DEMU as Generator Van?

[Titan]

Did anyone ever consider the use of a DEMU motor coach as a generator van to provide ETH for charter trains?

 

I can't help feeling that they would have been a better alternative than sticking a loco on the back, especially if the cab could be used for propelling moves.

 

I don't know if there would be any point retaining the traction motors, it would not be able to recover the train although it might help push a bit if the loco was struggling, you would have to turn off the ETH first! Might be useful for shunting itself and maybe a couple of coaches if required.

 

It could also provide extra seating, but I would imagine they would have to be well discounted for there to be any takers!

 

Plus of course the restriction in passenger carrying on Mk1 stock at the rear of a train, although with a massive engine at the back, perhaps there could be dispensation?

 

I wonder how many coaches it's compressor could provide air for? Might assist in allowing a vac braked loco haul an air braked train without having to have a loco mounted pump. However I suspect that as a minimum an extra compressor on the DEMU would be required. As the aux generator would at most be providing ETH for one coach rather than three, perhaps there would be enough spare capacity to run another compressor.

 

Over to you!

[Dunsignalling]

Sticking a loco on the back isn't just to drive the eth/aircon, it's there for insurance in case a defect develops on the steam loco.

 

Train paths are ever more difficult to come by now that most lines run a clock-face service throughout the day, and having a fall-back to minimise the disruption that even a partial failure can cause to the "bread-and-butter" service will increasingly become conditional unless operators are willing/able to carry full delay liability as other TOCs do.

 

Also, on many routes, run-round and/or turning facilities are limited or non-existent, whilst steam locos are only permitted to haul trains tender first up to a maximum of 45mph.

 

That doesn't apply when the steamer becomes part of the train, so the diesel is needed for haulage over parts of some journeys with the "star of the show" following on behind.

 

One car from a DEMU is surely going to look even more odd than a diesel loco tacked on the end, anyway, so, when one isn't required, I'd rather see a BG or the support coach with a generator in it.

 

John

Edited May 7, 2018 by Dunsignalling

[Titan]

Sticking a loco on the back isn't just to drive the eth/aircon, it's there for insurance in case a defect develops on the steam loco.

 

Train paths are ever more difficult to come by now that most lines run a clock-face service throughout the day, and having a fall-back to minimise the disruption that even a partial failure can cause to the "bread-and-butter" service will increasingly become conditional unless operators are willing/able to carry full delay liability as other TOCs do.

 

Also, on many routes, run-round and/or turning facilities are limited or non-existent, whilst steam locos are only permitted to haul trains tender first up to a maximum of 45mph.

 

That doesn't apply when the steamer becomes part of the train, so the diesel is needed for haulage over parts of some journeys with the "star of the show" following on behind.

 

One car from a DEMU is surely going to look even more odd than a diesel loco tacked on the end, anyway, so, when one isn't required, I'd rather see a BG or the support coach with a generator in it.

 

John

 

Perhaps all fair points except the last, It looks like much more like a coach, than a diesel ever will - same mk1 profile and even has windows and seats. Painted in the same livery as the rest of the stock - and why wouldn't you, it is a passenger carrying vehicle, and it would be hardly noticeable apart from the noise, and almost completely unobtrusive when taking a picture of the whole train from the front, something a diesel loco could never do. Unless you decided to use a Hastings power car which would be a bit odd.

 

There are several trains which manage without a diesel loco at the moment, and it would be far more versatile than a support coach/generator van.

[The Stationmaster]

All the DEMUs I ever rode in had a tendency to roll when the engine started or revved and they didn't ride very well either.  I suspect that if there were any still about that could be used they would have to be speed restricted.  On the other hand there are various generator equipped vehicles which have survived and were designed to run at speed and if none can be found at least they are a guide to what could be done with a converted vehicle.

[Titan]

All the DEMUs I ever rode in had a tendency to roll when the engine started or revved and they didn't ride very well either.  I suspect that if there were any still about that could be used they would have to be speed restricted.  On the other hand there are various generator equipped vehicles which have survived and were designed to run at speed and if none can be found at least they are a guide to what could be done with a converted vehicle.

 

True, but when providing ETH the engine would be running steady, and they were permitted to run at 75mph IIRC which would be adequate for almost all steam charters.

 

I presume that they were not able to do this for the highland lines instead of ETHELS as at the time all the DEMU's were still required. I guess they may also have needed vacuum brakes as well.

 

But how useful could it be to have a cab for propelling moves - similar concept to the PCV vehicles for RES?

 

The greatest fun I had in a DEMU was when I was at Strawberry Hill testing Networkers. We had  a spare test path to Shepperton,  two withdrawn DEMU motor coaches coupled back to back, and a driver who signed them... About as close as you can get to nicking a train and going for a joy ride - Drive em like you stole them! Acceleration was quite rapid, although I worked out that to get the same power/weight ratio on a Deltic would need six coaches on it to be somewhere near the same power/weight ratio...

[uax6]

500Hp to pull 11 coaches and a steamer (They were designed to pull a max of three trailers)? That's not really going to clear the line very quickly if the steamer falls apart is it? And then you've got to add a ETH generator to the engine block, and add some extra insulation go kill the noise.

Also there is the fact that only the Hastings line ones are still main line registered, and they don't match a Mk 1 profile at all......

 

Andy G

[Titan]

500Hp to pull 11 coaches and a steamer (They were designed to pull a max of three trailers)? That's not really going to clear the line very quickly if the steamer falls apart is it? And then you've got to add a ETH generator to the engine block, and add some extra insulation go kill the noise.

Also there is the fact that only the Hastings line ones are still main line registered, and they don't match a Mk 1 profile at all......

