This 'hotline telephone' was connected directly to the War Cabinet.
For total secrecy it was housed in its own booth and had an armed guard outside.
It was positioned between the plotting control room and the Commander in Chief's office to provide easy access to the officer in charge.
It is one of only two such surviving telephones in the UK.
History of the Building Personal MemoriesThe role it playedDiary of a Wren Battle of the AtlanticTour the building Battle of the Atlantic - from BBC History
