Flying Boat Hangar

This is a flying boat hangar built between 1917 and 1918, designed by the HM Office of Works under the direction of Sir Frank Baines. The hangar covers an area of approximately 7,000 square metres. Later additions are present, including a brick building extension at the east end, which has been re-clad.

The exterior of the hangar is clad in colour-coated corrugated steel, replacing the original steel cladding, and features a saw-tooth profile roof with four apexes containing northlight glazing. Raking angle-iron buttresses are visible on the south, east, and west elevations. Some of these buttresses have been reinforced with welded sections of rectangular steel tube. Sliding doors run along the entire north side of the hangar, opening onto an apron. Doorways that originally appeared on the south elevation have been overclad, modified or removed and replaced with smaller doors. The glazing in the external walls, the north-elevation sliding doors, and the northlights has been replaced with double or triple-wall polycarbonate sheet. The brick building extension at the east end is not considered to be of special interest.

Inside, the saw-tooth-profile roof is supported by deep lattice trusses with stanchions and steel rakers. Channels have been bolted to the underside of the original steel tie-beams to add stability. The hangar’s original, large volume has been subdivided to create separate work areas, including a mezzanine floor along the south side that is supported by steel-joist portals fixed to the concrete floor. The building’s current uses are arranged in a simple grid layout between the mezzanine and the north-elevation doors. Some areas require complete containment, achieved with freestanding structures within the hangar. The mezzanine structure and modern internal partitions are not of group value.