Why is LHCS unfavourable nowadays?

[NSEFAN]

Just back from Switzerland and the seem to regularly use additional carriages bolted onto an EMU . Seen 4 additional to a 3 car emu. They must have high power emu to cope
Best of both woelds

I've also been in Switzerland recently, and saw plenty of loco changes and shunting at Zurich. I have to say that the practice there is efficient but dangerous by British standards. In particular they seem to have no problem with multiple trains and propelled movements shunting around in the platforms simultaneously, which looks like a recipe for collisions! It also needs infrastructure and the staffing level to do it, which is unlikely to make a comeback in the UK. Push-pull fixed formation loco haulage is better, but in that case you might as well have EMUs and DMUs. I get the impression most European loco haulage is because the stock is already there, with new trains almost entirely being formed of multiple units.

 

[bavvo]

Given all the advantages of multiple units then, does anyone know why Serco is building new LHCS for the Caledonian sleepers?

I would have thought purpose built EMUs rather than purpose built carriages would have worked out much more flexible, freed up platform space at Euston, and eliminated the loco hire (and reliability issues) between London and Scotland. Even if they still had diesel locos for the highland haul beyond Edinburgh it would still seem the better long term option.

 

[ac6000cw]

Sleepers have more complex 'hotel' services than day trains, so I suspect you need all the space you can get under the floor for those. Also quietness is very important, so you don't want whiny traction motors, gears and electronics plus buzzy transformers intruding on that...

 

[jopsuk]

Sleepers have more complex 'hotel' services than day trains, so I suspect you need all the space you can get under the floor for those. Also quietness is very important, so you don't want whiny traction motors, gears and electronics plus buzzy transformers intruding on that...

Have you used a mark 3 sleeper? Noisy damn things... the quiet when the power goes off during splitting/joining is bliss!

 

[petegunstone]

I was in Austria last week and took an IC train from Salzburg to Vienna which was LHCS, with a mixture of corridor and open carriages. We had a compartment to ourselves for some time, and appreciated both the lack of any noise from below and the general quiet ambience of the carriage owing to the compartments. All for a second class ticket!

Off topic: the lack of lineside fencing in some rural areas was startlingly noticeable! However, the onus seems to be on the farmers to keep what cattle they have constrained. Higher speed and urban sections did have walls, however.

 

[Bletchleyite]

I've also been in Switzerland recently, and saw plenty of loco changes and shunting at Zurich. I have to say that the practice there is efficient but dangerous by British standards. In particular they seem to have no problem with multiple trains and propelled movements shunting around in the platforms simultaneously, which looks like a recipe for collisions! It also needs infrastructure and the staffing level to do it, which is unlikely to make a comeback in the UK. Push-pull fixed formation loco haulage is better, but in that case you might as well have EMUs and DMUs. I get the impression most European loco haulage is because the stock is already there, with new trains almost entirely being formed of multiple units.

Indeed, all SBB's recent orders have been MUs, and they tend to work their LHCS like MUs anyway.


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[Shaw S Hunter]

Given all the advantages of multiple units then, does anyone know why Serco is building new LHCS for the Caledonian sleepers?

I would have thought purpose built EMUs rather than purpose built carriages would have worked out much more flexible, freed up platform space at Euston, and eliminated the loco hire (and reliability issues) between London and Scotland. Even if they still had diesel locos for the highland haul beyond Edinburgh it would still seem the better long term option.

As things stand the main maintenance base is Inverness and the vehicles are rotated around the different portions to get them there. That inevitably involves a certain amount of shunting, sometimes of individual vehicles. And this is one case where being able to swap out single vehicles when necessary is a genuine advantage.

 

[AnonymousUser1]

It makes you wonder why some operators chose to go against the trend and use LHCS, especially Transpennine. I was also going to add that multiple units don't need to have complicated running around procedures, although this has been negated by the development of DBSOs and DVTs (as mentioned elsewhere in the thread).

With regards to Europe, the picture is similar. New units have replaced loco hauled stock in the likes of Germany and Poland, but some operators like DB Regio and fernverkehr are also sourcing new LHCS.

the TPE LHCS purchase reflects the likely scenario of electrification mid franchise combined with a lack of capacity to deliver MU stock in time for the accessibility cut off dates ...

 

[SpacePhoenix]

Ever seen a class 166 accelerate before?

