Heavy Anti-aircraft gunsite, 350m west of Butt Farm


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:


Ordnance survey map of Heavy Anti-aircraft gunsite, 350m west of Butt Farm
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The building or site itself may lie within the boundary of more than one authority.

East Riding of Yorkshire (Unitary Authority)
National Grid Reference:
TA 01636 36951

Reasons for Designation

Although of comparatively recent date, 20th century military sites are increasingly seen as historic survivals representing a defining episode in the history of warfare and of the century in general; as such they merit careful record and, in some cases, preservation. One of the more significant developments in the evolution of warfare during this period was the emergence of strategic bombing in World War II, and this significance was reflected by the resources invested in defence, both in terms of personnel and the sites on which they served. During the war, the number of people in Anti-aircraft Command reached a peak of 274,900 men, additional to the women soldiers of the ATS who served on gunsites from summer 1941, and the Home Guard who manned many sites later in the war. A national survey of England's Anti-aircraft provision, based on archive sources, has produced a detailed record of how many sites there were, where they were and what they looked like. It is also now known from a survey of aerial photographs how many of these survive. Anti-aircraft gunsites divide into three main types: those for heavy guns (HAA), light guns (LAA) and batteries for firing primitive unguided rockets (so called ZAA sites). In addition to gunsites, decoy targets were employed to deceive enemy bombers, while fighter command played a complementary and significant role. Following the end of World War II, 192 HAA sites were selected for post-war use as the Nucleus Force, which was finally closed in 1955. The HAA sites contained big guns with the function of engaging high flying strategic bombers, hence their location around the south and east coasts, and close to large cities and industrial and military targets. Of all the gunsites, these were the most substantially built. There were three main types: those for static guns (mostly 4.5 and 3.7 inch); those for 3.7 inch mobile guns; and sites accommodating 5.25 inch weapons. These were all distinct in fabric, though they could all occupy the same position at different dates, or simultaneously by accretion. As well as the four or eight gun emplacements, with their holdfast mountings for the guns, components will generally include operational buildings such as a command post, radar structures including the radar platform, on-site magazines for storing reserve ammunition, gun stores and generating huts, usually one of the standard Nissen hut designs. Domestic sites were also a feature of HAA gunsites, with huts, ablutions blocks, offices, stores and amenities drawn from a common pool of approved structures. Sites were often also provided with structures for their close defence; pillboxes are the most common survivals, though earthwork emplacements were also present. The layout of HAA gunsites was distinctive, but changed over time, for example to accommodate the introduction of radar from December 1940, women soldiers from summer 1941, and eight gun layouts from late 1942. Nearly 1,000 gunsites were built during World War II, and less than 200 of these have some remains surviving. However, at only around 60 sites are these remains thought sufficient to provide an understanding of their original form and function. This includes 30 of the 192 examples which continued in use until 1955. Surviving examples are therefore sufficiently rare to suggest that all 60 well preserved examples are of national importance.

The heavy Anti-aircraft gunsite, 350 west of Butt Farm, is a well preserved example of a mid-World War II gunsite, retaining the functional core of the station, the command post and gun emplacements.


The monument includes standing, earthwork and buried remains of a World War II heavy Anti-aircraft (HAA) gunsite, known as both Station H31 and Walkington gunsite in official records. It includes the functional core of the gunsite of four emplacements and the command post, located 350m west of Butt Farm. Station H31 is first mentioned in the War Diary of the HAA Divisional General Staff on 13 October 1941 when it was in the control of 173/62 Battery (173 Battery of 62 HAA Regiment). It was taken over by 391/113 Battery on 16 February 1942 and then by 439/113 Battery on 4 March. By June it was equipped with four mobile 3.7in guns supported by a GL mkII radar. On 14th July 1942 the station passed to 514/151 Battery which used it for its Battery HQ, with control over two other nearby HAA gunsites. This battery was from a mixed sex Regiment which used women from the Auxiliary Territorial Service (ATS) to operate radar, communications systems and other support roles with men operating the guns. Unlike most places in the country, Hull suffered air raids throughout the war. Between the end of June and November 1942 Station H31 was used for training, allowing batteries from around the country to gain operational experience. In September to October 1942, the gunsite's four mobile guns were replaced by static 3.7in guns mounted in permanent gun emplacements. At the end of the war Station H31 was in the control of 152 Regiment and was allocated six 3.7in mkIIc guns, four of which were emplaced, two held off site. In January 1946 it was confirmed to be one of the 192 HAA gunsites in England to be retained as part of the post-war Nucleus Force. This provision of anti-aircraft gunsites was further reduced in scale in the following years and Station H31 was probably abandoned by 1950, by which time only 78 gunsites were operational nationally. The gun pits do not have the extra holding down bolts for the 3.7in no.5 mounting which was introduced in 1954. The gun emplacements and command post are all constructed out of brick with flat concrete roof sections and concrete floors. They broadly follow standard designs. The four gun emplacements are arranged in an arc around the north west side of the command post which also faces north west. The gun emplacements are of DFW 55414 design, which was issued by the Directorate of Fortifications and Works (DFW) on 10 October 1942 for static 3.7in guns. Each emplacement is the same with a central octagonal gun pit 7.5m across, with a standard ring of holding down bolts for fixing the gun mounting. The entrance to each pit is on the side nearest the command post and these retain the hinges for the original iron blast doors which have since been removed. Opening through each of the other seven sides of the pit is an external roofed recess for ammunition storage. Behind two of these recesses on opposite sides of the gun pit, there is a pair of roofed shelters. One was typically used as a relaxed duty shelter for the gun crew, the other for gun maintenance. The command post effectively follows the standard DFW 55402 design with an additional room added to the rear for a central heating boiler, but without an emplacement for a light Anti-aircraft machine gun at the front. The command post measures approximately 8m by 20m, its long axis orientated north east to south west. It is divided into two main parts with a series of semi-sunken rooms forming a wide horseshoe around the raised frontal area which is open to the sky. In operation, this open area was used for an identification telescope and for two other pieces of equipment, the predictor and height finder. These fed information to the plotting room, the long room in the covered part of the command post to the rear of the open area, where the bearing, elevation and range was calculated and relayed to the guns. The other five smaller rooms acted as offices, stores and communications rooms. The shell of the command post is complete and retains fragments of its internal fittings. Opposite the command post, just beyond the middle pair of gun emplacements, there is an area of earthwork remains of another structure with a set of angle iron posts set in to concrete blocks. This is identified as the remains of a radar transmitter used by the gunsite. A number of features are excluded from the scheduling; these are all modern fences and gates, water troughs and telegraph poles, although the ground beneath these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


The contents of this record have been generated from a legacy data system.

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This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

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