Generator vans - pros and cons

[Shimbleshanks]

Catching the Enterprise from Belfast to Dublin yesterday morning, I noticed that the consist included a generator van between the coaches and loco. Why do the railways in Ireland favour generator vans whereas the GB rail system does not? I know there were the ETHEL units converted from Class 25s as a stopgap measure for sleeper stock, but were such things used more generally in GB? I know SNCF also had four-wheeled vans for the same purpose (I had a Jouef model of one) but that is the only Continental European example I know about.

Are there pros and cons? I guess pros might include having a 'guaranteed' power supply for coach heating, air con etc without drawing on the power available for traction. Are vans more reliable?
Cons might include having to haul an extra carriage about and possibly limitations on train lengths.

 

[61653 HTAFC]

I know the US for a long time favoured generator cars over Head-End Power (what we would call ETH or ETS), and Ireland sourced many of their locos from General Motors. Whether the two are related would be conjecture on my part.

 

[OVS Flatbottom]

Ireland had a tradition of not fitting train heating to diesel locos that went back to the steam-heat days, and I think generator vans for electrically heated trains were just an extension of this. (I believe it was a mixture of negative experience with the boilers on the two initial Sulzer prototypes, which were the only diesel locos anywhere on the island ever to be capable of supplying steam heat, plus a desire to abolish double manning that led CIÉ to go for heating vans in the first place.)

Later steam heating vans were actually fitted with small diesel generators to power train lighting, but I don't think this came in until around the same time as the first pure generator vans.

I can't imagine American practice had any significant influence. The first generation of mainline diesels came from Metrovick and BRC&W, and none of them had any form of train heating. When CIÉ began buying from EMD, electric heating (apart from an abortive experiment with the C201 class on branch-line trains) was still more than a decade in the future.

 

[Elwyn]

I have no real technical knowledge but I have travelled on the Enterprise service for 40 years or more, and was on board several times when there was an electrical failure. When the De Dietrich coaches first arrived there was no generator van. All the power was obtained from the locomotive. However this reportedly meant that a lot of the time time it was working flat out, providing traction power, air con and power to the galley etc. One of the traincrew explained that no machinery responds well to being worked flat out for hours at a time and that method of operating was leading to too many failures. As I understand it, that led to an operational decision to ease the demand on the loco by providing a separate generator for power supply to the coaches, leaving the locomotive self-sufficient.

 

[Ken H]

Having an extra vehicle on the train makes the train longer meaning it wont fit in some stations, especially bays. And the extra weight means more fuel and less acceleration. And another maintenance job - the bogies and the brakes etc.
But having a separate system from traction must help reliability.
Do Irish railways have a problem running heavier locos?

 

[Gloster]

An oddity was that the Loughrea branch, which was operated by a small G611 shunting locomotive, had a coach that was heated by night storage heaters that were plugged in at Loughrea overnight. There were probably two of these coaches, with one replacing the other: the second may have been used on the Ballina branch after the Loughrea one closed.

 

[dgl]

And, I understand, even their 29000 CAF DMU's have auxiliary engines, quite unusual compare to over here.

 

[Richard Scott]

There is something about this is another thread but can't remember which one! The 201s used in Ireland had to run at maximum engine speed to provide Head End Power resulting in spectacular failure of one loco. This then resulted in generator coaches being used in the future.
Remember having generator coaches in Portugal for trains hauled by 1400s a few years back. Talgo sets used in Spain have their own on-board generator set so locos do not provide power for on board services. Believe this is also true when electric hauled, which seems daft but there we go.
Also remember one being used in UK for providing ETS to an HST set when short of power cars and a set was loco hauled.

== Doublepost prevention - post automatically merged: 24 Feb 2023 ==

And, I understand, even their 29000 CAF DMU's have auxiliary engines, quite unusual compare to over here.

As do the 3000s in Northern Ireland, I believe. To be honest both are horribly noisy units to ride on with constant drone from auxiliary engine. Think centre cars of Spanish 592s also have auxiliary engine for on board services. That car also best avoided!!

 

[fgwrich]

There is something about this is another thread but can't remember which one! The 201s used in Ireland had to run at maximum engine speed to provide Head End Power resulting in spectacular failure of one loco. This then resulted in generator coaches being used in the future.


As do the 3000s in Northern Ireland, I believe. To be honest both are horribly noisy units to ride on with constant drone from auxiliary engine. Think centre cars of Spanish 592s also have auxiliary engine for on board services. That car also best avoided!!

Correct on both counts. You could always tell when the Enterprise was sat in Belfast Central (now Lanyon Place) as you could hear nothing but the roar of a 201 sat there on full bore. The other problem with having it this way of course is the excessive fuel use and the west and tearing of components. It just amazed me that it took them so long to switch to using some of the redundant Mk3 Gen Vans, as running a 201 around on full power all day really must have had some effect on those big GM engines!

