order, Graham Roberts has been keeping members of the East African Steam mailing list up to date with the work on the locomotive. I'm told he has a day job as well! His reports make a very interesting diary of the ongoing work. Much of the work is being carried out by members of the Steam Team, formed of retired Kenya Railways men, lead by Joe Kamau.
Tuesday 7th December 2004
We pulled all the covers to ensure no one had pinched the brasses. They were all there.... Externally of course she is nice having benefited from a very good "GR" repaint....
I feel she will need a retube. Joe states he has the tubes and now has has the proven skills to do a retube.
She last steamed in 1979 at Voi as the Engineers train loco. She last moved in 1992 (December) for filming but was not steamed at that time. No prediction on a return to service. More details later.
Thursday 9th December, 2004
We used 6217 to shunt her. There was no driver or shunter available so we just borrowed the engine and did our own shunting and switching.
Friday 10th December 2004
While gone, 2409 was shunted into place in 6 shop. She is now under cover for the first time since the 1970's. Estimation for restoration is given at 4 months. I'm told she will get a retube and go up on the jacks.
Her oil tank is at Voi a result of the 1992 filming contract when she was depicted as a wood burner. When 5918 goes to Voi for filming in January, a flat car will be taken and the tank recovered.
Saturday 18th December 2004
Tuesday 4th January, 2005
A problem has presented itself - all the copper lubrication piping was stolen years back, and Kenya Railways no longer has a piping drawing for 24 class locos. The drawing is need so that piping runs can be put back accurately, particularly to make sure that the driving wheels and axleboxes get the necessary lubrication.
I understand that the original 24 class piping drawings may have been sold to enthusiasts in the UK. It's also possible that there is an archive of material from Vulcan Locomotive Co. Ltd of Newton-le-Willows where the loco was built in 1924.
Tuesday 11th January 2005
Wednesday 4th May 2005
I recently met the works manager and suggested that if he could reawaken interest in the project, I would do what I could to find outside funding for the supplies needed in restoration. He showed interest. We shook the dust off the project folder and marked four initial stages: replacement of stolen copper lubrication and air- brake piping; boiler refurbishment; cylinder and side-rod refurbishment; and driving wheel and brake rigging refurbishment.
We intended to spend today measuring up the amount of copper piping of varying bores needed (the loco was lubricated purely by sight-feed and oil-cup methods, no Wakefield or other pressure system). However, as a side task, we tracked down KR's boiler inspector to 'book' his time for an initial boiler inspection. After all if the boiler's no use, there's little point in going further (there are five remaining 24 class boilers in Kisumu and Mombasa, but they will be sold for scrap later this month, and realistically it is most unlikely we will reboiler 2409).
The inspector duly turned up and said he could either make a visual inspection of the boiler tomorrow at 0730, or we'd have to wait for about a month. Oh, and could we please remove the steam dome, so he could get a clear view inside? Joe Kamau was reluctant. I pushed him to 'go for it'... I soon found out why he'd hesitated!
I was vaguely aware that there must be something substantial underneath the dome cover... after spending the afternoon helping the fitters remove 34 three-quarter-inch bolts by hand, and then lift off the dome forging using a block and tackle from the rafters of shop 006, I now have a rather more intimate knowledge! Still, we finished the job fifteen minutes after knocking-off time which wasn't too bad.
The main large missing item - the manifold turret which distributes steam from the boiler to various ancillary uses for firing, lubrication and braking - was resolved by recovering two suitable turrets (along with several other useful fittings such as clack boxes, washout plugs and gauge glass test cocks) from the Kisumu boilers when I visited a couple of weeks ago. (More hard work in the sun with hand tools. I have come to the conclusion that Vulcan Ltd. didn't want anyone to take their locos to bits easily).
Once we have the boiler inspector's opinion, I'll pass it on to the group. Meanwhile, anyone visiting Nairobi is very welcome to bring a boiler-suit!
Thursday 5th May 2005
Bwana Bushishi also wants us to refit a standard-style EAR boiler identification plate... I will try to get an authentic one cast in the foundry using another plate as a pattern.
He'll reinspect the boiler in three weeks and follow up with a hydraulic test. So we have, quote, a lot to do... Geoff, your boilersuit should definitely be top of your packing list!
Friday 13th May 2005
I have spent a couple of mornings this week getting truly filthy cleaning the soot and light scale deposits in the smokebox and removing old cementing. We'll clean the tubes on Monday and prepare the firebox for the mason to repair the firebricks. A new boiler rating plate is being cast in the foundry using an old plate (from 2406) as pattern, and replica makers' plates are being machined after being very nicely cast from a pattern made in the workshops using a rubbing of an original plate (from another 1923-series 24 class) kindly sent by retired EAR&H shedmaster Don Owens.
This is all very good news since it cuts down the cash required (since Kenya Railways has none, funds will be raised from well-wishers, so economy is important!). However, the workshops have no descaling chemicals, and 2409's boiler is fairly heavily scaled. Given the time wasted on 3020 with poor steaming, it seems sensible to make an effort to give 2409 the best chance of steaming well from the start. However, the boiler holds about 3500 litres when completely full, and local costs for descaling chemicals are quite high - we will need $400 to $550, depending on supplier, to treat the boiler. Can anyone with experience offer advice here? Are there shortcuts or cheaper options, or is the only way to bite the bullet and buy the descaling chemicals? Do we have to use these at manufacturer's dilution recommendation (1:10) or can we use a lower dilution for a longer period?
Next week should see more visible progress since the monthly 3020 trip will be out of the way and more resources should be available for 2409. The plan is to get lubrication and air brakes sorted out first, with work preparing the boiler for testing going on in parallel.
Sunday 15th May 2005
Thus :- 'Obtain a quantity of eucalyptus leaves, macerate them well, place in a large container and boil slowly for not less than four hours. Strain off the liquid and add 1-1/2 pints to the boiler water of the engine. Keep the dome cover off. Light up and maintain fire for 24 hrs. Cool off and wash out thoroughly. Repeat if necessary.'
He performed the 'maceration' in Atbara by arranging two old 8" cog wheels with a 4" face so that they were turned by hand and the leaves fed through them from a hopper above. The method was found to be successful so S.R. created a special plantation of eucalyptus and made a habit of adding ½pt of the brew each time a boiler was filled.
Might this be a possibility for you ?
Sunday 15th May 2005
The one snag is that we don't have a facility to keep water hot in the boiler; there is currently no oil tank nor oil firing control gear on 2409 and we don't plan to fit them until after the boiler's viability is proven. We can get hot water from one of the other locos though, and the dome cover is off 2409 already (not a job I would want to do regularly mind you!)
Maybe we can find a way. I suppose we could burn kuni (firewood) after initially filling with hot water and washing out once to heat the boiler. I'll discuss with the team tomorrow.... it's preferable to spending $400, as long as it really does the job!
1.5 litres of macerated liquid doesn't sound very much (boiler capacity is 3500 litres)... did I get this correctly?
I'll keep you posted!
Thursday 19th May 2005
Also [b.] that the author was describing re-habilitating loco that had been put to one side even then so presumably they would not be new, and thus may not have been as large as your loco. I'll also send a scan from a NBL diagram book showing a typical SR loco that would fit into that period and you can compare with what you have.
On the other hand if SR went to the bother of creating a special plantation of trees then it must have worked for them to their satisfaction.
Wednesday 8th June, 2005
We have achieve the following to date:
Cylinders, motion, frames:
Wheels and bearings:
Monday 20th June, 2005
Still to do (boiler): rebuild firebox brickwork. Service damper mechanism. Re-cement smokebox. Re-fit washout and inspection plugs with new lead washers, fill boiler and identify leaking firebox stays, and caulk them. Refit dome, make a pressure test fitting, blank off other orifices, and hydraulic pressure-test the boiler to 215psi. Fix any revealed problems, then chemically descale boiler and make a second hydraulic test to check weak spots in descaled tubes. Overhaul and replace fittings such as clack boxes, manifold turret, safety valves, whistles, main steam slide valve, blower and air pump exhaust rings in smokebox, and burner. Stamp and fit boiler inspection plate. Find and fit new injectors, and water delivery piping to clack boxes.
Cylinders, motion, frames:
Wheels and bearings:
Tuesday 5th July 2005
Anyway, back to 2409. I have now gained limited access to all the original works drawings for 24 class locos (about 250 of them) and the Sanctions for Alterations which document the minor changes made through their sixty-year active life. The S for As however don't seem to cover the major changes such as upgrading and moving the Westinghouse pump from the right-hand side on the firebox to the left-hand side on the smokebox in 1949, nor of altering the bulk of the class from coal fuel to oil fuel in the early 1950s. Perhaps there is another class of records I have not yet discovered. The original drawings are very complete indeed, right down to the tools supplied with the original locomotives. (I wish we still had these!) The drawings and S for As solve some of the questions we had but not all.
Regarding the loco itself, I can report the following:
Cylinders, motion, frames:
Wheels and bearings:
We need to find a way of increasing the work rate on 2409. The obvious way is to get a few weekend work squads organised so that the millwrights who are busy keeping the workshops running during the week can concentrate on 2409. This will of course have a financial aspect, and Kenya Railways is unlikely to make funds available. We will explore other options after I return from a week's travel away from Kenya.
Tuesday 26th July, 2005
Help is at hand however! As you will have seen, several well-wishers recently made generous contributions to 2409's revival, in response to the appeal by Trevor Heath and Graham Kelsey. I am immensely grateful for these since it allows us to run a program of Saturday work-ins, with the millwrights and the retired men working together exclusively on 2409. The men receive a small honorarium from the revival fund and we make significant progress on the project. We can also fund purchase of consumables and spares not available within the workshops - KR is in a cash crisis and cannot help with funding, and in any case procurement takes months.
The first of these work-ins was on 23rd July and the following was achieved:
Water delivery pipes (two-inch copper pipes on each side of the loco, from the injectors under the footplate along under the running board and up to the clack box behind the chimney) cut, fitted and brazed in place. Gaskets still to be fitted.
Copper piping from air pump governor to main air reservoir fitted
Piping from main air reservoir to cab control cock and then forward to front sand boxes fitted
Two new oil boxes fitted behind the front sandboxes, with syphon trimmings and piping to direct oil to the piston rods. (Originally the pistons are lubricated by hanks of oily worsted material secured so they rest on the rods, and the oil boxes will supplement these).
Steam pressure gauge (an original EAR unit, recalibrated in the workshops and with the correct working pressure of 165psi marked in red) fitted in the cab.
Auxiliary steam manifold (small manifold in the cab which feeds a number of auxiliary functions) prepared for cocks to be fitted. Lack of suitable elbow joints (discovered at the last moment to be galvanized, and unsuitable) prevented full progress.
Blower pipe prepared for fitting, needs to be annealed in the forge which will be done this week
In the preceding week, a start was made on renovating the electrical wiring. The front headlamp now has a working bulb for the first time in several decades! The Stones generator is being reconditioned in the electricians' shop.
The millwrights' mason is collecting firebricks and cement from stores, and he expects to make a start on rebuilding the refractory bricks in the firebox this week. After this is completed, the cementing in the bottom of the smokebox which protects the metal from overheating will be replaced.
Chemical descaling of the boiler is yet to start, we want to wait until we have made arrangements for heating to 80 deg centigrade using the oil burner, which depends on completing the firebox brickwork and on fitting a temporary oil tank if we cannot get the original tender tank back from Voi in time. We will also need to complete work on the small manifold so that we can use the factory air supply for lightup (atomising the oil in the burner) and for the blower, to keep the fire going.
A new set of brake-blocks for loco and tender in being cast in the foundry and will be fitted when available.
A manifold turret (main manifold on top of the boiler, which on a 24 class is integral with the safety-valve casting) recovered from another boiler is being reconditioned by the millwrights and will be fitted when available.
Lubrication copper piping from the "Eureka" sight-feed lubricator in the cab to the cylinders and piston valves on each side is to be fitted soon, progress on Saturday was not possible since connectors of the correct type had not been found. These will need to be made in the turning shop before the next session.
We have yet to decide when the next work-in will be. It probably makes sense to leave a gap while other work to be done during the week catches up. I am going to be away from Nairobi for ten days at the Coast: my wife has agreed to break the journey at Voi where I hope to make progress on recovering the missing tender oil tank (I told her this after she agreed to stop there!). Six months of pressure on KR to divert the breakdown crane to lift this onto a wagon has borne no fruit; not from any lack of co-operation, but simply because the single remaining crane in working order was so overworked it could not be spared. Two more cranes have now been returned to working order after a crisis in which it became necessary to hire a crane from Uganda Railway Corporation for a particular recovery (costly!).
Hardly a week now goes by without a serious derailment ("capsizement" as they call it here) of a goods train somewhere on the system, due to insufficient investment in track and vehicle maintenance. To further increase crane availability, serious consideration is now being given to reviving the 1926-built Tanganyika Railway 35-ton Ransomes and Rapier 4-8-4 steam crane EAR 1104, most recently based at Voi, which has been out of service for several years. If this happens this will be the only steam breakdown crane working in Kenya (perhaps in Africa?) and one of the few from that era active in working service anywhere in the world; I believe there is another one active at Tolosa in Argentina. (Three Grafton two-ton steam cranes are still in the central workshops in Nairobi, and one is still in working order; it is used from time to time for moving wheelsets between CXR and foundry, and is fired with kuni [wood] fuel).
Monday 1st August, 2005
Voi used to have three boilers sunk into the earth, from a 13, 24 and 60 class. The 60 class (6013) was moved to Nairobi last year and has been renovated for use in the smith's shop of the central workshops. The 13 and 24 boilers are on the scrap list and have been dug up and put on flat wagons preparatory to moving elsewhere.
Voi has a four-road running shed, still open but sadly more or less idle now since the Taveta branch was mothballed about six months ago due to lack of motive power for the twice-weekly passenger train. (The preferred power was a 71 or 72, but only one of the these, 7105, is still working and is currently working at Kilindini docks). A 62 class is not a very satisfactory substitute since the branch has a ruling gradient of 2.5% and a 62 has to work on full power for four unbroken hours, which is not very good for it. Even on the heavily-graded Nanyuki branch the grades are more balanced. Anyway, Voi's previous allocation of a 72 and 62 has been withdrawn and the shed staff are more or less without work.
This was to my advantage, since the two senior staff there had both worked for Joe Kamau in the past and were pleased to hear of the plans for 2409. They became very helpful. A rummage around the moribund stores racks produced a few surviving steam spares - including two fusible plugs for boilers which are like hen's teeth in Nairobi, as well as a number of useful control valves and pipe elbows. The exhumed boilers also had their fusible plugs still in position, so these were extracted as well. The 24 boiler had its small manifold intact - another precious item - which was easily removed as well. A little later, the whole lot was in a cardboard box in my car (unbelievably given the usual bureaucracy-mad KR setup) and I was watching a vast herd of elephants in Tsavo East national park. Quite a successful morning!
The hope now is that the oil tank is loaded as promised and makes it to Nairobi without further incident. This will be a major step towards getting 2409 back to life.
Thursday 11th August, 2005
Thursday 11th August, 2005
Can anyone suggest how critical it is that we heat the boiler while using the descaling liquid? The data sheet says the solution works better when heated to 80 centigrade, but doesn't rule out lower temperatures. I am wondering if we could achieve the same descaling result with the solution at 15-20 centigrade for two or three weeks, thereby avoiding the need to make the oil firing functional at this stage and the cost of oil fuel (and nuisance of the smoke in the shed).
Anyone any thoughts, or even better, experience?
