April 6th, 2016

Diesel Department – April 2016 Update

Photo: Michael Drew

Photo: Michael Drew

Half Term Working

You would have thought the chances of many people turning up at the railway on a damp cold, overcast Wednesday in the middle of half term holiday as pretty remote however…

I signed on at North Weald and was meet by our business development manager, who informed me that, due to the high volume of advanced internet bookings, the train had been made up to six cars, top and tailed by Jennifer (the little steam engine) and the class 31 (also supplying train heat as well as traction power.) The fuel transfer pump on the Thumper was still playing up, which meant we were running a special one-train Ongar/Epping Forest timetable.

The service had been advertised as ‘Kids for a Quid’ (bring your own picnic.) The train soon became packed with families all setting up their ‘picnic camps’ in seating bays. When we left Ongar at around, twelve almost every seat on the six car train was taken. When we arrived at North Weald bound for Epping Forest, there were even more people waiting; the train left with standing room only, the passenger count tallying 450 passengers on board.

Such was the passenger demand that the two heritage buses abandoned the advertised service and were running a continuous shuttle between Epping and North Weald. It was nice to see so many families enjoying a day at the railway, in a warm comfy environment. (Thanks to the class 31 train heat.)

Good Friday was another very successful day, running both a six car train and the Thumper. Both trains experiencing high passenger numbers and at times, again, standing room only.

Development of North Weald Maintenance Shed

Cleared engine shed

The underfoot working conditions in the shed (being rough ballast) could never have be described as the best, being difficult to perform good quality maintenance work on. Also not so good was working on equipment on the ground. A decision was made to make a start on the developing of the shed, turning it in to a quality maintenance facility for coaches, Steam and Diesel Locos. The first job was to concrete the floor…

The shed was been completely cleared (which was a monster job in its own right), the track was checked and spot repaired as required, and the ground/track areas were levelled off using about thirty tons of hard-core that was compressed down. As you can imagine, there were many hours of detailed preparation work required, and things such as the wash basins and some electrical equipment had to be re-sited to allow for the change in floor levels.


At this stage it is intended to concrete the shed floor with the exception of the front half of Number One road. In this area, a new ‘clean’ maintenance pit will be constructed. Once the pit is finished the new concrete floor will be completed. In due course permeant access platforms on number one road, and a mezzanine storage floor at the Ongar end of the shed will be constructed. A new lighting system will be installed and other electrical work will be carried out.

The development of the shed is a huge investment in both time and money, but should provide a quality maintenance depot once completed.

Thumper 205205

After a number years of constant use, during which the unit has proven to be a reliable performer, and as you would expect she is due for some heavy maintenance work. The motor coach has had to be fitted with two new springs and a spring hanger. Quite a big job, as was sourcing the parts, but the task is now completed. One of the springer hangers had siezed and, despite valiant efforts to free it, in the end a new hanger was sourced and the old one cut off.

Both the main and auxiliary generators have been inspected and the commutators cleaned. There was an ongoing issue with the fuel transfer pump, whereby the top seal (which holds the drive shaft upright) had worn beyond limits. The problem is sourcing the small seal. It is not possible to go in to a ‘main dealer’ and ask for a part for a 1957 pump – a new seal has had to be made from scratch. One was made locally and only lasted four hours in service before allowing air into the system, causing the diesel engine to shut down at Ongar whilst working a school’s special service.

The class 31 went to the rescue; the kids thought it was part of the ‘school trip plan’ and all came out onto the platform to see the unit coupled to the Loco. We have traced a source of the original type of seal, which has now been fitted and the unit is back in full service. There are still a few non-urgent outstanding jobs; the fuel injectors are due for overhaul, one of the cylinder heads has to be changed (due to a worn rocker arm) and the engine room exterior bodywork on the signal box side is now showing signs of rust, and will need replanting and respraying in due course.

Class 117 DMU Railcar

DMS: Due to the development of the main shed at North Weald, work on the DMS has slowed. The roof has been completed and almost all the body preparation work is completed, ready for first primer coat of paint. Hopefully by the time you have read this all the masking work will be completed and the coat will be completed.

