...rings the world
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Wood Street, a brand new ITSC (International Telephone Services Centre), built next to Wood Street Telephone Exchange, opened in 1972 and was fitted with TXK2 equipment, the ATE 5005T manufactured by Plessey. It was described as a 'modern 4-wire gateway international exchange.' |
The Wood Street exchange building was constructed to house 3 x 10,000 line local Director units. The first two units Metropolitan, and National opened during 1929.
In World War II the building was bombed and burnt out on 29th December 1940. Temporary arrangements allowed lines to be diverted until rebuilding was possibly, shortly after the war.
One of the first (manual) international exchanges opened in the Monarch ATE building as early as 1947. Monarch TE included Continental and Assistance manual boards.
During the Sixties, the growing number of calls led Wood Street to be developed as a major ITSC (International Telecommunications Switching Centre) with the installation of 'state of the art' switching equipment in the early Seventies. However, by the late Eighties, switching technology had greatly improved and thus the building was sold off and demolished during the early Nineties as land prices in London were at a premium and call centres were located away from the capital city.
Director Units
Noticeably, London exchanges handled growth by controlling the balance between physical and hypothetical exchanges and number ranges. New exchanges were opened once the capacity of a building was exhausted, unless capacity existed for a hypothetical range in a nearby exchange.
The first multi-unit automatic exchanges Metropolitan, and National opened in the original Wood Street building in 1929. The name, Empire was never used but instead, the third unit was to be London Wall. Metropolitan Director was BIS 31 August 1929, followed by National Director on 7 September 1929. The third unit’s name of Empire wasn’t used but London Wall Director was finally BIS in 1936.
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Wood Street simplified BIS Dates: |
The Relief Unit
The Strowger installation in Faraday had previously switched all the traffic to and from the UK, but was unable to keep pace with the ever increasing demand for international calls. There was little room in Faraday to expand either the manual boards or the automatic equipment. The new Wood Street building was to allow decentralisation of manual switching while catering for further growth in directly dialled calls. The building was ready by June 1970, but the switching equipment was delayed. Peter Walker, recounts..
"Wood Street relief unit was the next exchange. This was a small 5005T crossbar unit imported from previous use in Sydney, Australia. It was modified to work on London IDD traffic until Wood Street proper was ready. It was installed in a new building alongside the Wood Street local exchange. It had a capacity of around 2000e."
The relief units were installed on the 5th floor on 20th June 1970.
The ISC
Wood Street proper, opened in April 1971. The building was of reinforced concrete construction with pillars at 25ft centres. No beams were used, the necessary strength was provided by heavy reinforcement of the floor slabs- a technique which provided a clear ceiling and allowed easier provision of air conditioning and overhead cabling.
The layout was:
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Sub-basement Car park |
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Special Features
Far removed from the 21st century, CCTV 'Big Brother' series, small rack mounted cameras kept a watchful eye on the equipment in Wood Street. Continuous scanning of the images from the 6 CPIs (Call Progress Indicators) were distributed to the 15 test consoles, so that the human technicians could monitor the equipment... Call Progress Indicators (CPIs) To monitor the progress of calls through the exchange equipment, circuits could be connected via the test access system to one of six CPIs which displayed the input/output signals via filament lamps held in multi-digit indicators. Each CPI contained up to 500 lamps.
The 6 CPIs were for the following types of signals:
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Peter Walker explains...
"The display panels were quite large (pixie tubes, I seem to remember), so a camera was put in front of them and the picture relayed to a small VDU on the test desk. You can see this screen on the picture of the Mondial ISC test desk, top right of the left hand panel."
The End
Relocation of telephone exchanges to meet the changing needs of the business is not a new idea. In the Eighties, the crossbar switches were mechanically wearing out, rates in London were high, and the advent of digital technology allowed manual boards to be remote from the switches that they controlled. Peter Walker recalls... "I was involved in the Wood Street sale project. It raised £54M so was too good to pass over." Sources state that Wood Street was due to close by 1990.
The International Control Centres (ICCs)
MONARCH ATE (1947)
An overseas (International) exchange opened in the Monarch ATE building on 24th November 1947. This was to provide relief for the growing number of radio circuits. The switchboards operated via the Radio Telephony Terminal (RTT) with equipments being housed in Faraday Building (Blackfriars) and Brent Building (Hendon).
The boards were 4 feet 81/2 inches high, sleeve control type with 105 positions:
84 main operating positions, 21 enquiry, record and obs. positions
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"When we moved into the top floor of Wood Street from Faraday in 1947 it was the only building still standing amongst all the bomb damage. " |
"When we moved into Wood Street from Faraday in 1947 it was the only building still standing amongst all the bomb damage. The Overseas Exchange was all very new and all communication was by radio. We shared the building and facilities with Monarch Exchange and we certainly did not have the luxury of a bar in the canteen. "
[See later comments about the bar in Wood Street.]