Friday 12th August 2005
Saturday 13th August, 2005
1. Reactivity of the chemical reagents;
To some greater or lesser extent, any one or more of these factors could compensate for a lack of any one or more of them, within reason. As a rough guesstimate, I'd say that you could get the 80degC results at 20degC in about 8-times the 80degC time. Probably would help if you could shake the boiler around a bit in the process.
Let us know what happens. I assume you are now using the commercial preparation, not the eucalyptus leaves?
Saturday 13th August, 2005
Monday 15th August, 2005
The next priority is to finish the cylinder and valve lubrication piping. If we cannot get the right people available during the week, I will press to do this next weekend.
Sunday 21st August, 2005
The main saturated steam manifold (manifold turret) of the loco is integral with the safety-valve casting. We have a choice of five such castings: two recovered from boilers in Kisumu, two from scrap dumps in Nairobi, and one from 2409 as she came from the Museum. None was in perfect condition, but by combining parts and some welding, a serviceable main manifold has been produced with the traditional cocks-comb relieving lever for the safety valves.
The main manifold is now in place above 2409's firebox, with the large steam pipes to the injectors running down each side of the boiler, and the large pipe running to the small steam manifold (auxiliary manifold) casting in the cab on the fireman's side. The blower pipe from the small manifold along the boiler to the smokebox is in place. The light-up cock connection has also been completed. Only the pipes for the oil heater, oil tank blowback, and burner atomiser from the small manifold needs to be done now, and these await lagging and cladding of the oil heater (hopefully this week) and arrival of the missing oil tank from Voi.
The main manifold casting weighs about 120kg by the way. No fancy cranes to get it onto the firebox top; just a rope round the casting with a man up top and two men heaving from below. Up it went!
The steam pipe from the main manifold to the sight-feed (Eureka) lubricator is also in place. The condenser for the lubricator and the associated piping has yet to be fitted, and the oil feed pipes from the sight-feed lubricator to the cylinders, pistons, and Westinghouse air pump are next on the weekend work list (as is the Westinghouse pump itself).
A whistle valve and whistle have been found and will be fitted to the main manifold. Finally, the steam pipe for the Stones dynamo and for the boiler pressure gauge will hopefully be added during the week.
The team this time was smaller: two fitters and a welder, plus myself on Saturday only. This was more effective than a large party and will be the preferred style in future.
Monday 29th August, 2005
Monday 6th September, 2005
The next work party will concentrate on reconditioning the Westinghouse pump, fitting the check valves to the oil piping, and finishing a few other tasks where connectors or elbows were not available.
Another task remaining is the oil heater (which requires lagged and cladded, and fitted with associated pipework, some of which is missing and needs to be found or fabricated). The oil tank is still in Voi.
Descalant for the boiler has been purchased and delivered and will, hopefully, be used tomorrow after new fusible plugs have been fitted and the mudhole door put back in place. I aim to soak the boiler with the descalant solution for two weeks (cold), inspecting a test piece of scaled tube to monitor progress. If boiler inspector Bushishi is also satisfied, we will put the dome back on and hydraulically test in the last week of September. If descaling is not completely successful we will add more descalant or heat the boiler. (The commercial solution is designed for fast use - 24 hours - in a working boiler, but it seems reasonable that it will also work more slowly at lower than recommended dilution and temperature. It's a lot cheaper and we're not in such a rush! We will see.)
Monday, 12th September, 2005
Also last week the boiler descalant was added to a boilerful of water after refitting the mud door and the two fusible plugs. We will see how things look after a couple of weeks.
Next weekend we hope to progress further with 2409 : finish the Westinghouse
pump, start on the oil pipework, withdraw the pistons and piston valves for
inspection. We have found some oil heaters and oil control valves; we have a
burner regulator and, I think, a floor bracket for it. We have the swivel
joint which goes in the oil pipe between tender and locomotive. We are
missing the other steel piping parts and the reach rod from the burner
regulator to the control valve, but these can be fabricated. If we can find
check valve ball- bearings and springs we will finish the lubrication piping;
if we can find a test cock for the gauge glasses we will fit and finish the
associated drain pipes. The front and rear market lights need stands
fabricated. And that's before touching the brakes, motion, and wheel
bearings. Plenty still to do!
Friday, 16th September, 2005
Sunday 30th October 2005
Preparation consisted of washing out the boiler thoroughly and re- making the seals for the mud doors, and making and fitting blanking plates for the main mainfold, clack box, main regulator valve, gauge glases, and generator cock. We still have to remove an old weld on top of the dome forging so that the threaded rod there can be removed; normally this rod retains the dome cover, but for the pressure test is removed to leave a hole which receives the adaptor for the pressure gauge.
The hydraulic test consists of filling the boiler full of water until it squirts out of the highest point (on top of the steam dome forging), ensuring there is no air in the boiler. The calibrated pressure gauge is then fitted to this point and pressure is introduced elsewhere - in the case of this boiler, via a blanked pipe on the side of the firebox wrapper which I think was formerly used for a superheater pyrometer. Pressure is built up via a manual pump (manufactured in Kilmarnock, Scotland); a squad of four is used with a long handle on the pump, turn about, until the required test pressure (215 psi for a working steam pressure of 165 psi) is reached without any leaks being apparent.
The squad who prepared the boiler will make their own test and remedy any leaks before handing the boiler over to the inspector; they are keen that it passes the test first time.
There are only four working days next week (Friday is a public holiday for Eid al-Fitr, marking the close of Ramadan) so it is not certain that we'll be able to finish the test, but we will try.
We also continued to overhaul the Westinghouse air pump, completely disassembling the steam and air sides of the pump. The cylinders and rings show little wear, and the inlet valve springs are in good condition (important, since we have no spares) but the valves themselves are corroded and will need to be replaced. The gasket for the air cylinder lower cover is also broken. We can probably find these parts in the steam stores, but there are also about fifteen scrap Westinghouse pumps still lying near the works foundry, as a source of last resort.
Thursday 24th November 2005
The normal procedure is for the boiler team to make their own pressure test ahead of calling in the boiler inspector, to ensure that everything is as it should be. The boiler is completely filled with water, so that no air space remains, then pressure is applied by a team of four men using a hand pump. Weak spots are soon exposed by water leaks.
In fact, it took two weekends to get 2409's boiler satisfactorily ready for its official test. The first weekend was spent checking and remaking gaskets for the various blanked-off orifices which leaked first time round when even slight pressure was applied. With this done, pressure was taken up to 80psi, but the test plugs in the front and rear tubeplates then leaked and had to be tightened. After that, the pressure was taken above 80psi, but problems were encountered with leaks from the large inspection door beneath the boiler. We had not previously disturbed this door (about the same size as the dome orifice; not to be confused with the small mud doors used for washouts). Work was held over until the following weekend.
The inspection door cover is secured by nuts to a large number of threaded studs in the boiler, like the dome forging. Removing these took most of the weekend, they were rusted solid, and the large air receiver on the running plate had to be removed to allow easier access. The nuts were heated with a gas torch and eventually freed; three studs were broken in the process and had to be replaced.
Once the door was off, it was possible to remove a large quantity of scale and rust from the bottom of the boiler; the door's copper gasket was removed for annealing and re-shaping, and a rubber gasket fitted for the test. This time, there were no leaks; full test pressure of 210psi was maintained. After two days this had reduced to 80psi. The boiler was declared ready for testing when the inspector returns to Nairobi at the end of November.
The team decided to release remaining water pressure via the dome forging where the test gauge was mounted. Muriuki was the man who cautiously loosened the union, forgetting that the smoke cowl in the shed roof was directly above him. The high-pressure water jet bounced downwards from the cowl, dislodging years of oily soot in the process, and Muriuki was drenched head to toe in cold wet filth. I guess he will get someone else to do the job next time!
In between work on the boiler, the team also managed to complete reconditioning the air pump, and lagged the oil heater ready for cladding and fitting. The Eureka sight-feed lubricator in the cab has been replaced with a new unit from stores. The connecting rods have been dropped from the crossheads, to allow the pistons and piston valves to be withdrawn once a special gudgeon pin with square threads is made to help in the process.
Last weekend, attention was turned to the tender water tank. A large hole was flame-cut in the tank top to allow a full internal inspection. The external plates and internal baffles turned out to be largely in good condition, with only light rusting (the baffle plates have been renewed at some point in the tender's life). Several water leaks were repaired, and the drain cock at the back, and twin feed pipes to the injectors cleaned and serviced. (The latter revealed that the control valve on one side was missing and the pipe blanked off; presumably 2409's final duties on engineering trains at Voi took place using a single injector. We will have to find and fit a new valve).
The water tank is now ready for internal painting with bituminous paint before new plates are welded on to the cut section. After that, we will fit the oil fuel tank waiting in shop 010.
I hope that a new wooden front buffer-beam will be fitted next week, as well as louvred cab side window shutters. If we have a work party this weekend it will probably concentrate on the oil fuel feed and the air brake reservoirs.
Monday 28th November 2005
Work continued this weekend fitting the fuel oil supply piping from the tender to the locomotive, which was originally coal or wood fired. The oil fuel system was installed in the late 1940s and was supplied by Alco of the U.S. as part of the fleet-wide conversion to oil firing of most EAR steam locomotives at that time. (Some 24s based at Kilindini port were built as oil-fired locos, but not 2409).
A 2-inch steel pipe leads from the tender tank through a control cock down to the tender frames and under the fallplate. Rigid pipes, not flexible hoses, are used to bridge the gap from tender to locomotive, with three flexible right-angle ball joints allowing flexibility to negotiate curves.
Once on the locomotive, the pipe leads under the cab's left side and up onto the running plate, into the oil heater (a steam jacket of about six feet fed from the small manifold). The pipe then leads to a blowback union (steam feed from the small manifold), and the firing control valve (with a reach rod for control from the cab). The pipe, now reduced in size to 1.5 inches, drops between running plate and boiler to the burner at the front of the firebox, where steam from the small manifold is fed to atomise the oil and blow it into the firebox as a fine spray. Dampers at the front and back of the firebox provide primary air for combustion and are controlled from the cab by rods.
Everything is missing on 2409 apart from the burner itself and the dampers. I am sure the Alco 24 class oil fuel system drawings must be in the CME's drawing store somewhere, but we could not find them where the index says they should be. Instead, the fitters made a careful study of 2401 in the Museum, which has its oil firing system complete.
A search of the steam stores provided an oil heater, the three ball- joints, and the firing control valve. Steel piping of appropriate size was also obtained with help from the head of the millwrights' shop. A team of two fitters, a welder and a turner worked to fabricate this into the shapes required, not helped by the lack of pipe-bending equipment. By the end of the weekend, the job was only about 50% complete, but at least it was the difficult 50% !
To finish the job we need to locate a blowback union, finish lagging and jacketing the heater and fabricate new fixing clamps, fabricate the run of 1.5-inch piping, fabricate the reach rod for oil control, mount the firing control and its stand in the cab, and fit steam piping from small manifold in the cab to the blowback union.
I am a little unclear on the precise functionality of the blowback union. The idea of course is to allow steam to be blown back into the tender oil tank to warm it or clear pipe blockages. In operation, the firing valve is closed, tender control cock opened, then the control valve at the small manifold opened so that saturated steam pushes the oil back into the tank.
What I am naming the "blowback union" is a simple T-shaped union, and it's not obvious on 2401 whether this has a nonreturn ball valve built in to prevent hot fuel oil entering the steam pipe to the small manifold control valve, or whether this is unnecessary. Probably one of the older fitters will remember, or at worst we could take 2401 to bits to find out, but perhaps one of the group members can advise what's typical practice elsewhere?
Sunday 4th December 2005
The blowback union on 2401 in the Museum was dismantled during the week and proved not to incorporate a non-return valve, which meant there was no problem in sourcing a suitable part. The swivel pipe link between tender and loco was also dismantled to check the exact method of ball joint packing. Suitable packings were obtained from stores.
The steam piping for blowback and burner atomiser has been connected, as well as the oil bunker sludge drain piping. (The piping for the latter was removed from a scrapped 87 class diesel, which is in a way appropriate since the 87 concerned was manufactured by English Electric at Vulcan Foundry, the birthplace of 2409). The furnace control quadrant and stand, and the reach rod to the control valve itself, were also completed. Still to complete at lunchtime today was the assembly of these, repacking the swivel links for the oil piping from tender to loco and adjusting to increase clearance above rail level, and completing the lagging of pipework and the sheet metal cladding of the heater.
The next job will be to manufacture a preheater for the oil bunker, using a design sent by Ian McKay in New Zealand where they have been fitted to several of their preserved locos. A hole will be cut in the oil bunker allowing the preheater assembly to be fitted as a complete unit (and removed easily for servicing, should it ever be necessary). Once this is complete and the oil bunker is steamed out and checked for leaks, we will be ready to fit the bunker to the tender. Before that we will have to paint the inside of the water tank with bituminous black paint and weld in new top plates where they were cut away for access.
The boiler then needs to pass its official hydraulic test. After that, blanking plates and rubber gaskets will be replaced by the appropriate permanent fittings and newly-annealed copper gaskets. Various steam pipe unions and details such as the condenser for the sightfeed lubricator need finished off, and choke valves for the sightfeed lubricator pipes need to be fitted. The injectors need to be serviced and water feed piping fitted. The clack boxes and the anti-vacuum valve need serviced. The smokebox cementing needs to be replaced by the mason, the smokebox door sealing rope replaced, and the pistons and piston valves need to be drawn from the cylinders and inspected for wear, and most likely have their packings replaced.
At that stage we should be able to steam the loco for the first time, although there is much finishing off work to do before it can move more than a few feet. The blower ring needs to be removed, annealed and replaced. The blast cap casting is broken inside the smokebox and needs replacing if we can find a spare in the stores, or welded if not. A broken spring leaf on the bogie needs to be replaced. The brake rigging needs to be serviced and adjusted on loco and tender, and the air brake receivers steamed out and replaced. The air brake regulator needs to be fitted and the triple valve serviced. Lubrication oil cups and piping need cleaning, and wicks and trimmings made and refitted. Axlebox keeps need to be repacked with worsted material and filled with oil.
If the loco then shows it can start and stop itself reliably within the confines of the workshop yard and no obvious mechanical problem arises, we will aim to make a short test run to evaluate the condition of the axlebox bearings, hornblocks and cheeks, motion bushes, and valve settings. This will determine how much servicing these components require.
In short, the more we do, the more there seems to be left to do! It seems unlikely we will steam the loco this year, but it is reasonable to hope we might do so in early January.
Monday 12th December 2005
We wanted to pass the boiler hydraulic test on Saturday, and accordingly the test gauge was mounted on the steam dome and the hand pump coupled up. The team of millwrights rather enthusiastically pressed the boiler to 250psi before I arrived (210psi is the ordained test pressure, and 165psi the working pressure). The pressure shown on the gauge fell back relatively quickly however. There were no signs of leaking stays or tubes, so we started to hunt for other problems. Two mudhole plugs were weeping slightly, and the inspection door below the boiler (or mud collector as the fitters call it) was also dripping. Not enough to really explain the pressure problems though. Then, following up a tell-tale stream of drips, we realised we'd completely forgotten to blank off the blowdown valve, hidden away under the boiler. Out of sight, out of mind!
The valve turned out to be tricky to remove: even after heating with a gas torch, one stud out of the four securing it to the boiler was broken in the process. Nothing daunted, the millwrights, well-used to broken studs on recalcitrant old iron machines, welded on an extension to the stub of the stud, heated the whole lot again with the torch, and succeeded in removing it. It turned out to be just as well we took the valve out - it was badly in need of servicing, and will now be much more reliable.
