Excellent evening with update from Andrew A.
For member - slide set
hereThe mention of
GWR▸ /Chiltern - might this be the battery train?
It might be a multi-mode train
GWR could just about get away with battery
EMU▸ ▸ , but realistically anything over about 60 miles (or 30miles out and 30 back) off an electrified line, especially in cold winter or very hot summer day is pushing it. Battery technology is improving so maybe this will go up a bit to nearer 80 miles.
If looking at regional train (say 5-6 cars, capable of 100-110mph on electric, maybe 90-100mph on diesel or battery, with seats and comfort suitable for 3+ hour journeys) then as GWR operate to Portsmouth, Weymouth, Gatwick really needs to be dual voltage.
But a quick look at a map, will show that routes like Cardiff-Exeter, Exeter-Basingstoke, Bristol-Great Malvern/Worcester etc are too far for the battery. So either got to add few miles of electrification where charging can happen, or fit train with diesel generator set too.
Chiltern probably need ability to work off Metropolitan line 4th rail. I think this is now 500v outer rail, -250v centre rail, but at least it is effectively 750v not the old 600v (400 and -200)
To be honest, if
GBR▸ ▸ (or its shadow version) had ordered 70-100 of these, a cascade would probably solve 90% of train shortages or types coming up for renewal.
So yes,
SWR» » doesn't really need anything different to GWR regional fleet, or even others like Cross Country Cardiff-Nottingham. Can see why it is one type desperately needed (have built high speed bimodes, lots of commuter electric units in last 10 years, but no regional units for 34+ years). Nothing really that can work on part electrified routes that's mid to long distance, but not full intercity high speed