The C3Ks or 3000 class are certainly intriguing units to ride on - built at a time when quality meant something to CAF, from a passenger perspective they are excellent. Except for the somewhat odd Auxiliaries Engine running all the time (the main engine is the same MAN engine used under the 769s if you want to get an idea of what it sounds like just with a smaller Cummins bolted on further down the chassis).

 

[AngusH]

Possibly here in a thread mainly about the class 67:

Under utilised class 67s

er, Wikipedia says The fires were due to large HEP requirements placed on the prime mover. Co-Co is always going to be better for RA and tractive effort which are two failings of Class 67.

www.railforums.co.uk

 

[Taunton]

I know the US for a long time favoured generator cars over Head-End Power (what we would call ETH or ETS), and Ireland sourced many of their locos from General Motors. Whether the two are related would be conjecture on my part.

Afraid no connection. The US did not go for generator cars, there might have been a few but I don't recall, and for much longer had steam-powered coach supplies, both summer and winter, with steam-powered air conditioning, which came from the steam locomotive era and which they actually made a notable long term success of. When Amtrak was formed in 1971 pretty much all their stock was still steam-supplied, and the first new Amtrak diesels still had steam generators, always supplied from a steam boiler in the locomotive which the fireman had to attend to. It wasn't until the mid-1970s that they started to have electric supply, generally from a separate small diesel generator within the locomotive after abortive early attempts with tapping the main engine, plus buying new ETH coaches and converting the existing ones. Even the new mid-1970s E60 electric locos for New York to Washington initially came with oil-fuelled steam boilers.

There were a few steam heater cars, but they were only used in deep winter on lines over the bitter mountains of the North West in sub-zero temperatures, at the rear, when the steam supply from the locomotive cooled too much along the long train, so it was supplied half each from loco at the front and heater car at the rear.

CIE in Ireland had their first diesels without heating supply, the Crossley locos, almost 100 of them in the mid-1950s, which together with a large batch of diesel railcars pretty much dieselised the system. They built a series of steam heating vans to go with them, initially 4-wheel, later 6-wheel and then bogie, as the coaching stock was still all steam heat. This pattern continued with the 1960s General Motors locos, and into the electric train supply era which started in the 1970s; some of their heating vans could do both steam and electric supply, with boiler and diesel generator - there are photographs of trains with them mid-formation with ETH air-con stock on one side and older steam-heat stock on the other. Incidentally, the CIE General Motors locos, although commonly termed from the USA, had a significant proportion of them built in Canada, at the GM plant in London, Ontario, which did much of the GM export loco production.

 

[fgwrich]

You’ll have to excuse the talking in it, but this video on YouTube demonstrates how loud those 201s were when having to provide HEP. Basically, think of it as having a 66 revving itself loudly for hours on end while not doing much else.

 

[craigybagel]

As do the 3000s in Northern Ireland, I believe. To be honest both are horribly noisy units to ride on with constant drone from auxiliary engine.

Not sure that they're any worse than a similarly aged DMU in Great Britain to be honest - the auxillary engines are pretty quiet compared to the traction engine that does all the hard work.

It just amazed me that it took them so long to switch to using some of the redundant Mk3 Gen Vans, as running a 201 around on full power all day really must have had some effect on those big GM engines!

The MKIII Generator vans were needed on the MKIII services out of Heuston. It was only when those ended that they became available for the Enterprise.

 

[ShadowKnight]

I'm not aware of any generator vans having been recently used in GB. Other than plans for the EPS Nightstar services for the non electrified routes west of London.

 

[zwk500]

I'm not aware of any generator vans having been recently used in GB. Other than plans for the EPS Nightstar services for the non electrified routes west of London.

There is one that does Charter work but very much a niche case!

 

[Shimbleshanks]

I wonder what the modern take on the generator van might be? Would it have a big battery instead of the diesel generator? And if the modern power plant was more compact, could the rest of the van be used for other purposes like luggage space? (Using it for passenger accommodation might be problematic given the fire risks associated with Lithium batteries.) Could you even have it recharge itself with solar panels on the roof and wind turbines powered by the motion of the train?

 

[ShadowKnight]

Although thinking of it now it seems that the class 73 on the unelectrified portion of the Caledonian highland sleeper are de facto generator vans when those services are also hauled by class 66s in addition.

 

[DelW]

I'm not aware of any generator vans having been recently used in GB. Other than plans for the EPS Nightstar services for the non electrified routes west of London.

There is one that does Charter work but very much a niche case!

