Could the Southern region DEMUs been built as bimodes?

[hexagon789]

Could a DEMU work in multiple with other 50s/60s built DMUs (101s etc)?

No, completely different set-up - to say nothing of the brakes...

 

[D7666]

I see, some sources suggest it was rewired.

Some sources do say that yes, but upthread I also said about this. These sources got it wrong at the time and this error has been plagiarized ever since

They did not rewire 1111 as it needed to retain mu capability with other unrewired DEMU and there was no need for it to mu EMU.

If the then planned Oxted EMU +DEMU idea had gone ahead, the idea was to modify but not rewire other DEMU ahead of time of requirement, then do a very short term rewire right when needed.

== Doublepost prevention - post automatically merged: 13 Jun 2024 ==

The use case I heard, but have no proof for, was as part of the BedPan electrification to allow extension beyond Bedford to Wellingborough, Kettering and Corby. Assume would have delivered a speeding up of MML InterCity services and a more frequent service to those Northants towns than a 90 minute InterCity service.

Yes now you mention it I think you are right that one was mentioned at the time. Whether it was a rail industry intention or rail crank speculation I don't recall but yes it was a contemporary idea somewhere.

 

[D6130]

Could a DEMU work in multiple with other 50s/60s built DMUs (101s etc)?

No....completely different power train. The other DMUs had machanical gearboxes and were vacuum-braked. The DEMUs were air-braked.

EDIT: Sorry....just seen that it's been covered in post #31.

 

[Sun Chariot]

Could a DEMU work in multiple with other 50s/60s built DMUs (101s etc)?

The DEMUs had high level MU cables, not bufferbeam ones. Incompatible location and incompatible control.

Oh - too slow off the mark

 

[D7666]

210s

Were not cheap. Another poorly documented fact lost on time by plagiarism is 210 motor cars were NOT mk3 construction but most writers say they are. 210 motor coaches were HST underframes and floor plans with special body construction using standard mk3 parts where possible. This use of the HST hardware with special construction was hard to justify expense when a smaller 150 type engine arrangement could fit to a somewhat lesser modified standard mk3 shell.

I always say that class 210 re-creation project was doomed to fail if their /only/ plan was to take EMU mk3 cars and plonk a big engine in it. The body can't take it. Anyway that project all gone quiet.

Digressing further, but in the same vein, the NIR 80 Class DEMU motor coaches are not MK2 but are MK1 underframes with body built up out of MK2 components. Same underlying reason as 210 : the MK2 body can't take a big engine weight like that just as MK3 can't.

 

[43096]

Some sources do say that yes, but upthread I also said about this. These sources got it wrong at the time and this error has been plagiarized ever since

They did not rewire 1111 as it needed to retain mu capability with other unrewired DEMU and there was no need for it to mu EMU.

If the then planned Oxted EMU +DEMU idea had gone ahead, the idea was to modify but not rewire other DEMU ahead of time of requirement, then do a very short term rewire right when needed.

The Blood and Custard site (https://www.bloodandcustard.com/BR-2H-3H-3T-Hampshire.html#Modified) has this to say on the matter:

During refurbishment all blue asbestos insulation was removed and various other modifications made to the cabs and control systems, each cab being fitted with new control desks similar to those in 4 VEP electric units. This included an automatic engine starter (which operated when a driver’s key was inserted) and a four-position master controller as opposed to the usual DEMU seven-position type.

The unit was made capable of easy modification to run in multiple with electric units, but as it was used with other DEMUs, this was not possible without alteration to the function of certain control wires; BR(S) diesel-electric units could only work in multiple with other diesel-electric units.

In terms of the conversion no.1111 had been rewired and fitted with a four-notch controller so it could be configured to run in multiple with electric units instead of diesel units. The complete unit ran on test to Stewarts Lane 30th November 79 and was also used on tests coupled to a 4 CIG unit on the Shepperton branch 30th December 1979.