Or a class 350, 360 or 380?

Say a LHCS is 12 coaches with say a class 47 on the front, that can only have a maximum of 6 traction motors (assuming a traction motor on each axle).

Now take a 12 car (3x4) class 350, assuming each axle on the driving trailers has a traction motor, that's potentially 24 traction motors on the train. You've got a much greater surface area of wheel-rail contact

 

[43096]

Or a class 350, 360 or 380?



Say a LHCS is 12 coaches with say a class 47 on the front, that can only have a maximum of 6 traction motors (assuming a traction motor on each axle).



Now take a 12 car (3x4) class 350, assuming each axle on the driving trailers has a traction motor, that's potentially 24 traction motors on the train. You've got a much greater surface area of wheel-rail contact

If it's got traction motors it's not a driving trailer, it's a driving motor!!!
Driving = vehicle with driving cab
Motor = vehicle providing traction power (with engine (DMU), traction motors (EMU/DEMU))
Trailer = vehicle not providing power with no engine/motors

Class 350s do have 8 motors per set as you describe.

 

[najaB]

As things stand the main maintenance base is Inverness and the vehicles are rotated around the different portions to get them there. That inevitably involves a certain amount of shunting, sometimes of individual vehicles. And this is one case where being able to swap out single vehicles when necessary is a genuine advantage.

I'm not sure that it's still the case.

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[ac6000cw]

...also if the new sleepers were EMUs, Inverness would have to be equipped to test and maintain the 25kV traction equipment (presumably, unless maintenance moved elsewhere, and they may be political reasons to keep it in Inverness).

Sleepers are such a niche product that some of the reasons for it being LHCS don't really apply to day train stock, where passenger capacity and 'get you home' reliability are king.

 

[Harbornite]

the TPE LHCS purchase reflects the likely scenario of electrification mid franchise combined with a lack of capacity to deliver MU stock in time for the accessibility cut off dates ...

Good point. They could have ordered more Hitachi bi modes in theory, but the advantage of LHCS is that they can be hauled by diesel and electric locomotives.

 

[Philip Phlopp]

...also if the new sleepers were EMUs, Inverness would have to be equipped to test and maintain the 25kV traction equipment (presumably, unless maintenance moved elsewhere, and they may be political reasons to keep it in Inverness).

Sleepers are such a niche product that some of the reasons for it being LHCS don't really apply to day train stock, where passenger capacity and 'get you home' reliability are king.

Sleeper maintenance transferred to Polmadie when Serco took over, in preparation for the new CAF stock, which Alstom has agreed to maintain under contract with CAF and Serco. That would have removed any 25kV AC OLE testing issues.

 

[AnonymousUser1]

Good point. They could have ordered more Hitachi bi modes in theory, but the advantage of LHCS is that they can be hauled by diesel and electric locomotives.

but could they get them in time ?

in the absence of assurances of getting enough stock in time and the absence of another Bi-mode product ready to go ...

 

[Controller1701]

Push-pull operation is also less reliable than MU operation, and you need a special vehicle at the non-loco end.
I don't think we have ever had a good push-pull solution.

I can recall a very good push pull operation, it comprised of a Class 33/1 locomotive and a 4 car TC set and always worked just fine, sadly replaced by those nasty Class 442 units (boo hiss)

 

[RobShipway]

but could they get them in time ?

in the absence of assurances of getting enough stock in time and the absence of another Bi-mode product ready to go ...

Well, Hitachi as far as I am aware could potentially have three Production lines. Yes, all the bodies would be coming out of Japan, but you also have production facilities in Italy as well as here in the UK for the Class 800 plus the original Production line in Japan.

But as has been pointed out the LHCS are more flexible as if styled as per the tPE order would come with an end driving car trailer that essentially as mentioned before can be used with either electric or diesel locomotives.

One question is on my mind which is could the LHCS carriages from CAF if not required to be loco hauled at some point in the future, be added in as extra carriages to the Civity UK Inter City Electric trains?

 

[Harbornite]

Could the CAF LHCS carriages, if not required to be loco hauled at some point in the future, be added in as extra carriages to the Civity UK Inter City Electric trains?

What would the point of this be? It wouldn't be as simple as plonking the coaches within each EMU because they wouldn't be fully compatible and would lack traction motors. I highly doubt that this will ever happen.