Rubbed down DMS Cab

The cab ready for the first coat of primer. (Note the must have tea mug on the lamp bracket!)

What appeared on the face of it to be a fairly straightforward job – the refitting of the last three yard section of gutter and getting a short two foot section of gutter fabricated – turned out to be anything but straight forward. I was working with Derek (one of our highly skilled engineers) who had replaced the other sections of gutter on this coach, but this section threw up problem after problem. We spent days lying on our sides drilling new offset holes for the pop rivet fittings every two inches. I won’t bore you with all the issue but it stretched Derek’s ingenuity to the limit. We even had to fabricate some special ‘angled clamping tools’ to hold the gutter on to the bodywork.

Derek - with the aid of a right angled drill - refits the guttering.

Derek – with the aid of a right angled drill – refits the guttering.

The shame of these types of jobs, when completed in a neat and tidy manner you would never guess the amount of skilled work it had taken to get to the finished stage.

DMBS: Where to start…

The team have been working on this car in the platform; maybe it would be best if I explained the route of the problem and go back to basics:

The railcar roofs appear to have been fabricated as a separate structure, then bolted and welded to the top rail of the body work during their construction. The main issue is that the galvanised roof panels do not overlap the body work, but stop short, leaving a slight gap. This gap is sealed by the aluminium gutter sections which are mounted on sealant and pop riveted in place.

On the DMBS there has been a similar issue to the DMS; a large hole formed in the roof panels at some stage which had been repaired, or – as we call it – bodged up! A new panel placed on top of the existing roof and overlapped on to the bodywork. The position of the new panel meant that the large gutter section could not be refitted using pop rivets, but was bonded on, leaving gaps which were filled with sealant. The rain, however, quickly found its way behind the gutter over a three yard section (Yards – showing my age again), leaking in between the exterior and interior walls.

Over the years, the exterior, interior and internal walls (oh, and not forgetting the floor) have all rotted. The team have been stripping back the internal walls both in the guards compartment and a section of the passenger coach; the guard’s compartment wall is also rotten and has had to be removed. We are now sourcing the new body structure parts; our engineers are confident they can fabricate the required body and roof panels.

The interior of the DMBS (or what’s left of it!) after the removal of internal walls and cladding to allow access to the rusted areas of external body work.

The interior of the DMBS (or what’s left of it!) after the removal of internal walls and cladding to allow access to the rusted areas of external body work.

The plan is, once we have finally removed all the rotten internal structure to allow access to the external body structure, one section of the rotten support structure will be cut out at a time, a new piece welded in, and only then cut the next section out – this will ensure the integrity of the body work.

We have found problems with the stitching of the material that makes up the vestibule connections. Guess what – it’s gone rotten!

Class 31

Class 31 to the rescue!

Class 31 to the rescue!

She has been the main stay of our service of late, with the 37 stopped for injector change. Apart from an oil leak on the top of the diesel engine, she has been her usual reliable self. It is just coming up for the twentieth anniversary of withdrawal from main line working, so we gave her a bit of a clean the other day.

Class 37

There has been a lot of pre-planed maintenance work taking place on this loco, including overhauled injectors, and also some work on the air system. During maintenance of the main generator, certain insulators were found to be defective and will need changing. New parts are on order.


Class 47

Stopped and sheeted up pending remedial work on the roof. One of the tarpaulins self-destructed in the recent gale.

Class 03s

03 170 has had its new alternator system modified with a smaller drive pulley. This means even on tick over the battery receives a full charge if required. Both Locos are generally restricted to yard duty’s and can normally be found around North Weald.

Class 25


Work continues off-site at Shackerstone, with new bodywork welded in place on the sides, and work now taking place around the bottom of the cabs.

Diesel Gala

Should be an interesting Diesel Gala, with one of the early builds of 08 shunt locos and a class 20 locomotive set to appear. How often do you get to ride behind a vacuum braked 08 Loco? Pre-booked for the Autumn gala is a Deltic – unbelievable!

Chris Travers
Diesel Restoration group