Kingsway Telephone Exchange
September 2013
Approximately one hundred feet (30 metres) below Holborn is one of London’s best kept historical secrets. The Kingsway Exchange, so named for the purposes of misdirection, was originally built as a deep level bomb shelter for up to 8,000 people in 1942, although never actually used as such. Upon completion the tunnels were requisitioned by MI5 and MI6 and other agencies for wartime covert operations. After the war the General Post Office took over the site and extended the complex for use as a trunk telephone exchange (an exchange that connects smaller exchanges) that would be secure in the event of a nuclear war. Dug using shovels in what must have been back-breaking work, the facility was so secret that the soil was spirited out of London for disposal so as not to arouse suspicions. Kingsway continued to be a state secret as important government and defence communications were connected through it. These included the lines to Number 10, the Cabinet Office and the Cold War hotline between the White House and the Kremlin.
Approximately one hundred feet (30 metres) below Holborn is one of London’s best kept historical secrets. The Kingsway Exchange, so named for the purposes of misdirection, was originally built as a deep level bomb shelter for up to 8,000 people in 1942, although never actually used as such. Upon completion the tunnels were requisitioned by MI5 and MI6 and other agencies for wartime covert operations. After the war the General Post Office took over the site and extended the complex for use as a trunk telephone exchange (an exchange that connects smaller exchanges) that would be secure in the event of a nuclear war. Dug using shovels in what must have been back-breaking work, the facility was so secret that the soil was spirited out of London for disposal so as not to arouse suspicions. Kingsway continued to be a state secret as important government and defence communications were connected through it. These included the lines to Number 10, the Cabinet Office and the Cold War hotline between the White House and the Kremlin.
The British public only became aware of the complex in the 1960s when it was removed from the secret list. British Pathé made a film in 1968 showing the exchange in operation, but without revealing its location. At its height, the exchange could deal with 6,000 calls simultaneously and handled up to two million calls a week, around 15% of London’s trunk (long distance) telephone traffic. Following the introduction of Subscriber Trunk Dialling from 1959 (where the caller could make a long distance call without the help of an operator) the exchange became less important and was closed in 1980. In the 1980s the government used part of the structure as a back up for its PINDAR nuclear bunker located beneath the Ministry of Defence in Whitehall. Since 1990 it has been used for storage only.
