S.R. 4SUB & 4EPB trailer coach end details / photos

[HGR]

Been trawling through photos etc. of S.R. design SUB and EPB units to work out which way round the trailers are positioned in the unit and what electrical fittings / conduits there are at each end. As originally built the 'standard' all-steel SUBs and the S.R. design EPBs had the trailers a particular way round - if you look for the red-painted handle of the communication cord alarm at the cantrail it's at the inner end of the unit on a compartment trailer (which should have a wearing plate for the centre coupling), and at the end of an open trailer adjacent to the motor coach (this coach has a centre buffer at both ends). The other (non-communication cord) end of each trailer on a SUB should have the terminal box mounted high up on the end with a large box sticking out lower down to the right that contained the lighting contactors / switches. At the roof line there are three connection boxes for the control train lines, lighting control, and power train line. Far as I know on all SUBs the jumpers between the coaches were hard-wired in at both ends, and not plug / receptacle as they were on later units EPBs etc.

 

Does anyone have any photos of the ends of the vehicles where you can see the layout of the conduits please ?

 

At the inner end, do the jumpers cross over each other or are they straight across the gap between the trailers ? [ they need to be crossed over / swap sides somewhere, and this doesn't appear to be done in the roof conduits ? ]

 

Later, when the compartment trailers were exchanged to have all-open coaches in the units in traffic, the substituted TSO appears to have been randomly either way round ? It would have had to have the centre buffer at the inner end changed to a wearing plate. Anyone know how the jumper connections were altered please ?

 

The units going for scrap with two compartment trailers would have also needed a centre buffer / wearing plate swap at the inner end, but I guess they never needed to bother with the electrical jumpers if the units were hauled to the storage locations / scrapyard. 

 

On EPBs there was a large terminal / connection box at roof level for the control, heating, and lighting jumpers, with a separate terminal box for the power train line jumper. The jumpers were hard-wired to the coach end that had the centre buffer adjacent to the motor coach, and plugged into receptacles on the motor coach end with the wearing plate. The inner end of the compartment trailer had a wearing plate and the open coach a centre buffer, but I think both had receptacles with loose plug-to-plug jumpers between the coaches, if anyone can confirm please ? Again, how / where was the crossover done ? There's a photo of the end of the TSO from 5176 at Coventry that has an extra-long power jumper that looks long enough to reach across to the other side as this unit had its compartment coach exchanged for an open. When this was done on EPBs the coach appears to have always been put in with the hard-wired jumper end facing the motor coach (red alarm handles at outer ends). Similar was done for the 4COM units that ended up with two compartment trailers.

 

For facelifted EPBs the orientation of the trailers depended on whether they started out as compartments, converted to open, or were originally open. Some units were facelifted 'complete' with original trailers one TS and one TSO that remained the same way round. Others had exchanged one or both trailers for compartment ones prior to going for facelifting so the orientation varies. At the inner end of the unit the loose jumpers were replaced by jumpers hard-wired to the trailer that had the centre buffer and receptacles on the other one that had the wearing plate. Does anyone have photos of the inner ends of facelifted units please ?

 

Inside the trailers, which way round was the 2+3 seating and which end was door 'A' at ? Originally I think 'A' was always the inner end of both trailers, but I've seen photos of later coaches with the little white downward-pointing wheel 1 arrow at the end adjacent to the motor coach - possibly exchanged TSOs ?

 

Any help would be appreciated. I could do with a trip to Margate to look at 4732 but I'm at the other end of the country !

 

[roythebus1]

Having driven SUBs for 3 years and EPBs for about 10 years, I can honestly say I never took much interest in what was between the coaches, only the outer ends! I took a lot of detail shots of 2EPB units at Staines which may just give you a clue. Remember on SUBs everything worked at line volts including all the control circuits and saloon lights.

 

I'm just testing my memory as to what was in the SUB jumpers! The big one was the "bus line jumper" which was the main feed connecting all the shoes not only in the 4-car unit but to other units as well. There were IIRC 2 smaller jumpers, one was driving controls the other was guards controls, lights on, lights off, heaters on, heaters off. Control leads would be forward, reverse, shunt, series, parallel, overload trip, overload reset, compressor synchronising wire and that was about it!

 

EP stock had a bus line jumper, but only in each unit, there was no 750v jumper on the end. the control jumper was 28 way IIRC, which as well as the above for the SUB, would have a weak field position, there was no overload trip, just a reset which also acted as an engine start when a 33/1 or 73/1 was coupled to it, bell signal, Loudaphone between driver and guard, maybe a couple of other things I've forgotten!

 

It might be worth you looking at the southern electric group further down the menu page on here. Lots of pics and info there.

 

Edited February 10, 2023 by roythebus1

[keefer]

One of the few photos i remember seeing is of 1951 2EPB unit 5706 on this page:

https://sremg.org.uk/emu/class415.shtml

 

[RFS]

What you need is the publication "Bulleid Coaches in 4mm Scale" by S.W. Stevens-Stratten. There are very detailed drawings of the 4SUB coaches as part of this publication, including the coach ends. Out of print no doubt, but several available at the moment on Ebay - see here.