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A network at war

Bomb damage in Wood Street telephone exchange, 1941. Almost all lines were back in operation within a couple of weeks.

Damage to the network (1940) : keeping out of danger

Communication centres were a high-profile target during the world wars as the combatants were fully aware of the strategic importance of telecommunications. The Central Telegraph Office in London suffered attacks in both wars and was badly damaged by a direct hit in 1940.

Other notable casualties were communications buildings in Birmingham, Bristol, Plymouth, Exeter, Cardiff, Coventry, Bridlington and Liverpool. London's Wood Street exchange building was burnt out in 1941.

This period of sustained bombardment forced the Post Office into changing procedures and updating security. This lead to a prolific growth and deployment of new technology, leading to much replanning and relocation of the network and equipment. In the long term this provided benefits to the customer as well as protection from modern-day hazards such as fire, natural disaster and the threat of future conflict.

Gas unit WWII

Preparing for war (December 1, 1940) : be prepared

As the military increasingly relied on telecommunications, the Post Office made prudent efforts to protect its networks as the onslaught of the Second World War intensified.

The main concern was to provide alternative facilities should any network or office be knocked out of action. The importance of the Central Telegraph Office meant that alternative reserve facilities were built underground. These were used during air-raids and became fully operational after the CTO was gutted by fire in December 1940.

Voice-frequency telegraph working was introduced around the country, carried over the telephone networks. Four main ring offices were opened around London in 1941 to provide bypass routes in case direct cables were destroyed. Similar provision was made at strategic locations across the country.

Poster PRD 298, 1943 - from the BT Archives

Back-room developments : keeping the operations running

During the Second World War Britain's defence system was heavily reliant on telegraph, telephone and wireless communication. A third of the Post Office's engineering staff were working with the armed forces to develop, build and manage the arteries of military communication and the technology.

Communications played a vital role in warefare, and telephone and radio had become part of the fabric of war. Every gun-emplacement, air raid siren and barrage balloon control groupwas connected; radar stations were linked to RAF fighter command; military camps and depots needed vast networks and the government placed huge demands on the Post Office too.

Technology had progressed so far that military personnel gave little thought to the equipment needed to keep everything operating, it had become so efficient that all the attention was placed on getting the job done rather than how it was done.

Telephone operator - (in case of attack) : Betty Roper

Betty Roper, born in 1924 joined the GPO as an operator when she left school in the early days of the Second World War.

To begin with she was more scared of the people she worked with than the bombs outside, but once she settled in she thoroughly enjoyed the job.

She recounts the steps taken to arm themselves against an invasion and how the war encroached on their world when the telephone exchange was under attack from German planes.

audio clip


When there seemed to be a threat of invasion we were issued with a pepper pot. When we asked what this was for, it was to throw in the eyes of the invaders if they ever got into the exchange. We had to work with this little pepper pot sat beside us. Also we had training with gas masks on and we had to have a tin hat (and) a gas mask on and work like that for half an hour, I think it was about every week. We were still sitting at the switchboard on the top of the post office. Part of it at the back was a glass roof and for some unknown reason there was a lull and we got up and walked away from the switchboard. About two minutes afterwards a tracer bullet came through the back, through the window and lodged itself in the back of the chair. If someone had been sitting in that chair they would not be alive today. We used to bail out and go down into the basement and we had one lady that was expecting a baby and so when the siren went and we got busy we used to send her down to the basement. This particular night was a pretty bad night and we'd forgotten all about her, and about eight o'clock next morning her mother rang up to find out where she was and we'd forgotten to tell her the all clear had gone and she was still there.

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