"I remember the divisional Supervisor sitting in the middle "listening in"; we used to make excuses to walk behind her to see who it was, but she always had a piece of paper over the jack so we couldn't see. The whole of International as we then became, moved to Wren House in the early 60s and I spent many happy years with them till I left to get married in 1967."
Although the International section moved out, Wood Street carried on...
Wood Street 1 [LWICC I]
ICC (1962)
By 1962, the 117 positions of the International exchange (in the Monarch Building - see above) were reduced to just 96 to be converted for continental working.
Thus on 25th August 1962, The London Continental Control Centre opened in Wood Street with an initial 55 positions. Wood Street handled all overflow calls from Faraday for countries using English as the main operating language. [Subscribers in London dialled 105.] Traffic to countries requiring linguist (mainly French speaking) operators was retained at Faraday.
Into the Eighties
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"In the early 1980s an international phone call sounded quite different from today. Even if the subs making the call weren't paying, calling overseas was still quite an event for a lot of people, so on hearing: 'This is the United Kingdom calling. Will you accept...' we would hear squeals of delight...!". |
ICC (1972)
In 1972 another ICC opened in the new extension which formed part of the ITSC. Wood Street 2 was equipped with 114 positions. It used crossbar switches for the bypass switching and a peculiar form of multi-level DC signalling (confusingly called DCC) into the ISC.
The remaining ICC in the old building was officially renamed Wood Street 1, but generally continued to be known simply as Wood Street. Wood 2 (later to become Wood SPC) was on the 5th floor of the new wing (closest in the photograph) and overlooked London Wall.
The new canteen also overlooked London Wall. A telephonist writes, “I Remember being in the canteen and watching Pan’s People dancing to ‘Bridge over Troubled Waters’ on the footbridge. It was being recorded for Top of the Pops.”
Official notice in the PO Gazette: At 18:00 BST on 3 June, 1972, the second International Control Centre at Wood Street, London, was brought into service. The new control centre will be known as London Wood Street International Control Centre II, abbreviated as LWICC II, and will connect calls to Europe, Australia, Canada, South Africa and the USA from some exchanges in the LTR and SETR. The existing control centre will now be known as London Wood Street International Control Centre I abbreviated as LWICC I.
Wood Street AXE/OPS (circa 1985)
Over the years, the technology in Wood Street had become outdated. The TXK2 switch had worn out, and the other international analogue switches in Mondial House were due to be phased out. Digital international switches were to be deployed in Keybridge, and Kelvin House, so while Wood Street remained open, it was worthwhile to align its ICC to the new exchanges.
Wood Street AXE/OPS (likely named after the AXE Ericsson kit) was a screen-based computer system, replacing the cord-boards. The processor was in Keybridge House which then also worked the upgraded ICCs at Brighton, and in Mondial House. Some operators who trained on this system then went to the new ICC in Judd Street shortly before the Wood Street building closed.
INSIST
"Once the sleeve control units had gone, we never got as much fun. What we did have was Caller Line Indicator (CLI) which meant if the chargeable number did not match the one the caller gave we could always recall. We also thought we'd lost the ISOCC tickets until a Senior Operator (SO) or Operator Services Supervisor (OSS) had to do the rejects from the INSIST list onto ISOCC tickets."
"INSIST appeared in the form of a huge printout of call details that didn’t compute. In the AXE-OPS SPCs, if anyone did a COD99 or a DUR input, it appeared in the INSIST days later. If we input the B-No (distant end number) in such a way that it didn’t read correctly it also appeared in INSIST. Needless to say, INSIST got nicknamed INCEST, though the person who ended up re-entering the details on ISOCC tickets, occasionally myself, did not look forward to doing that job. Some had 0 (zero) values on both A-No and B-No sides, so heaven knows where those calls came from nor went to."
Relocation
In April 1988, Telecom Today reported :
"A new international operator centre is to open in Grimsby, Humberside. It will take over the work of London's Wood Street centre, which is due to close in 1990. Staff currently working at Wood Street will be offered relocation to Grimsby on compulsory transfer terms."
References
Metropolitan and National Exchanges, Post Office Electrical Engineers Journal October 1929.
'Wood Street Rings The World' by E T C Harris from Post Office Telecommunications Journal Autumn 1972.
The Wood Street (London) ITSC by G J Beckett.
Thanks to memories from Wood Street operators and engineers.
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