Restoration diary

The restoration of the power unit ex-50008 Thunderer which was purchased by RRRG for use in 50030 is now almost complete.  This has involved removing all sixteen cylinder heads and either overhauling them or replacing them with overhauled heads, then removing all sixteen pistons and con rods before replacing both big and small end bearings, piston rings and if necessary pistons to effectively return the power unit to "zero hours" status.  Even with highly dedicated volunteer labour this has been a lengthy process but is now well into the "home straight".

Dave Rolfe has concentrated on an external overhaul of the unit, cleaning and painting especially auxiliary items such as water rails (blue) and oil feed pipes (pink).  This will enable us to identify potential problems such as oil leaks when the unit is in service inside 50030.  Ian Kemp, RRRG's mechanical team leader, and his fellow dedicated volunteer Peter Carter have been refitting the auxiliary pipework to the unit.  This has now reached the stage of refitting the lower cooling water rails.

In common with other Class 50 owners we have decided to manufacture our own gaskets as this is much cheaper than buying ready-made items.  Ian and Pete were busy today cutting out and fitting the water rail gaskets to one side of the power unit before refitting and attaching one of the water rails.  This is not an easy task because the casting of the engine block makes accessing the fastening nuts very difficult!  The corresponding water rail on the other side will be refitted in due course.

The tasks remaining to complete the overhaul of the diesel engine part of the power unit are to complete the refitting of oil and cooling water feed pipes and to test and overhaul the Woodward engine governor if necessary.  We also need to source a set of braided hoses which feed cooling water to the turbos - these were either missing or rotten when we bought the power unit.  The main generator attached to the engine is in good condition and will be detached and overhauled separately nearer the time the unit is ready to be installed inside 50030.

The power unit currently in 50030 is also practically complete and serviceable.  We did start an overhaul of this power unit before the Thunderer power unit came on the market and it is turn intended for use in 50029, to replace the power unit in that locomotive which suffered a serious seizure that was the cause of 50029's BR withdrawal in 1992.  An exchange of main generators is possible, to mate the good generator on 50029's damaged block with the good block attached to the main generator with flashover damage that is currently in 50030 - however this is a decision some time in the future.

Recent work in the cabs of 50030 has been concentrating on freeing off the power controllers.  Ian Kemp and Dave Rolfe have sprayed them liberally with WD40 and worked them backwards and forwards.  As a result they move for the first time since 1992, albeit rather stiffly in the case of no 2 end controller at the moment.  Andy Rowlands fitted, tightened up and reconnected the cables on the replacement set of contacts Dave had removed from one of our spare power controllers, to replace the set found to be broken during our freeing-off of the controllers. To achieve this you need to unbolt the plate that holds the sets of contacts so it swings away from the cams, and refitting the bolts that hold the plate is difficult as the contact springs keep pushing the plate away from the cams, which makes it not the easiest job when hunched up under the driver's desk and you need three hands!

The controller in no 2 cab is still quite stiff despite repeated applications of various lubricants, but the one in no 1 cab is much easier to move. If we cannot make them easier to rotate, we may have to look at removing the entire controller pedestals and dis-assembling them totally to see if the nylon bearings need replacing.

Ian and Peter Carter oiled the main big end bearings and barred the engine round.  Andy Rowlands has also been working to refit the reverser air piston in the electrical cubicle of 50030.

Ian, Pete and Dave spent the day unfastening the bolts to allow the main generator fan to be removed.  The fan is between the generator and power unit (but bolted to the main generator itself) and is normally hidden by the surrounding cowling. It sucks in cold air from under the body to help cool the gen and the cowling keeps the air circulating round the gen rather than blowing it all round the engine compartment. It has to come out to give access to the next layer of bolts that actually connect the engine to the generator. This proved to be a very fiddly task in the limited space between the fan and engine block.  Ian is seen proudly displaying his dirty hands after the day's work!

Mark brought two of the refurbished KV10s, paperwork, test sheets and circuit diagrams up to site. After a test fitting they were removed once again! Dave, Pete, Ian and I hoisted one of the intercoolers up onto the ex-50008 power unit and bolted it in place. The other is ready to be refitted but needs painting first. Dave started making a hoist arm to be fitted on a corner of the container over the workbench. I started fitting the cubicle air circuit pipes, which was somewhat difficult with all the cabling in place, so if I ever do that again, the lesson is fit the airpipes before the cabling, then the cables wouldn't be in the way!

The new airpipes are just visible in the photo below, between M4, M5 and M6.

I discovered the air connections on the reverser air cylinder are a different thread to all the others, so I brought it home with me to take to the supplier I got the other fittings from to see if they can provide the correct-thread fittings for it.