However, Southern Region’s CM&EE could only do one or other. So, the plan was to modify all the 2H /3H fleet as they went through works and leave the connections set as “multiple to Diesel only”. Only when the whole fleet had been through works would the units be switched over to the “EMU” method of operation.
Due to a lack of funds no further units were modified and so this fleet conversion did not come to fruition although many units (but not all) did have heavy C1 overhauls in the early 1980s when the blue asbestos insulation was stripped out.

With testing completed the unit was released to St Leonards for commissioning 27th February 1980 and entered passenger service. However, unit no.1111 (and in its subsequent no.205101 numbering) was unpopular on the Hastings – Ashford line as the four-notch controller was much less controllable than the seven-notch variant it replaced, particularly on Ham Street bank in the Autumn. It could also be somewhat unpredictable when working in multiple with a seven-notch unit.

 

[AidWall]

11th May 1986's farewell trip produced a sprightly run above their theoretical top speed. This extract from 'Six Bells Jcn':
... The speed through Tonbridge was quite hair-raising and the train was still doing well over 80mph through Grove Park.

Six Bells Junction

Last weekend’s Lincolnshire Poacher rail tour saw the 7-car unit running at 78/79 mph back up along the ECML (according to fellow travellers); the ride seemed fine to me and the unit ran faultlessly throughout the day.
Michael Welch in his book on Southern DEMUs quotes reports that the last Brighton -Exeter DEMU working (30 April 1977 with 1033 and 1034) reached 98 mph descending Honiton bank; the comments of the buffet car steward were not recorded.

 

[Sun Chariot]

... the last Brighton -Exeter DEMU working (30 April 1977 with 1033 and 1034) reached 98 mph descending Honiton bank; the comments of the buffet car steward were not recorded.

Perhaps: "this Caesar Salad is tossing itself" or: "yes, that  is a large coffee in your cup - well, it  was in your cup ten seconds ago".

Back to the OP's topic; I'm unfamiliar with other countries' approach to bi-mode. Is any reader aware of a successful application of bi-mode elsewhere?

 

[30907]

Deleted

 

[DelW]

Back to the OP's topic; I'm unfamiliar with other countries' approach to bi-mode. Is any reader aware of a successful application of bi-mode elsewhere?

Were you meaning bi-mode multiple units specifically? There are certainly bi-mode locomotives elsewhere in the world, including diesel + 3rd rail. An example of the latter is New Haven Railroad's EMD FL9s, using 3rd rail for running into New York via tunnels where diesel running is forbidden.

 

[Sun Chariot]

Were you meaning bi-mode multiple units specifically? There are certainly bi-mode locomotives elsewhere in the world, including diesel + 3rd rail. An example of the latter is New Haven Railroad's EMD FL9s, using 3rd rail for running into New York via tunnels where diesel running is forbidden.

Yes, units - my bad . Those New Haven FL9s piqued my interest in the US scene, some 40 years ago. Then my eyes were swayed to the big Tunnel Motors of the D&RGW.
I regret not getting to Tennessee Pass, before it was closed.

 

[hexagon789]

Some sources do say that yes, but upthread I also said about this. These sources got it wrong at the time and this error has been plagiarized ever since

They did not rewire 1111 as it needed to retain mu capability with other unrewired DEMU and there was no need for it to mu EMU.

If the then planned Oxted EMU +DEMU idea had gone ahead, the idea was to modify but not rewire other DEMU ahead of time of requirement, then do a very short term rewire right when needed.

Thank you.

Perhaps: "this Caesar Salad is tossing itself" or: "yes, that  is a large coffee in your cup - well, it  was in your cup ten seconds ago".

Back to the OP's topic; I'm unfamiliar with other countries' approach to bi-mode. Is any reader aware of a successful application of bi-mode elsewhere?

Plenty of bi-mode units in France, both a TER type, the AGC in use since 2004 and an Intercité type, the Régiolis in use since 2013.

The AGC has four variants, two of which are dual diesel and electric, one type is single 1.5kV dc; the other type has dual dc and 25kV ac capability.