Once the blowdown valve was removed, a blanking plate and gasket was fitted and the boiler brought up to hydraulic test pressure again. This time we were successful and the test, holding full pressure for ten minutes and then observing the rate of drop-off for the ensuing 24 hours, was passed.
Two machinists were meanwhile working away in shop 004 making the special tool required to help free the piston rods from the crossheads. These are secured by cotter pins, but the great force from the pistons ensures that after a period of service, there is an immovable (and inaccessible) interference fit between rod and crosshead which hammering will not budge.
The special tool operates on the same principle as a car jack. The gudgeon pin, which links the small end of the connecting-rod to the crosshead, is removed, the connecting-rod dropped, and the Walschaerts gear combination lever separated from the union link so that the crosshead is not linked to the piston valve spindle. It can then move stiffly with the piston rod given a firm tug. A modified gudgeon pin is fitted, with a threaded hole bored through it in the axis of the piston rod. A matching spindle is then screwed in until it meets the end of the piston rod jammed into the crosshead. Turning the spindle further presses the piston rod away from the crosshead, breaking the interference fit. After this the piston slides smoothly in the cylinder with hand pressure.
Square threads are required on spindle and pin to ensure the required force (which is considerable - four men straining on long tommy bars) is transferred properly. It took a day and a half to machine the tool from EN24 steel (the hardest we could get from stores), and a few anxious moments of bent tommy bars and hopeful spraying of penetrating oil onto joints, but eventually rod and crosshead parted and we were able to withdraw the piston from the cylinder. The piston rings were removed from the piston and placed back in the cylinder on their own. The end of the rings did not quite mate, indicating they require replacement. However the piston itself and the cylinder appear to be in good condition.
The piston valves, which we also dismantled, require new rings as well, carbonisation from soot and oil sucked into the wrong places in the valve would have made that clear even if the mating test had not, but again the piston valves themselves look in good condition. We are hopeful of finding the right size of new rings from the considerable range still in the workshop steam stores.
In the meantime we also completed lagging and cladding the oil heater, and serviced both injectors (the cones of which turned out to be in good condition), and the water delivery cocks from the tender. The flexible reinforced rubber water pipes linking tender and loco turned out to be perished and will be replaced from stores. The anti- vacuum valve on top of the superheater header was overhauled. The asbestos-rope packing between valve casting and smokebox has dropped away resulting in a gap which will destroy the smokebox vacuum. It will be replaced. Inside the smokebox, the blower ring and brake pump exhaust ring were removed for cleaning and heating to remove rust and scale. The blower ring had a large hole, invisible before removal, which will be repaired with a welded patch.
We removed the steam dome cover (another four-man lift) and checked the main steam valve's fit and operation from the regulator handle in the cab. The old fitters pay great attention to adjustment of this valve: "the heart of the engine" as they put it. Having seen 3020 hold a stalled train on a 1-in-50 gradient by steam pressure on the pistons alone, when there was too little boiler pressure to work the air pump for the train brakes, I can begin to appreciate why one needs to have full confidence in this valve!
Finally, the inspection door / mud collector underneath the boiler was removed so that the fitters could repeat their extraction magic on the three studs broken when its gasket was replaced for the hydraulic test. This took several hours of very awkward work, but was eventually successful.
The next work session will focus on servicing and re-fitting the various boiler mountings with new gaskets and completing servicing of the cylinders and pistons. The lubrication piping will be completed. The tender water tank will be painted inside and left to dry until after Christmas, when we will replace the top panels previously cut away for access. The preheater for the oil bunker will have its design finalised and drawn, then will be manufactured and fitted.
It's just over a year since Trevor Heath, acting on impulse, convinced Kenya Railways' MD to move 2409 from the Museum to the workshops, and over six months since I started the weekend work sessions after finally realising that nothing would happen during the working week. In spite of progress since then being in fits and starts, today was the first time I thought seriously about ordering EAR maroon undercoat and topcoat paint for 2409. We may just need it !
Sunday 8th January 2006
Saturday 17th December saw no activity since it was the day set aside for the steam team's "Christmas Party". This year we widened the invitations to include many of those who have helped in one way or another but who don't actually work on the locomotive. We shifted a whole goat, a fair quantity of beef, side dishes, and a not inconsiderable amount of beer, sodas and for the diehards, local firewaters. (In case anyone is worried their restoration donations are ending up as bottles of warm Tusker, I should explain that Trevor and I funded the party, an annual tradition he started three years ago).
Sunday 18th saw most of the steam team disperse for the Christmas break, but a three-man team worked on removing the right-hand piston and piston valve for servicing.
During the Christmas period, the inside of the tender water space was sprayed with bituminous black paint. A search in the stores for new piston rings and piston valve rings proved successful for the former, but oddly we could not find any rings for the 24 class piston valves. (There are literally hundreds of spare rings of other sizes). Instead, a suitable block of cast iron will be cast in the foundry from which new rings of the correct size will be machined. Another casting job will be to make a new blast cap - the existing one is fractured in several places, and has been tack-welded so that a pattern can be made from it for casting. A new mahogany buffer beam was ordered from a timber merchant. Unfortunately it was substandard when delivered, and has been returned. Once the correct item is available the carpenters will prepare it for fitting to the locomotive. Other carpentry jobs include new support blocks for the air reservoir between the frames, cab floor repairs, cab window side screens, and rubbing strips between tender water and oil tanks.
Work recommenced on Saturday 7th January. The new piston rings and pistons were introduced to the cylinders and the cylinder covers replaced. The cylinder cocks and pressure release valves were serviced and replaced. The boiler was once again given interior proddings to remove remaining pieces of scale and thoroughly washed out. The clack box was removed for servicing. On Sunday, the dome cover was replaced with a new copper gasket and bolted down; the mud collector door was replaced under the boiler, we modified a copper gasket to fit, and the water delivery hoses from the tender to the injectors were replaced. There was no time to replace the blower and air pump exhaust rings in the smokebox. Both have been serviced, and the blower ring sports a large patch welded over a rusty hole.
I hope we will steam out the tender oil tank in the coming week. A replacement unit has been found in stores for the left-hand bogie spring which has a broken leaf. This considerably simplifies the task since we can simply put the spare spring in after jacking, and get the broken leaf repaired at leisure. The blowdown valve has to be re-fitted, the sightfeed lubricator condenser fitted, safety- valve/main manifold and clack-box castings refitted, and a large number of small piping and rodding jobs completed. The right-hand- side crosshead slipper needs remetalled on one face, and we will probably find plenty other bearings and bushes requiring attention. Overhauling the brake system is one of the bigger jobs still to do. No doubt the list will get longer before it gets shorter.
Sunday 15th January 2006
There will unfortunately be a delay in getting any further castings made, since the foundry has run out of coal and the Supplies people have not yet got the necessary three quotations before they can place an order. Not being a coal-producing country, coal merchants are not exactly thick on the ground here. The domestic cement industry uses some, as do (presumably) some commercial foundries, but they may not be willing to sell some to Kenya Railways. At worst, we may need to get the castings done commercially, which will be expensive and will pose quality problems. The commercial foundries typically do not analyse the metal composition of each casting run, since most of them do not have laboratories. The railway's foundry sends samples to the workshops lab as a matter of course. Some commercially-supplied wagon brakeblocks recently turned out to be harder than the wheel tyres, so that the tyres, rather than the blocks, were worn down in service. This is precisely what we do NOT want to happen inside 2409's cylinders!
This weekend, the plate we cut out of the top of the tender water tank to allow inspection and repair was welded back in. The blower and air pump exhaust rings were repositioned in the smokebox. The front of the loco was jacked up so the broken front bogie spring could be removed, unfortunately the spare spring from stores was found to be second-hand, and to have damage to its bolt holes, so the loco will remain on jacks until both springs can be repaired.
Both crosshead slippers were removed. The whitemetalling on both is worn, one badly, and will need to be renewed. The blowdown valve was re-fitted below the boiler. The choke valves, three from stores, one from 2401 in the Museum - were brazed onto the cylinder end of the lubrication pipes. The main steam manifold was replaced on the boiler after a recalcitrant stud was loosened by heating with a gas torch, and replaced. The various cocks and unions leading from this manifold were removed and serviced, as was the clack box. The anti- vacuum valve was re-fitted above the smokebox.
The coupled wheel brake blocks were removed, ready for the new blocks to be fitted, the castings are nothing great and need quite a lot of fettling before they fit the hangers neatly. A start was made on servicing the brake rigging on the locomotive.
For some weeks, the brass numberplate and worksplate castings have also been ready for finishing, but the machine shop has failed to find time for us. The patternmakers, frustated at not seeing their work completed, finally did the work themselves on their milling machine, after we built up metal over a few minor casting flaws by brazing . They have made a very nice job of both plates and finishing, and I am very happy with the result. It has to be said that the Foundry team is a pleasure to work with, always supportive and willing to help wherever they reasonably can given their "day jobs".
It is now looking rather tight to steam 2409 this month, since we only have two more weekends and we don't have any piston valve rings, but if we get the oil tank steamed out and fitted back on the tender, we will not be far off reaching that milestone.
Sunday 22nd January 2006
The air pump was stripped again and inspected by an experienced man, pronounced to be in good order, and reassembled. The piston valve spindles, which for some reason were both badly "mushroomed" at the combination lever end, were ground back to shape. Presumably they had been "adjusted" with a sledge hammer at some point in the past. The cocks and valves of the main manifold were repacked and refitted, and all pipework connected. On top of the boiler, the clack box seating remains to be tackled.
A start was made on freeing the cylinder cock rocker shaft. The reach rod linking the firing control in the cab to the main oil valve was manufactured and fitted. We have realised we have to remove both injectors in order to service the water cocks, but had no time this week. We completed fitting new brake blocks to the coupled wheels.
The coupling and connecting rods were removed from both sides of the loco. The bushes are in good order on both sides, but the large securing nuts on the left side are loose and need to be repaired or replaced. The right-hand-side combination lever needs all three steel bushes renewed, as does the associated radius rod bush.
The keeps under the coupled wheels' journals were withdrawn for inspection. Unfortunately the news is not very good. Both the driving and trailing axles show signs of damaged bearings so these two axles will have to be removed so that the bearings can be withdrawn for repair. To do this we will have to move the loco to the former steam loco erecting shop (010), where a wheeldrop is still in working order (it is used for breakdown crane repairs). This shop is intensively used for diesel-electric repairs so we may not get immediate access. One of the underhung springs on the driving axle is displaced and will probably need to be removed and serviced. More bad news awaited us at the bogie: the side-control spring is broken and will need to be replaced (a spare spring is thought to be available in stores), and the spring above the bogie pivot is either jammed or broken. We will remove the bogie while the loco is in shop 010. All in all this is quite a lot more work than was anticipated and we cannot move the locomotive to 010 until the leaf spring from the bogie is returned after repair.
We have still to complete overhaul of the brake system: steam out the air receivers, check the triple valve and the steam and air brake application cylinders before adjusting the brake rigging so everything operated smoothly. No date set yet for first steaming.
Sunday 29th January 2006
Pipework from the sightfeed lubricator to the air pump was completed, and the lubricator condenser was fitted next the generator and associated pipework completed. An attempt to remove the clack box seating by heating and hammering was unsuccessful. Instead, we will remove the stands which secure the clack box and grind the seating surface flat in situ. If the joint turns out to be imperfect we will resort to making a puller tool.
The burner atomiser steam pipe was connected. A start was made on removing and servicing all oil cups and associated lubrication piping – most are blocked by years of dirt. Mr Mekenye, the mason, spent a day renewing the cementing in the smokebox. Both injectors were removed and the water cocks serviced. On inspection the injector steam cocks turned out to have no functional parts inside their casings so these will require to be found and fitted. The gauge glasses were prepared for refitting.
The grey iron casting for the piston valve rings was found to be too hard on lab testing and it was realised a mistake had been made in material preparation. A new casting was made on Sunday which will be sent for machining into rings this week.
A blowhole in the blast cap casting, not thought serious enough to condemn the part, was remedied by welding, and the casting was machined to take its four teeth set in the blast. The teeth themselves were also machined.
A plan has been made to allow renewal of coupled wheel bearings at weekends using the wheeldrop in shop 010, two axles per weekend. Due to pressure of other work the locomotive will require to be towed in and out of shop 010 before and after each working session. The plan will be presented to workshop management this week for their approval. (Shop 010 has seen activity seven days a week for the last month-and-a-half, repairing the accident-damaged 9308 and 9315. Both had buckled main frames requiring major surgery. 9308 was finally re- bogied early on Sunday morning and is now moving under its own power. Work continues on 9315. We will have to ensure our use of the wheeldrop and the overhead crane does not conflict with other activity).
With all other identified tasks included in the plan, and making the rather large assumption that no delays occur due to dependencies on other workshops activity, we will aspire to a first trial steaming of 2409 on 26 February. In all likelihood this date will slip, but with luck only by a week or two. Apart from refitting the oil bunker, remetalling the coupled wheel bearings and servicing the bogie, servicing the brake system is the other major outstanding task.
Sunday 5th February 2006
The wheel drop is a pit about five feet wide with a hydraulic jack (dating from 1954) in it running on a short transverse track. The axle concerned is positioned above the jack, which is then pumped up (oil hydraulics) to lift the axle off its springs. The rail sections bridging the pit then have their fishplates unbolted and are slid out of the way. The wheelset can then be lowered and run sideways on the jack's transverse track for pickup by the 60-ton overhead crane.
On Friday afternoon I removed the brake pull rods under the coupled axles so that there would be no impediment to dropping them. We left the coupling rods in place for the shunt, since it is easier to adjust the position of the wheels when replacing the rods at the wheel drop, using the overhead crane rather than hand-pumped jacks.
On Saturday 2409 was shunted onto the large ("B") traverser at the works and then to shop 010. We had expected this to be a short shunt to the "A" traverser along a straight track, then final positioning into shop 010 by winch. But the shunter had other ideas, and set off at a merry pace with a string of wagons as well as 2409, to the other end of the works sidings, from where we were propelled into the other end of shop 010. This exposed some oversights in preparing the loco for movement. First of all the equalising cylinder for the air brake, mounted under the right-hand-side foot framing near the cab, started to work loose (it had been temporarily repositioned after steaming out several months ago). The coupling rod started to thump into the air cylinder at the top of each revolution. Eventually we had to stop the shunt, quickly remove the cylinder, and throw it in the cab. While we were stopped I noticed that the coupling rod retaining nuts had almost fallen off, we'd removed the cotter pins to inspect the bearings, and forgotten to put them back. Now the rods were catching the back of the nuts as we ground round the curves. I put the cotter pins back in as best I could and spent the rest of the shunt trying to spot loose nuts where they'd fallen out again!
Once safely in shop 010, the coupling rods were quickly removed, and a start made on dropping the driving wheels. The first task was to pump out the oily sludge which had collected in the pit.
The 24 class has underslung springs and it took a little head- scratching and false starts before we settled on the best way to proceed. Eventually we realised we had to remove the split pins and loosen the nuts of spring hangers and horn stays before relieving the weight on the axle slightly so that the large pins linking spring buckles with axleboxes could have their locking pins driven out and then be removed.
Removing all these pins (most of which were rusted in) took a long time, but finally we were able to drop the springs using the jack to support them. With these out of the way, the axle was jacked up, the rails removed, the axle dropped, the rails replaced and the horn stays bolted back in position. It was by then 6 pm on Saturday, but we had dropped the driving axle successfully and taken it to the other end of the shops ready for remetalling.
I believe this is the first time a coupled wheel axle has been removed in the central workshops since the early 1980s. We moved and raised the loco when necessary using the 60 ton overhead crane.
