I didn't say that, what I said was the fleet like any other fleet has a maintenance schedule which means that any given unit will have to go to the depot.
Yes, but the number of trains required to visit the depot for exams or significant mechanical maintenance each day is much smaller than the number of trains in the relevant fleet.
Train Presentation can be done at terminus stations but that is only light cleaning such as bins, wiping DOO cameras free of dirt etc, deep cleaning such as the floors, washing out of the bins etc can only be done on depots.
And these tasks also only have to be performed relatively infrequently, and the bins could even be taken out of use since I am not aware of any LU stock having bins at the current itme, and the Crossrail core is functionally a tubeline if the ends have been lopped off.
Ever seen a train covered in graffiti? The only place that graffiti removing can take place is on depot simply because they have the equipment to deal with this anti social behaviour.
Yes, especially in Paris!
But I can't help but imagine the Crossrail core would be a relatively secure location to stable a fleet, given that most would likely spend there nights in underground station platforms or similar other facilities.
Also most of the places that grafitti can be applied to a train does not actually impair it's ability to function does it?
AIUI grafitti on places like windscreens is relatively rare, and grafitti applied to the sides of a train is almost always purely cosmetic in nature.
Being dusty has nothing to do with it, trains are booked to use a wash plant either on depot or at specific outstabling locations eg carriage sidings etc.
Yes, but how regularly does a train have to visit a full carriage washer facility in order to remain in service?
Passengers who would otherwise be crushed on overloaded tube lines are likely to be rather forgiving of a less than stellar appearance from their rolling stock.
And? They aren't going to stay spotless just because of that, ever heard of something called brake dust?
Do they need to stay spotless?
The only part of the train that has to be clean is the cab windows and the headlamps, anything else is an irrelevance.
For rescue yes but the idea of using them to drag a number of units around is not what they were meant for.
There's always translator vehicles etc...
The important part is they have some means to couple to something.
Translator vehicles can be provided if necessary.
The passenger capacity of an even partially operational Crossrail core is so enormous that it is a good idea to do almost anything to gain even a marginal capability.