During the summer of 1940 following an airborne attack on Crete by German forces, Britain’s airfields were considered to be exposed to a risk of enemy bombing or a paratroop attack. Until then, airfields had only been lightly defended with a few Lewis anti-aircraft guns scattered around the perimeter.
To counter this threat, new defences were constructed, these included slit trenches, pillboxes, more light anti-aircraft guns and barbed wire. Two new types of defence structure also appeared that were specifically designed for airfields. One was the Pickett-Hamilton Fort, a retracting hydraulically operated pillbox sited close to runways. This remained flush with the ground to allow normal operation of the airfield but during an attack it could be raised up to permit cross fire.
The other new structure was the battle headquarters. These were designed to be occupied only if the airfield came under attack and would have been used to co-ordinate the defence of the airfield. They were generally located at the highest point of the airfield which was sometimes outside the perimeter fence. Occasionally they were located close to the control tower and a few (like RAF Downham Market in Norfolk) were linked to the control tower by a tunnel.
There were three types; the first design (MS 2779) is only seen at fighter stations protecting London. This consisted of a pillbox with two rooms below it, one above the other; the upper room being entered down a flight of steps from the surface. The next design (Air ministry drawing 3329⁄41) replaced it and was confined to the other (non-permanent) fighter stations; this was smaller and was entered through a hatch. The third and most common (air ministry drawing 11008⁄41) was originally erected at bomber stations but appears to have been adopted by all RAF Commands sometime after 1942.
This consisted of a network of five underground rooms entered by steps at one end leading down into a lobby. Straight ahead was a latrine and to the left the office; passing through the office there was a door in front to the sleeping quarters and a door to the right into mess room. A door on the right hand corner of the mess room led to the emergency escape ladder and from the bottom of the ladder there were three steps up to an observation cupola which was built 3 feet higher than the other rooms. The cupola was 6’ square and projected three feet above the ground with a thick re-enforced roof and at ground level, a 2” wide observation slit running all the way around to allow the Local Defence Officer a 360 degree view.
The battle headquarters at Dunsfold is the third type and is semi-sunken with the top half of the structure covered over with soil. It is on a high point overlooking the south side of the airfield, alongside a public footpath and outside the present perimeter fence. The structure is heavily overgrown although the observation cupola is clearly visible from the footpath. The access stairway has been backfilled with soil but some of this has been dug out again and it is possible to squeeze in to the lobby. Internally the structure is clean and dry although stripped of any original fittings.