Welsh Electrification

[The Stationmaster]

To me it is very important that any new trains can at least match the current timings when on diesel power. If the IEP does come in running slower off electric with slower acceleration times that the current HST those of us in the Southwest could notice much longer journey times even if the sets will go faster on electric. Going down the B & H it will be off the electric from Reading. That would give about 40 miles on followed by up to 260 ish miles of the power.

 

And to maintain present timings (or better still regain the original HST timings) you are going to need a lot of installed diesel horsepower - not so much for the bits where you can bash along at 100mh plus but for the really hard bits where you have to be able to tackle the various banks such as daintain and accelerate away from frequent station stops in Cornwall plus off the numerous speed restrictions (because I can hardly see straightening as part of the exercise. In very simplistic terms the HST needs 4,500hp to be able to do what it does with 8 trailers - a bit under under 400tons in round numbers. So another 400 ton train - however the power is distributed - is going to need the roughly the same hp to do the same job unless gravity in the West of England can be arranged to work to a different set of natural laws. something broadly similar goes for 'west of Cardiff' where some banks plus the speed profile need that sort of installed hp to be able to deliver something on a par with existing or historic HST timings.

 

So in simplistic terms design of the IEP then comes down to a very simple starting point - you need roughly 11 installed 'engine' horsepower per ton of nett train weight to equal existing timings. And anything lees than that, as with an HST with an engine out, and you need loco assistance on the South Devon banks unless you impose considerable signalling restrictions to avoid the likelihood of a train having to restart on steep gradients. If the diesel component of the IEP delivers that sort of horsepower it will work, and if it doesn't it might not get past Newton Abbot.

[steve fay]

Personally I welcome the electrification but when will it start ??? I do have a few friends who work for network rail and they haven't seen any credible way of wiring the Severn tunnel yet it could be a stumbling block a new bridge maybe!!!!!!!

I do agree with the idea of a loco coming on at Cardiff though for the short journey to swanse and the slower on ward journey to west Wales. Seems silly for an electric train dragging all that extra weight around from Cardiff to London. Bi mode on the west country route but not in Wales.

As for the valleys a great idea finally get shot of them pacers.

Just need to fill in from Maendy junction north wards to Crewe.

[tomparryharry]

By the time this gets going, there won't be a Severn Tunnel, more like a Severn Barrage. This is liable to happen, despite what the 'neer-sayers' think....

 

Regards,

Ian

[Ron Ron Ron]

.....So another 400 ton train - however the power is distributed - is going to need the roughly the same hp to do the same job.......

I'm not disagreeing with what you say Mike, but are you sure it will be "another 400 ton train" ?

The original IEP spec called for a lighter and stronger structure, as part of the drive for greater efficiency and reduced impact on the infrastructure; but that was when we knew that the Inter-City versions of the new train would be 10 cars long with power sources at either end and traction motors distributed along the train..

Now the talk is of 5 car trains, used both singly and in multiple, with smaller underfloor engines distributed along the train. However no one knows for sure what's going on and what form the train will now take?

 

 

 

[Edwin_m]

I haven't seen any technical data on the latest incarnation of IEP but I would imagine the bi-mode puts an engine similar to that in a Voyager on all coaches except the transformer coach, or maybe a bit less power but also less weight as Ron suggests. Voyagers seem to have no problem keeping to HST timings even with one engine out. So while the original configuration might have struggled to match the HST on the non-electrified sections (hybrid helps a bit but sustained maximum speed running or a long climb would soon flatten the batteries) I think that is no longer an issue. Another benefit of the latest arrangement is an extra passenger coach within the same length.

 

Downside is the weight and cost of all those diesel power packs (possibly more than a separate power house), the probable loss of hybrid operation (can't see there being the space) and the noise and vibration of underfloor engines. On a journey such as Swansea however the diesel leg is relatively short so likely to be less of an issue than long journeys on Voyagers. If these trains are to serve Penzance or Inverness then it becomes more important.

