Something I thought about recently, is if the new fleet has battery power options, this could finally allow the long-defunct carriage siding at Dartford to come back into use. The siding (no.2?) is 16 carriages long, but because no safe walkway could be provided to it (it was surrounded by third rail), it had to be de-electrified and locked out of use. But if battery units come to the network, presumably the siding could be accessed again without any third rail surrounding it. I suspect there are a number of other stabling points that this could be done too as well.