Orientation of centre trailer in 3H DEMU

[HGR]

Please have a careful look at photo's of three-car class 205 / 3H DEMUs with their original centre trailers to see if you can see which end the pass comm butterfly is at (the red tell-tale tablet at cantrail just under the end of the gutter). Or, if you can see the EP brake chest (the big box below the underframe), or its two isolating valves and pressure gauge just under the solebar. Or, if you can see through the windows which way round the seating is arranged - it's 2+3 so the centre aisle is not on the longitudinal centreline of the coach but is offset nearer to one side.

 

The reason behind the request is to see if the internal seating layout always matched the external bodywork orientation. The trailers were built to the same diagram, so you would expect them all to be the same orientation made to the same drawings. But, were the later ones with window frames reversed compared to the earlier ones ? When originally built the TS was half non-smoking and half smoking so the red NS labels would be visible in the widows of that half of the coach, but later this became all non-smoking. When you look at photographs of green liveried units, the non-smoking half of the coach as evidenced by the red triangular window labels is not always towards the same end of the unit. 

 

If you look at the seating layout that is shown in the Appendix to the Carriage Working Notice of units 1127 - 1133 it shows the 2+3 seating of the centre trailer TS the opposite way round to the other two vehicles (MBS and DTC). The non-smoking saloon in the TS is the end adjacent to the MBS. However the earlier units 1101 - 1118 when strengthened to three car had the trailer seating the other way round so as to be the same way round as the other two cars in the unit. Not sure if 1123 - 1126 were the same, though their trailers were part of the same lot. Does anyone have an Appendix to CWN that shows a seating layout for units 1101 - 1118 / 1123 - 1126 ?

 

For the strengthened 3H, the orientation was :

Pass comm tell-tale at the end adjacent to the motor coach. If this is to the left, it's the 2 seat side. If it (and motor coach) is to the right, it's the 3 seat side and the EP brake unit and pressure gauge may be visible this side under the TS. If you see any that are the other way round, please can you post a picture on here.

 

[EddieK]

It is possible that the orientation could change as a result of the centre car becoming "turned" relative to the outer vehicles.

When I worked at Selhurst, the prototype refurbished set 1111 was brought into the Repair Shop with the aim of a quick rub down and repaint from Blue Grey to NSE livery. The job took longer than planned when  it was found that one side of each vehicle was suffering from corrosion. What was odd was that the centre car was rusty on the opposite side relative to the other two cars.

[HGR]

That's weird ... can't think why the centre trailer would end up the opposite way round unless it happened during the refurbishment, but there's no reason for it to be.

 

The vehicles in a DEMU are all 'handed' and can only go one way round in their place in the unit.

 

A two-car unit has a motor coach with receptacles on its inner end to take the jumper plugs of the driving trailer. When made up to three cars, the centre trailer in effect extends this so has jumpers at the end that will be adjacent to the motor coach, and receptacles at the other end adjacent to the DT, but is otherwise wired 'straight through'.

 

The thumpers had high-level brake pipes between coaches within the unit, but these only ran down one side of the unit - the nearside of the motor coach. Hence the centre trailer was also handed from the point of view of the brake pipes.

 

When you look at Hastings units, the six-car formation is in effect a pair of three-car sets coupled back to back, but without intermediate cabs of course. The intermediate trailers are fed from the motor coach that is nearest to them. One of the trailers has to be a 'crossover' coach to allow the jumpers to swap sides. In the Hastings six-car units it is done at the inner end of the TFK.

 

On the Thumper motor coaches the inner end has a duplicated control jumper on the opposite side to the receptacle, and high-level brake pipes on both sides, allowing two motors to run back-to-back, or one to be tagged onto the end of another unit.

 

When 1111 was refurbished to become 3H(M) it had gangways cut into the inner coach ends, but I'm not aware that the jumpers or brake pipes were altered, so the centre car should have remained the same way round as built.

 

[Nearholmer]

54 minutes ago, HGR said:

When 1111 was refurbished to become 3H(M) it had gangways cut into the inner coach ends, but I'm not aware that the jumpers or brake pipes were altered, so the centre car should have remained the same way round as built.

 

I've got a photo I took of it at Strawberry Hill, during test/acceptance after the refurb. Currently deeply buried in my store cupboard, but I'll see if I can find it next week, and if it throws any light on this.

[keefer]

Similarly, when the ex-EPB DTS was used as a TS for the 3T cl.204s, a couple of extra jumper sockets had to be added to the front end (secondman's side) to connect the jumpers from the adjacent coach. The air pipes on that side of the DTS were used but the original control jumper wasn't, so remained parked in its dummy socket.

Edited April 17, 2021 by keefer

[Zomboid]

Did they keep the vehicles together at all times? I could imagine that they swapped them around as and when necessary. Certainly seems to have happened with the DMMUs, and I think the southern's EMUs got mixed up from time to time too.

 

In which case the centre car would just be the way it came.