I've certainly been on railtours on a charter set (from Riviera?) which has a diesel generator mounted in a converted coach. I assume the benefits are uninterrupted power (especially to the catering cars) during loco changes, and the ability to run the train using non-ETS fitted freight locos.

 

[LowLevel]

You’ll have to excuse the talking in it, but this video on YouTube demonstrates how loud those 201s were when having to provide HEP. Basically, think of it as having a 66 revving itself loudly for hours on end while not doing much else.

I remember hearing about the problems but never saw it demonstrated so clearly, crikey! That would drive you nuts.

 

[Krokodil]

The US did not go for generator cars, there might have been a few but I don't recall, and for much longer had steam-powered coach supplies, both summer and winter, with steam-powered air conditioning,

Was that just using the steam to power a turbo generator?

 

[Taunton]

One thing I've never understood is why the 201s had to run at the equivalent of full power to supply ETH on the Enterprise sets, and yet class 67s in the UK with the same basic engine only need to run at the equivalent of notch 3.

It's all down to what sort of ETH supply is required. Amtrak had the same issue with their new GM F40s in the late 1970s. If the train supply was required was AC, in order to get the current at the desired frequency the alternator had to run at the rpm to do that, so for standard USA 60Hz frequency it had to run at 60x60=3,600 rpm. For Europe at 50Hz it had to run at 50x60. The alternator is geared to the engine, something like 4:1, so the main diesel didn't have to run at 3,600 rpm, but it did have to run at something like 900 rpm full speed, hence the noise. AC voltage is by-the-by, it can be transformed as required, the key thing is frequency. Incidentally, the rise and fall in tone of the loco when standing is more noise from the air compressor and radiator fans than from the diesel engine itself, which maintains its rpm well.

Amtrak eventually fixed it by installing auxiliary small diesels in the F40 loco carbody, specifically to provide ETH, so the main diesel just idles when stationary. They seemed to have better luck with these than what the Scottish Region did with the Class 27x2 push-pull on Glasgow-Edinburgh in the 1970s, when they installed auxiliary Deutz diesels for this, which brought a whole range of unanticipated problems.

BR long used DC for their ETH. There are a couple of decision points for one or the other. Modernisation PLan BR diesels had generators, producing DC only; alternators for locomotives came later. AC allows the use of normal commercial equipment down the train, such as vacuum cleaners, rather than custom-made DC ones. Another is that to transform the train supply down to the required voltage it long needed it to be AC; transformers had to work on AC, they could not transform DC until much more recently power electronics invented current inverters, which allow this and let you play with the current frequency, which has also allowed the full-speed engine problem to be overcome on new locos - though not of course on older ones.

== Doublepost prevention - post automatically merged: 25 Feb 2023 ==

Was that just using the steam to power a turbo generator?

No, this was in steam heat days. I think the Amtrak Chicago to Seattle 'Empire Builder', the key train for this heat problem across Montana/Idaho etc in deep winter, changed over to HEP Superliners, all electric from the loco, in the early 1980s.

 

[Richard Scott]

Not sure that they're any worse than a similarly aged DMU in Great Britain to be honest - the auxillary engines are pretty quiet compared to the traction engine that does all the hard work.

They may not be any louder but the constant drone from the auxillary engine is incredibly annoying.

 

[Gloster]

BR had ADB975325, formerly BG 81448, and later 6310, which was used to provide power for HST coaches running without power cars. There were also 6311 to 6313, also former BG, which produced normal eth.

 

[craigybagel]

It's all down to what sort of ETH supply is required. Amtrak had the same issue with their new GM F40s in the late 1970s. If the train supply was required was AC, in order to get the current at the desired frequency the alternator had to run at the rpm to do that, so for standard USA 60Hz frequency it had to run at 60x60=3,600 rpm. For Europe at 50Hz it had to run at 50x60. The alternator is geared to the engine, something like 4:1, so the main diesel didn't have to run at 3,600 rpm, but it did have to run at something like 900 rpm full speed, hence the noise. AC voltage is by-the-by, it can be transformed as required, the key thing is frequency. Incidentally, the rise and fall in tone of the loco when standing is more noise from the air compressor and radiator fans than from the diesel engine itself, which maintains its rpm well.

Amtrak eventually fixed it by installing auxiliary small diesels in the F40 loco carbody, specifically to provide ETH, so the main diesel just idles when stationary. They seemed to have better luck with these than what the Scottish Region did with the Class 27x2 push-pull on Glasgow-Edinburgh in the 1970s, when they installed auxiliary Deutz diesels for this, which brought a whole range of unanticipated problems.

