Details

The monument includes a World War II Heavy Anti-aircraft gunsite, known as
TN2 (Thames North 2), which is situated 380m south of Butler's Gate.
The monument, originally sited in open fields, had four octagonal gun
emplacements in a semi-circle facing east; with a further square gun
emplacement at each end of the semi-circle. Some 100m to the west, on the east
side of Shopland Road, were the accommodation huts and other associated
structures.

The four octagonal gun emplacements, built of concrete blocks and poured
concrete, are extant. Each emplacement is some 14m in diameter (externally,
measured from the rear of its opposite ammunition recesses) and 2m high. The
octagonal emplacements are all of the same design: each has seven external
integral ammunition recessess and two external shelters alongside for the
guncrew. Each ammunition recess measures some 2.5m square; some retain the
lettering `A' to `G' in white paint. Other painted signs on the walls appear
to refer to the type of ammunition stored in each recess and include `day';
`night' and `shrap' (the latter clearly the remains of the word `shrapnel').
On opposite sides, between the ammunition recesses, are two small chambers
which lead to the shelters. These are integral with the main structure and
measure 4.5m long by 2.5m high.

The inner parts of each emplacement, where the guns stood, are almost circular
and measure some 9m across. In the centre of one emplacement a holdfast of
four steel girders (each 1.80m long by 0.23m wide) is embedded in the concrete
base; there are signs of stud or bolt holes.

To the rear of the semi-circle the site of the central command post is marked
by a large earthen mound with broken brick and concrete lying on top of or
partly buried in the earth. It is thought that the command post remains
largely extant beneath this mound.

The earliest documentary reference to the site known as TN2 dates from 1940
and the latest to 1946. In 1942 the site is documented as having four 3.7 inch
guns operational.

MAP EXTRACT
The site of the monument is shown on the attached map extract.

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 380m south east of Butler's Gate survives in
good condition as one of the few remaining examples of its type in the
country. The design appears to conform to that known as DFW 55414 - an
emplacement with seven integral ammunition recesses and two external integral
shelters. The emplacements are important historical structures which provide a
pattern both for study and as a physical record of similar emplacements
elsewhere, now demolished. The remains of the command post also add to the
importance of the site.

Source: Historic England

Sources

Books and journals
Dobinson, C S, Twentieth Century Fortifications in England: Volume 1.3, (1996), 469-72
Nash, F, World War Two Heavy Anti-Aircraft Gun Sites in Essex, (1998), 59-60
Other
HQ 6th AA Division Location List, (1940)
May, RAF, 106G-UK 1496-3361, (1946)
October; 11 colour prints, Nash, F, (1998)
Tyler, S, MPP Film, (1998)

Source: Historic England