[EddieK]

39 minutes ago, Zomboid said:

Did they keep the vehicles together at all times? I could imagine that they swapped them around as and when necessary. Certainly seems to have happened with the DMMUs, and I think the southern's EMUs got mixed up from time to time too.

 

In which case the centre car would just be the way it came.

The SR DEMUs were not subject to the frequent reformations of some depots' allocations of mechanical units. There were deliberate reformations when Tadpole units were disbanded, for instance, but generally the allocated vehicles stayed within their units.

[Wickham Green too]

This ought to help with 1111 205.101 ..... looks like the butterflies were adjacent to the Driving Trailer at this date - 27/2/88.

 

Edited April 21, 2022 by Wickham Green too
Photos reinstated

[HGR]

The DMMUs were intentionally designed to be 'fluid' formation. The only restrictions were maximum of six motors in a train, and maximum of twelve vehicles in all, mainly because all of the control EP valves being fed from the leading car (or at least, the one with the key in). For this reason the control jumpers were duplicated both sides and both jumper and receptacle provided so any ends could be coupled together in any orientation. Hence you could get plain twins (DMBS - DTCL), power twins (DMBS - DMCL intended, but pairs of DMBS wasn't unheard of), and any permutation of triples with one or two motors, and quads with two motors. Some of the IC / CC / TP sets were up to six car sets, or pairs of sets coupled up to the 12 vehicle limit. When the diagrams were first drawn up for these mechanical DMUs they were as sets formed for the routes that they had been ordered, but that was quickly dropped. The motor brake then retained the original diagram number and the other vehicle(s) in the unit formation given their own separate diagrams.

 

The DEMUs and EMUs were 'fixed' formations. Similar vehicles could be exchanged between units, for example to cover for maintenance shortages, but the relative positions within a unit would be maintained. There were a few exceptions, for example an unexplained handful of 4 SUB and both S.R. and B.R. type 4 EPBs with the intermediate trailers reversed. These had the centre buffer. Motor coaches had a rubbing plate at the inner end, so one trailer had a buffer at both ends, and the other had one buffer at the MC end and rubbing plate facing the other trailer. In addition, one trailer was electrically 'straight through' and the other was the crossover coach to allow the jumpers to swap sides. There was also a CEP motor coach 61035 that acted as a spare. It was a No.1 MC, but with a bit of minor terminal adjustment could be dropped in to replace a No.2 MC at the other end of a unit. There was a trailer 70044 with similar abilities that could occupy either trailer position in a unit. This had duplicated receptacles at one end because of its earlier conversion from TFK to TSK, so you only needed to have a loose set of jumpers to put it into the No.2 trailer position and disconnect a couple of wires in the terminal box.   

 

To use an EPB driving trailer as a TS in a thumper, the extra receptacles for lighting and heating were needed at the former cab end as these don't pass over between units, only within the unit. The now unused driving controls were disconnected at the coach-end terminal bars to prevent any unwanted operation. Also because of the strange choice to have the EP brake chest use different terminals in a DEMU than an EMU, the wires for this had to be moved to the correct terminals for DEMU use.

 

[HGR]

40 minutes ago, Wickham Green too said:

This ought to help with 1111 205.101 ..... looks like the butterflies were adjacent to the Driving Trailer at this date - 27/2/88.

Now that IS interesting. As well as the butterfly, it looks like the EP brake box is not visible under the TS, which it should be visible under the frames on this side. Can you have a closer look at your photo please to see if you can see either a large box under the middle of the coach, or a white pressure gauge just below the solebar near the middle of the coach. 

Edited April 17, 2021 by HGR
typing finger can't keep up !

[Wickham Green too]

Just looks like a whole load of dark on max blow-up and light adjustment !

Does the position of the footboard cut-out give a clue p'raps ?

[HGR]

The footboards changed over the years. The original ones were full coach length. Then as long lengths of timber became more scarce whenever they needed to be replaced they would often be replaced with shorter length ones. The extreme case towards the final years was the only boards available were for individual doors. (they're actually wider than the door so you can stand on the step to the right of the door, holding on to the commode handle and still swing the door open unobstructed - e.g. if climbing in from rail level).

 

So if the EP unit is not visible, it may well be that the coach is the other way round, but don't know why that would have been necessary.

 

[Wickham Green too]

On this coach the footboard is not quite full length as it has two cut-outs ....... presumably there are a couple of things on the solebar which might indicate whatever we can't make out below - presumably fittings which weren't present when the footboards WERE full length !!?!

[keefer]

https://sremg.org.uk/dmu/class205.shtml

 

There's 3 photos in a row of b/g 205031 (click to show a bigger version) which show the orientation of the 3 cars, the TS photo also shows the 'tell-tale' and the 'handed' jumper arrangement.

[keefer]

 

From left to right:

Blue dummy socket of control jumper (used for when coupling motor cars as stated earlier?)

Two control jumper cables on TS go into sockets on DMBS

Hi-level air pipes.

IIRC on the other (left) side there was another control jumper from the DMBS into a socket on the TS. EDIT: It actually might be the other way round, jumper cable on TS going to a socket on the DMBS, like the other two. 

