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Renown Repulse Restoration diary

A blog of factual reports and personal thoughts on the ongoing restoration of ex-British Rail diesel locomotives 50029 Renown and 50030 Repulse at Peak Rail in Derbyshire, UK.

Power unit progress

Power unit progress

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.

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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.

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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.

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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.

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Wednesday, 06 December 2023

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