A short history of Sigint in Scarborough

Last Updated: 09 Apr 2016
The Royal Navy established a Wireless Telegraphy Station at Scarborough in 1912. Since 1914 it has conducted signals intelligence (Sigint) in support of both the defence of the United Kingdom and of our armed forces.

​1912 to 1935

The Royal Navy established a Wireless Telegraphy Station at Scarborough in 1912. Since 1914 it has conducted signals intelligence (Sigint) in support of both the defence of the United Kingdom and of our armed forces.

During The Great War the station’s role was to monitor the German High Seas Fleet which was making harassing attacks on the East Coast of England. Following the cessation of hostilities in 1918, Scarborough’s mission widened to include diplomatic communications, with resources eventually being evenly split between Naval and diplomatic intercepts.

In 1932, a proposal was made to close Scarborough, and to transfer operations to Flowerdown, Hampshire; fortunately this decision was reversed and in 1935 our interception of the German Navy was restarted.

1936 to 1945

At the beginning of August 1939, Y Service, the organisation responsible for intercepting enemy and neutral radio transmissions, were prepared for war. Scarborough intercepted German Naval and Naval Air communications, and controlled a Direction-Finding network.

It was during this period that the civilians working in Sigint for the Admiralty became known as the Admiralty Civilian Shore Wireless Service (ACSWS), and the complement soon became a mix of both civilian and service personnel, augmented during the war years by members of the Women’s Royal Naval Service. 

During May 1941, the station at Scarborough played a key role in the location and subsequent destruction of the German battleship Bismarck. The following is an extract from a review of ‘Y Work’, written by Lt. Cmdr. WR Rodger, Officer in Charge, Scarborough, 15 November 1945: 

'The old Y Station in Sandybed Lane (1914-1943) was altered out of recognition to meet increasing demands in equipment and the need for more personnel and space, particularly necessary for aerials and the servicing of [Wireless Telegraphy] apparatus. The buildings on the present site on Scarborough Racecourse were occupied on 1st March 1943 during the course of a forenoon watch, without a stoppage of [Wireless Telegraphy] cover or passing of [Enigma] traffic to Bletchley Park.'

As indicated above, the station moved to its present location (some three miles from the town centre on the site of the old Scarborough racecourse) in early 1943. A half-buried bomb-proof bunker covered in hundreds of tons of earth served as the main building at the site. The working conditions in the bunker were far from ideal. Space, heating and water supplies were inadequate, and rainwater would seep into the building.    

In 1945 our next major task was the collection of Soviet Armed Forces communications during the period of the Cold War, and Scarborough became the main station for the interception of Russian Naval traffic. 

The Cold War Years

In 1965 it was agreed that the station and the ACSWS should be transferred to GCHQ, which formed the Composite Signals Organisation to unify the civilian stations subordinate to different ministries and the station became CSOS Irton Moor.

Work on the present building began in 1972, and all operations had transferred from the bunker by 1974. 

The fall of the Iron Curtain in the early 1990s resulted in the reduction of the UK’s interception. The missions of our sister stations at Cheadle and Culmhead were transferred to Scarborough in 1995 and 1998 respectively.

In July 2001 the site was renamed GCHQ Scarborough. 

The site was transferred to GCHQ ownership in 1965.


Scarborough station aerial view, 1947
Scarborough station aerial view, 1947. The site was not transferred to GCHQ ownership until 1965.


Scarborough site model, circa 1971
Scarborough site model, circa 1971, showing proposed building works. Operations had transferred to the new building by 1974.


GCHQ Scarborough circa 1972
GCHQ Scarborough circa 1972 (taken from the top of the bunker), around the time construction on the current building started.