Details

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.

Source: Historic England

Reasons for Scheduling

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.

Source: Historic England