Combined Control Tower And Operations Block, Twatt Airfield (Former Hms Tern)

The Combined Control Tower and Operations Block at Twatt Airfield, formerly HMS Tern, was built between 1940 and 1941. This structure serves as the main building of the airfield and is constructed from rendered brick. It features a three-storey control room and watch office that connects to a single-storey operations block, forming a T-plan layout.

The operations block is flat-roofed and single-storey, surrounded by an outer brick blast wall and earthwork embankments, with a blast wall entrance located at the southern corner. The main entrance to the operations block is centrally located on the west elevation, flanked by two small windows. The south elevation includes two doorways and three windows. A staircase at the southeast corner leads to the roof, which is parapeted and holds stone chippings. There is a concrete drainage gutter that bridges the gap between the outer blast wall and a tall, narrow brick chimney with a clay can. The building also features cast-iron rainwater goods.

The control room and watch office predominantly have narrow horizontal openings. An external metal stair rises from the roof of the operations block to a cantilevered, shuttered concrete walkway that surrounds the north, south, and east elevations of the watch office. The watch office has large openings flanked by narrower lights on its north, south, and east elevations.

As of 2010, the interior of the operations block consists of an arrangement of 11 rooms, with the ground floor of the control tower surrounding a central operations room. Brick shelves are arranged in an L-plan in the central room, and there is a square hatch opening that rises through the floors of the control tower to the watch room above.