 

I notice also from the press release that the build is to be a mix of straight electric and bi-mode versions. Hopefully the straight electrics include some full length units so that the Bristol route can be run with a single crew per train. For the bi-modes a five-car might be a better choice, perhaps with some five-car straight electrics too, as the end of the wires usually coincides with a drop in passenger numbers so the train can be split here. Compare and contrast with the alternative of attaching a diesel loco...

 

I guess the design will put the diesel engine, generator, fuel tank and associated gubbins in a single raft that is simply omitted on the electric versions (though it might need a ballast weight in replacement, as weight distribution is critical to ride quality). This would also allow relatively easy conversion of a bi-mode to a straight electric and vice versa.

[frobisher]

I guess the design will put the diesel engine, generator, fuel tank and associated gubbins in a single raft that is simply omitted on the electric versions (though it might need a ballast weight in replacement, as weight distribution is critical to ride quality). This would also allow relatively easy conversion of a bi-mode to a straight electric and vice versa.

 

As I understand it, the small auxillary generators were a feature of the original IEP proposal to allow the electric only sets to move themselves in emergencies and were provided in every third or fourth carriage. The bi-mode proposal we have now has beefed up those generators (and I suspect they'll stay beefed up for the sake of standardisation on the electric units) and provides those one per carriage with an enlarged fuel tank. So you're probably right

[Gwiwer]

5- car units will require fully duplicated services including two catering cars and crews unless a way can be found to fit through gangways to the outer ends of 125mph stock. Slab ends create too much resistance and fitting a gangway at the end of a Voyager type unit might be an interesting challenge. And that also assumes catering will not be downgraded from the present service; we already went through an era of poor service when the LHCS included nothing more than a TSOT.

 

The more this is discussed (and with regard to our present lack of knowledge as to the train type and configuration to be used) the more it seems to have been a poorly-thought out decision by those who are only concerned with the financial side and have no understanding of railway operations nor of passenger expectations.

 

Diesel engines beneath the floor are undesirable and can be uncomfortable and intrusive on longer trips. Ask anyone who has endured Euston - Preston on a Voyager (particularly when an electric Pendolino might have been expected) or made just about any cross-country journey of late.

[Ron Ron Ron]

As I understand it, the small auxillary generators were a feature of the original IEP proposal to allow the electric only sets to move themselves in emergencies and were provided in every third or fourth carriage.

IIRC, it was only one auxiliary generator - to provide emergency hotel power in the event of failure and to enable the SET to limp along under its own power (I seem to remember something like 10 or 20 mph being the requirement) in order to clear the tracks.

i may be mistaken?

 

 

 

[The Stationmaster]

I'm not disagreeing with what you say Mike, but are you sure it will be "another 400 ton train" ?

The original IEP spec called for a lighter and stronger structure, as part of the drive for greater efficiency and reduced impact on the infrastructure; but that was when we knew that the Inter-City versions of the new train would be 10 cars long with power sources at either end and traction motors distributed along the train..

Now the talk is of 5 car trains, used both singly and in multiple, with smaller underfloor engines distributed along the train. However no one knows for sure what's going on and what form the train will now take?

 

 

I don't know Ron but I started from 400 tons as a way of getting to the hp/ton as much as anything else being aware, as you have said, that they are talking about lighter vehicles (I wonder what has happened to BR crashworthiness standards, interesting point there possibly?). What you say about 5 car sets (or possibly sub-sets?) is very pertinent and conjures up in my mind horrific visions of a sort of super Voyager with perhaps a bit more oomph and even less overall comfort as the noise level increases. But it would introduce - as Gwiwer has mentioned - the possibility of intermediate splitting, with all the problems it would bring.

