Regarding the HST's replacing some SWT Class 159s, I think this is highly unlikely, as the stop start nature of the route, requires something with rapid acceleration and the sprinters will do the job a damn sight quicker than the HST's.
There was a proposal in the mid eighties to replace the loco hauled trains on the Basingstoke, Exeter route with shorter, slightly less powerful HST's, but that came to nothing. I think the Class 180s would be most suited for that sort of work. Really I think the future of the HST once replaced by the IEP will be scrap.
That doesn't mean they wont be around for much longer, they will still be a regular on the West of England services for quite some time yet.
The HST is designed to do one thing and thing only, express trains, they are unsuited for any other sort of passenger work.
Its a bit like using a drill when only a screwdriver is required.
There was a proposal in the mid eighties to replace the loco hauled trains on the Basingstoke, Exeter route with shorter, slightly less powerful HST's, but that came to nothing. I think the Class 180s would be most suited for that sort of work. Really I think the future of the HST once replaced by the IEP will be scrap.
That doesn't mean they wont be around for much longer, they will still be a regular on the West of England services for quite some time yet.
The HST is designed to do one thing and thing only, express trains, they are unsuited for any other sort of passenger work.
Its a bit like using a drill when only a screwdriver is required.