Scheduled Ancient Monument: TWO PICKETT-HAMILTON FORTS AT HONINGTON AIRFIELD, 750M AND 1.25KM SOUTH WEST OF BROOMHILL COTTAGES (30606-01)

The monument, which is in two separate areas of protection, includes two of the three Picket-Hamilton forts which were installed late in 1940 as part of the ground defences of Honington airfield. The third Pickett-Hamilton fort is believed to have been destroyed during post-war construction work. RAF Honington was constructed during the period of rapid expansion of the RAF between 1934 and 1939 and opened in 1937. It was designated a heavy bomber station, originally with a grass strip flying field, and was one of six airfields under the control of No.3 Group of the newly formed Bomber Command. During the period up to the outbreak of war it housed various squadrons flying Audaxes, Harts, Heyfords, Wellesleys and Harrows, but in 1938 the new Wellingtons came into operation, and between 1939 and 1942 were flown from here, as were Ansons, Battles and Blenheims. In the summer of 1942 the airfield was handed over to the USAAF, who set up an advanced air depot on the north west side for the repair, overhaul and modification of B17 Flying Fortresses. A steel mat runway was also constructed, with additional taxiways and hard standings, and in 1944 the airfield was enlarged to receive 364th Fighter Group, flying Lightnings and Mustangs. It was handed back to the RAF in 1946 and remains in use. Pickett-Hamilton forts were designed specifically for airfield defence on the flying field and were a form of retractable pill box, the upper section of which could be lowered flush with the ground surface when not in use, so as not to obstruct aircraft landing and taking off. Each consisted of two hollow, concentric pre-cast concrete drums resting on a concrete base. The outer drum and the base, measuring approximately 2.5m in depth overall, were sunk into the ground. The inner drum, pierced by three rifle loopholes, formed the lifting head and was designed to be raised approximately 0.75m by means of a central jack, using a compressed air bottle or hand pump, although this system proved unreliable and was later supplemented by oil pumps. When the lifting head was in the lowered position an external flange rested on the upper section of the outer drum, which incorporated a precast concrete surround or collar. Access was by means of a metal hatch in the roof of the lifting head and metal rungs set into the inner face. The interior fittings included a free standing circular firing step around the central column, a small electric light and a telephone for communication with the airfield battle headquarters. The tops of the lifting heads of the two Pickett-Hamilton forts at Honington are visible as circles of concrete approximately 2m in diameter, with the metal hatches set off centre. The upper sections of the outer drums extend about 0.3m beyond, giving an overall diameter of 2.6m. The better preserved of the two, in the first area of protection, is located about 70m to the south of the main runway of the modern airfield. Its principal components, including the firing step and the jack, survive and the lifting mechanism is in working order, having been restored and tested in 1987. In the second fort, located approximately 500m to the north of the runway, the jack has been removed and the firing step is broken, but the outer structure and lifting head remain intact. The metal bars and padlocks installed to secure the hatches for reasons of safety are excluded from the scheduling, although the hatches are included in the scheduling.