Details

The monument, which lies in four separate areas of protection, includes a
World War II Heavy Anti-aircraft (HAA) gunsite, and its domestic camp,
situated about 1km north of Upchurch village south of the River Medway.
The gunsite, known as TS3 (Thames South 3), formed part of a chain of
batteries positioned to defend the industrial and military targets in the
Lower Thames and Medway areas from high flying strategic bombers approaching
from the south and east. The gunsite was equipped with Gun Laying Radar and
sources indicate that it was established by February 1940 and was armed with
four 3.7 inch (mobile) Anti-aircraft (AA) guns by 1942.
Measures taken in 1944 to combat the German V1 flying bomb included the rapid
deployment of AA weapons across the south east and east of England. The
battery at Wetham Green was located within the deployment zone around the
fringes of the Thames Estuary, an area known as the Diver Box created for the
eastern defence of London. At this time the battery came under the operational
control of 28 AA Brigade, and was enlarged to accommodate two additional HAA
guns. In January 1946 the battery was selected to form part of the reduced,
post-war layout known as the Nucleus Force, with its guns held in readiness
off-site.
The earlier installation consists of an ENE-facing semicircular arrangement
of four octagonal gunpits (three of which survive) of concrete block
construction, and a central command post for the 3.7 inch guns. The command
post was partly infilled after the war, and will survive in buried form. The
steel pivot for the range finder equipment remains exposed at the front of the
structure. Each emplacement consisted of a central gun, anchored by a steel
holdfast, surrounded by six ammunition lockers and protected by an outer,
externally embanked concrete blast wall. The surviving emplacements retain
some of their original features, including the steel holdfasts and the small
generator sheds which flank the entrance to each gunpit.
These emplacements and the later guns were served by a five-bay magazine
located about 50m north of the 3.7 inch gun positions. This is a single
storey, semi-sunken concrete structure set within a concrete walled
enclosure. The flat-roofed structure is entered from an open corridor on its
eastern side, which is reached from ground level by a slope at each end. The
magazine retains many of its original fittings and features, including the
heavy steel door and the wooden covers to the ventilation shafts. Also in this
area of the site is a large square single storey concrete engine room, built
onto the southern wall of the magazine enclosure. Its ventilation holes
survive, set high in the wall beneath a modern timber roof.
A radar set, which appears to conform to the 1943 design known as `DFW 55497',
lies about 100m south west of the engine room. It was raised on a low
concrete platform with a gentle ramp on one side. Its associated Ground
Laying mat (a large horizontal and octagonal wire mesh, which enhanced the
performance of the radar by eliminating interference) has been removed.
The battery is reached from the main gate on Poot Lane, via a concrete service
road, which loops around the central command post with offshoots leading to
each of the gun positions.
Two later gunpits, constructed to accommodate the additional ordnance deployed
during the Diver campaign, are located to the south west of the earlier
emplacements, and are also reached from the service road. These almost square
installations are of concrete block construction and were originally embanked
externally. Since the war, one of the emplacements have been roofed and its
floor has been resurfaced, although the holdfast within the other emplacement
survives.
The domestic site is situated about 50m south east of the gun emplacements,
and is reached via a branch road from the main access track. It consists of a
linear arrangement of accommodation huts and associated structures, the
majority of which are red brick, modular buildings with pitched corrugated
asbestos roofs, although there are also several Curved Asbestos huts. These
structures survive well and retain many of their original features and
fittings, including the remains of the stage lighting at one end of the NAAFI
building.
Additional buildings associated with the post-war use of the site within the
Nucleus Force are located on the northern side of the access track from Poot
Lane. These include a motor transport shed and two Curved Asbestos huts which
have since been re-roofed in corrugated iron.
The following items are excluded from the scheduling: the modern stabling and
barns constructed within and against the southern edge of the engine room; all
modern surfaces, fences, gates and structures; materials used to seal the
doors and/or windows of some of the surviving buildings; all modern materials
and equipment stored within and around the emplacements, camp buildings and
other structures. However, the ground beneath all these features is included.

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.

Furthermore, the World War II Heavy Anti-aircraft gunsite (TS3) at Wetham
Green, 460m north of Red Brick Cottage is one of only nine sites
nationally to survive with its layout, including its domestic site,
substantially intact, and is one of only two such sites in Kent (the other is
at Iwade). Its surviving elements represent at least two stages in the
development of the site, each with distinct building types. This physical
record of the site's development is significant, and is rare nationally.
Historically, the importance of the site is further enhanced by the
significant part it played in the defence of Britain against aerial
bombardment throughout the principal conflict of the 20th century.

Source: Historic England

Sources

Books and journals
Dobinson, C S, Twentieth Century Fortifications in England: Anti-aircraft artillery, 1914-46, (1996)
Other
Ordnance Survey, OS/78149; 385, (1978)
RAF, 106G/uk/1444; 4208, (1946)
RAF, 58/1779; F22/0192, (1955)

Source: Historic England