The Régiolis has bi-mode electric and diesel with bi or tri-voltage capability.

All these units appear right across France now.

 

[D6130]

Back to the OP's topic; I'm unfamiliar with other countries' approach to bi-mode. Is any reader aware of a successful application of bi-mode elsewhere?

Stadler bi-mode units - very similar to the Greater Anglia class 755s, with a short power car in the centre - have been in use in Northern Italy on the Torino-Chivasso-Ivrea-Aosta route for a few years now....changing mode at Ivrea. The much newer Hitachi class HT312/412 bi-mode units - with both regional and InterCity interior versions - are in the process of replacing the class D445 diesel-electric locomotives and elderly diesel-mechanical railcars on the secondary routes from Siena to Firenze, Chiusi and Grosseto, as well as Firenze-Borgo San Lorenzo....while the InterCity version are taking over the Taranto-Reggio Calabria InterCity services on the 'Linea Jonica'.

 

[Dr_Paul]

My memories of the SR DEMUs is that performance was quite 'sedate', I used the East Grinstead/Uckfield services quite a bit when growing up, and leaving Clapham Junction heading south they were much slower than the electic units. Had they been 'bi mode' I suspect performance might have been better, but it didnt seem to cause a problem back in the day.

I travelled on a few SR DMUs, mainly East Croydon to Clapham Junction, and didn't notice any difference in performance. An exception was one trip when the driver went like the clappers, and the DMU was pretty rough-riding and bounced and jerked all over the place, far worse than any SR EMU ever did, even when the 4-SUBs were getting tired.

To return to the original question, from what I understand the SR DMUs were brought in to replace steam services on lines on which electrification was not considered worthwhile on grounds of cost.

 

[nw1]

I must admit, I don't think I've ever experienced a 205 or 207 on a fast(ish) run.

They did London Bridge-East Croydon non-stop so I guess that must have been pretty fast.

My DEMU experience is limited and restricted to slower journeys: on the Watercress line on the 10th anniversary event in 1987, and Southampton-Dean / Eastleigh-Botley / Hamble-Southampton (all in early 1990). Strangely all my mainline DEMU journeys were in the final months of their existence on the South Western!

 

[30907]

They did London Bridge-East Croydon non-stop so I guess that must have been pretty fast.

70mph line limit IIRC (was 60 when DEMUs were introduced).

 

[edwin_m]

I travelled on a few SR DMUs, mainly East Croydon to Clapham Junction, and didn't notice any difference in performance. An exception was one trip when the driver went like the clappers, and the DMU was pretty rough-riding and bounced and jerked all over the place, far worse than any SR EMU ever did, even when the 4-SUBs were getting tired.

Was this a Hastings unit? The report into the Hither Green derailment in 1967 (? - can’t link from phone) talked about how the suspension travel was limited to stay in gauge, and if this was a factor.

 

[nw1]

70mph line limit IIRC (was 60 when DEMUs were introduced).

Ah ok, I thought that because it was dead-straight it might have a faster speed limit, at least on the fast lines.

 

[30907]

Ah ok, I thought that because it was dead-straight it might have a faster speed limit, at least on the fast lines.

The SR was cautious within the suburban area (out to South Croydon on the Central), with a blanket 60 limit (which probably also helped pathing). IIRC both Fast lines were raised to 70 in the late 60s (to 90 outside London).

 

[Irascible]

I had one trip on one from Poole ( or could have been Bournemouth but that would be a pretty odd place to get on a DMU! ) to Salisbury probably just pre electrification, I don't remember it feeling any worse than any other secondary service stock at the time. DMU with compartments was a bit wierd.

 

[etr221]

Were you meaning bi-mode multiple units specifically? There are certainly bi-mode locomotives elsewhere in the world, including diesel + 3rd rail. An example of the latter is New Haven Railroad's EMD FL9s, using 3rd rail for running into New York via tunnels where diesel running is forbidden.