On Sunday, we removed 2409's trailing axle by lunchtime, leaving only the leading and intermediate wheels in place. We then proceeded to remove the bogie. We had intended to do this using the wheel drop, but found out the hard way the bogie was too long for it. You're right – a tape measure would have saved the red faces.
Some further discussion ensued. Eventually, we removed the bogie pivot pin nut over the wheel drop pit, then raised and packed the back of the locomotive (so that the brake gear would not ground later on), before lifting the locomotive at the front so that all coupled wheels were off the rails. The bogie was left on the track.
It was then rolled forward out of the way, and the loco returned to a normal angle, resting on a large packing block instead of the bogie. We had to remove the damper control rods at the rear, and the headlight at the front, to make space for the crane cables.
The plan is to remetal the bearings and then return the driving and trailing wheels next weekend, before removing the leading and intermediate wheels in their turn for servicing. We will also have to service the bogie, in all probability including its bearings, since the oil cups look to be in poor condition. Removing the coupled wheels has exposed many broken parts (spring hangers, rocking washers, and so on) which would not have come to light otherwise, so the exercise has to be worthwhile.
Sunday 12th February 2006
On Sunday, the oil bunker was fitted on the tender using the overhead crane. This took a little time since a plate at the rear had to be removed, and then the bunker offered up to the mounting brackets while suspended from the crane. A new bracket had to be fabricated at the front, and tack-welded on. The bunker was then removed and a proper welding job done. Finally, the bunker was placed back on the tender to keep it out of the way during the planned tour of the works by the new transport minister tomorrow. (These tours are usually cancelled at the last moment, but at least it means the workshops are tidied up from time to time).
Earlier in the week the bearings from the driving and trailing coupled wheels were examined more closely. They are quite badly damaged: two of the brass shells have large fragments broken away from the edges, and one of the brass horn cheeks is broken in two pieces. Since we don't know the condition of the other two axles' bearings yet (they're still under the loco), it seems prudent to manufacture new bearing shells and horn cheeks for all four axles and replace the whole lot, given that they must all be fairly worn.
The pattern shop is up for the challenge, and I aim to find the drawings for these parts next week so they can commence work. There will be a fair bit of machining needed to finish the parts, always a bottleneck - but we will find a way. One advantage of doing this is that it should be possible to service the remaining two axles in a single weekend, since the new parts can be put straight on. Meanwhile, the bogie is being thoroughly serviced in shop 005.
Monday 20th February 2006
The bundles of two hundred or so Crown Agents drawings for the 24 class were easily found, but on extracting and examining the axlebox drawings it became apparent something wasn't quite right. The axleboxes on the locomotive did not match the drawings. So I had to go through the Sanctions for Alterations files, where I pieced together the sequence of events. It seems the axleboxes were redesigned around 1930 to simplify and no doubt improve lubrication. After that the design was fiddled with every few years, a whole sequence of alterations, until, I conjecture, post-war deliveries of new Tribal and Governor class locomotives relegated the 24s largely to slow goods, shunting and engineering trains. The design staff seem to have then lost interest in marginal improvements in 24 class axleboxes!
Unfortunately, the Sanctions for Alterations referred to drawing numbers which didn't seem to exist. They made no sense to the chief draughtsman. It seemed we would have to make patterns for new castings by copying the worn, old parts, not at all desirable.
Back in the workshops, I discussed the problem with the patternmakers. They turned out to have a card index of old patterns for steam loco parts, which some far-sighted individual saved (along with the patterns) when disposal was suggested after the end of steam in Kenya. Searching through this using the "missing" drawing numbers, I found the card for the axlebox patterns one of which referred to "old" and "new" drawing numbers. This was the missing link. Back at the drawing store, we were able to find the "new" drawing number, and in the same roll, all the other missing drawings.
Even better, the patternmakers spent a morning searching their store from top to bottom, and succeeded in finding the original patterns for the axleboxes, keeps, bearings, and side and front slides. These were made for sizeable production runs using shell casting technology, producing a casting needing relatively little machining to finish, a great advantage to us. So now we have drawings and patterns matching the worn axlebox parts, and we can see that three sizes of bearings were used, depending on the amount of journal wear in the axle.
We also know the exact alloy composition used for the castings (from the index cards), and, incidentally, the last time the patterns were used, in 1971. We discovered that there should be leather gaskets for the steel dust covers on the keeps. We will need a large number of castings: eight bearings, sixteen side slides, and eight face slides for the coupled wheels, and four bearings, eight side slides, and four face slides for the bogie. The patterns have now been overhauled in readiness for casting. The electric elements in the furnace for shell casting are broken, but we hope to get this repaired, then cast and machine the new parts. Setting up the axleboxes will require careful measurement of the horn faces in the main frames, to ensure everything is square, but the retired fitters' experience will guide us through.
We also received the first few piston valve rings from the machine shop. These are fitted to the piston valve by bouncing the ring on the ground so that it splits; a half-round file is then used to shape the broken ends so they fit the locating pin in the groove in the valve heads. Each head has four rings, so sixteen will be needed in all, plus spares. Once the rings are coaxed into position on the valve heads, the valve spindle can be slid into the valve chest, using a sheet of paper to align the rings so they don't jam. That's the theory, anyway! We hope to get the rest of the rings delivered in the coming week, and fit the piston valves to the locomotive thereafter.
The bogie spent the week in a bosh tank, removing old oil and dirt using a heated caustic solution. Now that it is clean, we can see that the side control spring is not broken, it is in fact too short, and has obviously been pressed into service using a couple of spacers and nuts to pad out to the correct size. This it seems did not work well, since one of the side control pins is broken, and the axlebox face slides are very worn. If we cannot find the correct spare part in stores we will have to consider finding the drawing and making a new spring in the smiths' shop.
During the week, the oil bunker was also given two coats of black enamel paint. Work this weekend consisted of fitting wooden support pads for the oil bunker, and completing the fuel delivery piping. We also started to manufacture the oil preheater and its steam supply from the small manifold in the cab, using a flexible Neoprene steam pipe to cross from locomotive to tender. The limitations of my back- of-an-envelope/scrap material approach to designing the preheater became apparent when we ran into some dimensional problems, but we hope to overcome these and complete the preheater by next weekend. We also completed the new blast cap, and I spent time trying to dig nine inches depth of solid oily muck out of the enclosed area above the bogie so the oil pipes can be serviced. Due to restricted access and poor lighting and working position, this job is truly infuriating. I am sorely tempted to ask someone else to have a go at it next weekend!
Further progress will now depend on delivery of the axlebox castings and resolution of the bogie spring issue. We will then have to service the two remaining coupled axles, put the copper pipwork back in place, and service the brake system. It is unlikely we will steam the loco until well into March.
Sunday 5th March 2006
Finding suitable replacement heating elements for the oven at reasonable cost took some time, but one oven was finally put in working condition. The shell moulds can only be used once, so two men spent this weekend producing the 36 moulds for the side and face slides for coupled and bogie wheels. The bearings themselves use conventional patterns in sand moulding boxes so no shell moulds are involved. Hopefully the casting will take place early in the coming week, followed by machining and whitemetalling. It is unlikely we will be able to finish this before the weekend of 18/19 March.
Twenty piston valve rings have been turned, but cannot be ground to size until the surface grinding machine is repaired. Meanwhile, other miscellaneous jobs have been tackled. The clack box seating has been ground flat and the securing stands replaced. Injector water and steam valves and spindles/handles have been fitted. The preheater has been manufactured and installed in the oil bunker, which has itself been installed in the tender on wood packing. The pipework from the bunker has been completed. Both rear sandboxes have been serviced. The six lubrication pipes for the front bogie have been removed for servicing.
One unresolved problem is the bogie side control spring and side cheek. I was unable to find suitable spares in the stores so we may have to locate the drawing and manufacture new parts for these. This will be a priority next week, starting by locating the relevant drawing.
Monday 13th March 2006
Enough successful slide castings were completed last week to allow two men to spend a full weekend machining the parts. They started by marking out the castings according to the drawings and proceeded to remove the excess metal using milling and boring machines. Problems soon became apparent. The castings had much more metal to be machined away than is normal for shell mould technology. Worse, it became apparent the slides could not be machined to the correct dimensions without milling away holes cast into the part. Something was seriously wrong.
I set up a long meeting to discuss this with the pattern-makers, casters, and machinists, with the new cast parts, the originals from the locomotive, and all the drawings available. Eventually, by removing the worn slides from the bogie axleboxes, we became convinced that several detail modifications have not been recorded in drawings or in the Sanctions for Alterations which are meant to cover every design change. Either the system broke down almost fifteen years before the end of steam – which seems unlikely – or there was a practice of using older axleboxes modified to suit on individual locomotives, without recording the details in records which applied to the whole class. This detailed knowledge is presumably now lost, these patterns were last used in the late 1960s.
Either way, we cannot machine the parts accurately using drawings alone (apart from the face slides, which will need more machining than usual to finish but should be usable). The side slides will have to be made to fit the axleboxes, using a combination of measurements from the guides on the frames and the axleboxes themselves to ensure a good fit. It remains to be seen whether the axlebox brasses will also need modification. This is all very disappointing and has been an expensive lesson. I am fortunate that the foremen of the various shops concerned are keen not to be beaten by the setbacks and are giving me their support rather than finding excuses to do something else.
In some ways, it might be better not to disturb the side slides of the axleboxes. After measuring the play between guides and side slides we will review whether they are beyond scrapping limits or can be left for now. We really have no choice with the face slides, which are very badly worn. Fortunately they are the simplest to repair with new parts.
We still do not have an explanation for why the shell mould patterns leave quite so much excess metal as a "machining allowance", well over a centimetre rather than the customary few millimetres. The foundry supervisor recalls that two decades ago, the practice was to use much larger allowances, something he had to work hard to change. No wonder so many staff were employed in the workshops formerly!
The surface grinding machine is still out of action. This is partly due to electrical problems caused by the leaking workshop roof (the civil engineers are meant to be fixing the roof, but at the moment work stops when it rains due to the danger of electrocuting the machinists as water pours onto the lathes, milling machines and grinder). However, the grinding stones are also worn out and will be expensive to replace, several hundred UK pounds. New parts were requisitioned several months ago but have not yet appeared. I will try to get the head of the supplies department to help, but until then we cannot grind the rings to repair the piston valves.
All in all, a very frustrating week, not helped by traffic jams that made my usual thirty-minute trip to the workshops three times as long. The only mildly positive development was the discovery (from the maker's drawings) that the bogie side control spring should actually be two coil springs face-to-face. This means I may have overlooked suitable parts in the stores, I have been looking for a spring twice the correct length. Moreover, even if we have to resort to manufacturing new springs, we now have complete and detailed dimensions and test loads. Finally, Trevor Heath has reminded me of the option of removing the springs from sister loco 2401 in the Museum, and this may well be the best way to proceed; we would replace them with the incorrect spring from 2409 so that 2401 could still be shunted if necessary. I have checked 2401's bogie springs and they look good, although removing them with the bogie in place will be hard.
Monday 20th March 2006
We therefore decided on a new approach: we will repair the old liners in situ on the axleboxes, building them up by brazing and facing off on the milling machine to the original liner dimensions. We will then reassemble the axleboxes and test clearances before finally machining the liners to suit the worn guides. In one or two cases we will need to fit new liners, but it's less work than replacing the whole lot.
The bogie axleboxes will have to be completed first since we cannot move the loco back over the drop pit until the bogie is replaced. The bogie face slides were therefore brazed up and faced this weekend; test assembly and measurements from a datum will take place this week.
The axlebox brasses (half-shell bearings above the journals) have been sent to shop 047 for whitemetalling. There is no coke for the furnace (again!) but we hope to find a way round this shortly. Once the bogie brasses are remetalled, scraped, and fitted, the liners machined, and the check spring replaced, we can replace the bogie under the lcoomotive and start work on the coupled axleboxes.
No progress on grinding the piston valve rings. More grinding will be needed when we make new mild steel hub liners of the bogie and coupled wheels.
Monday 27th March 2006
We need to decide whether to replace the hub liners (mild steel discs fitted to protect the wheel hubs from wearing against the axlebox face liners). Some of the hub liners are very worn, down to 2mm or 3mm from the original 9.5mm. We have the choice of fitting new liners or building up the existing ones by welding, but either way we will need to machine the surface true on a wheel lathe. Neither of the two suitable wheel lathes in Shop 005 are operable. We may be able to use one in the wagon shop; failing that we will not be able to replace the hub liners.
2409 has been sitting in shop 010 blocking access to the wheel drop for several weeks now. Inevitably, the one vehicle which still uses the drop (the Ransomes and Rapier 75T crane) required attention after derailing last week. 2409 had to be moved about a locomotive length. Since the bogie and two of the four coupled axles are missing, this was accomplished using two 60-ton overhead cranes to relieve most of the weight of the loco so the packing could be removed. The loco was then towed to its new position using the two cranes in unison (alarmingly fast!) and the packing replaced.
Still no progress on grinding the new piston valve rings. We are investigating whether this can be done commercially, but it seems few firms in Nairobi have large enough surface grinders.
Monday 10th April 2006
Last weekend we spent a day trying to coax the old wheel lathe back to life. Although there are five or six other large lathes in the workshops, none have toolposts able to do the work we want (trueing hub liners). After a lot of oiling and fiddling, we had all motions of the lathe working under electric power, and a bogie wheel mounted in the centres. Unfortunately when we tried to actually do some turning, the multi-link flat drive belts proved to be too slack to start a load from rest. There is no tensioning arrangement, and the tool to remove links from the belt went missing when the lathe's operators were retrenched a few years back. Apparently the workaround is to help the lathe build up momentum by pushing the workpiece round by hand as speed builds up. Sounds a good way to lose an arm. Unfortunately, unless we get the lathe working, we will not be able to renew the hub liners and thus get the correct side play in the wheels. Further study needed!
The search for a large surface grinder continues. The problem is that commercial engineering companies do not have magnetic workpiece holders large enough for the 9.5" diameter piston valve rings. However, the KR procurement machine is churning slowly on, and we may yet get new grinding segments for the KR surface grinder. Quotations for the parts (cost about $500) were to be opened this week.
We replaced the front buffer on 2409 this weekend as well, which will make it easier to move once we have the wheels ready to go back under the engine. We also replaced the coupled wheel axleboxes, with their reconditioned face liners, in the frames temporarily so I could measure the face-to-face distance. There is meant to be 0.250" total side play on each coupled axle; unless we can replace the hub liners, we will not be able to reach this, but it will be a great deal better than it was before servicing.
Sunday 17th April 2006
Monday 24th April 2006
We await remetalling and scraping of the bearings, grinding of the piston valve rings, servicing of the wheel lathe drive belts, and recovery of bogie spring beams from the bosh tank, the same hold-ups which have applied for almost a month now.
Tuesday 2nd May 2006
The wheel lathe was finally coaxed to work reliably by manufacturing a tool to allow removal of two links from the flat drive belting. I had hoped to use the lathe to true up the axle journals, which have coning of about 10 thou and some pitting in places. The wheel shop staff advised however that axle journals should be ground, not turned. To do this we would need to press the wheels off the axles, which I think is too risky, since we have no new wheels if the castings are damaged. Instead we used the lathe to polish the journals with emery paper and to remove worn hub liners. Unfortunately, when we came to fit new liners and attempted to true them up using the lathe, it became apparent that it cannot make any size of cut without the toolpost moving, which of course makes it useless for accurate work. The solution is to reduce the liners to size before fitting and take a light final cut with the wheel lathe to true the liners. This is not ideal but should at least result in the correct sideplay in bogie and coupled wheels. Two days were spent dangling wheelsets from the overhead crane and getting used to the lathe, fun, but also frustrating, and I am a bit disappointed we did not achieve more with it. The automatic feed is faulty, seemingly due to a broken gearwheel, which translates into scores and ridges when turning. It would require quite a lot of servicing to be put back in good order.
