This new class though will have to be 3rd rail, overhead and battery, capable though, but the genius of it will be that it can be introduced across the entire network, a common design that with just internal fit that might differ, such as some having no first class, or is it even possible to have a one size fits all design, that again, cuts design costs,
Much of the tech already exists, we have dual voltage units in the 377/8 family, could this form the basis of the design, adapted to have batteries included, It actually might have other possibilities, such as when diversions are in place over non powered lines, a battery unit, can still power its train, and mobile recharging plants be introduced, that can be deployed at non electrified termini, in the case of diversions, so that units could recharge whist laying over,