The steam cleaner was in itself a problem. The steam generator would not function as the heater's burner spray nozzle was continuously becoming blocked (dirty fuel). The Chief Mechanical Engineer (CME), Dave Potter, finally coaxed it into life on Sunday 23rd June 1996 but not before being singed as the diesel which had been spilt on the floor flashed. The next attempt to coax the steam cleaner into life occurred over the weekend 29th/30th June 1996 when Kevin Dingle's delicate touch got it to erupt, literally, into life. The burner emitting great clouds of smoke but at least hot water nay steam emanated from the nozzle. It continued to emit great clouds of smoke even after it was switched off as the residue of past use was burnt off the heater walls. Engines Nos. 876 and 1161, both spare gearboxes and the underside of No. 2 engine bay were cleaned. Then yours truly had to be steam cleaned after resembling an outcast from the Black and White Minstrel Show!!!!
No. 1 engine bay was cleaned during Saturday 6th July 1996. However because of the proximity of the coaching stock on the No. 1 road of the siding and the overflow from the land drains following a torrential storm the job will need to be done again in a more open environment in order to better see what has and has not been cleaned.
Cleaning the engine bays provided an ideal opportunity to do a 'visual' on all components before the engines were replaced on Sunday 7th July 1996. All the original pipework was there to be seen and the various modifications that had taken place over the years could easily be traced.
Two replacement engines, Nos. 900 and 275, were prepared for fitting into the unit to replace Nos. 124 & 876. After inspection engine No. 876 was deemed to be in good enough condition, despite the broken casting, to be rebuilt. Engine No. 124 was in no condition to be rebuilt and a decision was made to make it the spares donor for the other engines. No. 900 required various fuel pipes, oil filler pipes and the fuel lifter pump fitting from No. 124. No. 275 came complete from Rotherham. Both needed fitting with the special throttle cables as fitted to the AEC engined Class 122s.
To check each engine it was decided to start them both 'on the ground' to find any problems. As there were no heavy 'lorry' type batteries to start the engines the unit's own batteries were wired up with crocodile clipped jump leads to the starter motor of the engine. The fuel line was connected to a specially constructed fuel tank, an unused paint can with a rubber hose out of the bottom! Hanging from the fence using gravity feed it worked well especially when the return waste fuel was returned to the can by a Heath Robinson arrangement made of scrap copper piping.
Engine No. 900 was tried over the weekend of the 15th/16th June 1996 but was very sluggish in turning over. In fact it only managed to turn over once. The problem was purely battery power and voltage drop down the cables. Despite being charged by my own 2 kilowatt charger each weekend it was obvious that either the batteries were in a worse condition than originally thought or a lot more power was needed. To this end the compressor which incorporated a 4 kilowatt generator was placed ready for use on the unit.
The batteries and all connections were removed cleaned and checked on Saturday 22nd June 1996. It was found that two batteries were down to 1.0 volt and the rest were between 1.5 and 1.8 volts. The optimum value being between 2.0 and 2.1 volt. Three packets of 'Batt-aid' tablets were distributed between the cells to help clean the plates and they were put on charge. The generator was started and a charge of 35 amps gradually reducing to a steady 20 amps was put into the batteries for approximately 15 hours. Within 3 hours all batteries had begun to built up charge with voltages all up to the prescribed value 2.1 volts.
Late on Sunday 23rd 1996 engine No. 900 was retried but failed to start although it obviously wanted to go.
Why did it fail to start? Apart from only using the single jump leads I'd connected the input fuel line to the waste output on the engine!
After consultation with the CME it was decided to 'double wire' the connecting leads. Armed with one set of crocodile clipped leads, one set of welding leads and the fuel line now connected to the input fuel line another attempt was made.
Sunday 23rd June 1996 became a red letter day as engine No. 900 was started for the first time at Chinnor. The engine behaved impeccably and even the CME was happy. Engine No. 275 was subsequently tried. It turned over but did not fire successfully and the CME was not happy. Another attempt was made over the weekend of 29th/30th June 1996 when the batteries had been given a good charge. No problems were envisaged at this point as diesel was getting to the injectors and although the cranking speed appeared somewhat sluggish it was adequate. The only pointer to the injector problems to come was the amount of fuel flowing back through the waste pipe.
