Boltar wrote:
"Richard J." wrote in message
...

Unprotected 3rd rail would not be allowed today on an entirely new
railway, but that has nothing to do with mixing tube and mainline,
both of which use the same technology at Richmond, except that LU
is 4-rail rather than 3-rail.

I never said that it did. Its to do with what happens to the
different types of trains if they collide with each other. Tube
trains usually come off worse because the buffer beam of the
mainline train hits the tube train on its body rather than its
buffers.

"Usually"? Which crashes between tube stock and mainline trains did you
have in mind for this statistical comment?
--
Richard J.
(to e-mail me, swap uk and yon in address)