what if multiple units had not been invented?

[Chris M]

Something that just occurred to me seeing photos of Met 1 in action today, is how different would the TfL network be if multiple units had never been invented and all trains had to be loco hauled?
Any other technology, e.g. electric traction, central door operation, etc, that can be found on loco hauled services today that doesn't depend on multiple unit technology would still be available. But how different would the network look in terms of stations, lines, etc? What other differences would there be?

[mods/admins: Feel free to move this thread if you prefer it somewhere else, there is no obvious place for alternate history type questions]

[tjw]

Interestingly part of the train behind Met 1 was / is a multiple unit.

The majority of that train consists of so called Chesham set carriages, (their last duties were part of 2 fixed 3 carriage rakes (units) on the Chesham branch) A better name for them would be Ashbury Carriages the name of the manufacturer although one of the carriages was built by Cravens.

These carriages are interesting as they are close coupled using a rigid bar, only the outer carriages have full length buffers and normal couplings. This feature would have made them more likely to run in fixed rakes (units). More interestingly these carriages were converted to electric operation, The Brake Third becoming a Driving Motor Third and the Third becoming a Driving Trailer Third. A twin sister of the Third can be seen at Covent Garden with it's Motormans compartment intact. So for most of their operating lives were Electric Multiple units.

More information here, www.bluebell-railway.co.uk/bluebell/bash/hist.html

While in this country we have fixed multiple units, a look at the Swiss Railways will see not only Loco hauled stock, but variable multiple units.

N.B. I spent a few years working as a carriage joiner in the same shed the Ashbury carriages were stored and restored (rebuilt).

[norbitonflyer]

I would imagine the system would feature a lot of terminal loops, and that the Circle Line would still be a true circle!

If you're going to uninvent multiple unit operation, that may also preclude having two driving cabs in the same vehicle, which would make single-car units (like the South Acton shuttle) impossible.

[superteacher]

Sept 13, 2015 8:29:45 GMT norbitonflyer said:

I would imagine the system would feature a lot of terminal loops, and that the Circle Line would still be a true circle!

If you're going to uninvent multiple unit operation, that may also preclude having two driving cabs in the same vehicle, which would make single-car units (like the South Acton shuttle) impossible.

Push - pull locos?

[class411]

I think what you are really asking is what would happen if you could not drive from each end.

As someone pointed out when it was first introduced, and HST is a DMU!

When I first looked at your question, I thought: "Well, they'd just put a loco at each end". But if the loco's couldn't fully communicate it would have repercussions.

[stapler]

The steam auto-trains and push-pull units worked by a system of bell signals, didn't they? Two man operation needed

[superteacher]

Sept 13, 2015 9:55:39 GMT stapler said:

The steam auto-trains and push-pull units worked by a system of bell signals, didn't they? Two man operation needed

I daresay you're right. Looks like OPO would have been a non starter then!

[Chris M]

Well OPO would be possible with terminal loops or a loco at each end, but stepping back would presumably be extensively used in the latter circumstance.

[theblackferret]

Sept 13, 2015 0:34:11 GMT Chris M said:

Something that just occurred to me seeing photos of Met 1 in action today, is how different would the TfL network be if multiple units had never been invented and all trains had to be loco hauled?
Any other technology, e.g. electric traction, central door operation, etc, that can be found on loco hauled services today that doesn't depend on multiple unit technology would still be available. But how different would the network look in terms of stations, lines, etc? What other differences would there be?

[mods/admins: Feel free to move this thread if you prefer it somewhere else, there is no obvious place for alternate history type questions]

I suspect the Underground would still be needing two guards on every train, which was the case on some lines until into the 1930's.

On LOL, would platforms have been extended, or would there have been more desire to keep alternative termini like Holborn Viaduct & Broad Street alive?

[whistlekiller2000]

Sept 13, 2015 0:34:11 GMT Chris M said:

[mods/admins: Feel free to move this thread if you prefer it somewhere else, there is no obvious place for alternate history type questions]

Hmmmmm........it's a bit like an Inverse RIPAS isn't it Chris? I daresay we could have a chin wag about where this should go if indeed it needs moving at all.

[Chris M]

Yeah, I wondered about RIPAS but it's not a proposal or suggestion (costed or otherwise) for how things could be in future and it's not really historical as it's about what might have been the case currently not about what was.

As for your edit note...

[whistlekiller2000]

Sept 13, 2015 12:12:50 GMT Chris M said:

Yeah, I wondered about RIPAS but it's not a proposal or suggestion (costed or otherwise) for how things could be in future and it's not really historical as it's about what might have been the case currently not about what was.

