Anchor telephone exchange
It originally formed one of a network of 18 Zone Switching Centres within the United Kingdom (UK) that provided trunk switching facilities within its own charge group and to Group Switching Centres (GSC) within an area broadly comprising the West Midlands and central Wales. The exchange formed part of the trunk mechanisation plan commenced in 1939 to permit operators from originating GSCs to dial through to a distant U.K. subscriber without requiring further operator intervention. Later, it was additionally used to switch subscriber dialled trunk calls after its introduction at Bristol in 1958.
It was subsequently augmented and superseded by a Transit Switching Centre (TSC) equipped with a crossbar switching system (TXK4) which formed part of the Transit Network. It parented two of the first three GSCs at Worcester and Wolverhampton  to go-live when the transit network was inaugurated in 1971 which eventually provided universal U.K. automatic subscriber dialling and was completed in 1979.
It was built together with the Guardian Exchange in Manchester and the Kingsway Exchange in London to provide hardened communications in the event of nuclear war. In common with most civil defence structures of the time it was designed to withstand an attack by atomic bombs short of a direct hit.
- Birmingham Anchor Exchange Opened - Ness, A. 1958 The Post Office Telephone Network. Student Quarterly Journal. pp 217-219.
- Ballard, Sebastian (2003-03-19). "Birmingham Anchor Telephone Exchange". Subterranea Britannica. Retrieved 2008-12-02.
- "Trunk Mechanisation Commenced in U.K. Network (1939)". Retrieved 8 September 2012.
- "Transit Network Opened (1971)". Retrieved 8 September 2012.
- "Full UK Subscriber Dialling Completed (1979)". Retrieved 8 September 2012.
- "Birminghams Nuclear Bunker (1998)". Retrieved 9 September 2012.
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