wrote in message
...

AFAIK there are no plans for a new type of signalling on the sub surface
lines
so they could easily have fixed what was there first then bought new
trains.

That's a completely wrong assumption though:

http://www.tfl.gov.uk/corporate/medi...ive/20253.aspx

"Bombardier will install the CITYFLO 650 ATC system, a state-of-the-art
communication-based train control technology..."

So the new stock IS being brought in immediately prior to a full
resignalling of the SSR.

Paul S