As for your edit note...

Ha! I hate making spelling mistakes in posts. Once I've spotted one I have to do something about it Chris!

[stapler]

There is a whole dossier on the working of auto-trains including the bell signals and where the guard was not to be at
www.warwickshirerailways.com/gwr/autocar-services.htm
And since these are GWR rules, They Must Be Right!

[norbitonflyer]

Sept 13, 2015 10:20:45 GMT Chris M said:

Well OPO would be possible with .....a loco at each end, but stepping back would presumably be extensively used in the latter circumstance.

If both locos are under power there would have to be a driver in each one, so double manning would be necessary. (quick turnrounds would be possible without the need for stepping back though!)

The alternative is for the rear loco to be "dead-in-train", (or at least idling) which results in a lot of dead weight being trundled about. If not designed for it, constant idling is bad for diesel engines - when Class 91 production got ahead of schedule, the Mark 4 coaches were not ready, so they were couples to HST sets, minus one power car. The other was retained to act as a DVT and to provide power for lighting etc (which the class 91 couldn't do for HST stock, but they started developing oil leaks so they were arranged to run under power, resulting in a super-powered class 43+91 pairing!)

Maybe if MU control were never invented, track-based control would have happened sooner - with all powered cars taking signals from the track instead of just the leading one - think of the way a double-header is controlled on a Hornby-Dublo layout! So maybe, rather than double manning, in our non-mu world there would be no drivers at all!

[whistlekiller2000]

Chris M, thanks for asking about where to put this. After a brief discussion the thread can remain where it is - provided it doesn't veer off into more obscure territory, in which event there'll be a rethink.  

[spsmiler]

Sept 13, 2015 9:55:39 GMT stapler said:

The steam auto-trains and push-pull units worked by a system of bell signals, didn't they? Two man operation needed

...and physical coupling rods which ran from driving position to steam traction unit.

Being steam powered they needed a fireman, as well as the driver.

btw, trams were usually double ended but was that multiple unit, even for solo tramcars?

Simon

[rincew1nd]

Sept 13, 2015 21:41:49 GMT spsmiler said:

Sept 13, 2015 9:55:39 GMT stapler said:

The steam auto-trains and push-pull units worked by a system of bell signals, didn't they? Two man operation needed

...and physical coupling rods which ran from driving position to steam traction unit.

Being steam powered they needed a fireman, as well as the driver.

I had chance to travel in one recently at Llangollen. In the cab there was a lever connected to the loco regulator, and a chain connected to the whistle valve. There was also a vac brake valve and a gong. So, some driving was done directly, bht there was another element done by the fireman on the footplate. I wonder if firemen on autotrains were paid a different rate for doing more work?

[spsmiler]

Probably the GWR Railmotor which lives at Didcot railway Centre.

Here is a cab view ride where you can see the train driver using the regulator which is attached to the steam traction unit via a long rod below the carriage.




btw, a steam multiple unit train!...
For some reason this film did not play smoothly... I've no idea why but if anyone has problems please let me know and I'll uplift it again.



Simon

[roythebus]

Surely the definition of a "multiple unit" is that of a train that can be couple to another and driven from one position under the control of one driver. On that basis an old style tram could not be a multiple unit, neither is an HST as they cannot work in multiple with other units! The Park Royal railbus et al is not a multiple unit, nor is it a locomotive; it cannot run with other units and cannot couple to anything except in emergency!

Similarly an auto push-pull train is not a multiple unit; it cannot couple with other auto trains to be driven from one cab. Yes, I know the GWR variants with auto trailer/loco/auto trailer, but that trailer can't be used to couple with another auto train with loco to be driven from one cab. 2 locos = 2 firemen! Incidentally, auto-train firemen were "passed men".

For other railways for auto-train read push-pull!

[norbitonflyer]

Sept 14, 2015 19:18:14 GMT roythebus said:

Surely the definition of a "multiple unit" is that of a train that can be couple to another and driven from one position under the control of one driver. On that basis an old style tram could not be a multiple unit, neither is an HST as they cannot work in multiple with other units! The Park Royal railbus et al is not a multiple unit, nor is it a locomotive; it cannot run with other units and cannot couple to anything except in emergency!

Similarly an auto push-pull train is not a multiple unit; it cannot couple with other auto trains to be driven from one cab. Yes, I know the GWR variants with auto trailer/loco/auto trailer, but that trailer can't be used to couple with another auto train with loco to be driven from one cab.