I follow too Gwiwer's other point and continue to wonder just where the practicality of daily operation has been injected into the heady mix of bright ideas for energy saving and clever approaches to bi-mode operation. It's almost a potential re-run of the APT and HST tale where fortunately those with their feet pretty firmly on the ground were able to get something into service while the brave new ideas wound their way through expensive development. A lot of that alternative way of thinking has gone out of the industry or if it survives is sitting quietly in the corner trying to keep its copybook annotated with sufficient buzzwords to avoid notice while waiting for the date of optimum move to pension income. Maenwhile the moneymen and corporate wizards ply their trade and if the past suggestion from one such to run Regional Eurostar from Bristol instead of Birmingham is anything to go by I suspect they might buy anything they are told is good.

[Geoff Endacott]

Why don't they just put a piston underneath the electric power car? Then in South Devon they could have a pipe between the rails, pumping stations every few miles...

 

Geoff Endacott

[woodenhead]

All that leather, it would attract rats and animal rights campaigners

[Ron Ron Ron]

.....I wonder what has happened to BR crashworthiness standards, interesting point there possibly?

BR crashworthiness standards have been improved upon if modern stock is anything to go on.

For example, I understand that the Mk3 coaches wouldn't make the grade today if presented as a new design.

The Grayrigg accident demonstrated the excellent crashworthiness of the Pendolino vehicles, where in contrast, even slower accidents involving Mk3's have resulted in far more damage.

The IEP spec used the latest requirements.

 

 

What you say about 5 car sets (or possibly sub-sets?) is very pertinent and conjures up in my mind horrific visions of a sort of super Voyager with perhaps a bit more oomph and even less overall comfort as the noise level increases. But it would introduce - as Gwiwer has mentioned - the possibility of intermediate splitting, with all the problems it would bring.

Splitting was always part of the IEP spec.

Originally the requirement was for 10 car trains (the main order) in various configuations; plus 5 car commuter versions that could be run in pairs.

There were both 10 and 5 car Bi-Modes included as well as 10 and 5 car all-electric. The all-diesel was only 10 car (longer, more powerful and lighter than an HST).

 

All that has now changed as the DafT have completely muddled everything up.

[multiprinter]

All this talk of 10car or 2 x 5 car seems vaguely reminiscent of WR's use of the Blue Pullmans - 8 car sets or 2 x 6 cars.

[The Stationmaster]

Why don't they just put a piston underneath the electric power car? Then in South Devon they could have a pipe between the rails, pumping stations every few miles...

 

Geoff Endacott

 

Might improve train performance too (as long as they use a plastic flap to seal the pipe). Talking of which I bought a GWR 1875 public timetable yesterday - in 1875 a train on my local branch (broad gauge of course) took 10 minutes end to end with one stop. We now have fancy diesel trains, albeit on the narrower gauge, which take 12 minutes to do the same journey although there are now two intermediate stops. In 1875 a monthly season ticket to London cost £3/17/0, in 1969 the same ticket cost c.£30, today it costs £294.60. So overall it looks like Mr Brunel was onto quite a good thing. Mind you that gentleman's ideas of specifying motive power were probably almost as daft as DafT's.

[woodenhead]

Mind you that gentleman's ideas of specifying motive power were probably almost as daft as DafT's.

 

Maybe, but in principal it worked just a little problem of maintaining vacuum pressure and rats gnawing at the seals.

 

Imagine if it had worked as planned and he had extended it - locomotives would only have been needed for shunting and we wouldn't have had all those lovely big express engines - steam, diesel or electric. Over the years the pump houses would have been the ones developing in power and technology not the motive power we know, it would have changed everything.

[Gwiwer]

It is way too early to look at service patterns and timetables but there are pros and cons to splitting trains.

 

If it is done at a major stop then there may be little time penalty over the present journeys. Something like a single set coming up from Penzance attaching to a second set starting at Plymouth during a 5-minute booked station stop. If that pattern ran hourly (which the re-doubling of Probus - Burngullow makes possible provided things run smartly at Saltash) we might then be able to enjoy an alternate-hours train via the Berks & Hants while the other goes via Bristol. The greater distance of the latter would be offset by the superior timings which should be obtained from electric traction over that part of the route.

