"Roy Badami" wrote in message

On 22/09/10 11:55, Recliner wrote:

I don't think it was ever more than a plan. And I think originally it
was only going to work in stations, not the tunnels between them.

I'm almost certain there were at least plans to have it work in the
tunnels, because I remember the discussion of leaky feeders at the
time.
Basically, you run a piece of coax along the tunnel (that's the
feeder), and at intervals the shielding is removed from a short
length of coax, which causes the feeder to leak RF (i.e. act as an
antenna).

Yes, I know, but I think their initial plans were less ambitious. I
don't know if the close fit between metal bodied tube trains and the
mainly metal tunnels would cause any problems with reception.