As much as the proposed Alstom alternative seems to make sense, alot of time seems to have gone into the Hitachi IEP, they are prefered bidder and are going to build an assembly plant in the UK (that is the big clincher, why I don't think IEP as a whole will go away). There is, I hope, still a little time to make DfT decide to order only EMUs, but my uninformed opinion is that Hitachi IEP in some form is now inevitable unless the government decide they can't afford any new trains at all.
This is a good point. In fact, acceleration could be seen as a bad thing on Intercity services. Personally, I think alot of the 22xs and diesel IEP ability to accelerate as fast as an electric train is down to increased power rather than distributed traction (though that might be helping, but remember the acceleration advantage from distributed traction tends to be greater starting off, once you are up to, say 90mph, some LHCS trains might actually be able to accelerate from 90 to 125 faster than some MUs). That increased power and hence acceleration comes at a cost, increased fuel consuption. I consider that to be a big negative and I don't consider the increased acceleration to be worth the extra fuel consumption.
In my opinion DMUs are never suitable for Intercity services. Some, for example the Pembroke Coast Express, would be equally suited to an EMU or a LHCS solution, but a DMU would, in my opinion, not be acceptable. There are a few cases on the Intercity network where I believe LHCS would be a better option than an EMU. However, I admit these are few in number and an EMU would not be far off being suitable, so if we didn't have the sleepers to make up the numbers, then it might not be worth having a fleet of LHCS. However, I think the few services where LHCS is better than EMU, plus the sleepers plus perhaps the odd route where LHCS and EMU are totally equal make LHCS an important component of the UK's train fleet.
I was reading the Foster review of IEP earlier. This did comment that seasonal poor rail adhesion conditions can have an impact on the effectiveness of LHCS versus EMU. However, the report also states that: "an alternative, well established practice for similar long-distance services across Europe is to use a high powered electric locomotive fitted with sanding equipment (which lays sand on the rail beneath the wheels of the locomotive, improving adhesion when it is low) and conventional coaching stock which allows variable length trains to operate".
There are counter-arguments for most of the aspects being debated. It appears to me that there are suituations where LHCS has certain advantages over MUs and vice-versa. Also, some of the aspects where MUs win might be more important in some suituations, but in other suituations the (different)advantages of LHCS may be more important.
Now, we come to what should be the bigger debate. Rather than arguing as we are about LHCS versus MUs, we should be trying to ensure that no-one is going to build any more DMUs. Right now, it looks as if DfT might be going to sign on the dotted line for the IEP bi-mode, which is (essentially) a DMU. The Great Western franchise consultation seems, to my supprise, have re-introduced 8-car bi-modes and lost 5-car electrics. The weekday IEP diagrams listed in the document are:
- 26x 5-car bi-mode
- 11x 8-car electric
- 12x 8-car bi-mode
The GW franchise consultation also mentions using IEPs for one train per day to Paignton and Carmarthen, a waste of guage clearance monies which could be used to pay for wires to Swansea or Cheltenham.
There's also the issue of lost capacity with a 5-car IEP, 309 versus the 474 of a low-density FGW IC125. Ok for the Cotswolds line maybe, but I don't see that needing 26 diagrams. Where do they intend to deploy the 49 diagrams listed above?
By the time the 180s are expired hopefully we will have more electrification and the Aberdeen / Inverness will be dragged.
