The secret Anchor telephone exchange is situated 100ft. below Telephone house and Newhall Street in Birmingham City centre. It was built to withstand nuclear attack and provide vital a communication link in the event of nuclear war. The name Anchor comes from it being situated partially underneath the assay office in Birmingham and the hallmark applied to gold there is that of an anchor.
It was opened on 9th November 1957 (having cost £4 million to build) and was outdated as soon as construction had been completed as it had been designed to withstand a Hiroshima sized nuclear attack. The development of the hydrogen bomb made this inadequate. The main entrance to Anchor is a lift at the back of Telephone house. Next to the lift shaft there is emergency access by ladder in case of power cut. There is also staircase access across the road in Newhall Street. At the bottom of he lift there is a huge door (weighing several tonnes) that can be used to seal the area. Inside it looks very similar to tunnels in the London underground. The tunnels are constructed of blast proof concrete. There are rooms packed with old distribution frames and repeater stations. There were 1000 copper cable pairs going out to repeater stations around the city (Selly Oak, Lyndon Green and Queslett) and 8000 speech circuits linking Anchor to Telephone house above. There is another staircase down into the cable tunnel level of Anchor where the dark tunnels go off into the distance. The tunnels run as far as Essex street exchange (going under Birmingham New Street), and there were plans to extend to the Jewellery quarter.
Power was supplied by a private sub-station, and the three generators were kept as a back-up. Anchor was the first exchange to get fluorescent lighting and air conditioning to keep the equipment at a safe working temperature. All the water for the complex (including the cooling system) was provided by a 300ft well. The water table was initially far below Anchor, but now it has risen, and it is being constantly pumped from the exchange.
The exchange was unclassified in 1967 when the press were allowed down for the first time.
It is now derelict with access restricted due to safety. The rooms are full of antiquated telephone equipment, and junk packed up into ration boxes which would have initially been used to hold food able to sustain someone for many days. There are storerooms which contain spare parts for all the equipment, and the vast water tanks are unused. The roof and walls are damp, dripping in places, and it is very cold. It is now silent where once there might have been 100 engineers working at one time in its construction, and then after many technicians and operators would have worked within Anchor’s walls.
It was only ever put on standby once during the Cuba crisis of 1962 when only selected men were allowed down.
British Telecom does not invite people down into Anchor and as I have said nobody goes down there now anyway. However if you look behind telephone House you might be able to see a huge air vent leading down into the ground which is probably the only outward sign of its existence.