 

Andy G

 

There is no intention to pull the train, or clear the line, it's main function is to provide ETH only as far as power is concerned. It would do this from the existing traction generator, in the same manner as the ETHEL units did. And for this purpose 500bhp is plenty. So no generator to add, just a little modification to wiring and engine governor. It could possibly be used the same way as a PCV to avoid having to find an engine to release the stock at a terminus, and a PCV did not have any engine at all!

 

And if you can actually sell tickets for the seats, then it will bring in a little revenue too, unlike the other alternatives.

[Nearholmer]

I guess a lot depends upon which DEMU power car we’re talking about. An HST has got quite a lot of installed power.

 

Mind you, I’ve honestly never quite “got” main line steam specials, because once on board and comfortably seated, with some nice scenery to look at, it could be anything ‘up front’. It’s not as if having a steamer suddenly converts the world outside of the window to, say, 1963 ....... now, that would be worth paying extra for.

 

I think I might even enjoy a DEMU tour more, especially if it was a 6B, with functioning buffet. The sound of a weedy 1000hp trying to do exciting things is rather good, and they rode very well, except for the power cars on jointed track. The compartment firsts on the Hastings stock were especially smooth and cosy.

 

I’ll probably get banned from RMWeb for saying that.

[uax6]

Get yourself on one of the Hasting Diesels tours then, although its not a full hastings unit, some EMU stock is providing the Buffet these days....

 

Andy G

[Dunsignalling]

There is no intention to pull the train, or clear the line, it's main function is to provide ETH only as far as power is concerned. It would do this from the existing traction generator, in the same manner as the ETHEL units did. And for this purpose 500bhp is plenty. So no generator to add, just a little modification to wiring and engine governor. It could possibly be used the same way as a PCV to avoid having to find an engine to release the stock at a terminus, and a PCV did not have any engine at all!

 

And if you can actually sell tickets for the seats, then it will bring in a little revenue too, unlike the other alternatives.

PCV stood for "propelling control van" - so they had a limited form of push-pull capability permitted for low speed movements.

 

A DEMU car used as you suggest would provide little more control over a steam loco at the other end of the train than sticking a bloke with a mobile phone in the rear carriage.

 

Class 33s and 50s in days of old used to shove Waterloo sets out over the river Exe at St Davids at a quite rapid pace with the driver obeying hand signals from the other end.

 

That was then, this is now, and propelling has been a very dirty word on the railway for many years.

 

As for selling tickets, you have evidently never ridden very far in a Southern Region DeMU power car..........

.

John

Edited May 7, 2018 by Dunsignalling

[Davexoc]

There is no intention to pull the train, or clear the line, it's main function is to provide ETH only as far as power is concerned. It would do this from the existing traction generator, in the same manner as the ETHEL units did. And for this purpose 500bhp is plenty. So no generator to add, just a little modification to wiring and engine governor. It could possibly be used the same way as a PCV to avoid having to find an engine to release the stock at a terminus, and a PCV did not have any engine at all!

 

And if you can actually sell tickets for the seats, then it will bring in a little revenue too, unlike the other alternatives.

You can't put passengers in a Mk1 on the end of a train these days, not that there are many seats anyway. Also the non-Hastings units were not gangwayed and didn't they have some odd narrow gauge style of central buffing gear inter set? I am going back to memories of when the south coast route was not electrified between Portsmouth and Southampton.

 

Dave

[Nearholmer]

All this rude commentary about DEMU power cars!

 

I used to seek out the power car no in use by the guard, hop aboard with my bike, sit in the comfy guard’s chair, and go to sleep. Surely that indicates that they were comfy..... or that I was tired.

[Christopher125]

You can't put passengers in a Mk1 on the end of a train these days, not that there are many seats anyway. 

 

That's no longer the case, the need for barrier vehicles went a few years back.

 

As for using a DEMU, I really can't see the point - there are already generator vans for trains that don't need an assisting locomotive, and where one is needed (often for ECS moves) a DEMU power car won't be sufficient.

[newbryford]

Sticking a loco on the back isn't just to drive the eth/aircon, it's there for insurance in case a defect develops on the steam loco.

 

 

 

The Fellsman and Dalesman trains certainly don't have diesel backup - neither does the Jacobite operation on the West Highland.

 

The Fellsman and Dalesman swap to steam traction at Hellifield and leave the diesels in the loops all day.

 

The entire train will turn round at Carlisle using the Newcastle/S&C line and Upperby south curve, requiring two reverse moves - all powered by the steamer with no other assistance.

 

Depending on where the train's final destination is can throw up an interesting move at Hellifield. (to fully understand requires some knowledge of the track layout at Hellifield)

Two diesels parked in the down goods loop all day. Before the steamer arrives, one of the diesels heads towards Settle Junction. 

The tour arrives in the up goods loop, detaches the steam loco plus support coach and trundles onto the up Clitheroe branch.

Diesel number two is already on the down branch line and reverses onto the front of the tour.

Steamer then backs into the goods loop and runs round the support coach using the down platform line and then departs tender first towards Carnforth.

In the meantime, the first diesel has arrived from crossing over at Settle Jn and tagged on the back of the train.

 

Train departs for wherever with top and tail diesels so that no run-round is required later in the day.

[Covkid]

Several points here.

 

Pax can travel in a Mk1 at the end of the train. The restriction was temporary.

However there is an issue with secondary door locks which needs stewards to "police" the doors when in passenger service.

 

Yes the English Electric power unit would be useful in generating ETS for the train, but would need some serious electrical work.

 

The traction output from a DEMU car would not benefit the train loco.

 

In short the vehicle would need the sealing up of most of the doors and secondary on the others, rewiring to provide ETS cabling and ideally a Pullman style gangway on the inner end.

 

Far easier to drop an industrial genset into the brake area of a BSK or BFK like the ex Royal genny car or Mk1 35469.