I bit the bullet and purchased some foundry coke from an (expensive) outside source. As a result the wheel brasses have been remetalled and will now be machined and scraped to fit individual journals. I also finally found an engineering works with a machine big enough to grind the new piston valve rings and hope that this work will be done this week. I have been quoted some truly frightening prices for doing the job, but I hope the firm concerned will take a helpful view. Fingers crossed!
Overall progress has therefore been rather gradual, but I hope that the main blockages have now been overcome and we will get the project moving forward again. This week's puzzle is to find a brass union for the top of the Westinghouse pump, none in stores and none in the local commercial boiler suppliers.
From Stephen Gifford:
That's basically what we did for 2409's journals, but of course rotating the axle as we clamped the emery paper on, and wetting the emery with light lubricating oil. The clamp - exactly as you describe, two handles joined by a strip of canvas with a recess in each handle to take the axle - is used in Nairobi to polish journals for diesels on more modern lathes. We found an old one and adapted it for the steam loco axles. The result was quite good, taking most of the corrosion pitting off the surface. Some deeper pits and cavities are still evident and I suppose we will have to get the axles tested by the lab for flaws. However, as long as we mark the pitted journals and warn operating staff to check them rigorously for heating, I don't think it will be a huge problem - there are no flats or seriously damaged areas. The wheelshop staff say one way to deal with the pits is to smooth the edges using a round-edged grinding stone, to reduce the tendency of dirt or grit to catch in the hole rather than be washed out of the bearing.
We are lucky in that our crankpins are all in excellent order, so we don't have to try polishing them - it sounds like it would take quite a while.
Monday 8th May 2006
After a bit of practice the machine shop team became better at working round the wheel lathe's limitations, and in fact succeeded in slimming the hub liners to size wholly on the lathe with acceptable finish. We should now have the correct sideplay of 1/8" each side of the wheelset.
The piston valve rings were duly surface-ground commercially for £4.00 each; we needed a total of twenty. I had hoped to get the work done for free, but it is still a lot more reasonable than some quotations I was given. The job was well done and held within the correct tolerance of plus zero, minus two thousandths of an inch. The rings are then bounced on the ground to split them, then a segment is removed so that they will just fit in the valve chest liner, and a recess is filed to take the locating dowel in the valve head. Each of the two heads in the piston valve is then fitted with four rings. So that they can be inserted into the valve chest without jamming in the steam and exhaust ports, it is necessary to wedge the rings hard into the valve head slots using strips of paper. This simple-sounding operation turned out to be very trying in practice, and we broke a couple of rings before we really understood what we were doing. Since we have very few spares this was bad news! Eventually we realised we must shorten a couple of the rings very slightly to get them to sit flush with the valve head. By then it was almost dark, so we stopped work on the valves and will start again next weekend. I feel confident we will succeed however.
Rebushing of the Walschaerts gear was completed, and a start made on machining the white-metalling of the bearing brasses. The latter will take some time and will be followed by scraping so they fit the journals precisely. Then we will be able to reassemble the axleboxes and put the wheels back under the loco. The copper lubrication piping, which we had removed and stored for security, is now half refitted (and rather more carefully than before) after annealling. We also started to overhaul the brake system under the direction of a retired fitter; the driver's brake valve, triple valve, governor and Westinghouse pump top head were all examined and serviced, and a suitable part found for the missing brass union from the top head. The actuating cylinders on loco and tender will now require to be dismantled and serviced.
A couple of weeks more work is probably needed before we can get the bogie coupled wheels back under the loco, and then we will have to service the two remaining coupled axles (leading and intermediate). After completing the lubrication piping we will need to refit the crosshead slippers with their new liners and refit the piston valves, valve gear and side rods. In principle we can then steam the loco.
Sunday 14th May 2006
Today (Sunday) the remainder of the pipework on the locomotive was fitted complete with gaskets and seals. Only the clack box and large manifold now require gaskets. One of the steam cocks for the injectors was dropped and will require replacement. An extra tool locker for the locomotive was also welded up from steel sheet offcuts, courtesy of the rebuild of diesel-electric 9315 damaged last year in a head-on collision. There are already four lockers on 2409's tender but my view is that you can't have too many!
After seven hours of struggling we finally got one of the piston valves back into the valve chest in one piece. So much for my confidence last week that we knew how to do it ! The lessons learned were that ring size is critical, and alignment of the valve heads to prevent ring ends dropping into the steam ports and breaking, similarly so. However, we took these lessons to heart, and succeeded in getting the other piston valve back in on the first try after only three hours, finishing by torchlight at 1900. We broke all but one of our eight spare piston valve rings as part of our learning curve, and we cannot easily manufacture more, so I was on tenterhooks by then.
Next jobs are to machine and replace the slidebar brass liners and remetalled slipper blocks, re-erect the valve gear, replace the bogie and two coupled axles, drop the other two coupled axles for inspection and possible repair, and finish overhaul of the brake system (service the brake actuating cylinders on loco and tender, and finally replace the dismantled brake rigging under the loco).
Monday 22nd May 2006
On Sunday we put the bogie back under the locomotive and started to reassemble the exleboxes on the driving and trailing axles in readiness to be put back into the frames. Further work took place on gaskets for boiler mountings and on fitting the gauge glass cocks and columns. Since there are no suitable (Klinger AB18) sleeve packings for the gauge cocks in stores I was forced to buy some locally, about £13 each, and we needed eleven of them (five for each column and one for the whistle). If anyone has a significantly cheaper source abroad I would be interested to know, but as far as I can see from the Internet they would cost at least £8-£9 over the counter in the UK. Those I could find here were imported from UK but are not good quality.
I suppose anyone used to steam preservation elsewhere in the world will find this a trivial amount of money, but each sleeve packing costs more than a ten-hour day of skilled labour, so it's quite a hole in the budget.
The numberplates went to the buffing shop during the week, surfaces are prepared using rotary tools, first a wire brush, then lustre polish on a cloth mop. The resulting high shine is very satisfactory.
A new problem emerged concerning the coupled wheel springs: the smithy finally got round to reconditioning the four springs we removed, and found so many broken leaves that they ran out of material of the correct thickness and width to make replacements, with one spring still to repair. A long search of the workshops and the running shed finally yielded three suitable long leaves which we hope can be cut down to make the five we need. However, the four springs still under the locomotive will very probably also have some broken leaves, and we will have no suitable spring steel. Fingers crossed!
Tuesday 30th May 2006
We collected the various coupled axlebox components together in readiness for assembly. Only then did we remember that one of the keeps had a broken corner, which we had not repaired. Closer inspection showed that it was also cracked, and so incapable of doing its job as an oil reservoir. Fortunately the foundry had cast a spare keep for me in brass some time back, so it was relatively easy to machine this casting as a substitute. If brass turns out to be unsuitable in service, we will make another casting in iron.
On Saturday we prepared the axleboxes and springs on the driving and trailing coupled axles, and on Sunday we put the driving axle back under the loco and removed the leading axle, using the wheel drop pit. Some welding work was necessary to repair worn rocking plates on the frame brackets for the spring hangers. The seals on the hydraulic jack in the pit are failing, which means it has a tendency to sink under load; in fact we had to relieve the weight on the axle using the overhead crane before the jack would pump the last couple of centimetres. It was a relief to find that the machining of face and hub liners we had done, based on measurements, seems to have resulted in the correct side play of the axleboxes in the horns. It would have been very embarrassing if they had not fitted.
We prepared the trailing axle for replacement, and prepared the intermediate axle for removal from the loco, but ran out of time with the wheel drop on Sunday evening (lighting in shop 010 is very poor, and when the sun sets at 1830 it's time to find all the tools and lock them away before it's too dark to see). I hope we will complete this work during the coming week. We also continued to fit and erect the valve gear, including the remetalled crosshead slipper blocks with their new brass liners. We had miscalculated the latter's thickness, fortunately leaving them oversize, so more machining was necessary. The air brake actuator cylinders were serviced and new floorboards fitted in the cab, making it a much safer place to work. New wooden packings were fitted to support the main air reservoir under the boiler before the driving axle was replaced.
Checking the condition of the leading and intermediate wheel bearings and side, face and hub liners is the next important task. If we are lucky there will be little damage and they can go straight back under the locomotive; if not we will have to renovate them, but we have now the experience from the last few months' work to draw on. We then have to re-erect the connecting and coupling rods, finish work on the brakes (including re-erecting and adjusting the pull rods under the loco), and give everything a final check (and no doubt complete many small details not quite finished). Then we can fill the oil bunker and boiler, light up, and see if we can raise steam pressure.
Thursday 1st June 2006
On Wednesday morning I went over the axleboxes and horn guides with a tape measure. The most likely reason for jamming was that we had left too little side play between the horn guides and the axlebox side slides, but the dimensions seemed correct. Eventually I realised that one of the axleboxes was not sitting snugly against the wheel hub liner. A quick check showed that the face liner of the axlebox had not been machined correctly, it was several millimetres thicker on side than the other, meaning that the axlebox, if forced against the hub liner, was bound to jam in the slides. The box was taken back to the machine shop and worked on for several hours after the end of the normal shift.
Thursday (today) is a public holiday, which allowed another attempt at fitting the trailing axle with the newly-modified axlebox. This time we succeeded, although much hammering and shaking was still necessary to convince the axleboxes to go up the slides smoothly. The side play now looks to be just about correct. We also dropped the intermediate (i.e. third from the front, between driving and trailing) coupled axle and dismantled the axleboxes. In the process we had to lift the loco from the tender end to relieve the weight on the axle. This caused the front of the loco to dip and the main frame smashed the oil cups mounted above the bogie wheels (there is only about a half inch of clearance with the springs slack, which none of us remembered). Replacement will be simple, but it was rather chastening to make this mistake.
The state of the leading and intermediate axle bearings is not perfect, but not as bad as the driving and trailing axles. The hub liners, though worn, are acceptable. The face liners of the leading axleboxes are only lightly worn and are acceptable; those of the intermediate axle are worn and loose, and will need to be built up by brazing then machined. Three of the four brass bearings have damaged whitemetalling (cracks rather than melts) and will need to be re-metalled and machined. Three of the pins connecting axleboxes to springs are broken and replacements will have to be manufactured. The springs themselves seem to be sound. We will start on these remedial works tomorrow, but will probably not be able to have everything ready for the coming weekend. Fortunately, the workshops recently had a delivery of foundry coke, so re-metalling should be less problematic than before. Which reminds me, I must ask them to cast some more iron cores for piston valve rings while the coke lasts!
We finished the day by moving the locomotive (using the overhead crane) so that the tender is over the drop pit, to facilitate inspection and repair of the triple valve and the brake rigging. Several tender spring hanger pins are loose or broken and will need to be replaced. We will also inspect the keeps carefully for any sign of damage to the bearings and if necessary will drop the axles to check. Finally, we removed the bogie from the locomotive again so that it can be painted and have the keeps filled with new worsted material soaked in oil.
Thanks, Trevor and Ian, for your suggestions on the rubber seals for the air brake actuating cylinders. In my ignorance I had not realised they were standardised. If we cannot find spares in the stores tomorrow (this time we will check for complete cylinder assemblies as well as individual seals), I will investigate further.
Tuesday 6th June 2006
Due to family demands I was not able to be around much during the weekend, but the valve gear was worked on further, the Westinghouse brake actuator cylinders renovated, the tender triple valve removed and serviced, and the tender wheel bearings checked for signs of having running hot (none were discovered). Thanks to Trevor and Ian's suggestions, we consulted staff in the wagon shop (021) and found that they could give us all the Westinghouse cylinder rubber seals we needed. The tender right side cylinder is too badly corroded to be easily serviced, so we aim to fit a complete new assembly; which we think we have found in store.
The intermediate axleboxes were machined over the weekend. The same mistake was made as before, side liners not orthogonal to face liners, rather to my annoyance. They are now being corrected, and the axle bearings are being machined.
Painting also commenced at the weekend. Red undercoat replaced the grey of the originally-planned KUR graphite livery. I am sorry to see it go, since I like the locos in graphite, but am forced to admit the EAR maroon will be more cheerful. The bogie and loco frames were painted black, and preparations made to paint the insides of the frames red.
On Tuesday we managed a three-hour work session after hours. The bogie had its keeps filled with soaked worsted packing, and the horn stays fitted. The recalcitrant taper pin securing the right hand union link in the Walschaerts valve gear, which had refused to budge, was eventually removed after careful heating with a gas torch. The union link was taken to shop 004 for rebushing. A loose cab footstep was removed and readied for more secure refitting.
Friday 9th June 2006
It then took over an hour to convince the spring cross-shaft to go back in place. The next stage was to tension the underhung bogie springs, raising it so that there would be more clearance for the oil boxes. The nuts on the spring hangers cannot simply be tightened with a spanner against the spring's tension, since a retaining washer above the nut has wings designed to stop the nut turning. Instead the spring has to be jacked up to take the tension off the nut, so the retaining washer can be lifted and the nut turned. We did this by successively lifting, packing the springs, then lowering and tightening the nuts.
By the time we finished it was 8 p.m, long since dark and the two overhead crane drivers marooned in the gloomy heights of the shop showed considerable patience. Even then, we were not able to complete tightening the springs and had to leave the front end of the loco packed up before the cranes could release the load.
On Thursday we completed the spring tightening and removed the packing. The inside framing of the tender was also painted red, in spite of the pit being full of water and the pump breaking down; the painter simply rigged up a plank over the water and got busy with his brush.
I also realised one of the axleboxes from the leading wheels had a loose face liner, which I had previously overlooked since the liner was not badly worn. We replaced the worn liner screws with new ones then brazed up the surface of the liner so it becam secure. The axlebox was then sent to have the face liner machined back to size.
Geoff Warren made a welcome appearance back in Kenya. It is sobering to realise he last visited a year ago, when I was just starting to dig the muck out of the smokebox. As usual Geoff was keen to get involved and not fussy about whichever task was available. He did a nice job cleaning the brass cab window surrounds and getting a good shine on them, as well as helping with the bogie spring packing escapade.
One of the team had mentioned that the workshops lab had an ultrasonic axle tester, so we thought it would be a good idea to get 2409's axles checked out. This was duly carried out this morning (Friday). My worst fears were realised when a serious flaw was detected in the driving axle; we had seen visual evidence of a damaged area but hoped, vainly, it was superficial.
Within ten minutes we had found several suitable spare axles (from the same 1950s batch as 2409's driving axle) in the stores compound, and I began to feel happier. The wheel shop staff sounded confident when I discussed the prospect of pressing out the old axle and installing a new one. One of the wheel shop fitters, with twenty- eight years'service, started out in steam days and has fitted new steam axles before. The horizontal hydraulic press seems to be capable of taking the wheelset complete with crankpins, although it will be some time since it has dealt with such large diameters. The staff are also used to setting the quartering of axles since the 47 class diesel shunters,which are rod-coupled, require it.
An afternoon in the CME's drawing office store produced the correct dimensions for machining the axle. Although it is quite a setback, it doesn't seem to be the insuperable obstacle I had initially feared. Interestingly, it turns out neither 5918 nor 3020 has had its axles tested since revival, although it is standard practice for all diesel classes and passenger and freight stock. I understand that the lab team will give them some attention in the coming days.
