Well FGW doesn't seem to think so, given how quickly it dropped HSTs from quieter Cotswold Line services after putting them on the route in place of 180s in 2008-9.
My understanding is that FGW had an overall shortage of rolling stock thanks to retiscence on the parts of the TOC, the DfT and everyone else concerned.
If there is no possibility of new stock ordering no matter the economic case then my point no longer holds.
Carrying around air is incredibly expensive, particularly for the type of leasing / availability contract which IEP will be provided under. Taking into account that an IEP carriage will typically cost £20k a month more that a pendolino carriage, you definately want to make sure that the passenger demand is there all day to make use of that capacity to make the investment worthwhile.
That is not a result of the cost of actually carrying around air, that is a result of the trains being ordered under an absurdly bad value-for-money PFI.
Do you have any numbers for that? It seems surprising, but then again, I don't know how much it costs to run a train. What's the break-even point for bums-on-seats to cover the running costs of the train?
Of course, it doesn't detract from the capital costs of buying the additional vehicles, but if they're cheap enough to haul around empty most of the day, maybe there's some merit to the idea.
Well, if we assume the vehicles are ~£2m each (comparable to the cost of the new IEP vehicles) and are otherwise comparable to Class 222s, then this means that extending a four coach set to ten coaches would cost something on order of £12m.
If this amortises down over 30 years and state money is used (see Crossrail's rolling stock order) then that brings us to something on order of £920/day in interest/capital repayments for the entire six car addition.
If we assume this train is running a CrossCountry diagram then it will run typically, one and a half round trips on Bristol-Glasgow. (I know that is not an actual diagram but it seems reasonable in distance terms).
That translates to about 2100km per day.
Using known figures for the Class 222 (0.52L/vehicle km) the six additional vehicles will consume something on order of 6240L of diesel during the day. This translates to a cost of approximately £4370 at current diesel prices.
Maintenance costs on the vehicles will be approximately 25p/vehicle kilometre, which increases the cost by roughly another £3150.
Finally we come to access charges: 10.55p/vehicle-mile for the Class 222, or roughly 6.6p/vehicle-km.
That translates to essentially £832.
This means the excess cost of running a ten vehicle train compared to a four vehicle onei s approximatley: £920+4370+£3150+£832 or £9272.
That is for a diagram of roughly
2100km.
That means that it costs roughly £4.40/km to run this very large new train instead of the old one. But it does not account for the reduction in costs due to the total elimination of the double manning inherent in running doubled up units.
Even so, given that the price of a ticket in the XC core (say Leeds-to-Bristol) is £104.40
off-peak you would only need to sell
90 additional tickets in the XC core.... during your
three trips through it to be better off.
And that is before we even calculate the amount of extra custom generated by the advertising campaign that follows this "XC overcrowding is a thing of the past!" with lots of pictures of ten coach trains running past and half empty vehicles.
Ticket prices are so high and the marginal price of operations is so low that very minor increases in passenger numbers can cover them.