On Sep 28, 10:31*pm, 1506 wrote:

This is good news and the correct way to go. *Tried and true train
technology should be utilized on new routes. *New technology should be
used in upgrades to existing routes. *Risk should always be minimized.

I'm struggling with your logic there.

New routes are best for new ideas.

The WHOLE problem behind the Jubilee line resignalling is putting in
something new onto something old - Seltrac S40 only ever been
installed on new built lines.

New on old means you have all the problems with interfacing new trains
new systems new anything with old kit which increases risk,
hyperbolically where multiplke systems are in use. New on new you
don't have to do that as much and that reduces risk.

--
Nick