(13 Jan 2016, 8:44 pm)GX03 SVC wrote Both spare E400s are spares and don't have set allocations. Only 4659 is the spare vehicle that has a set allocation.
4 vehicles are required for the X20.
7412-5 can't be spares as they are not permitted to do the X18 due to the height of the vehicle.
Are 7412-5 taller than 7511-3 like?
Can't think of any low bridges on the X18 route? (418 yes, but not X18, that I can think of anyway)