What will replace trains like this?

HST at Redruth
Originally uploaded by seadipper.

This is Britain's Inter-City 125 High Speed Diesel Train. It was introduced as a stop-gap design in the mid-1970s. The type is still in front line service on Britain's non-electrified main lines, and the fleet is just being refurbished and fitted with new engines to keep it going for another fifteen years.

Nobody can work out what to replace them with.