After discussion, we plan to complete 2409's revival, steam it, and run some light tests before replacing the flawed axle. If I run out of time and have to leave Kenya before the job is finished, it is a lot better to hand over a working loco with an axle flaw which can be fixed with a week's effort, rather than an unfinished project with a sound driving axle !
We finished up tonight by building up the axleboxes on the intermediate axle ready for rewheeling tomorrow. The spring hanger nuts have been freed, and the buckle eyes eased out by hammering, after heating to red heat with a gas torch. The bearings are ready, and only one spring pin and one trailing axlebox require machining. We hope therefore to make good progess this weekend.
Sunday 11th June 2006
The locomotive looks a good deal more cheerful with all wheels present and clean red undercoat paint. We tidied up all the junk which had accumulated on the foot framing and front bufferbeam. The next stage is to fit the coupling rods to the wheels, then the connecting and eccentric rods.
Tuesday 13th June 2006
The whole procedure was then repeated on the right hand side of the loco. Some small final adjustments to wheel positions were necessary to get the rods onto the crank pins smoothly. We then shifted the loco back over the pit using the crane; everything moved smoothly .The crank pin nuts were renewed and so needed to be set up tightly then marked and drilled for the taper pins which ensure they do not spin off in use.
Yesterday Geoff Warren and I spent some time cleaning old paint and grease off the inner frames so that they could be painted red. Meanwhile the brass "E A R" letters for the tender had arrived from the foundry, still warm from casting, and we cleaned up the rough edges with files and an angle grinder. The burner and atomiser were removed from the front of the firebox and cleaned. The gap was set correctly and the assembly returned into position and connected up. The lubrication cups and pipes for the crossheads were then fitted. The cowcatcher was also put back in place.
It transpired that the blowdown pipe (which allows boiler sediment to be exhausted from near the lower front of the outer firebox and blown between the wheels) has gone missing since the weekend. It was only a steel pipe and therefore probably accidentally tidied up as scrap. We will have to make a new one, which is annoying.
The next stage is to move the loco back to the larger pit in shop 006, next 5918 and 3020, and replace the brake pull rods under the coupled axles. Many small jobs of fitting and tidying up require to be done. The missing tender brake actuator (held up by stores bureaucracy) has to be fitted and the whole brake system checked. The sightfeed lubricator also needs to be checked, and the tender sides needs to be marked and drilled to take the "E A R" letters which will be rivetted in place. I hope we will complete most of these tasks today and tomorrow evenings so that we can steam the loco over the weekend, leaving it warm for two days to see how the joints react to pressure. If all this goes well, we will check all the nuts, cotters, taper and split pins again, check the oil cup trimmings and axleboxes, and cautiously try to move up and down the workshop yard.
Saturday 17th June 2006
We made some progress with other tasks in the meantime. The water delivery pipe on the left hand side, which fitted badly, was coaxed into the correct place behind the foot framing with repeated use of a large hammer. The brake pull rods were re-erected below the coupled wheels. A new blowdown exhaust pipe was made and fitted. The Westinghouse pump's suction valves were fitted, as was the tallow lubricator for its air head.
The sightfeed lubricator in the cab was dismantled, examined, filled with water to test for leaks, then filled with oil so operation can be checked with the loco in steam. New cab seats were fitted, and the regulator handle was secured properly.
I finally found a local source of thick (0.25 inch) leather, sold by the kilogramme for boot sole repairs. The upholstery shop used this to cut eight new gaskets for the tender oilboxes. The alternative would have been to use neoprene rubber sheet, but apart from costing twice as much I was not convinced that the neoprene had the necessary "give" to make a good seal on the rough castings.
An electrician started to fit the front and rear market lights. The rear light was originally an oil lamp, later updated with an electrical fitment, and this will be retained. The front lamp was missing when we got the loco so a more modern (but still steam-era) lamp will be fitted instead.
The air brake actuator on the tender right hand side was finally replaced, with some difficulty due to poor access to bolt heads. We had connected the factory compressed air supply to the brake system and were starting to find and fix leaks in joints when the shunting engine finally arrived and we moved 2409 to shop 006 at dusk on Friday. Everything went smoothly and no strange noises came from the loco, more than could be said for 5918, whose cylinders protested horribly when shunted a short distance. They must be dry as a bone.
Today (Saturday) a small team worked to fill the fuel bunker with oil and the boiler and tender with water. The oil delivery piping is all newly-fitted so we opened one cock at a time along the pipe route, expecting to find some leaks. In fact only one union turned out to have a problem, but fixing it was not simple, and a replacement union was eventually required. Fitting this took most of the afternoon. Filling the boiler revealed some minor leaks from the mud collector (inspection door) beneath the boiler as well as from the blowdown valve. These will be fixed tomorrow morning, then we hope to light up the burner using factory air pressure connected to the atomiser, and raise steam.
We are far from finished however; I have a list of over 50 small items which need resolved, not to mention the need for a new driving axle and any other problems we uncover after steaming.
Sunday 18th June 2006
We had also discovered yesterday that the bogie was riding far too low, in fact the pivot pin of the bogie is bearing on the brake hanger cross-shaft directly below it, instead of having two inches clearance as it should do (and did before we dismantled it!). We spent quite a lot of time today jacking the loco up at one end or the other using manual screw jacks and plenty of muscle power, in order to tighten spring hangers nuts. For a while, it seemed we had fixed the problem, when we tightened the spring nuts on the driving, intermediate and trailing wheels. When we did the same on the leading wheels and the bogie springs, however, it reverted to its previous position. At the end of the process, however, we seemed to be no nearer getting the bogie to behave properly. Some reflection is called for, since none of us can work out what we are doing wrong. Suggestions are welcome!
Around two p.m. we connected the factory air supply to the light-up cock, turned on the blower to create a draught and the atomiser to spray the fuel oil from the burner into the firebox, and lit the fire by throwing in pieces of flaming cotton waste. After a couple of hours, the boiler was warm, but no steam pressure was shown on the gauge. We found and fixed a number of blowing joints in the atomiser, blower and elsewhere, much easier with compressed air than with steam, since you can feel for the exact source of the leak with your fingers. This improved the draught from the blower, but two hours later the pressure gauge was still obstinately at zero. We experimented with different fuel, atomiser and blower settings, and eventually got a more business-like fire going.
Still nothing on the gauge though; then I saw a curl of steam coming from, of all places, the anti-vacuum valve behind the chimney. This could only mean that (a) the regulator was not properly closed and (b) we had assembled the anti-vacuum valve wrongly, since it is meant to open to prevent a vacuum in the steam chest, not to vent perfectly good steam before it gets to the cylinders!. Sure enough, the regulator was open a crack. (The tender handbrake was on, the loco in mid-gear, the cylinder cocks open, and the traverser in place in front of the loco, before you ask!)
Around 7 p.m., the pressure gauge was still perversely at zero. However steam was clearly being produced. Opening the steam cock to the left side injector resulted in a jet of steam; and when someone pulled the whistle cord, the loco gave voice for the first time in maybe 25 years; not a watery gurgle, but a strong sharp blast.
We were forced to conclude that the pressure gauge, which had supposedly been tested in the lab, was faulty. I think we probably had about 50 or 60 psi pressure when we shut the fuel supply off. The Westinghouse pump began to thump, and steam began to issue from all the right places, as well as many of the wrong ones!
Since it was now well after dark, and the team had been working for over twelve hours, it was too late to do much about fixing the many small blows, but I made a thorough survey by torchlight and listed the defects. Yet more stuff to do! All of it looks achievable though. One disappointment was that the firebricks in the firebox have bulged or even collapsed, even though the loco did not move an inch. I can only assume the mason used the wrong cement, but will try to find out more tomorrow. We are a long way from having a reliable and useful loco to add to the Kenya steam fleet, but I feel we made an important step forward today.
Friday 23rd June 2006
By 8pm last night we were all set for a steam test today. We had pressed and refitted the regulator lever so that it fitted tightly on its spindle, and I wanted to make sure it had been set so that the main valve was firmly closed before the lever met its stop in the "shut" position. I gave it a good rattling open and shut. There was a clanking in the boiler in response, and then the lever jammed half open ! No amount of persuasion could restore its full range of travel.
It seems probable a pin has dropped put of the control linkage to the main valve. On the 24 class, unfortunately, this is entirely within the boiler, so we will have to remove the steam dome forging to find out what has happened and fix it. This is a four-man, four hour job, so we cannot steam the engine today as planned. Planned maintenance of the mains power supply in the workshops will also mean we have no air pressure to light up during the weekend, so it may be Monday before we can try again. This is frustrating, but it is better to have found a problem with controlling the main valve before going on a line test rather than during it ....
Sunday 25th June 2006
We also noticed that the pins were a loose fit, and decided to machine new ones to replace them. This took the rest of Friday evening and we went home late.
On Saturday, it was disappointing to find that fitting the new pins resulted in the small and big valves binding so that they operated together, instead of the small valve opening first. On the 24 class, simple slide valves in the dome do the job, a small slide operating directly in sympathy with the control rodding and the big slide following it via a slotted linkage. Now we had a problem - we had lit up at 0630 aiming to get the pins fitted and the dome back on while the water was warming up and still have time to raise steam using factory air pressure before the mains electricity supply was turned off for maintenance at 0900.
There we were sitting on top of the boiler wrestling with the tight pins in water which was growing appreciably warm. We had no machinist on Saturday and tried hastily and in vain to file and grind the pins so they'd let the two valves operate smoothly. The water got warmer. Eventually, the penny dropped: the people who fitted the loose pins knew what they were doing and had found the best way to make the worn linkages work reliably. We put the old pins back and satisfied ourselves that the regulator operated the valves smoothly. All was well and we got the dome cover back on and started to bolt it down around 0830.
With the boiler already warm, it seemed feasible to raise steam if we could just get a little more time with factory air pressure. I set off to see the head electrician and negotiated a one-hour extension. Back at the loco I told the team and watched them continue bolting down the dome. I vaguely heard someone complain about the black smoke pouring out of the chimney a few feet from where they were working, and busied myself with something else.
Around 0945 I went back to the cab and found the fireman had swept and cleaned the cab floor beautifully and was fiddling with a blowing steam joint on a minor pipe. But the boiler pressure was still low and the fire seemed timid. When I pointed out he had fifteen minutes left before the air went off, he jumped as if shot and it turned out he'd eased back the burner in response to the complaint about smoke. It seemed he'd lost concentration and forgotten we had limited time. He opened up the fuel and burner cocks again but failure was now inevitable and sure enough, the power went off on the stroke of ten, before we had enough steam to become independent of the air supply. My frustration is better imagined than described, since we had the whole team there ready to work all day. Nothing for it but to go home and take the kids swimming.
On Sunday, with electric power assured all day and the dome firmly in place, we started to raise steam again at 0700. By 1030 we had about 60 pounds pressure and were able to do without factory air. Our pressure gauge, in spite of being calibrated during the week, still did not work. The trouble was finally traced to a blocked copper pipe and remedied. Most of the steam blows previously identified had been fixed, but the blowdown valve under the boiler was still leaking, and as pressure rose above 100psi a gasket partially failed and the steam and water leaks became significant.
Since we could not fix the leak until the boiler was cold, we continued to raise steam. I wanted to ensure that the safety valves blew off at 165psi as the top priority, and to test the Westinghouse pump and air brakes. We had also found hat the reversing gear was very stiff indeed. Partly this was due to interference with pipework on the right side of the loco, but even after this was fixed it was hard to move the gear from full forward to full reverse. We spent some time taking down the valve gear and reassembling it, checking fits of pins and slides, but did not get the problem solved satisfactorily. It may well be a worn scroll nut on the screw reversing control in the cab, but we did not have time to go into it further. Meanwhile, the sight feed lubricator had been tested an adjusted, and some issues with pipework resolved. The generator was tested successfully, although the electrician still has some work to do on wiring and switches before I will be satisfied.
Another problem presented itself. We were using water and steam faster than normal due to the leaking blowdown valve, as well as various other blows, and it turned out the right side injector was inoperable, faulty cone suspected, and the left side, though capable of lifting water, leaked steam. We had fitted a new steam cock but had not appreciated that new or not, it requires to be ground to fit the valve seating before it is properly steam tight. We could not build steam pressure above 120 psi; since every time we got to that level the losses from leaks were such that we had to turn on the injector and watch the pressure fall as cold water came into the boiler.
It became obvious by 1600 we would not reach 165psi, so we concentrated on ensuring the Westinghouse was in good shape, which it seems to be. We adjusted the brake pull rods under the loco as best we could given the amount of steam and hot water pouring out. In spite of the pump thumping away, air reservoir pressure stubbornly refused to rise above 20psi. Eventually we found and fixed a blowing union in the air piping in the cab, but by now it was 1730, the water was falling again, .we had about 90psi on the gauge and everyone was tired.
Omondi, a regular KR driver and usually the stabling fireman for 5918 and 3020, had been tending 2409's fire. He was very reluctant to risk moving 2409 without brakes (the tender hand brake functions but is an unknown quantity at this point, and we did not have enough steam for the pump to raise working air brake pressure). Behind us were 5918 and 3020. In front was the traverser, with the wheel shop building on the other side without any kind of buffer or stop-block. Still, I was damned if we had come this far without trying to move the engine.
Omondi wound the loco into full back gear, whistled, and tugged the regulator open. Steam gushed through the open cylinder cocks on the left side, but not on the right side. Nothing else happened. Eventually we realised that the piston was at the limit of forward travel on the right side and that the lack of steam through the cocks was nothing to worry about.
Another tug on the regulator, then another. This time there was a very slight jolt. Twice more, and 2409 rolled gently backwards under its own power for the first time in two decades, until checked as the tender centre coupling met that of 5918. We coupled on and wound into forward gear. 2409 responded, but was not able to move 5918 from a dead start (and in retrospect it was not a good idea to add momentum with 250 tons of Garratt if we had got her moving!). Set back again, lift the chopper coupling, back into forward gear (each reversal a big effort due to the stiff mechanism), then we moved 2409 gently forward a few feet, staying under cover of the roof in Shop 006 and not going as far as the traverser.
So the engine can move itself forwards and backwards. I was delighted, and the team was amused and pleased for me. We have a lot of work to do in the coming week, fixing blows and faulty injectors, before we can steam again, test the safety valves, and check the brakes. At that point we should be able to get the boiler inspected and certified, move up and down the workshops yard, and then concentrate on solving the issues of stiff reversing gear, bogie spring settings, and pressing in a new driving axle.
Thursday 29th June 2006
Today I planned to steam the engine, but only one of the two Central Workshops air compressors was working today. This meant that some of the air system had to be closed down in order to ensure the wagon shop had enough pressure for rivetting and the paint shop for spraying. In fact, we did not get air pressure until 1430, and then the fire was badly adjusted until 1600.
As a result it was 2000 before we had enough steam to disconnect the factory air supply from the light-up cock. After that, however, we raised steam rapidly. A few faults are still in evidence: in particular, the left side injector is still blowing steam badly. Otherwise, however, only minor problems arose.
We continued to raise pressure above 120 psi, and were able to test that the air brake operated satisfactorily. Pressure continued to rise until the red mark on the gauge was reached at 165 psi then the needle kept going without the safety valves lifting! It turned out the springs we have used are for a higher boiler pressure and the holes for a securing split pin above the safety-valve nuts are therefore in the wrong place. We will modify the bolts tomorrow.
