"Peter Corser" wrote in message
...

The original Liverpool St box (Bishopsgate Junction) was superseded by a
new cabin with a power frame in 1954. The power frame (type unknown, but
pobably an N or N2) was converted to air working (similar, but not
identical to later interlocking machines) remote controlled form
Farringdon (quite common LUL practice) in 1956 and the cabin became an
interlocking machine room.

There was also an IMR at Barbican. Farringdon Box had two push button
control desks - one for Farringdon and Barbican, one for Moorgate ( inc
CWL) and Liverpool Street. The old electromechanical signal cabin at
Farrindon was stripped out in late 1956 and converted to this push button
arrangement. Barbican was a "true" IMR with a V type interlocking machine.
Algate had its own box.

The CWL control was transferred to temporary cabin for eventual control by
BR in 1965 and various layout simplifications occurred during 60s & 70s.
The logic usewd was that decommissioning the bay and associated pointwork
and then classing the remaining east to west crossover as am emergency
crossover (not normally used for timetabled passenger routes. The
remaining siding and connection between the Circle & CWL were abolished
and Farringdon became an automatic site.

This allowed the number of controlled routes at Farringdon to be reduced
below the number required for higher grading of the signallers!

Barbican was abolished on 20th October 1979, Liverpool Street IMR remained
open. The LS bay was taken oos with this changeover, but I have no
details of when the building work started. I was one of the DO team who
did the design work for the signalling changes, but had always (as a
railway enthusiast) expected that it would be recommissioned one day and
was most surprised to find one one of my later forays through the station
that the bay was being used for building works!

Politics and Senior Operating staff moved on and Farringdon was given
control of the new Aldgate IMR on 25th Jan 1988. Transfer to Baker Street
SCC was 25th March 2001

As others have stated the building works now mean that it is impossible to
reinstate the bay to accomadate any useful train length and it would,
obviously, be uneconomic to even envisage the works required to make it
usable!

Peter
PS Details of all LUL signal cabins can be found at
www.metadyne.co.uk/LTSB.pdf (a very useful site all round! - not my site)
--
Peter & Elizabeth Corser
Leighton Buzzard, UK

Very interesting, indeed, but I was just asking about the Bishopsgate box
itself. Are they going to keep it at its current place or will they
eventually remove it? Does it have any particular use at the moment?