OPO's on platforms.

The Victoria Line was built with OPO from the outset. I was of course still at school when the Victoria line opened and LT was my second job after leaving school so it was 10 years before I saw what was involved in the original system. the first site I worked at was Warren Street in 1977 where as part of the signal department I was a wireman installing PA loudspeakers on the Northern Line platforms but it gave me the opportunity to get to grips with the operations room sited above the concourse at the bottom of the escalators, you can't miss the mirrored windows!

Basically the Vic Line system used a Redifusion 8x5 CCTV switching matrix, i.e. a maximum of eight cameras could be connected to a maximum of 5 monitors. Generally speaking two cameras were fitted to each platform i.e. one at each headwall and tailwall and a maximum of a further four would be fitted to cover the ticket hall and lower concourse. A monitor was provided per platform for the driver, where reversing moves were possible I believe an additional monitor was parallelled at the back end of the platform. The 'station agent' i.e. station supervisor had two monitors in the ops room and usually this was duplicated in the passimeter with a switching arrangement allowing control from either point.
OMO was also before my time but I saw the yellow signal heads with diamond backboards and yellow platform mounted emergency plungers before we went round removing them all. However, one legacy of the OMO programme was indeed the installation of OMO monitors worked off track circuits and these were certainly in situ and working on sub surface lines in some places in the 1970s. A case in point was indeed Whitechapel where I was based in 1977, there were two OPO monitors on the west end of the eastbound which showed trains in the platform whenever the track was dropped whether there was a train occupying the track or not. This of course was due to 'burn in' which was a real problem for those early monitors which worked on 240v ac and only ever saw a picture of the same image most of the time so that image became remanent.

The original OMO installations were followed by OPO installations all of which were installed and maintained by LU staff at that time as I recall. Thinking about it I was involved with the original stage 1 Line Controller's CCTV installations at Baker St, Waterloo, Piccadilly Circus, Tottenham Court Road, Oxford Circus and one other site. I was installing Baker Street throughout 1980 and as part of the job I installed three OPO cameras to replace the earlier OMO installation such that the station supervisor would also be able to view the OPO images which until then appeared only on dedicated platform monitors.

In 1982 I went into the training division for four years and when I returned 'to the tools' OPO was in on the subsurface lines and circa 1987 was outsourced for installation and maintenance so I had little to do with it although I caught the tail end of some of the ongoing work at Waterloo Northern line where OPO monitors had to be installed at both ends of the platform as OPO was imminent but guards were still on the trains.

In real terms OPO must by now be fifth generation equipment at least at most sites and fully integrated to the Station and Line Control/BTP long line CCTV system.