DMU coupling to EMU

[edwin_m]

mixed part-AB/part-VB on on train has to my knowledge never been approved for normal passenger operation.

Didn't the mixed trains that ran to Mallaig use VB coaches and AB wagons?

I once had a ride on the train that was used to do brake tests on new wagons under possession on the Down Slow north of Crewe. This was hauled by a dual brake 47 with a Mk1 test car ahead of the wagon to be tested. I think the test car was dual braked and ran as an AB train on the transit from Derby to Crewe, but during the actual tests the test car ran VB and the wagon ran AB via a through pipe in the coach.

The tests involved slipping the wagon with with the loco and test car keeping ahead of it and backing up once it had safely stopped, to re-couple the wagon and record the net forward distance travelled (=wagon stopping distance). However after 25 years I don't recall why this was necessary, as it would surely be possible to run the whole lot as AB and close a brake cock before slipping the wagon.

I do remember musing that as they were only just testing the wagon brakes they didn't know how well they worked, and that after a few miles the Down Slow converged with the 110mph Down Fast. At which point the staff produced a couple of hair-raising stories which were no doubt kept on tap for the benefit of visiting graduate trainees.

 

[D7666]

EP+vac working was tested out, there were 4Cep+MLV+'3set' test trains, the 3set being not Mk.1 but a Bullied BSK-CK-BSK set. AIUI it all worked, in the technical sense, but the way things went there was - like EMU+DEMU - no serious operational need for such working, and mixed part-AB/part-VB on on train has to my knowledge never been approved for normal passenger operation.

The first iteration of the Bournemouth line electrification rolling stock plan - before authorisation - included a significant number of vacuum braked sets of loose loco hauled Mk.1 that with an appropriate number of translation vehicles - probably, at that time, intended to be all the designated Bomo line 73s batch. There were no 74s in the project plan then, and as the working would be 4/6/8car EMU + EDL + stock, you'd not want anything as powerful as a 74. But there was a significant amount of LH stock involved as the Bomo line project at that time included all the Southampton boat train sets. I assume as they really did pare down the project to save costs, they moved away from this idea.

Just to add more, those Bullied LH stock, and equivalent Mk.1, as well as vacuum braked were also steam heated.

To haul them by EMU with or without a DL/EDL you have to heat them. EMU (4Rep excepted) don't have end ETH jumpers. So simple haulage of VB SH LH stock by EMU turns into a need for EMU as ETH sources. Etc. It all started to get expensive.

--
Nick
--- old post above --- --- new post below ---

Didn't the mixed trains that ran to Mallaig use VB coaches and AB wagons?

Yes.

But that is not what I am talking about.

I am referring to one passenger part of the train having air (EP) braking and another part of the same passenger train with vacuum brakes.

What you are descrbing is something different - freight wagons do not carry passengers.

Likewise test trains.

Likewise the postal "Special" 1S09 / 1M44 was required to be formed of all dual braked TPO etc stock with fully operative AB and VB. It did not carry passengers.


--
Nick

 

[Taunton]

I've said it before in other threads and say it again here, there is much MUCH more to multiple working than plugging things together.

Just a side trivia, but I understand that when the first Modernisation Plan diesels back in the 1950s, the class 20 (D8000 then) were first connected up in multiple and the controller was opened, they (attempted to) set off in opposite directions

 

[Beveridges]

If any DMU's can work with EMU's, there certainly isn't many of them, if any at all.


A 142 for example can only work with a 143, 150, 153, 155, 156, 158 & 170 and that is all.

 

[455driver]

Didn't the mixed trains that ran to Mallaig use VB coaches and AB wagons?

Yes, If memory serves the freight wagons ran coupled between the loco and coaches because they were only through piped and so ran unbraked.
--- old post above --- --- new post below ---

Just a side trivia, but I understand that when the first Modernisation Plan diesels back in the 1950s, the class 20 (D8000 then) were first connected up in multiple and the controller was opened, they (attempted to) set off in opposite directions

probably a myth, any loco has a front and back (actually no1 and no2 ends) so what difference it would make when a loco only has one cab (at the no2 end) I cant quite work out!

