Details

The monument includes a World War II Heavy Anti-aircraft (HAA) gunsite,
situated on the southern side of Lodge Lane, on the eastern outskirts of
Cobham village, about 3km west of Rochester. The gunsite is located on the
southern crest of a low ridge which forms part of the North Downs.
The gunsite, known as TS15 (Thames South 15), formed part of a chain of
anti-aircraft batteries, positioned to defend the industrial and military
targets in the Thames and Medway Gun Defended Area from high flying enemy
bombers approaching from the south and east.
Sources indicate that the gunsite at Cobham was established by February 1940
and was armed with four 4.5 inch guns. The gun park occupied the south
eastern corner of a polygonal, fenced enclosure which was entered by a gateway
on Lodge Lane at its north western corner, or via the accommodation area to
the north east. The perimeter fence has not survived, although a steel
gatepost remains next to the former entrance on Lodge Lane. The gunsite
consisted of a south east facing, semicircular arrangement of four octagonal
gunpits, with a sunken magazine, located between the two forward emplacements,
and a command post to the rear. Each emplacement contained a centrally placed
gun, anchored to the concrete floor by a steel holdfast. The guns were
surrounded by six roofed ammunition lockers protected by an outer, concrete
blast wall, externally embanked with earth. The ammunition lockers survive, as
do the external brick shelters for the gun crew, attached to each emplacement.
The single storey, flat-roofed magazine is set within a sunken, concrete
walled enclosure and is entered from the open passage to the rear, which also
provides access to the smaller concrete structure situated opposite the
magazine entrance. The internal dividing walls of the rectangular, five-bay
magazine retain the painted grids on which the ammunition holding of each bay
was recorded. The magazine passage is reached via a slope at each end, which
leads down from the two forward gun positions.
The roughly rectangular, concrete command post consists of three open bays at
the front of the building, which held the fire control instruments, and a
semi-sunken roofed element behind, which housed the plotting room and an
adjacent rest room.
The domestic camp was situated about 100m north east of the monument, and
consisted of accommodation huts and associated structures flanking the
entrance roadway from Lodge Lane. The camp buildings were reused for a short
time after the war, as temporary shelters for the homeless, but were
subsequently demolished, and this area is therefore not included in the
scheduling. Only the ruined remains of the guardhouse survive on the southern
side of Lodge Lane, although elements of hut foundations and connecting road
surfaces may survive elsewhere within the camp area.
All modern fixtures, fittings and materials associated with the stabling
of horses within the magazine, and all modern fencing, are excluded from the
scheduling, although the ground beneath these features, and/or the structures
to which they are attached, are 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.

Despite the loss of its domestic camp, the World War II Heavy Anti-aircraft
gunsite (TS15), 250m east of Cobhambury Farm survives well and is one of only
seven complete, or near complete, sites of its kind in Kent. The gunsite also
provides the opportunity for typological comparison with similar batteries in
the regional and national context, and represents an important physical record
as well as a visual reminder, of the significant part played by ground based
anti-aircraft guns in the defence of Britain during one of the most critical
conflicts 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)
Lowry, B (ed), Twentieth Century defences in Britain. An introductory guide, (1995)
Other
RAF, RAF: 26H/3/1; 1786, (1940)
RAF, RAF: CPE/UK/1923; 3173, (1947)

Source: Historic England