 

Problems arise if the attaching portion is delayed since it then begs the question whether to delay the starting unit and thus attract penalties for the entire service or to run that on time and terminate the late running unit with passengers decanted onto the next service.

 

Similarly a 5-car unit up from Swansea would attach to its twin at Cardiff.

 

The present need for computers to interface is one reason splits take a lot longer than they might. SR EP-type stock could be split or joined in a minute or less (though two or three were always allowed) while even GWT / FGW's Night Riviera could drop the Plymouth sleeper off the back in no more than that. Ask the good people of Haywards Heath just how long it takes to split or join trains now however .........

[Etched Pixels]

Similarly a 5-car unit up from Swansea would attach to its twin at Cardiff.

 

And in peak hours and evenings where would you put all the other passengers. Five car sets might make sense at 2pm but not in peak hours or for sports events.

 

The present need for computers to interface is one reason splits take a lot longer than they might. SR EP-type stock could be split or joined in a minute or less (though two or three were always allowed) while even GWT / FGW's Night Riviera could drop the Plymouth sleeper off the back in no more than that. Ask the good people of Haywards Heath just how long it takes to split or join trains now however .........

 

Seems pretty snappy at Mach

[Ron Ron Ron]

The present need for computers to interface is one reason splits take a lot longer than they might.

IIRC (it's all a bit fuzzy, but I can look it up), the IEP spec takes that experience into account and required a "less than X minutes" timing for splitting and joining.

 

 

 

[The Stationmaster]

IIRC (it's all a bit fuzzy, but I can look it up), the IEP spec takes that experience into account and required a "less than X minutes" timing for splitting and joining.

 

 

That's a very sensible approach (seems they've got something right) - it used to take about 7 minutes to set-up the computer on a Eurostar (that was once they had been properly sorted).

Portion working can bring all sorts of complications - even with modern couplers - and it will be interesting to see to what extent that has also been taken into account.

[Fenman]

It is way too early to look at service patterns and timetables but there are pros and cons to splitting trains.

...

Problems arise if the attaching portion is delayed since it then begs the question whether to delay the starting unit and thus attract penalties for the entire service or to run that on time and terminate the late running unit with passengers decanted onto the next service.

...

The present need for computers to interface is one reason splits take a lot longer than they might. SR EP-type stock could be split or joined in a minute or less (though two or three were always allowed) while even GWT / FGW's Night Riviera could drop the Plymouth sleeper off the back in no more than that. Ask the good people of Haywards Heath just how long it takes to split or join trains now however .........

 

It's a very slick operation at Cambridge, with splitting and joining portions to/from King's Lynn taking a minute or so, and this happening many times every day*.

 

There were some problems in the recent extreme cold weather where I believe the couplings were frozen solid, but I can't remember any other significant delays over the decade or so this has been happening.

 

Paul

 

*Although I suspect the Class 365s are not heavily computerised, what with them lacking even some of the most basic creature comforts we now take for granted on more modern stock. Funny: I thought computers were meant to make things more efficient, not less.

[Gwiwer]

My reference to Haywards Heath refers to the splits / joins there on the Victoria - Eastbourne / Littlehamptons. Where once two minutes was more than enough seven or more are now allowed while safety announcements are made, doors are closed, numerous platform staff supervise the movement and everything is reset for the onward journey.

 

The GGW main lines are not quiote as heavily congested as the Brighton (where this sort of operation does nothing at all to help improve overall capacity) but you still wouldn't want the trains to be sitting in a platform at Cardiff Central for any longer than they had to. Bristol TM probably the same. If units split at Exeter we can add that to the list with only perhaps Plymouth having a lot of spare capacity.

