Building 166 (Operations Block And Office Annexe) And Building 165 (Crew Briefing Room)

Operations Block (Building 166), Office Annexe (also part of Building 166) and Crew Briefing Room (Building 165)

These buildings were constructed in 1942 by George Wimpey for the Air Ministry to Directorate of Works and Buildings drawing number 9223/42.

The Operations Block has rendered 13.5 inch brick walls supporting a reinforced concrete roof. The Office Annexe and Crew Briefing Room feature rendered 4.5 inch brick walls with piers at 10 feet intervals supporting 28 feet span steel trusses carrying corrugated iron sheeting.

The plan comprises a large operations block containing smaller rooms for plant, a meteorological office, wireless transmission and general communications. Two parallel rectangular-plan ranges to the north contain the crew briefing room (positioned north of the office annexe), which originally provided rooms for rest, intelligence officers, interrogation of crews returning from missions, anti-aircraft operations and signals.

The exterior elevations are generally plain, with the office annexe and crew briefing room lit by steel casements in the side walls. A ventilation tower rises from the roof. The interiors retain their original plan form, with ventilation ducting visible in the operations room.

Historical Significance

The Operations Block at Dunkeswell is an unusually well-preserved example of a wartime operations block. It served as the nerve centre for US Navy operations in the Bay of Biscay area and is of great historical importance for its associations with the Battle of the Atlantic. Dunkeswell was the only British airfield where the US Navy Fleet Air Wing 7 was based during the Second World War, and remains the best-preserved site in western Britain associated with this strategically vital campaign.

The airfield was begun by George Wimpey in 1941 and transferred to 19 Group Coastal Command in May 1942. In August 1942, following high-level liaison between British and United States governments, it was occupied by the US Navy Fleet Air Wing 7 (not the US Air Force Anti-Submarine Group 479 as initially stated). The US Navy personnel, having previously protected shipping off the eastern seaboard of North America, Iceland and Greenland, were tasked with patrolling sea areas that had to be crossed by U-boats en route between their bases in France and hunting sites in the North Atlantic. From Dunkeswell, 6,424 anti-submarine missions were flown, principally in B24 Liberator bombers which possessed the greatest range over the Atlantic of any aircraft then available. US Navy liaison personnel were based at Coastal Command headquarters at Mount Wise, Plymouth, where Enigma decrypts from Bletchley Park were coordinated. At peak operations in 1944, just under 5,000 personnel were stationed at Dunkeswell. The US Navy remained until May 1945. The RAF then took over in August 1945 for ferrying and maintenance, leaving in 1949.

Shore-based aircraft operating from bases such as Dunkeswell proved decisive in the Battle of the Atlantic, accounting for 41.5 per cent of U-boat kills. Their effectiveness increased with aircraft technology: the 500-mile range of the Hudson, Wellington and Whitley bombers was extended by the Sunderland flying boat to 600 miles, and by the Liberator bomber (in service from 1943) to 1,100 miles. May 1943 is acknowledged as the turning point in the conflict, with shore and ship-based aircraft then accounting for two-thirds of U-boat losses.