BR long used DC for their ETH. There are a couple of decision points for one or the other. Modernisation PLan BR diesels had generators, producing DC only; alternators for locomotives came later. AC allows the use of normal commercial equipment down the train, such as vacuum cleaners, rather than custom-made DC ones. Another is that to transform the train supply down to the required voltage it long needed it to be AC; transformers had to work on AC, they could not transform DC until much more recently power electronics invented current inverters, which allow this and let you play with the current frequency, which has also allowed the full-speed engine problem to be overcome on new locos - though not of course on older ones.

== Doublepost prevention - post automatically merged: 25 Feb 2023 ==

Thanks, that ones been bugging me for years.

 

[Townsend Hook]

I wonder what the modern take on the generator van might be? Would it have a big battery instead of the diesel generator? And if the modern power plant was more compact, could the rest of the van be used for other purposes like luggage space? (Using it for passenger accommodation might be problematic given the fire risks associated with Lithium batteries.) Could you even have it recharge itself with solar panels on the roof and wind turbines powered by the motion of the train?

The Ffestiniog Railway, I believe, have started to move to battery banks instead of diesel generators in their service cars as a source of hotel power. Apparently gives a much better working environment for the staff in the service vehicle without the noise and vibration of an internal combustion engine.

 

[fgwrich]

I've certainly been on railtours on a charter set (from Riviera?) which has a diesel generator mounted in a converted coach. I assume the benefits are uninterrupted power (especially to the catering cars) during loco changes, and the ability to run the train using non-ETS fitted freight locos.

There are actually a handful out there in charter and departmental use:
Mk1 BG - Riviera Trains - 6310
Mk1 BG - LSL - 6311
Mk1 BG - Network Rail - 6260
Mk1 BG - Network Rail - 6261
Mk1 BG - Network Rail - 6262
Mk1 BG - Network Rail - 6263
Mk1 BG - Network Rail - 6264
Mk1 BG - WCRC - 6312
Mk1 BG - VSOE - 6313

Mk2 - Royal Train - 2920
Mk2 - Riviera Trains - 17105

I'm sure there's a Mk1 in the (former?) Riviera fleet with a generator in too?

 

[Krokodil]

No, this was in steam heat days. I think the Amtrak Chicago to Seattle 'Empire Builder', the key train for this heat problem across Montana/Idaho etc in deep winter, changed over to HEP Superliners, all electric from the loco, in the early 1980s.

So without using a steam-driven turbo generator, how do you get air conditioning from steam?

Mk2 - Royal Train - 2920
Mk2 - Riviera Trains - 17105

Both of which were converted for Royal Train use from mk2B BFKs. 17105 having been 2905 in Her Majesty's service.

 

[MikePJ]

So without using a steam-driven turbo generator, how do you get air conditioning from steam?

You don't need the generator part. Air conditioners are mechanical/fluid devices, and the main power input is a shaft drive to a compressor. Of course, on modern units they're typically electric, but in-car A/C can be driven mechanically off the engine. So air conditioners could be powered by steam engines (reciprocating or turbine), no problem. In fact, the first large-scale commercial refrigeration was in steamships to bring meat from New Zealand to Europe, and those were steam-powered.

 

[Taunton]

So without using a steam-driven turbo generator, how do you get air conditioning from steam?

If it sounds improbable ... it's not. Steam ejector air-con relies (GCSE Physics here, or for us older lot, O-Level Physics) on the concept of latent heat when things boil, they take extra heat out of their environment. Reduce the pressure in a vacuum with a steam jet and the boiling point of water becomes room temperature, or less. It's just how a fridge-freezer works, although there's no compressor or pump. Here's an explanation from the USA "Trains" magazine, where, as you can read, lots of others wondered just how it works

Steam ejector air conditioning - Trains Magazine - Trains News Wire, Railroad News, Railroad Industry News, Web Cams, and Forms

Trains magazine offers railroad news, railroad industry insight, commentary on today's freight railroads, passenger service (Amtrak), locomotive technology, railroad preservation and history, railfan opportunities (tourist railroads, fan trips), and great railroad photography.

cs.trains.com

The USA cracked this on trains around 1920 (good old George Westinghouse again), when it was still all steam locomotives. Previously they used to load ice, tons of it, into large compartments between the bogies, and had fans blow air over this and up into the coaches, and indeed into refrigerated goods cars carrying chilled foodstuffs around the country. 'Icing plants' for restocking were sited at intervals along the main lines, generally at crew change points, and there are still one or two lying rusting in the desert in the USA if you know where to look. But steam ejector cooling very rapidly replaced it.

Reading the article shows there are a good few who are just content to say "it's magic" about the process!

 

[Krokodil]

Thanks, I actually covered heat cycles at uni but I never really grasped the topic.