The weekend finally came around and the batteries were charged up. Engine No. 275 was wired up and ...... it failed to start. The engine was trying to start and as the oil pressure and circulation built up the turning engine became quite 'lumpy' but would not fire properly. The timing marks appeared to be untouched and the fuel pump had not been reset therefore it was concluded that the only explanation could be the injectors. As before the considerable amount of fuel was being passed back through the waste pipe indicated clogged up injectors.
The only solution therefore was to remove the injectors and see what was amiss. Presumably BR has an 'injector removal tool' I don't so once the rocker covers were removed and the retaining bolt and collar disassembled the injectors were removed by use of a long screwdriver down the back to release the injector barrel from the head.
The evidence was there for all to see. All injectors were carboned up very badly. Only three out of the six had spray holes showing and then only one per injector. Each injector has four spray holes each 8 thou. in diameter so it is not difficult to clog them up unless in constant use even at the ambient working pressure of 140 atmospheres. These, and the six from engine No. 124, were taken away to be overhauled professionally.
The injectors were ready for the weekend of July 6th/7th 1996. Before refitting the injectors a shot of engine oil was put into each of the cylinders to assist in providing lubrication and a good seal around the rings. The injectors were soon reinstalled in engine No. 275. One injector gave a small amount of trouble when the main fuel input stem came loose. After retightening it appeared to be allright.
The spare six overhauled injectors are to be used in engine No. 876.
The batteries on the unit were given a booster charge, the fuel line reconnected and the starter motor wired up. At midday the engine was tried but failed to start. After bleeding the fuel pump, fuel lines and injector pipes it was tried again without success. By this time I was beginning to wonder what could be wrong and what I could you next. I decided on the last recourse - Easy Start.
Leaving all my tools by the unit I went into Chinnor to buy some. Two minutes after leaving the site came the heaviest storm I've seen in many years. Hailstones the size of peas and not the ones from the moment the pod went pop, but those that were left out came down for thirty minutes. Chinnor and the railway were awash. Down the sidings the land drains overflowed and the site resembled a swamp. All my tool boxes were filled with iced water. When I returned I had to spend the next half hour drying my spanners etc.. Once dried out I decided to try the engine once more. With the can of unused Easy Start perched on the block the engine was turned over.
After a couple of turns it fired! The unit was enveloped in a cloud of blue smoke but the engine settled down to run quite sweetly. I think everyone on the site heard that engine fire because soon a whole crowd gathered around. The engine was tried again and it started first turn, and no Easy Start was needed. The CME was very happy.
The following day, Sunday 7th July 1996, was the last day that all the engineering staff would be together for two weeks. It was decided to put the engines back under the unit that day and the CME was unhappy. He had planned to work on Class 08 D3011 and Ruston 'Iris' in preparing the locomotive air tanks for insurance inspection. However with assistance from the other members of the engineering team the job was completed early on Sunday morning. This left the day open to re-engine W55003.
The last job done on the engines before putting them back was to fit the belts onto the rightangle drives. The job can be done with the engine in situ but is far easier out on the ground. It takes two persons, one to bar the engine over and one to feed the belt(s) over the pulleys. The job involved fitting two belts for each engine and then tensioning the drive itself. Remembering the problems already found with engine No. 876 the washers were inspected and all bolts done up as tightly as possible.
The CME provided the pallet truck whilst the engine mounting brackets were put in position under the unit. The unit was then shunted onto the concrete hard standing of Rugby Cement by the Class 20 D8001. The two engines were craned over onto blocks and the job started. It took two hours to get the engines in place. The CME was happy. D8001 then returned the unit to its position at the end of No. 2 road.
Once the engines were back in place and the unit back in position the task of connecting all the various pipes and wires began. Apart from the standard fittings such as starter motor connections, final drive connections, air intakes, oil pipes and driver's cab water heater pipes W55003 has 'A' series throttle motor connections.