In the meantime, we closed the burner at 170 psi, refilled the boiler, bringing the pressure down to about 110 psi, and then moved backwards and forwards a few times onto the traverser, using the air brake to stop. I couldn't resist asking to take the regulator for one of these moves. The only previous occasion I've driven a locomotive was aged nine, at a colliery in Scotland, with an 0-4-0T "pug", which, come to think of it, was only ten years older than 2409. We finished off at 2200.
If we are able to repair the injector and set the safety valve tomorrow, we will steam the loco again over the weekend.
Sunday 2nd July 2006
The workshops compressor was out of action until late this morning so it was 1600 before we had steam raised. Frustratingly, we still have problems with injector steam valves and other steam blows, but one injector works satisfactorily, meaning that we could refill the boiler.
My intention was to set and test the safety-valves, but by good fortune foreman millwright Fred Anyasi had convinced the boiler inspector to come into the workshops to follow progress with 3020 (having three new tubes put in this weekend) and 5918 (which has had its lubricators serviced and will now have its boiler chemically descaled). The inspector was able to witness the setting of 2409's safety valves, which were duly adjusted to lift at 165psi and 170 psi respectively. To my great delight he confirmed he would now issue a full boiler certificate.
We had moved the loco out of shop 006 onto the traverser to avoid the steam from the safety-valves dislodging soot from the smoke hoods in the shop. Since we had a full head of steam and an hour of daylight left, I asked fireman Omondi to take the loco to the other end of the workshop yard. The workshops shunting engine (4721, a Hunslet- designed 0-8-0 diesel-hydraulic built at Swindon works in 1979 by British Rail Engineering) was parked in the way, so we coupled up to it and propelled it in front of us. This was the first time 2409 has been on curved track since having its wheels out, and I held my breath in case we'd got the axlebox sideplay wrong, but all was well and the loco negotiated the points, curves and poor track of the workshops yard quite happily.
I was keen for Omondi to carry on out of the workshops towards the running shed, but he was unhappy about it. Eventually he explained that he'd never passed as a driver when he was a steam fireman, and was therefore technically not permitted to drive the loco onto the working railway. This gave me an idea, however, and after a quick phone call I established that regular steam driver Ben Mwoki had just booked off after driving a diesel-electric to Nairobi from Mtito Andei. He was quickly on the scene, very keen to see how 2409 would handle. With darkness now falling, Mwoki drove the loco out towards the running shed before returning to shop 006, still hauling the shunting engine. 2409 performed well, although a tendency to slip easily suggests that we have not got the springs correctly set.
I had planned to go for a line test before dropping the driving wheel set in order to change its flawed axle, but on reflection we cannot really risk a trip with dodgy injectors and badly set springs. Since I now have less than a month before leaving Kenya, the aim is now to get the loco over the wheel pit as soon as possible next week, remove the axle so that the wheel shop can deal with it, and while that is under way, fix the injectors and other faults. With a lot of luck we will get the loco back in working order and have time for a line test before the end of the month.
Sunday 16th July 2006
I decided to take the bull by the horns regarding the flawed driving axle. The side rods were lifted off, the brake pull rods dismantled, and the driving wheels removed using the drop pit. The axle was pressed out of the wheels in the wheel shop (005) using their Berry press with a pressure of 100 tons. A new axle (or rather, a 53-year- old spare axle from the stack in the stores yard) was machined to the same wheel seat and journal dimensions as the old one. First, the ends were centre-drilled to form recesses for the lathe and grinder centres. The old axle, in spite of being flawed, had had little journal wear, so preparing the new axle only required removal of about ten to twenty thous from the diameters, which was achieved by grinding.
The 24 class wheels are keyed to the axles to ensure alignment with crankpins, so the next stage was to put the new axle on the marking table and mark out the keyways, taking great care to ensure the 90- degree right hand crank lead was accurate. A boring machine was used to mill out the keyways (since the slotting machine was broken). Finally the axle ends were chamfered on a lathe to guide them into the wheels. The axle was returned to the wheel shop and the wheels pressed on. The first wheel went on very smoothly, but we did not take enough care to check keyway alignment when pressing the second wheel on and we got it a few degrees out. Fortunately this was noticed well before the wheel was pressed fully home, and a force of only 20 tons had been applied. The wheel was pressed off again, correctly aligned, and pressed on fully, a process which sounds simple enough but took two hours of work to effect, and was complicated by darkness falling and inadequate lighting. One of the most important pieces of project equipment of late has been my torch!
The brake pull rod on the 24 class is a two-inch steel rod centred under the axles, with threaded portions where nuts secure the brake hanger crossbeams. The nuts are tightened up as the brake blocks wear down with use. One of these threaded portions had become worn out over the years and the nuts could no longer be tightened. Since we had removed the pull rod to drop the driving wheels, we took the opportunity to repair it. The worn area was built up by welding, then new threads cut on a lathe.
While the wheels were out, we also corrected a mistake made earlier when we had welded rocking washers for the driving wheel spring hangers at the wrong angle. The washers were cut off and new ones welded in correctly.
I spent the second week of July away from Kenya, but arranged for painting work to continue. The loco was given a second undercoat of dark red paint, topped by two coats of EAR maroon. The numberplates and buffer beams were painted vermilion. This weekend, black edging and yellow lining were applied to the cab and tender.
I returned on Saturday morning and mechanical work recommenced.The driving wheels were prepared (a new hub liner welded on, then axleboxes and springs built up) and lifted back into the frames. The brake rods and side rods were put back, and the headlamp replaced in front of the chimney. The bogie springs were reset correctly, and a second set of new crankpin nuts and taper pins prepared; the first set had been very hard to remove due to jammed taper pins. We had not appreciated the importance of ensuring the taper of the hole through the crankpin nut, the taper pin itself, and the holes for it in the rim of the crankpin nut all matched, and as a result the old taper pins had bent and jammed in the crankpins. Getting this right has been time-consuming and frustrating but will pay dividends in future.
We still have to re-erect the left hand connecting and eccentric rods, but after that will move the loco back to shop 006 for steaming, and if no further problems emerge, will plan a line test later this week.
Wednesday 19th July 2006
This was inconvenient in several ways. We could not continue with repairs very openly since those working on 2409 would be seen by their colleagues as lacking soldidarity, with appropriate physical consequences quite likely. Instead I decided to raise steam in shop 010 after staff had gone home. This being a cold time of year or Nairobi (night-time temperatures around 13-14 centigrade), the heavy fuel oil is thick as tar and flows very reluctantly. We raised steam for six hours without getting any useful pressure in the boiler. At ten p.m. we gave up. On Tuesday we moved the locomotive in the morning to shop 006 but by the time we reached the large traverser, the kamukunji had already begun. I was about to ask for co-operation to let us use the traverser, which I'm reasonably sure would have been agreed, when prayers started, and things inevitably grew more passionate and heated as the orations continued. Discretion was definitely the better part of valour in this case, not least since we would have been blowing thick smoke at the kamukunji for the rest of the day. We retreated to the other end of shop 006 and raised steam inconspicuously. The fact that we were blocking an access line did not matter, since no production was taking place in any case.
We started to raise steam around ten a.m. Even though the boiler was still warm, it was growing dark before we had full working pressure. Then two minor defects arose, which nonetheless were disastrous for my plans to go on a test run. The whistle, which had had a steam valve and had been over-tightened, turned out to have sheared its threads an literally blew off the boiler when operated. Fortunately it didn't hit anyone when it came back to earth. In addition, we could not make the generator work. Ben the driver shook his head; he was willing at a pinch to run on the main line with no whistle, but not without a headlight. So we simply ran down to the running shed and back a couple of times, then returned to the workshops to try again the next day
Several other small defects had to be rectified, notably a cracked air pipe near the triple valve which meant only the tender brakes were effective. It was midday before we could start to raise steam again. The sit-down had ended (a circular from the managing director instructing staff to resume work and wait until August 1st to learn their fates, or leave now and forfeit all benefits) so work could continue openly. Raising steam was again a long slow process, but by six p.m. we were ready. The generator agreed to work this time, so we had lights. The oil was still thick and the fire hard to manage, and the fireman was nervous of running far, so we ran up and down the yard to the West Junction and came home again. The loco performed smoothly, with a good ride and no blows at all from the cylinders or valves. We had to creep around carefully; the yard and loco shed are busy places these days and several other locomotives were also in motion. Very impressive quantities of black smoke were produced (impressive, that is, unless you are a housewife in the adjacent Land Mawe area) as the fireman got to grips with the firing valve. We stabled the loco overnight so that we do not have to raise steam again.
Today (Thursday) 3020 is to be put in steam for a line test prior to Saturday's Naivasha excursion. She will be lit up using steam from 2409 instead of air pressure, which should speed things up. We hope to test both locomotives in daylight, and may try to run in tandem if two drivers are available.
The firing technique for 2409 seems to be slightly different from 5918 and 3020, and not because they are Giesl-ejector-fitted and 2409 is not. There is a tendency for the thick oil to block the burner lip before being ejected by the atomiser steam, resulting in a very small fire. The fireman, Omondi, has learned to overcome this using an occasional pulse of steam down the oil pipe from the blowback valve. This blows the clot of oil into the firebox with a loud "pop" and a burst of flame. Before the clot is blown out, the firing control valve has little effect, which was the reason for Omondi's nervousness; he was only able to control the fire using the main supply cock on the tender with a spanner. It could be that we have the burner gap set to be too narrow, or that we are using oil far thicker than was intended by Alco, who supplied the equipment to convert most EAR locomotives to burn oil in 1948. Perhaps both factors play a part. No doubt more experience will help.
As Trevor suggested in a posting a couple of days back, I am hoping 2409 might also make an appearance on Saturday for the Naivasha excursion, but there are many issues to resolve before that can be said with any certainty. Still, uncertainty is what makes East Arica interesting!
Thursday 20th July 2006
At Kibera, our air pump had also failed due to lack of lubrication. After a brief but futile struggle with the pump's reversing rod, and with a waiting down freight hooting for the road alongside us, Ben Mwoki told us to get in the cab and cautiously descended the 1.5% gradient back to Nairobi using the reverser as a brake. We did not want to be caught at Kibera for hours without water, and the tender was already one-third empty. I had called Control and warned them we needed priority, so we had been given the Line Clear, but that was before we knew the punp was acting up!
Because of the air pump fault, and one or two others issues, we will not now try to double-head the Naivasha excursion on Saturday. There is not time to make and test the necessary repairs, and 3020 also requires preparation time.
Wednesday 2nd August 2006
The burner itself was adjusted to have a gap of 15 thous, and the burner control valve altered to give more positive open and closed positions. After the Kibera trip, the valve stops had become loose, leaving the fireman a difficult job to close the oil supply positively. As a result we had more than once inadvertently dumped oil into a cool firebox with the burner air off, resulting in huge clouds of black smoke drifting across Nairobi yard towards the station, HQ building, and central business district of the town; not the best way to make friends!
During Sunday we had added the brass "E A R" lettering to the tender, drilling holes for brass rivets which were cold-hammered into place by a man inside with two of us outside holding a metal block as an anvil. The rivets were caulked inside afterwards using bituminous sealant intended for roofing. Unsure whether the rivets would leak with the flexing of the tender side during a journey, we lettered the left side of the tender only, until the line test showed if the method worked.
The repairs were completed by Tuesday night and on Wednesday we steamed the engine again, hoping to make a test run. Brazing the safety-valve had affected the valve seating however, and the front valve no longer closed properly, blowing copious amounts of steam at well below the boiler's working pressure. There was nothing for it but to shut down and try again on Thursday after repairs.
In spite of an early start, removing the safety valve before re- brazing the casing and removing the excess metal, then lapping the valve with grinding paste, took until early afternoon. The boiler was still warm, but steam was not raised until late afternoon, and the rear headlight once again decided not to work (the fault was later traced to the switch, rather than the wiring or headlight itself). We had tried to reset the safety valves nuts accurately to their previous position, but when we raised pressure, we found they were still not blowing off at 173 psi, well over the 165psi working pressure. We quickly slapped the injector on to bring the pressure down. To adjust the valve springs, the loco would have to cool down. Grinding my teeth, I postponed the test run by one more day. I didn't want to give up without moving the engine a short way, so we ran to the triangle next the running shed and turned the locomotive so that the smokebox faced Mombasa. I wanted to blow down the boiler, but the blowdown valve was jammed and would not open smoothly. Ben argued against hammering to open it in case it wouldn't close again, in which case the entire contents of the boiler would be ejected in a few minutes, probably damaging the firebox crown. This seemed sensible advice. We left the blowdown for another day and returned to the workshops.
Before shutting down the loco, we backed onto the water bogie and first class coach and carried out a brake test, which went smoothly. Omondi the fireman shut down the fire, put the injector on to fill the boiler, and went home. I stayed behind and, once the injector had knocked off as the pressure fell, blew back the remaining steam into the oil bunker for about an hour to mix and warm the oil ready for the following day.
On Friday morning Ben Mwoki the driver and Omondi came in at 6 a.m. instead of the usual 8 o'clock start, knowing that I had little time left in Nairobi and that Friday was liable to be the last chance for a decent test. The weather was miserable, grey cloudy sky, overnight temperature about twelve Celsius, and drizzling rain starting and stopping through the day. The boiler was warm, however, and by ten- thirty a.m. we had raised steam. 2409 had to wait a little while until two Class 87 diesel-electrics moved out of the way, then backed down onto the rake of water tank bogie and first class bogie, coupled up, and headed for the workshop gate.
I had called the regional controller and asked him for a load for Thika, forty kilometres from Nairobi up the Nanyuki branch line. The Thika line has two commuter trains in the early morning, then two daily freights if traffic warrants them, at nine and eleven a.m. The controller told me he had enough traffic and would set up the load at the Up yard, at the west end of the station. The fitters clambered aboard the first class bogie, and we set off out of the workshops. We were joined by a cheerful guy named Joe, a U.S. citizen working at the airport maintaining commercial jets. Joe had been on the previous Saturday's trip with 3020 and was keen to see how 2409 would get on.
Ben pulled up clear of the workshop gate and we went to look for sand at the drying shed. There was hardly any left, the shed had been swept clean by diesel drivers facing the climb to Kibera on greasy, wet rails in the drizzle. We filled two cans of sand with difficulty and brought them to the cab. Ben started to propel the rake westwards through a crossover. 2409 slipped madly most of the way, although the track was level and the load only about 95 tons at this stage. Eventually Ben cleared the neck of the shed access lines, then drew forwards on the exit line from the shed towards Nairobi East yard ground frame, stopping at the warning board. We sat there for half an hour while two 62 class shunters pulled wagons to and fro in front of us. Both Ben and I departed in an attempt to find out what was happening. No-one seemed to know what to do with us.
Two Dutch enthusiasts had turned up to visit the running shed, hoping no doubt to catch an 87 diesel-electric in from that morning's Kisumu passenger. Walking from the station, they rounded the rakes of sorted wagons and were suddenly confronted by the sight of 2409 hissing away on the exit road. You could almost literally see their jaws drop before they got busy with their cameras. For good measure, an 87 pulled up behind our rake. They only had half an hour before leaving to catch their flight and they used it well.
