2409 in number 6 Shop ©2005, Trevor Heath
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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
Mountings: 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:
Boiler:
Lubrication:
Tender:
Cab:
Cylinders, motion, frames:
Wheels and bearings:
Brakes:
Electrical:
Cosmetic:
Monday 20th June, 2005
Boiler:
Boiler descaling: 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.
Lubrication:
Tender:
Cab:
Cylinders, motion, frames:
Wheels and bearings:
Brakes:
Electrical:
Finish:
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:
Boiler:
Lubrication:
Tender:
Cab:
Cylinders, motion, frames:
Wheels and bearings:
Brakes:
Electrical:
Finish:
Other: 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). For the record the Steam Team is:
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 th |