"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. Not sure what the rules are for full
size tube trains such as A,C and D stock sharing mainline track however.
Anyone know?

B2003

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)

"Richard J." wrote in message
...
"Usually"? Which crashes between tube stock and mainline trains did
you have in mind for this statistical comment?

There was a collision in 1962 between a 38ts and a 501 at Watford High
Street, and another in 1986 between a 59ts and a 313 near Kensal Green. In
both cases the colliding Tube car was totally destroyed.

"Richard J." wrote in message ...
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?

Figure of speech ok? Listen pal , I'm just trying to have an interesting
discussion here. If you want to have a flame war go find some other patsy.

B2003

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

Figure of speech ok? Listen pal , I'm just trying to have an
interesting discussion here. If you want to have a flame war go
find some other patsy.

All I'm trying to do is to understand your reasoning. You say that the
HSE wouldn't allow a new situation where tube and mainline trains share
the same track, and cite the vulnerability of tube trains in a crash.
But that's not the logic that was followed after the Ladbroke Grove
crash where the leading car of the 165 was destroyed by impact with the
HST power car. The solution was not to segregate DMUs and HSTs but to
improve safety systems to reduce the risk of a collision. It seems to
me that the same principle would apply to any future tube/mainline track
sharing.
--
Richard J.
(to e-mail me, swap uk and yon in address)

"Richard J." wrote in message ...
All I'm trying to do is to understand your reasoning. You say that the
HSE wouldn't allow a new situation where tube and mainline trains share
the same track, and cite the vulnerability of tube trains in a crash.
But that's not the logic that was followed after the Ladbroke Grove
crash where the leading car of the 165 was destroyed by impact with the
HST power car. The solution was not to segregate DMUs and HSTs but to
improve safety systems to reduce the risk of a collision. It seems to
me that the same principle would apply to any future tube/mainline track
sharing.

Well I would agree with you , but whoever said the HSE were logical?
As far as
I'm concerned they're nothing more than a bunch of bed wetters who'd
like
nothing better than to cover everyone in cotton wool and lock us away
in a padded room for our own safety.

All I know from reading things in print and online is that the HSE
wouldn't
allow any new situations where sharing of track between tube size and
mainline
size trains occurs but they do allow the current status quo to
continue. IIRC
they even have a beef about the met and piccadilly trains sharing
tracks.

B2003