"Offramp" wrote in message
...
On Wednesday, 27 September 2017 08:01:47 UTC+1, Basil Jet wrote:
https://www.youtube.com/watch?v=j6RWMaAtTOY

The tunnels have TWICE the cross section area of existing tube tunnels,
to allow a walkway!

Great idea! Walking along tracks is bloody awful. If there is an evac then
a walkway will speed things up enormously. Same with getting mechanics to
problem scenes.

and how many times a decade is there an evacuation?

and, assuming a theoretical equal chance [1] of that happening anywhere in
the network

how many times a century will an evacuation occur at this specific location?

tim

[1] which may not be correct but I have no way of determining otherwise