The throttle connections are all by cable and not cable and rod as was made standard on all other BR DMUs. A certain amount of setting up was necessary to ensure the cable was in the correct position and length. It also involved swapping one of the arms off the new throttle motor(s) for one off the old throttle motor(s) to fit the cable end connecting bolt. The arm on the new throttle motor had too small a hole.
The driver's cab water heater piping involved altering the fittings on the water jacket casting and acquiring some extra flexible and copper piping. All these had to correctly fitted and filled with coolant, even if it was only water, because to test the engines in situ required all electrical fittings to operate correctly. This included the Mowbrey float switches on the coolant system which shuts the engine down on low coolant levels.
Engines Nos. 900 & 275 were refitted and ready to be tested in the unit on Saturday 20th July 1996.
Engine No. 876 had the cracked casting replaced with the one off engine No. 124. This required dismantling of the casing and right-angled drive on both engines. The casing came off engine No. 124 easily as the fuel pump had been removed during the setting up of engine No. 900. The removal of all connecting pipes AND the moving back of the fuel pump to clear the way for the connections to the drive was also required on engine No. 876. After fitting the engine was hand cranked over and appeared very free indeed. Quote the CME 'Are you sure there are any pistons in it?'. The main oil pipe and filler were then refitted.
The problem of the cracked casting was evidently a common problem during BR running days. It caused right angled drives to be 'thrown'. The right angled drive is a 'bolt on extra' to the engine held in position by a variety of nuts and bolts and tensioning mechanisms. It transmits the drive to the radiator fan. There are four 'legs' holding the body of the right angled drive firmly to a base plate. If standard washers are used on these 'legs' and the bolts are overtightened the washers distort. This allows the right angle drive to twist on the base plate as the belt drive from the engine crank shaft turns it. The base plate is attached directly to the casting by four bolts which bolt into the casting direct i.e. there are no associated nuts and washers to become loose. The movement causes considerable twisting forces to be set up on the casting at its weakest point, behind the bolt holes. Unless corrected immediately the forces can cause catastrophic failure of the casting as was the case in engine No. 876.
The right angled drive on No. 876 was only attached to the base with three legs not four as built and the washers were very distorted. I hope this failure was the cause of the severe accumulation of oil on the top of the block and that the oil pressure switches worked and shut the engine down with no damage. Only time will tell. Various bolts from the fuel pump and assemblies off No. 124 were used to refit No. 876. The oil filler pipe and filler casting were replaced and the injectors overhauled. No. 876 is now the third 'good' engine.
Engine No. 1161 was bought ostensibly as a non runner with various diagnoses from a severe carbon build up on at least one cylinder to a bent valve. Various parts were missing and the compressor was partially dismantled. The unit was covered in shards of broken glass. The unit was hand cranked over and as the oil circulated and the engine freed up the 'diagnosis' was infact an extremely good compression stroke, (said the CME).
The compressor was refitted on Saturday 29th June 1996. The missing electrical parts, two oil pressure gauges and the stop solenoid, were replaced with those from No. 124 on the same day. The people who had removed the stop solenoid had thoughtfully cut the wires from the main plug thus necessitating the removal of the complete wiring section from No. 124. As well as the stop solenoid they had removed the arm from the fuel pump to the solenoid. Once again No. 124 donated a vital spare. The replacement arm was fitted on Saturday July 8th 1996.
The water pipe assembly from the cylinder heads to the radiator and main pump was also missing. The piping from the top of the block had been modified to take one side directly to the water pump and the other to the radiator instead of both to the water pump as on the other engines. This necessitated a modification to the water pipe assembly removed from engine No. 124. On the inward side of the assembly were two blanked off holes one of which was unblanked and an appropriate fitting put in place. The copper piping from the top of the block of engine No. 1161 was cut back and a suitable flexible joint clipped on. No. 1161 also came with no rocker box covers so those from No. 124 were used.
In taking the rocker covers off engine No. 124 it was found that the rocker assemblies had been dismantled from one of the heads and all the nuts and bolts, together with some other nuts and bolts, had been stored out of sight in the cover! The injectors were then removed mainly to see how it was done. However this exercise proved beneficial especially in the case of engine No. 275 as mentioned earlier. The rocker box gaskets were replaced with newer ones as one side was missing and the other torn.