Eventually Ben got hold of the running shift foreman at the shed, who made a few phone calls. The 62s paused sorting their wagons and let us through so we could propel our rake to the Up yard and find our load. Again, wheelslip was a problem. Ben's buddies outside the yardmaster's office were smirking, and eventually he lost his cool. "Who set the main valve on this engine?", he roared. I was forced to admit that I had supervised setting the regulator inside the steam dome so that the small valve opened before the big valve, although in fact William Buoro, the experienced retired fitter, had also been on top of the boiler watching. Ben had pinpointed the problem: whenever he opened the regulator, the small valve was pulling the big valve with it, allowing too much steam into the cylinders and thus too much torque to the coupled wheels, which slipped instead of gripping the rails. We had been at pains to adjust the valve spring so this did not happen, but clearly the valves behaved differently when full boiler pressure was being applied to them, something only experience could have solved. I told Ben this. He grunted, still unhappy, but in fact from that point on the loco stopped slipping when he was in charge. He modified his driving technique to use smaller dabs on the regulator handle and was able to control the loco without problems. I later watched several other drivers learning how 2409 handled: some of them never quite got it right, but others were able to avoid slipping more or less from the word go. If we had had more time, we could have reset the valve, but it would have needed an extra day to take off the dome, adjust the spring, and put the dome back in place, and there was no guarantee we'd get it right the first time.
The shunter indicated our load: three covered goods bogies loaded with green wattle bark from Eldoret for the Kenya Tanning Company. Wattle bark was one of the earliest products grown by settlers in Kenya and it seemed fitting that, over ninety years after the Thika branch opened, we should be carrying such a traditional cargo. Ben shunted the train so that the CGBs were between the water bogie and the staff coach. Our train number was K3B: the load was ten units, 203 tons in total. Guard Osodo performed a brake test as a light drizzle was falling, then at 1328, Ben whistled and opened the regulator.
2409 headed eastwards through the yard parallel to Nairobi station, over a series of crossovers until the main running line was reached beyond the station east ground frame. We passed the east yard frame opposite the loco shed with steam shut off due to the slight falling grade, and rounded the curve towards Nairobi East Junction signalbox, with the old boiler park to our right still with two or three Garratt boilers rusting in the grass. We passed the gantry of lower-quadrant sempahore signals, collected the wicker hoop with the single-line Tyer's token from the signalman, and coasted down towards Makadara at about ten m.p.h, passing the many sidings of the industrial area on our right. The small ends of the connecting rods clanked rhythmically. The drizzle had cleared up.
Past Makadara we took the branch line, curving off to the left below the Jogoo Road bridge. Ben rounded the curve cautiously, carried on below the Outer Ring Road bridge, then opened the regulator as we neared Dandora station. 2409 responded with a crisp beat. All seemed to be going well, and we had plenty of steam. Ben looked like he was beginning to enjoy himself.
The Thika branch was built as an agricultural feeder line to create traffic for the Uganda Railway. The UR had been funded by the British government at a time when competition with the German and French empires for control of the headwaters of the Nile had loomed large in British foreign policy. By the time Lake Victoria was reached, three times over budget and several years behind schedule, Imperial priorities had changed, and the railway's strategic importance had vanished. The railway was handed over to the local colonial administration with a large debt to the Treasury to service, and no established source of traffic. From early times, therefore, the Governor was preoccupied with developing agriculture and other businesses along the railway. The Thika branch was conceived with this in mind, but the colonial office, still smarting from the cost of the Uganda Railway, rejected the Governor's proposal for the branch line outright. Only by reducing the cost to the bare minimum, and cunningly relabelling the proposal as a Tramway (at a time when tramways were rapidly extending into the suburbs of British cities), was funding for the branch approved.
The upshot was that the Thika branch was constructed very cheaply, with alignments which plunged down slopes to cross rivers with the smallest possible bridge span before climbing up the other side of the valley, rather than using expensive embankments and long steel spans to reduce gradients. Although the worst of the grades have been smoothed out in the intervening years, the line still swings wildly around, seeking to minimise earthworks.
This constant rising and falling to cross small rivers makes the Thika branch exciting to travel on in a steam loco. Often it is not possible to build up much speed on the downward part, as there is invariably a curve near the bottom which has to be taken carefully. 2409 didn't hesitate, however, climbing purposefully out of the dips past Githurai Halt and then on the long climb to Kahawa, slowing to a walking pace but then settling into a purposeful rhythm as Ben put the engine into full forward gear and the blast leapt high into the sky.
We stopped for ten minutes at Kahawa, where we got a new token for the section to Ruiru. A crowd of onlookers gathered, then we were off. Ruiru was quickly reached, and after another short stop, we left for the final section to Thika.
Just before Kalimoni station, there is an awkward gradient. The line drops to a river bridge, veering sharply left just beyond it, and then rises at something between 1.5% and 2% (1 in 75 and 1 in 50) before veering right and over the crest of the rise to Kalimoni. Ben eased the train down the hill, over the bridge and around the curve, and opened up, but I could tell from the start that we were not accelerating fast enough, and sure enough, we ground to a halt about two-thirds of the way up the rise. Omondi blew up steam and Ben tried to restart on the slope, but 2409 was having none of it, slipping madly. He backed the train up the hill on the other side and tried again, but with the same result, stalling half way up.
I had dropped off the footplate to watch from the lineside nearer the top of the hill. After sitting for ten minutes or so, and trying another standing start, Ben reversed his train over the bridge again, but this time kept going back until he was right at the top of the hill on the other side. Then he whistled and kept the regulator open on the way down.
2409 belted down the hill, over the bridge, snapped round the corner, and Ben wound into full gear and opened the regulator wide. Black smoke shot heavenwards. No risk of stalling this time; the train roared past me and round the corner out of sight. I followed slowly along the ballast. The train was waiting for me at the level crossing just before Kalimoni station. As I came level with the staff coach, Joe the American looked out at me. "You're not going to get that grin off your face for a week", he commented. I had to admit he was right.
After that, it seemed an easy run for the final hour or so to Thika. The countryside becomes more open with fewer settlements and fields, and more long, sun-bleached grass. At one point a Range Rover with a family inside bumping slowly along a murram track paralleling the railway stopped in disbelief, kids hanging out of the windows, at the sight of the maroon engine with its short goods train puffing through the bush. We waved, and they waved back, perhaps relieved to find they were not hallucinating.
Suddenly a new noise was apparent, a groaning squeak on the right hand side. Ben was of the opinion it wasn't the cylinders, and wanted to press on. Since we were on a rising grade and not doing much more than walking pace, I dropped down to the ballast (easy to do on 2409, with its low footplate: much harder on newer locos like 3020) and ran alongside the engine until I was certain the noise was coming from the valve chest. We stopped. The cause turned out to be a blowing union in the piping from the sightfeed lubricator. I knew about this blow; previous attempts to repack and close up the union had made it blow even more, and for fear of stripping the thread on the nipple we had simply left it slack at a "sweet spot" where the blow was insignificant. Now it was blowing the steam and lubricating oil out into the atmosphere rather than into the piston valve. Omondi put on the right hand injector, and the gasket on the clack box on top of the boiler chose that moment to start leaking, showering me with warm water. We tightened up the lubrication pipe union, fearing the worst, but to my great relief the blow stopped completely. The motion from the journey and the heat must have coaxed the nipple to fit the nut better. We set off again, and the squeaking stopped.
Twisting and turning through the scrub, the years seemed to roll away, and it took the sight of the Thika colour-light home signal, and the level crossing busy with modern traffic, to jerk us back to the twenty-first century. We reached Thika at 1746.
The shunting engine driver at Thika has steam experience and had shunted 3020 for us on a previous trip, subsequently being called on to drive during the RTC safari in 2005. He was delighted to see 2409, since he had driven 24s when based in Mombasa thirty years before. Ben happily handed over the loco to him to shunt the rake and turn on the triangle. I was impressed to note that, under his control, the loco did not slip once.
We had only used half a tenderful of water, but we topped up from the water bogie and cleaned the fire, which was getting choked with carbon deposits in the ashpan, before restarting at 1931, well after dark. Our load was now only about 90 tons and Ben wanted to get home. With increasing confidence he opened up on the grades. The headlight threw a small bright circle onto the track ahead, enough to see the rails curving sharply from side to side into the darkness. Seated high above the fireman on the left-hand tender toolbox, I could see ahead through the cab window as well as watch Ben adjusting the regulator and cut-off on the right side of the loco. There is little space on a 24 class footplate, and the boiler backhead is old- fashioned, tall and with few controls. The experience was remarkable; suddenly the early years of the Uganda Railway seemed very near.
Omondi called something over to Ben, and we drew up. "The firing control's broken", he told me. "Maybe there's a pin come out." Sure enough, when I got down to the trackbed to have a look, the pin holding the control rod to the control valve operating crank had fallen out after shearing its split pin. Fortunately it was still lying on the foot-framing. I found a new split pin and reassembled the linkage by torchlight, and we set off again. The fitters in the staff coach behind us did not stir.
We reached Ruiru at 2042, just in time to see the 25-coach commuter train empties leaving in front of us for Nairobi. (This is the longest passenger train currently running in Kenya; longer than the Nairobi-Mombasa trains). This meant a half-hour wait for the section to be cleared. Eventually we got line clear and set off again, reaching Kahawa a mere eighteen minutes later. After being held for ten minutes we received line clear to Makadara and took off into the darkness.
I remembered my last trip over this stretch, with 3020 steaming very indifferently. There is a long rising grade before Dandora, and 3020 had slogged up it at less than walking pace just before dusk, with large numbers of homebound passers-by looking curiously, and ultimately sniggering at us as the driver and fireman fought to keep the train moving. 3020 ultimately stalled not far from Dandora due to lack of steam. Tonight, however, 2409, with the same load, pounded up the Dandora bank at 25 mph, whistled for the level crossing, and coasted through the station before opening up again as we headed for Makadara. I think that was the single most satisfying moment for me on the trip, vindicating the care we had taken descaling the boiler and fitting the valve and piston rings tightly. It certainly spoke volumes for the simple and effective design of the loco. I knew Ben was thinking the same thing, for he had been the driver that day on 3020. We exchanged satisfied looks.
At Makadara, the outer home signal was defective, which we had not been warned about. After waiting fifteen minutes at the signal, and with clear sight of the line ahead, Ben moved at walking speed into the station and received line clear for Nairobi. We reached the East Junction at 2241. Subtracting the signal check and the time waiting for line clears, we had done the trip in a creditable two hours ten minutes.
Our route back to the workshops was blocked by shunting operations, so we were held at the East yard ground frame for a while. One by one the fitters slipped off into the darkness. It was well after midnight before we had the loco back in shop 006. Omondi put the injectors on and left the loco to its own devices. Tired but pleased with ourselves, we left the workshops for home.
On Saturday 29th we had a rest day. Sunday 30th was the day fixed for my farewell party, at the Afrosa Classique bar in the run-down Land Mawe area near the workshops. Warare, Maina the welder and I spent the morning rivetting the brass EAR letters onto the right-hand side of the tender; our technique seemed good enough to have survived the Thika trip without springing leaks. The celebrations were attended by about fifty staff from the workshops; it was surprising how many people had been involved when I started to draw up a list. The atmosphere was more muted than at previous parties. The men were still uncertain of their futures, since Rift Valley Railways had been unable to finish their financing arrangements in time and had asked for, and been granted, a three-month delay in their commencement date, which ordinarily would have been on August 1st. Former EAR driver Charan Singh Kundi had very generously sent me a contribution to the costs, and a goodly amount of alcohol as well as thirty kilos of goat and beef were consumed.
As the party wore on, we hatched a plan to have one more trip with 2409 before I left, on Tuesday 1st. Taking account of previous experience we put the loco in steam on Monday evening and stabled it overnight, to be ready on Tuesday. There were a number of repairs to be done, water and fuel oil to be taken on; all in all it was close to 1300 before we were ready to move. Ben Mwoki had been sent away to Nakuru on duty, so our driver was the regular 3020 fireman James Mathuva, also a senior driver. We collected our water tanker and staff coach and moved off to the yard. I had talked with the regional controller that morning and been promised a load to Uplands, on the line to Uganda. Our train number was to be B4A. I felt confident enough to ask a few friends to come: Roger Tanner and Rowena Buxton of East African Steam Safaris, and Bryan Harris, chairman of the Friends of Nairobi Railway Museum. The sun was shining and everyone was in a good mood.
Mathuva had no problem in moving 2409 without undue slipping. We were facing the right way for Uplands, so we propelled the rake out of the workshops and did not go to the triangle. There was still no sand at the loco shed. Mathuva waited until the crossover points had been reversed and moved forward towards the West junction. The line curves slightly to the right at this point before a number of sidings from the running shed trail in from the right side.
As we passed the first of these sidings, a bystander started to wave and point at the front of the loco. A second later we felt a heavy thump on the footplate. Mathuva took a couple of seconds to react, then applied the Westinghouse brake while I jumped down to the trackbed. At first everything seemed fine, then as I walked to the front of the loco, I saw that the front bogie wheels were off the track.
Someone went to fetch the breakdown gang, while I glumly called the regional controller and told him we would not be able to take the train to Uplands. A cotter pin from the bogie spring cross beam was also missing, and I could not find it despite searching the track back to the workshops. However, the beam had not moved significantly and I concluded it had no bearing on the derailment.
As we waited, Mathuva took a close look at the brake blocks on the loco, and
realised that only two of the eight brake blocks were doing any useful work.
Although we had set the rigging correctly before the Thika trip, it had
clearly "worked in" and required to be tightened up. Since the
brakes were hard on against the wheel tyres in the workshops, we had not
realised this. Again lack of running experience was slowing us down.
I stopped Mathuva and asked him to drive forwards again over this joint at dead slow speed. He obliged as I watched the bogie from track level in front of the engine. Sure enough, as it came to the joint, the bogie dipped, then suddenly the front wheels sprung sideways about six inches and derailed again. I remembered that 3020 had, in fact, derailed at exactly the same spot some eighteen months before, on its way to work a Naivasha excursion one Saturday morning.
The breakdown gang boss was a little incredulous when I told him we'd come off again at the same spot, although another small injection of "gasoline" (as the railwaymen call a tip) ensured they came out promptly enough. I had to leave the proceedings at this point, but I gather they got the front wheels of the bogie back on, only for the back wheels to come off as soon as the loco moved. It was 8 p.m. before they were safely back in the workshops.
It may seem strange to have deliberately brought the loco over suspect track in this way, but perhaps I am influenced by early exposure to software engineering and the need to identify the conditions which make faults repeatable! Anyway, I was pleased to have proved in my own mind at least that poor track was the reason for the derailment. The other possible causes, inaccurate vertical spring or side control spring setting, had to be eliminated before I was sure the loco was safe.
While I am not certain we have the vertical springs on the bogie set correctly, we have done our best without access to a weighbridge. (The loco weighbridge has not worked for years, and the wagon weighbridge in the workshops is reached via some very dodgy track, over which the shunters refused to allow us). Instead we used the split pin holes in the spring hanger bolts, as well as comparison with 2401 in the Museum, to set the spring tensioning nuts. As for the bogie side control spring (which is what caused the wheels to leap six inches instead of gently climbing over the rails) we set the tension according to instructions on the original works drawing, using an original spring removed from loco 2401. If anyone has any observations about this subject I would be very interested.
So my final view of 2409 was rather a sorry one, with the loco all dressed up with nowhere to go and the front wheels on the ballast. I left Kenya the following day to join my family in Switzerland. Fortunately I have the memory of the Thika trip to compensate, and some video. I've put a short clip, including Ben charging the bank at Kalimoni, at Trevor Heath's restoration page
If I'd had another week or two, I'm sure we would have got 2409 to Nanyuki.
Friday 25th August 2006
I am very pleased to hear that a German film company has expressed interest in using 2409 for a filming contract in October, as well as 3020. I had feared that 2409 would end up unwanted and unloved at the back of the workshops, where its copper piping would disappear in a matter of days. Let's hope not! A quote has been submitted to the film company and a response is awaited. 2409 may make a test run to Sagana on the Nanyuki branch next Thursday (31 August). 3020 is also to be tested I believe.
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