 

[O L Leigh]

I heard it was the first time that Met-Camm and BREL Networkers were coupled together.

O L Leigh

 

[bishdunster]

In the early 1970s the 13.40 Saturdays only Bournemouth - Waterloo was formed 8VAB 4TC and one, sometimes 2 class 73s, or occasionally a class 33 or two, this formed the 17.30 return working ex Waterloo. I was the signal lad in Bournemouth box at the time. Slightly off topic, but did anyone else on here start their railway career in this old fashioned named grade ?

 

[D7666]

In the early 1970s the 13.40 Saturdays only Bournemouth - Waterloo was formed 8VAB 4TC and one, sometimes 2 class 73s, or occasionally a class 33 or two, this formed the 17.30 return working ex Waterloo.

Vab+TC+33 I agree with .... the Vab being Vep cars had no end ETH jumpers so could not heat light and most importantly provide battery charge and auxiliary power. Without this the TC cab would not have luxuries like AWS when leading or red rear roller blinds when trailing. The 33 was provided to do all this, but was multipled with the train.

This is example of what I mean by there is much more to making a complete train work properly in multiple than simply plugging alike things together.

However I disagree that 73s were were used for this purpose. Mating a 73 with Vab comes to Conductor Rail index 12+8 which exceeds the maximum limits of 16, and somewhat over the normal 12. This simply was not done. Mating a 73/1 on diesel would not work, since if it is on diesel it can't supply anything to the ETH line.

Another example where plugging things together does not work to form a practical train.

What you probably saw when it was not Vab was 2x73+11TC or 73+8TC+4Vep on the same diagram - I certainly know of the latter formation on the equivalent diagram you mention. The Vab did have a fixed diagram like you mention but IME was somewhat irregular at working it, if other stock was available this was used in preference.

--- old post above --- --- new post below ---

Just a side trivia, but I understand that when the first Modernisation Plan diesels back in the 1950s, the class 20 (D8000 then) were first connected up in multiple and the controller was opened, they (attempted to) set off in opposite directions

This comment seems to come up in several places, some are urban legend, some are fact. I'd never heard it withs 20s before but that not so say it did not happen or that it is not a legend either.

Blue Star locos multipled and attempting opposite directions was a common fault IIMU caused by poor earthing (or possibly something earthing that should not). It could have happened to 20s. It might have happened to 20s when new if one pair of wires had reversed polarity or poor earths.

I have seen them plug 25s together in platforms at Rugby and 27s ditto at Perth and immediately do this on power - although in both case the locos pushed to each other. Makes a lot of 6LDA28B noise if nothing else


It is recorded when SLEO depot converted 6car Hastings units to 5L this did happen. SR 27 way lines within a set are cabled straight through on every coach except one intermediate, which is crossover cabled. It happened the car that was taken out was with the crossover cable and had been overlooked. The 5L were slightly delayed into service because of this while the right cable was fitted to another car. This of course would have caused further issues when reinstating 6car. ((4Cep to 3Cep conversions the same issue would have arisen as it was the intermediate TSO that had the crossover. Not sure about 3Cig))

There was also a thing about 56s built in Craiova. Because of low (or none!) manufacturing standards traction motors were not power cabled on some locos correctly - they were actually electrically cabled in reverse. Rather than re-cable them they did something much simpler like - not sure exactly what - alter controller contacts to be Forward when electrically the motors were Reverse, and Reverse when electrically Forward. This is fine within one loco, on it's own. Until you multiple two together where one is right and one is wrong. Then they move in opposite directions. Major re-cable job to rectify.

--
Nick
--- old post above --- --- new post below ---

A 142 for example can only work with a 143, 150, 153, 155, 156, 158 & 170 and that is all.

Rubbish.

What you have written is not correct ... there are certainly 3 errors, maybe 4, or even more that in what you have written.... if and you put in assertions like "and that is all" you will always be rebuffed.