Back in about 1930, to get rid of steam on the New York Central's West Side (of Manhatten) freight line, they had some diesel/battery/electric tri-mode locos from (American) General Electric. These lasted, I believe until the late 1950s.

Getting back to origin of this topic, the (English) Southern units of the late 1950s/early 1960s, my own thought (or wonder) is whether, with the technology of the time, was a battery/electric bimode possible - that could take power (and recharge) from the 3rd rail where present, and continue off it where not. Noting the battery capability of the MLVs, the single Scottish Battery unit, and the many more in Germany. So was it possible, or considered?

 

[Cricketer8for9]

Before the 171s were introduced there were a couple (maybe just 1 at the end) DEMU services from Victoria. These didn’t stop at Clapham Junction, which have them the same time to East Croydon (or near enough) as the electric trains which did stop at Clapham Jct.

 

[etr221]

Before the 171s were introduced there were a couple (maybe just 1 at the end) DEMU services from Victoria. These didn’t stop at Clapham Junction, which have them the same time to East Croydon (or near enough) as the electric trains which did stop at Clapham Jct.

Before electrification to East Grinstead, most - or at least many - of the Oxted line DEMU services went to Victoria. I forget how things worked date wise, but certainly AIUI the concentration of the Uckfield services (which stayed diesel) at London Bridge was connected with reccnstruction at Victoria with an over platform raft, and the desire not to have diesel trains under it.

 

[D7666]

deleted while I check something

 

[yorksrob]

They did London Bridge-East Croydon non-stop so I guess that must have been pretty fast.

My DEMU experience is limited and restricted to slower journeys: on the Watercress line on the 10th anniversary event in 1987, and Southampton-Dean / Eastleigh-Botley / Hamble-Southampton (all in early 1990). Strangely all my mainline DEMU journeys were in the final months of their existence on the South Western!

Ah, never did them all the way from London.

 

[Dr_Paul]

Was this a Hastings unit? The report into the Hither Green derailment in 1967 (? - can’t link from phone) talked about how the suspension travel was limited to stay in gauge, and if this was a factor.

It was an Oxted to Victoria train that I boarded at East Croydon; I'm afraid that I can't recall what class of DMU it was, as this would have been 40 years back, but I doubt if it was a Hastings one. I fancied having a ride on a DMU, and had quite an adventure.

 

[Sun Chariot]

It was an Oxted to Victoria train that I boarded at East Croydon; I'm afraid that I can't recall what class of DMU it was, as this would have been 40 years back, but I doubt if it was a Hastings one.

Likely a class 207 3D (Oxted) unit.

 

[D6130]

They did London Bridge-East Croydon non-stop so I guess that must have been pretty fast.

Uphill all the way from New Cross Gate, where the speed limit changed from 60 to 70 on the fast lines. More likely to have had a fast run in the Up direction....from East Croydon to London Bridge.

It was an Oxted to Victoria train that I boarded at East Croydon; I'm afraid that I can't recall what class of DMU it was, as this would have been 40 years back, but I doubt if it was a Hastings one. I fancied having a ride on a DMU, and had quite an adventure.

Likely a class 207 3D (Oxted) unit.

....or a 205 3H Hampshire unit - or possibly a lash-up of both. The 207s were slightly faster, as they were lighter and marginally more powerful.

Ah ok, I thought that because it was dead-straight it might have a faster speed limit, at least on the fast lines.

Despite what it looks like on the map, the are some quite sharp reverse curves in places - especially in the vicinity of Forest Hill. I used to work over it as a guard.

 

[Rescars]

They did London Bridge-East Croydon non-stop so I guess that must have been pretty fast.

It certainly felt it, especially on up workings thundering downgrade from Forest Hill!

 

[norbitonflyer]

. DMU with compartments was a bit wierd.

In the 80s, when mixed class 123/124 formations were operating, I once travelled on a dmmu which was all-compartment. Two Class 123 DMSKs sandwiching a Class 124 TBSK (ex non-driving motor)