In message , Clive
writes

In my case (on the Picc.) my line knowledge is such that I know where
to shut off and coast and start braking. Just comes with time.

I am a former Northern Line and Central line driver, and whilst I knew
where to shut off to coast, the diamonds were for economy. Have these
now gone?

Some of them are still there but are difficult to spot in the dirt and
dust generally, they don't seem to get cleaned.

There are also instances where signalling has been changed and the
diamonds have been left there. The approach to Cockfosters comes to
mind - after the Moorgate disaster there was a lot of protection put in
place so that you now have to approach the inner home at just under
18mph for it to drop. If you were to motor up to the diamond there, you
would have no chance!
--
Steve Fitzgerald has now left the building.
You will find him in London's Docklands, E16, UK
(please use the reply to address for email)