--
Nick

 

[34D]

Nick,

You'll probably know this better than me, but I seem to recall that 73/0 can operate with a different range of other vehicles to 73/1.

Also, can't a 73/1 chuck out ETH on diesel power, but while doing this not provide traction power?

 

[SpacePhoenix]

--
Nick
--- old post above --- --- new post below ---



Rubbish.

What you have written is not correct ... there are certainly 3 errors, maybe 4, or even more that in what you have written.... if and you put in assertions like "and that is all" you will always be rebuffed.

--
Nick

In what way is the poster not correct and what are the errors?

 

[hairyhandedfool]

In what way is the poster not correct and what are the errors?

I can't speak for D7666, but I was thinking they can also couple to 141s and 144s (and other 142s), though obviously the former isn't an issue anymore. I doubt anyone has tested a 142-170 combination.

 

[D7666]

Nick,

You'll probably know this better than me, but I seem to recall that 73/0 can operate with a different range of other vehicles to 73/1.

Also, can't a 73/1 chuck out ETH on diesel power, but while doing this not provide traction power?

HI

Yes a 73/0 is different to 73/1 both in respect of ETH and multiple unit capability and also push-pull capability, and, indeed as mentioned upthread, braking capability.

It is a 73/0 that can use its diesel while stationary to heat a train.

A 73/0 is also limited to 80 mph so although with different m.u. capability to 73/1 there were certain combinations that 73/0+EMU would work, but they would not want to mate a 80 mph 73 with express 90 mph EMU since the whole train would be limited to 80 mph. And there was never any need to m.u. with 75 mph suburban EMU.

A 73/1 to my knowledge can not heat a train at all off its diesel, not while moving, not while stationary, and not while under electric traction with the diesel running.

I have chartered 73s for railtours in the past, on hauled stock, on TC stock, on Gat stock, and in combination at different times with MLV and GLV and 33s.

To my knowledge 73/1 no heat off diesel at all. We had to take into account where you went hauled and push-pull with 73s to ensure lights auxiliaries etc could be maintained on battery. Indeed with some tours this point was almost an over ruling controlling input for tour's itinerary.

e.g. 2x73 to Seaford on electric not allowed, had to go on diesel, but push-pull Newhaven - Seaford - Newhaven is within Gat battery time so could be done. Ditto Ashford - Hastings, or Reading (from via Earley) to Basingstoke.
Or e.g. dragging Southampton Romsey Eastleigh.

With hauled trains, on diesel Basingstoke - Salisbury - etc is fine because Mk.1 coaches had axle generators for light, and there is no worry about roller blind tail lights or push-pull driving cabs. But you were officially not supposed to push-pull with 73/1 on diesel to Salisbury ... yes I know it has been done but should not have been allowed. When they push-pulled Basingstoke Southampton via Laverstock it was invariably 33s for TC battery reasons.

The Clapham Kensington phase of EDLs if anyone recalls those ended up with an EDL at each end - not because they needed 2 diesel EDLs to maintain timings (myth #1 at the time) , nor because one powered and one heated [myth #2 at the time] but because the duration of the duty exceeded TC battery time, and loss of auxiliary power when pushing meant things like no AWS in the TC cab or when pulling no tail lights, etc etc,



I'm open to be corrected on this point, but I'd like to see some official BR operating document if so


--
Nick
--- old post above --- --- new post below ---

I can't speak for D7666, but I was thinking they can also couple to 141s and 144s (and other 142s), though obviously the former isn't an issue anymore. I doubt anyone has tested a 142-170 combination.

Indeed, almost great minds think alike

142 one obvious error from the list i.e. he implied by "and that is all" that 142+142 not allowed.

That was one error I immediately saw.

144 as you posted is a second error.

I had not thought of 141 - good one - albeit academic now. I suppose then I could add 151 ?

The third error I thought of is 159. Certainly the P5 spotting books show 159 in this group.

The 4th one I was less sure of is 172 ... I think they can.