No. 1161 is now awaiting a main fuel pipe from the flexible input fuel line to the lift pump and the obligatory oil pipe and filler assembly. Once again all injectors have been overhauled. No 1161 is the fourth 'good' engine.
The CME fabricated some new parts for the throttle cable run for engine No. 900 and these were duly fitted with new cabling. Engine No. 275 was fitted with the cable runs and cables from No. 124.
These special cable runs were required as 55003 originally had 'A' series AEC engines and ancillary equipment and the two throttle motors were placed in accessible positions on the outside of the unit. Each throttle motor required a four foot (approx.) cable with return spring to activate the fuel racks together with a short two foot cable for manual ground starting.
Both throttle motors have been replaced with newer refurbished units but still situated on the outside of the unit. The old throttle motors are original AEC fittings complete with water drain plugs that had obviously never been used and the idea never perpetuated on later models. The actuating arm for the main cable had to be swapped from the old units to the new units as the bolt holes were of incorrect diameter.
The main throttle cable from the fuel pump to the throttle motor had to be fitted with care. At each end of the cable sheath was a metal fitting. This fitting had a circular groove cut into it. This was for the 'u' clamps to hold the sheath in place. The adjustment in the cable length was by the two end fittings. These end fittings were cut from standard throttle rods and were adjustable in length in exactly the same way as the rods, by screwing the end piece in or out and clamping in place by a lock nut. Once one end was set the other end could be adjusted accordingly.
Chris Hatton provided a quantity of 'Oildag' the correct lubricant for the throttle motors.
When it came to the replacement of the exhaust system it was noticed that certain parts of the original system were somewhat frail. Some of the curved pipes were very corroded and pitted. A idea was mooted to replace the piping from the engine to the silencer box with ex Class 108 components i.e. expansion box into large flexible pipe, then via a connector piece to the unit's own system.
The conversion would have been difficult because the engines on the Class 122s were hung 6 inches or so lower than that of the Class 108. Because of this the expansion box when fitted to the down pipe from the exhaust manifold was only 6 inches off the ground and 3 inches away from the rail head. This was not an ideal situation.
From the No. 2 engine the problem could be solved by laying the expansion box on its side. This gave the required clearance from rail level but the expansion box just fouled the air intake filter box. By using old pipe ends and cutting away everything except the bolt flange plates, inserts could be made to drop the box 2 inches sufficient to miss the air intake filter box.
Fitting the box this way gave would give a more or less the correct alignment for the flexible tube and connecting piece onto the silencer box. The silencer box has connecting flanges that are 90 degrees out from the flanges on the connecting exhaust pipes. To connect up to the Class 108 flexible tube a new connecting pipe would have to be made. The piece could be made by taking a standard pipe, cutting it in two, rotating one end through 90 degrees and rewelding together to the correct length.
On the No. 1 engine side the pipes passed under the engine as they went into the silencer. This did not give enough clearance for the expansion box and as another solution could not be found the idea was abandoned.
Because of the difficulties found with the Class 108 system the old exhaust was refitted. The old pipes were cleaned, treated with anti-rust solution and the painted silver. The only new portion was a new flexible pipe. The exhaust was refitted on Saturday 20th July 1996. All portions fitted together well except for the flexible pipe on engine No. 900. With all the other pipes in place there was a gap of approximately 3 inches. After stretching the flexible pipe manually the gap was still 1.5 inches. Some of the sections in the flexible portion had not expanded properly. To overcome the problem two long bolts bolted to the receiving pipe were used to draw the pipe out to fit. Once done the 'O' ring was inserted and ordinary bolts used to tighten up the whole assembly.
Shortly after delivery Kevin and I decided to have a complete week on the engine during the last week of Kevin's vacation. This was ostensibly to break the back of getting the unit mobile again although we didn't expect to do as well as we did as will be seen later.
The week in question was to be Monday 22nd July to Friday 26th July 1996.