"Paul Scott" wrote in message
...

Various explanations I think. Leaving St Pancras, I don't think it becomes
normal 2 track railway until very close to the tunnel entrance, there are
various cross overs, flyunders etc to sort out the routes to the Eurostar
and Kent domestic platforms without conflicts. Through the Stratford
station 'box', the through track is the centre 1 of 3, with platform loops
either side. Between the east London tunnel portal and the Thames tunnel,
can't say. Perhaps it was wrong line working, or the videoed in up
direction and video played backwards...

Paul

Its full BiDi.

At lest the tunnel between St.P and Stratford is anyway - that's the only
section I had anything much to do with. We still have the usual up and down,
but they can be used either way round. We would quite often be 'wrong
roaded' during testing so work could continue in the tunnel sections whilst
still running trains on the other side. My understanding it it will use the
traditional up/down now its open, and only wrong road in the event of a
problem, or other 'special' move.