I am sure there are other possibilities and restrictions.

--
Nick

 

[bunnahabhain]

You would need to fit whole new coupling system to sleeper coaches as only buckeye. Cannot see trailing loads returning in this day & age.

I beg to disagree... :P
https://flic.kr/p/anFAWj

https://flic.kr/p/anCNZn

 

[D7666]

I beg to disagree... :P
https://flic.kr/p/anFAWj

https://flic.kr/p/anCNZn

Excellent !!!

If they ran the West Highland with 185s (big engines) bet they could tow a SLEP !

Although heating it might be a problem

Come to think of it, you could tow it by LM 350 from Euston to Liverpool / Manchester then TP 350 to Edinburgh / Glasgow then 185 to West Highland. Desiros throughout, and as TP operate 185s and they are a First Group, as is Scotrail, there is a lot of synergy here !





--
Nick

 

[Taunton]

This comment seems to come up in several places, some are urban legend, some are fact. I'd never heard it withs 20s before but that not so say it did not happen or that it is not a legend either

It was described in a Trains Illustrated monthly magazine of the time. I doubt G Freeman Allen printed Urban Legends.

A further MU blunder (as we seem to be getting rather wide-ranging here) was that initially on the St Pancras-Bedford line the powerful Derby-built 4-car suburban units, Class 127, with hydraulic drive, were classed Blue Square, the same as the Cravens Class 112s also on the line, with the same engines but mechanical gearbox transmission. They were allowed to multiple together, for which the suburban units were fitted with an extra control to change gear on a trailing mechanical unit, only used if there was one. It really should have been envisaged that a driver might forget to do this, which inevitably happened, the Cravens transmission was grossly overspeeded by being dragged by the suburban unit ahead, the transmission failed, and then the whole car caught fire and was destroyed. The MU working was of course banned after this.

 

[D7666]

It was described in a Trains Illustrated monthly magazine of the time. I doubt G Freeman Allen printed Urban Legends.

Really ? I don't reading remember - that but it be a long time since I ploughed through any TI. Thnaks for the reference.

--
Nick

 

[34D]

HI

Yes a 73/0 is different to 73/1 both in respect of ETH and multiple unit capability and also push-pull capability, and, indeed as mentioned upthread, braking capability.

It is a 73/0 that can use its diesel while stationary to heat a train.

A 73/0 is also limited to 80 mph so although with different m.u. capability to 73/1 there were certain combinations that 73/0+EMU would work, but they would not want to mate a 80 mph 73 with express 90 mph EMU since the whole train would be limited to 80 mph. And there was never any need to m.u. with 75 mph suburban EMU.

A 73/1 to my knowledge can not heat a train at all off its diesel, not while moving, not while stationary, and not while under electric traction with the diesel running.

I have chartered 73s for railtours in the past, on hauled stock, on TC stock, on Gat stock, and in combination at different times with MLV and GLV and 33s.

To my knowledge 73/1 no heat off diesel at all. We had to take into account where you went hauled and push-pull with 73s to ensure lights auxiliaries etc could be maintained on battery. Indeed with some tours this point was almost an over ruling controlling input for tour's itinerary.

e.g. 2x73 to Seaford on electric not allowed, had to go on diesel, but push-pull Newhaven - Seaford - Newhaven is within Gat battery time so could be done. Ditto Ashford - Hastings, or Reading (from via Earley) to Basingstoke.
Or e.g. dragging Southampton Romsey Eastleigh.

With hauled trains, on diesel Basingstoke - Salisbury - etc is fine because Mk.1 coaches had axle generators for light, and there is no worry about roller blind tail lights or push-pull driving cabs. But you were officially not supposed to push-pull with 73/1 on diesel to Salisbury ... yes I know it has been done but should not have been allowed. When they push-pulled Basingstoke Southampton via Laverstock it was invariably 33s for TC battery reasons.

