Holborn ATE Home of BT Archives |
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Director Exchanges | Belgravia | Holborn | Whitehall |
BT Archives | |
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Holborn History Automatic Exchanges The first automatic exchange in London, the Holborn Tandem opened at 10.00 a.m. on Thursday 18th August 1927. The first Director exchange opened on 12th November 1927. The Speaking Clock The service was introduced on 24th July 1936 with a pair of clocks in Holborn Tandem exchange. For this early version of the speaking clock, Jane Cain's voice was recorded photographically onto four glass discs which rotated and were scanned by a beam of light. The output from the photo-electric cells were combined to produce a complete announcement to feed into the network. By 1963, a new machine was developed to give a better quality recording. A polymer of neoprene, loaded with iron oxide and stretched onto a drum produced a resilient track on which the new 'Golden Voice' of Pat Simmons was recorded. This later equipment was installed at Trunk Control North, Kings Cross, London. Toll B (Manual) Exchange Switching incoming calls from the Toll Area to the Director Area. Semi-Mechanical Tandem Which used 7-digit keysenders over order-wire circuits also to give access from the Toll Area to the Director Area. Temporary Toll B Non-Director (opened 1946) This replaced Toll B (manual). Trunk Switching Relief: Maxwell Non-Director I/C in Holborn In the Sixties, Toll B ND was equipped with incoming Register-Translators and became Maxwell ND I/C capable of switching traffic from adjacent charge groups into the Director Area. BT Archives From July 1997, Holborn became the new home of the BT Archives, a fitting place to safeguard the history of telecommunications. |
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