Not quite - multiple unit operation is operation of self-propelled railway vehicles coupled with other units of the same or similar type and being controlled from one driving cab. So this includes double-headed locomotives if both controlled by the same driver (as distinct from tandem operation where both loco are driven independently but the lead driver controls the continuous brake.
It also includes HSTs - both power cars are controlled from the leading cab.

A multiple unit trainset is a set of vehicles intended to operate in this way, and usually incapable of independent operation. It has been extended to include train sets where only one of the vehicles is actually powered but can be controlled from another - such as a power-trailer dmu, (or maybe even an autotrain) or for a single car that can be formed into an MU formation.

But yes, the railbus is not a muliple unit

[bassmike]

A lot of New York Subway cars had a driving cab at each end. You could even take one car off and drive it independantly to a different location.

[norbitonflyer]

.................as is done in The Taking of Pelham 1-2-3

[Phil]

Sept 15, 2015 17:37:29 GMT bassmike said:

A lot of New York Subway cars had a driving cab at each end. You could even take one car off and drive it independantly to a different location.

...............and as I did once on the WSR all the way from Minehead to Dunster. I was in the (rear) cab (of a 3-car Class 117 set minus the 'front' power car) driving, and the WSR Ops superintendent peering out of the open corridor gangway of the (then leading) trailer car.

Not in service obviously but still meant going over two road crossings........

Unfortunately I can't remember the reason but it was great fun while it lasted and totally safe....... (cries of 'oh-yeah??' all round!!)

But back on topic, as I understand it, the definiton of multiple unit is simply the control of more than one power unit/car from one (ANY one) driving position.

[norbitonflyer]

Sept 14, 2015 19:18:14 GMT roythebus said:

The Park Royal railbus et al is not a multiple unit, nor is it a locomotive;

According to the original meaning of "locomotive", it is. A "Locomotive engine" originally simply meant an engine that was self-propelled - as opposed to the stationary engines which had already been in existence for 50 years or so before they became efficient enough to move themselves. I have even seen it argued that an electric "locomotive" is no such thing because the "engine" (i.e the power station generating the electricity) is not carried on board.

[theblackferret]

Sept 13, 2015 22:48:46 GMT rincew1nd said:

Sept 13, 2015 21:41:49 GMT spsmiler said:

...and physical coupling rods which ran from driving position to steam traction unit.

Being steam powered they needed a fireman, as well as the driver.

I had chance to travel in one recently at Llangollen. In the cab there was a lever connected to the loco regulator, and a chain connected to the whistle valve. There was also a vac brake valve and a gong. So, some driving was done directly, bht there was another element done by the fireman on the footplate. I wonder if firemen on autotrains were paid a different rate for doing more work?

rincew1nd

Sorry I missed your question.

From my union duties with PCSA in the 1980's-1990's, I had a few contacts with other unions, NUR & ASLEF included.

I remember talking to an ASLEF man about this & I'm pretty sure BR initially proposed an extra payment for the fireman regarding these duties on a regional basis, but that it was made national, too.

Drivers also got extra for supervising a non-trained driver doing it. The payment wasn't more than a few bob a week in either case.

[brigham]

An electric haulage tractor is a 'locomotive' if the electricity supply is carried on-board. Otherwise it falls into the same category as an atmospheric piston carriage or a cable grip car.
This definition of a 'locomotive engine' goes back further even than Geo. Stephenson. It was already in use when the Wylam 'Dillies' were being built.
By this definition, the East Coast electric stock, in common with most electric trains, doesn't involve a locomotive.
The HST sets, conversely, use two each. Some overpaid 'seventies advertising executive presumably chose to downplay this fact in order to make the new toy seem more 'modern' and 'exciting' than it really was.

[norbitonflyer]

Oct 13, 2015 13:33:46 GMT brigham said:

The HST sets, conversely, use two each. Some overpaid 'seventies advertising executive presumably chose to downplay this fact in order to make the new toy seem more 'modern' and 'exciting' than it really was.

Which is strange given the public image of dmus in the '70s (and the positive marketing of the replacement of dmus by elderly Class 31s with Mk1 coaches in the 'eighties on some longer-distance local services like Newark-Cleethorpes, Birmingham-Norwich and Cardiff-Portsmouth, not to mention the push-pull services in central Scotland)

And the HST revolution was quite exciting anyway - has there ever been a 25% increase in maximum speed in one go before, or indeed since?

[brigham]

25% increase in speed AND 100% increase in number of locomotives per train!

[norbitonflyer]

Oct 13, 2015 15:31:56 GMT brigham said:

25% increase in speed AND 100% increase in number of locomotives per train!

One of these is worth two of these though!

[brigham]

Did they ever try double-ending with Deltics?