The Clapham Kensington phase of EDLs if anyone recalls those ended up with an EDL at each end - not because they needed 2 diesel EDLs to maintain timings (myth #1 at the time) , nor because one powered and one heated [myth #2 at the time] but because the duration of the duty exceeded TC battery time, and loss of auxiliary power when pushing meant things like no AWS in the TC cab or when pulling no tail lights, etc etc,



I'm open to be corrected on this point, but I'd like to see some official BR operating document if so

Thanks. Most interesting.

I had not thought of 141 - good one - albeit academic now. I suppose then I could add 151 ?

Obviously only class 141/1. Not really academic - I am sure the scenario will occur when a class 142 visits one of the preserved lines that has a class 141. I've seen a 141/1 multed with a 158 back in the day.

 

[185143]

I was thinking more of if Scotrail ever end up with a few voyagers or 180s

Platform lengths would be an issue & what an enormous waste of a DMU.

They could use the unit as the seated section sleeper(as I have never used it, I don't know how much demand there is for seated sleeper.) If the unit is a virgin voyager, use coach D as the lounge car! A corridor connection from the sleeper coaches to the unit would need to be worked on though.

 

[SpacePhoenix]

They could use the unit as the seated section sleeper(as I have never used it, I don't know how much demand there is for seated sleeper.) If the unit is a virgin voyager, use coach D as the lounge car! A corridor connection from the sleeper coaches to the unit would need to be worked on though.

Could unpowered sleeper coaches be built for the voyages if needed?

 

[1018509]

I assume a class 444 can couple to a class 220 a least mechanically as their couplers look similar?

 

[Crossover]

I assume a class 444 can couple to a class 220 a least mechanically as their couplers look similar?

The coupler height could as much of an issue as anything else
--- old post above --- --- new post below ---
I have also seen a video of a Voyager dragging a Pendolino, but I can't find it

 

[najaB]

Could unpowered sleeper coaches be built for the voyages if needed?

I've no doubt you could physically build them, but the sloped sides could make fitting the berths more interesting. It would be a waste of a EPS capable train though because it's rare that the sleepers would need to take advantage of tilt or higher speeds.

If Scotrail were to get Voyagers, it would make more sense to use them on inter-city flows e.g. Glasgow/Edinburgh-Aberdeen/Inverness.

 

[Qwerty133]

I've no doubt you could physically build them, but the sloped sides could make fitting the berths more interesting. It would be a waste of a EPS capable train though because it's rare that the sleepers would need to take advantage of tilt or higher speeds.

If Scotrail were to get Voyagers, it would make more sense to use them on inter-city flows e.g. Glasgow/Edinburgh-Aberdeen/Inverness.

Not all voyagers have tilt, the Voyagers with tilt are the VT 221s.

 

[najaB]

Not all voyagers have tilt, the Voyagers with tilt are the VT 221s.

That's true, I was assuming that Scotrail would get cascaded units from VT if and when they get their baby Pendolinos. Either way, the 220's still have the profiled body shell so it might make the top berth a bit tight.

 

[WestCountry]

I assume a class 444 can couple to a class 220 a least mechanically as their couplers look similar?

The 220s have their couplers at the same height as the 390s, which is 10cm or so higher than on the 350s (and 450s and 444s), IIRC.

 

[Rick1984]

Does the new Intercity Super Express dual-mode connecting to an electric only unit count?

 

[fyldetrainfan]

What about older units? Could a 323 couple to eg a 150? I assume the y both have BSI couplers?

 

[O L Leigh]

No. There are so many technical differences between the two that it would simply be impossible. If EMUs and DMUs are intended to work together in multiple they would have to be designed for that possibility from the outset so that they have compatible systems.

O L Leigh

 

[hairyhandedfool]

What about older units? Could a 323 couple to eg a 150? I assume the y both have BSI couplers?

150s have BSI, 323s have Tightlock.

 

[61653 HTAFC]

150s have BSI, 323s have Tightlock.

So in theory a 323 would have been able to rescue an unrefurbished 141, had they both existed at the same time.

Not sure I'd fancy doing that the other way round though!