15-02-2009, 11:12 PM
PJW Wrote:computers (not sure quite what from memory perhaps PDP11s, certainly "filing cabinet" type), these drove outputs ...
...
... controlling compressed air that then physically operated the frame (and I think the locking was still purely mechanical).
Exactly how it is still done on most lines - even with 1967 Victoria Line type ATO the interlockings were and still are mechanical (as mentioned in Wednesday evenings paper).
AIUI the last V-frame was commissioned as late as 1999 (Waterloo).
[quote]
Re the IRSE papers; don't forget that, thanks to the Australians, you can purchase for an extremely reasonable sum (I think