 

[CosherB]

One question is on my mind which is could the LHCS carriages from CAF if not required to be loco hauled at some point in the future, be added in as extra carriages to the Civity UK Inter City Electric trains?

I think that's another example of a solution looking for a problem. The LHCS is procured for a defined route, which has the benefit of changing haulage from Class 68s to an electric loco in the future. In the (highly unlikely) event First relinquish the LHCS (at no doubt great cost as they would need to procure further new stock as a replacement), who would want LHCS? And how would Beacon Rail feel about it?!

 

[RepTCTC]

I can recall a very good push pull operation, it comprised of a Class 33/1 locomotive and a 4 car TC set and always worked just fine, sadly replaced by those nasty Class 442 units (boo hiss)

Oh, you've got me all misty eyed now.

 

[47802]

I think that's another example of a solution looking for a problem. The LHCS is procured for a defined route, which has the benefit of changing haulage from Class 68s to an electric loco in the future. In the (highly unlikely) event First relinquish the LHCS (at no doubt great cost as they would need to procure further new stock as a replacement), who would want LHCS? And how would Beacon Rail feel about it?!

Why would it be highly unlikely, by the time the next franchise is due and timescale for any new EMU's procured the LHCS would be a similar age to the 185's that are being released, added to which there will be plenty of Diesel Trains that will need replacing by then.

 

[Harbornite]

Why would it be highly unlikely, by the time the next franchise is due and timescale for any new EMU's procured the LHCS would be a similar age to the 185's that are being released, added to which there will be plenty of Diesel Trains that will need replacing by then.

Well you answered your own query. Why bother going to the expense of converting old-ish LHCS for MU use when you could... y'know... Keep them as LHCS. There may well be a need for it in the future to replace older LHCS.

 

[Phil.]

Also acceleration is much quicker on multiple units.

...as well as irrespective of the number of coaches the power to weight ration is constant.

 

[61653 HTAFC]

...as well as irrespective of the number of coaches the power to weight ration is constant.

Though the practice of all DMU vehicles being powered wasn't always the case. With 1st generation units there were certain routes where power-twin sets were favoured due to gradients over power-trailer consists. Weren't there even occasional sets made up entirely of trailers which were fine if worked in multiple with a powered set but if dropped off somewhere was as much use as a chocolate teapot!

 

[SpacePhoenix]

How well could 3 car class 158s, class 159s and any 3 or more car DMUs from about when Turbostars came in onwards could keep to booked times if their intermediate coaches were unpowered?

 

[D365]

How well could 3 car class 158s, class 159s and any 3 or more car DMUs from about when Turbostars came in onwards could keep to booked times if their intermediate coaches were unpowered?

They wouldn't. And they aren't. So I don't know why you ask.

 

[Philip Phlopp]

They wouldn't. And they aren't. So I don't know why you ask.

It'll be a plan involving Mark 4 or Class 442 trailers.

 

[SpacePhoenix]

They wouldn't. And they aren't. So I don't know why you ask.

It'll be a plan involving Mark 4 or Class 442 trailers.

I was thinking more if they'd been built as having unpowered trailers rather then all powered

 

[61653 HTAFC]

I was thinking more if they'd been built as having unpowered trailers rather then all powered

Well, if a 3-car unit had an unpowered centre car, the amount of power would drop by 33% but the weight would drop by significantly less- so they'd be slower and more sluggish, along with a subsequent drop in performance under poor rail conditions.

Theoretically their performance in terms of timekeeping would be unchanged, but the timings themselves would be poorer as performance would have been poorer from the start.

 

[Grumpy]

The title is self explanatory. Why are new D/EMUs favoured so strongly over a loco set? Surely it can't just be the acceleration advantage.

Despite some of the comments above I remain just as confused. Whilst I can see that duplicating engines, pantographs, transformers etc may well promise reliability, presumably this duplication comes with an increased capital cost, increased maintenance cost, increased complexity and increased total weight leading to an energy cost.
Finances apart, the need to put all the traction kit onto passenger carrying vehicles leads to an inferior experience for passengers. Examples would be increased noise and reduced amenity due to the competition for space (raised floors to fit underneath kit leading to reduced overhead storage space(eg 180's) or inadequate toilet drainage (eg Voyagers)).
Carrying big underfloor engines up and down the ECML under the new Hitachi units seems bonkers compared to the option of new LHCS plus loco