Rubbing plate and buckeye coupler in the centre at bufferbeam level. 

[There was a good view of the inner end of a DTC in 'Motive Power Recognition 3: DMUs' (1st ed., Marsden/Ian Allan) but I don't have that book any more]

Edited April 18, 2021 by keefer

[keefer]

From the Bachmann 205 thread:

[HGR]

18 hours ago, Wickham Green too said:

On this coach the footboard is not quite full length as it has two cut-outs ....... presumably there are a couple of things on the solebar which might indicate whatever we can't make out below - presumably fittings which weren't present when the footboards WERE full length !!?!

When built these had full-length footboards. The photo in Motive Power Recognition 3 DMUs shows 1111 with these fairly fresh from refurbishing. The only thing on the solebar is a conduit running along the full length of the coach for the heater wiring on this side of the coach. This is tucked behind the bottom of the footboard, which has a fancy rebate to accommodate the conduit. There is a 'T' fitting in the conduit under each seating bay with a short upstand going up into the bodyside to feed the heaters under that seating group. You can see the shadows cast by these. There's a little cutout notch in the back of the footboard at each position where the conduit comes up. This photo shows the coach looks to have by then acquired a single footboard at the nearest end, and a pair of longer ones that would otherwise fit a DTC (with the gap under the toilet window).

 

As an aside, talking of DTCs, when they ended up with individual single door footboards towards the last years in service, there were DTCs running around with a full complement of footboards, including one under the toilet window where there would have otherwise been a gap ???

 

[Wickham Green too]

4 hours ago, keefer said:

... [There was a good view of the inner end of a DTC in 'Motive Power Recognition 3: DMUs' (1st ed., Marsden/Ian Allan) but I don't have that book any more]

That's an 'Oxted' car but the arrangement's the same : one cable to the left, two cables & two hoses to the right ....... a couple of pages earlier is a shot of  rebuilt 1111 - as it was at the time - with the centre trailer orientated as in my photo ( opposite side ).

[HGR]

5 hours ago, keefer said:

https://sremg.org.uk/dmu/class205.shtml

 

There's 3 photos in a row of b/g 205031 (click to show a bigger version) which show the orientation of the 3 cars, the TS photo also shows the 'tell-tale' and the 'handed' jumper arrangement.

Those three photos of 205 031 show everything as per how it should be expected in terms of orientation.

 

Ref earlier post, notice the DTC has the unexplained footboard under the toilet window !

 

[HGR]

4 hours ago, keefer said:

 

From left to right:

Blue dummy socket of control jumper (used for when coupling motor cars as stated earlier?)

Two control jumper cables on TS go into sockets on DMBS

Hi-level air pipes.

IIRC on the other (left) side there was another control jumper from the DMBS into a socket on the TS. EDIT: It actually might be the other way round, jumper cable on TS going to a socket on the DMBS, like the other two. 

Rubbing plate and buckeye coupler in the centre at bufferbeam level. 

[There was a good view of the inner end of a DTC in 'Motive Power Recognition 3: DMUs' (1st ed., Marsden/Ian Allan) but I don't have that book any more]

The dummy receptacle with the plug end of the extra 'loco' control jumper on this side of the motor coach is what is visible at the extreme left of the photo, on the back of the motor coach. The two jumpers from the trailer on this side are for lighting and heating respectively (the control jumper is on the other side of the end - as above a jumper on the trailer into a receptacle on the motor coach). The main res and train pipe with their high-level double cocks are on this side of the unit only. They are duplicated on the back of the motor coach for 'loco' use same as for the duplicated control jumper. See the end of the Bachman 2H for their arrangement on that coach.

 

The only difference between this and earlier trailers is that the thin pipe that connects to the PCA communication cord valve on the end of the coach between the butterfly tell-tales takes a more direct diagonal route on this coach, whereas on the others it goes across horizontally all the way to the corner edge to clear the double cocks before dropping down to connect into a branch on the train pipe. Train pipe is the one nearest the right / edge of the coach.

 

[HGR]

4 hours ago, keefer said:

From the Bachmann 205 thread:

From left to right ...

 

Left / near side :

Dummy receptacle for 'loco' control jumper, with jumper plug inserted.

Train Pipe (would be painted red)

Main Res (yellow) both cocks operated by one common handle. These would connect to trailer.

'loco' control jumper, plugged into the dummy receptacle at the left end.

Heating receptacle for jumper from trailer

Lighting receptacle for jumper from trailer

 

Right / off side :

Control receptacle (under the second roof access step) for jumper from trailer

Duplicated main res (yellow) and

Train Pipe (red) with double cock. These not needed for trailer so usually stowed.

 

Note the thin pipe from the PCA valve on the butterfly cross-shaft takes the more usual route over and around the right of the double cock to get to the train pipe.

 

The brake / res pipework from the double cocks runs down the body end and in through holes in the headstocks, roughly where buffers would otherwise be.