In article , Nigel Pendse
writes
I had assumed that it was a double tunnel from T123 to T5, with two
platforms at T5.

That's my understanding, though possible with three platforms.

The T4 loop would connect with the eastbound (northern) tunnel just
before the T123 station. To do this, the rebuilt loop will presumably
have to dive under the west-bound (and maybe both) tunnel, whereas the
current version is on the level -- hence the long closure.

Why rebuild the loop? Why not just have the new westbound tunnel dive
under the loop, thus not requiring any rebuilding?

I don't understand the need for the long closure.

--
Clive D.W. Feather | Home:
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