[Captain Kernow]

A lot of that alternative way of thinking has gone out of the industry or if it survives is sitting quietly in the corner trying to keep its copybook annotated with sufficient buzzwords to avoid notice while waiting for the date of optimum move to pension income.

 

Well, that made me smile!!

 

 

Interesting no one has yet mentioned the effects of the OLE on historic structures and through such 'sensitive' locations (eg. the whole of the Bath urban area ). All that might prove quite interesting as well.

 

 

Oh, and I trust that the new diesel trains operating in South Devon won't be afraid of a little salt water.....

[Gwiwer]

the effects of the OLE on historic structures and through such 'sensitive' locations

 

Same deal as on the ECML. Objections were overcome at Berwick on the Royal Border Bridge and through York station as just two examples. Floor-hung diesel engines might be more susceptible to inundation along the sea wall than HST / traditional locos. It is an occasional issue for Voyagers though the Pacer / Sprinter types seldom seem to be affected.

[Glorious NSE]

So in simplistic terms design of the IEP then comes down to a very simple starting point - you need roughly 11 installed 'engine' horsepower per ton of nett train weight to equal existing timings. And anything lees than that, as with an HST with an engine out, and you need loco assistance on the South Devon banks unless you impose considerable signalling restrictions to avoid the likelihood of a train having to restart on steep gradients. If the diesel component of the IEP delivers that sort of horsepower it will work, and if it doesn't it might not get past Newton Abbot.

 

I think the difference in that scenario is that an HST with one engine out is running on just 50% of it's normal power, one of these with an engine out will be presumably be at 75% (assuming 4 power units in a 5 car set) or 87.5% (assuming 8 power units in a 10 car set) - so an "up side" is it should be less likely to need turning at Newton Abbot or dragging.

 

I still can't help thinking of camels and committee's though, especially when you compare the train spec now to the original project spec.

 

Floor-hung diesel engines might be more susceptible to inundation along the sea wall than HST / traditional locos. It is an occasional issue for Voyagers though the Pacer / Sprinter types seldom seem to be affected.

 

From what I recall the issue with the Voyagers was due to the sea water affecting roof mounted components (dynamic brakes?) which then fed back strange readings to the onboard computers which then decided that Something Very Bad must be happenning and that the train really must stop.

Pacers/Sprinters don't have pernickerty onboard computers so they tend to just keep going until the Something Very Bad causes the unit to burst into flames, or launch an engine off into the scenery or much more mundanely just break down.

[Edwin_m]

BR crashworthiness standards have been improved upon if modern stock is anything to go on.

For example, I understand that the Mk3 coaches wouldn't make the grade today if presented as a new design.

The Grayrigg accident demonstrated the excellent crashworthiness of the Pendolino vehicles, where in contrast, even slower accidents involving Mk3's have resulted in far more damage.

The IEP spec used the latest requirements.

 

There are plenty of accidents where Mk3 coaches have stood up just as well as the Pendolino in similar circumstances, despite having neither current crashworthiness standards nor a driver "steering" them to safety [R Branson]. A 100mph derailment with any sort of modern stock causes little serious damage to the structure unless it hits something hard.

 

The current standards require energy absorption at the end of each coach, meaning that the last metre or so is a crumple zone can't be used for passenger space and probably can't be a vestibule either as the door opening would compromise the crashworthiness. That's getting on for 10% loss of capacity! I contend that these standards have saved exactly nobody's life since they were introduced, as collisions and high-speed derailments are so rare these days, and I would suggest that challenging nonsenses like this is very necessary if we are to get to a railway that carries more people and costs less. So I'm disappointed that IEP hasn't done so.

 

IMHO 400 tonnes for a full set as quoted by Stationmaster will be pretty near the mark. With a shorter vehicle and probably a smaller diesel engine Turbostars are around 45 tonnes per car. Class 220s are a couple of tonnes more and some cars of the class 180 are over 50 tonnes.