Class 91, 6 Mark 4's and a class 43

I was reading Rail this week and an article suggested that it could be possible to form up a train with a 6 Mark 4 coaches (1 first class) between a class 91 and class 43 to form a bi-modal train for ICWC. The logic being that it could then free up 221's to go to the MML to replace the HST's prior to 2020 without needing to make significant alterations to allow the Mark 3 to remain in service.

The suggestion is that the trains would have 40 first class seats and 380 standard seats (vs 26 and 252 in the 221's).

Such a train would be able to run beyond the wires whilst being mostly powered by electricity where the wires exist.

It would still (assuming 15 are created to replace 14 221's) leave sufficient IC225's for ICEC to use for their needs.

What are people's views? There is more details in the article so anyone who has read it and has particular points to make are welcome to add in any relevant extra details from the article, I've just provided the overview.

My thoughts are, although it would have about 50% more seating than a 221, don't most services from Euston which would benefit from such a train run as pairs of 221's. If this is the case then that would result in a circa 25% reduction in seats from Euston.

My other thought was that this all assumes no new bi-modal trains being purchased for ICWC's purposes. As although the AT300's (as would any non tilting trains) would be limited to 110mph, at least over the southern end, would it make difference?

So off the wires it will have the ETS and traction provided by solitary power car? Non starter. Not to mention the other issues with WCML non-tilt timekeeping, acceleration and all sorts of stuff that other in the know members might elaborate on.

Also, some form of TDM modification will need to be made to the power cars to allow both ends to talk to each other in both directions.

Is this a serious suggestion or another crackpot idea.

If you went back to separate trains for Birmingham Scotland services then you could use standard IC225's on these services with as many carriages as you want without to much problem I would think, obviously that would only allow a some 221's to be cascaded you would still need something for North Wales and Shrewsbury.

So the suggestion is a single HST power car hauling (or propelling) six coaches and a Class 91 loco.

So that's comparable with a single power car + 8 (given that the Class 91 = 84 ton), whereas in the real world HSTs seem to max out at 8 or 9 coaches shared between 2 PCs?

Eng274 said:

So off the wires it will have the ETS and traction provided by solitary power car? Non starter. Not to mention the other issues with WCML non-tilt timekeeping, acceleration and all sorts of stuff that other in the know members might elaborate on.

Also, some form of TDM modification will need to be made to the power cars to allow both ends to talk to each other in both directions.

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Send the work experience lad down the National Railway Museum to pull the plans for 43013 and the others.

It's a crackpot suggestion as you say, plus the Class 43 can't power the stock if it's Mark 4 stock being specified, there's no 415V conversion plans for the stock, though it really shouldn't be difficult modifying the LHCS to HST Mark 3 conversion plans, it's pretty much just a case of wiring round the motor alternator/static inverter units to connect the power car ETS directly to the ancillaries.
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swt_passenger said:

So the suggestion is a single HST power car hauling (or propelling) six coaches and a Class 91 loco.

So that's comparable with a single power car + 8 (given that the Class 91 = 84 ton), whereas in the real world HSTs seem to max out at 8 or 9 coaches shared between 2 PCs?

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They'll do around 90 to 100mph on level track with one power car out of service, providing limited ETS to the entire rake, but it's a long drawn out affair to get up to speed, and they really don't do steep hills in that sort of condition, hence extensive operating instructions for PCs operating on one engine featuring in the Sectional Appendixes.

I'm not that convinced it's that mad an idea, you wouldn't get 125mph service with a single HST, but then where would you need to use diesel traction ? Looking at the Network Rail overview plans, Crewe to Chester has a 80-105mph line speed, beyond that it's a mix of anything between 105mph and 40mph. Could a HST haul a 91 and 6 carriages at 80mph and get up to speed fast enough ?

Alternatively look at the costs of making Mk4 stock work between HST power cars verses making Mk3 stock compliant, and use them on the MML, and possible solution for XC HST's as well

Haydn1971 said:

Could a HST haul a 91 and 6 carriages at 80mph and get up to speed fast enough ?

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No. This was all looked at when Virgin CrossCountry thought about 1 HST power car and a Mark 3 driving van trailer instead of the 4 and 5 car Voyager units, acceleration in that configuration was going to be rubbish, adding another coach and a Class 91 locomotive, and you'll be looking at running them in 75mph paths.

I do agree that the big restriction would be the capability of a single class 43 to haul such a train - realistically one class 43 shouldn't be expected to haul any more than 4 or 5 coaches on its own. Replacing the 43 with a 68 however could be more feasible.

Philip Phlopp said:

No. This was all looked at when Virgin CrossCountry thought about 1 HST power car and a Mark 3 driving van trailer instead of the 4 and 5 car Voyager units, acceleration in that configuration was going to be rubbish, adding another coach and a Class 91 locomotive, and you'll be looking at running them in 75mph paths.

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Yeah I get that on the WCML this would be bad, but you wouldn't be using diesel power on the London-Crewe section, you'd be using it on the Crewe-North Wales section. A class 91 hauling/pushing a HST plus 6 carriages (effectively 8 carriage weight) would be better performing than the current ECML acceleration of a class 91 with effectively 10 carriages (9+DVT).

Or, just modify a pair of Class 442 motor coaches to run from the overhead, rewire them to work with MK4s, rewire the 43s to work with MK4s and the rewired and modified pair of former 442 MK3s and have one on each end...

Simple as that

Philip Phlopp said:

No. This was all looked at when Virgin CrossCountry thought about 1 HST power car and a Mark 3 driving van trailer instead of the 4 and 5 car Voyager units, acceleration in that configuration was going to be rubbish, adding another coach and a Class 91 locomotive, and you'll be looking at running them in 75mph paths.

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Did they ever actually look at that? As far as I understood they looked at the "Challenger" "class 255" sets which were 2+5, and all-new trains using a single-ended 67

jopsuk said:

Did they ever actually look at that? As far as I understood they looked at the "Challenger" "class 255" sets which were 2+5, and all-new trains using a single-ended 67

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They looked at various options for reusing their HST fleet, splitting HST sets in half and adding a DVT was one way of increasing frequency without needing new stock. It was mentioned in meetings and I think very quickly discounted as being unworkable.