In a previous thread it was mentioned that one option considered for HS2's London terminus was for it to have through tracks to a depot somewhere outside central London. Trains would unload in the London terminus, then run ECS to the depot where they would be prepared for their northbound journey.
This would have the advantage of significantly reducing the footprint of the central London terminus, at the cost of a few (tens of) miles of extra track.
It does seem like quite a good idea, are there examples of this setup in practice elsewhere in the world?
I suspect I might have started this...
Sounds like Berlin is the only real example, all the others seem to be turn-back sidings or similar... but I was thinking that (like Berlin) we wouldn't just have one terminal station in a conurbation, but maybe 3 successive through ones with good connections (like HS2 to Crossrail and 1 or 2 others...) after which the train would continue out to a useful outer suburban station (Gatwick?) before running on to either a depot or out to e.g. Brighton.
On HS2, it wouldn't really reduce the footprint that much. You'd probably still be looking at a dwell time of at least 5 minutes in each direction to kick passengers off/do a security sweep, and with plenty of time to load potentially a very large number of passengers. To enable trains to arrive at 3 minute head ways, this would mean a minimum of 6 platforms - 3 per direction.
Then you'd have to find a tricky new alignment for quite a few miles out to the other side of London, and then a very large brown/green field site to form sidings and a depot. Environmentally impacts on far more people, increases operational cost substantially (greater ECS mileage and staff platform costs), and doesn't actually reduce total land take at all (just shifts some of it somewhere else).
Why a security sweep for a Manchester to Gatwick or Brighton train?
Why assume everyone has to get off at the same central station if there are useful connections to be made at 2 or 3 stops?
and why not have a 6-platform low level station - mind you that is probably only needed if you have the "London (Euston) ONLY" mindset? If the low( or deep) level station was engineered right
why a tricky new alignment?
and if trains run right through, why
any ECS mileage? And why waste platform dwell time while a driver changes ends or his relief does?
Less environmental impacts all round as far as I can see, and what additional land take? A depot or expansion of one has to go somewhere!
It will be less wasteful of capacity (i.e. save paths) if you don't run ECS out of central London. As the depot has to be somewhere, why not boost employment at the outer end of suburban lines where it is cheaper to do everything than resourcing things in city centres?
Thameslink and Crossrail (and Crossrail 2) are telling you something! I can't find it now, but I am sure I remember "pendulum" services replacing terminating trains in a European city...
