On Mon, 24 Nov 2008 20:32:20 -0000, wrote:

"Mr Thant" wrote in message
...

Replacing the fourth rail isn't going to be cheap. You also have stuff
like installing one-person-operation equipment (Bakerloo trains have
lost their guards since the line closed. London Overground hasn't) and
communication systems and so on.

As for
extra stock - where did it all go when the line was cut back to
wealdstone?

It still had 1959 and 1938 stock back then, so the answer is either
for scrap or the Isle of Wight.

Is a fourth rail really necessary out that way, however?

It is if you want the same train to work both there and on the
Underground.

I always understood
that they were really needed only for the tub sections of the tube, to help
power flow into the motors.

No the LU 4-rail power supply is intended to keep the traction current
within the two conductor rails and not find its way back via other
bits of metal with consequent damage.

I heard this on the Island Line, where 38 stock operates only with a 3rd rail.

No tube tunnels or aforementioned metalwork to worry about.

Also, what sort of equipment would you need to ensure safe one-man
operation? Are the stop arms still working?