The airfield was built at Twatt during WW2 as a naval air station to augment the 1939 HMS Sparrowhawk at Hatson. It opened in April 1941 and remained operational until 1957. Many of the buildings were demolished or repurposed for agricultural use and the runways returned to farmland.
There are a number of precast arched concrete personal shelters around the domestic area of the site, including adjacent to the camp cinema and around the access road. These are generally in very good condition without graffiti. Of those inspected one was partially flooded but the others were either clean or had mud/soil debris on the floor.
Two designs in use – one with entrances at either end, the other a single entrance and an emergency exit hatch in the roof. Both variants had simple right-angle revetments to provide some degree of protection against blast and evidence of a (now removed) door. They were protected by banks of earth covering them.
The remains of the camp cinema are interesting – the projection room and vestibule remains along with a raised concrete stage area at the other end. There is a flooded area below the stage accessed by steps. The floor was concrete which has been then coated with bitumen (which remains) and perhaps had a carpet over it? It has now cracked and is overgrown with weeds. The outline of the arched corrugated metal roof that formed the main shell of the building can be clearly seen on the projection room end, along. The building is secured and is managed by the Birsay Heritage Group.
The control tower is the other significant area of interest. It is formed of a fairly typical WW2 design with big windows apertures and a balcony with railings and two rooms. These were usually accessed externally by an iron staircase (all the rungs now rusted away) with an additional (emergency?) route via a (missing) ladder to the first floor below. The top floor was not accessible.
The first floor was accessed by a badly deteriorated external staircase from the ground level. It gave access to two rooms – one with narrow high windows in 3 directions and the hole to the floor above. In a matching position on the floor a wooden board has been screwed in place, suggesting a continuation down to the ground floor.
The other room, with a single high window had multiple electrical junction boxes that connected via a conduit over the roof and away from the building. The white paint in this room was in good condition.
The ground floor is semi-sunken and protected by brick-built walls and earth banks. This level was intended to provide a protected battle headquarters and is unusual in being situated under the control tower rather than at another location.
On two sides the gap between the external brick wall and the wall of the building is about 1m or so to allow easy passage, round the rest of the building it narrows and is only just passable, presumably to allow maintenance and to avoid damp from the ground getting into the building.
There are several doors, painted RAF green (probably not original based on the condition) and moderate sized windows. The doors and windows are secure and access to these is only possible on a guided tour with Birsay Heritage Trust.
A number of other buildings remain in the site including the decontamination block, the generator building and the main stores as well as several small pillboxes and ammunition magazines. Earth mounds and supporting walls are evident in both ammunition areas as well as around the concrete pads where the hangars once stood.
Birsay Heritage Trust run regular guided tours during the summer months.
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