Reasons for Designation
Slade's Green Heavy Anti-aircraft battery, of late 1930s date, is designated at Grade II for the following principal reasons:
* A well-preserved Heavy Anti-aircraft battery of the Second World War which retains its core structures including a command post, gun emplacements, air raid shelter and perimeter defences;
* Of historic interest as the most easterly battery of the London Inner Artillery Zone with a strategic Thames-side location on the Crayford Marshes such that it was well placed to engage enemy bombers attacking the capital.
Details
959/0/10037 WALLHOUSE ROAD
02-DEC-09 Slade's Green
(Off)
World War II Heavy Anti-aircraft (HAA)
battery
II
Heavy Anti-aircraft (HAA) battery, including four gun emplacements, command post, two pillboxes, air raid shelter and Bofors gun emplacement. Constructed in the late 1930s.
MATERIALS: Of reinforced concrete and brick construction.
PLAN: The main part of the battery is centred on a command post with four gun emplacements arranged in an arc to its NW to SE. There are two defensive pillboxes, to the NW and SE of the emplacements and a surface air-raid shelter to the SE. To the NE are the overgrown remains of a Bofors gun emplacement. There are remnants of the support buildings and domestic site, located to the SW of the command post, including foundations and concrete building platforms. While these are an integral part of the history and development of the site, they are not included in the listing because of their fragmentary survival.
DESCRIPTION:
GUN EMPLACEMENTS: Four gun emplacement for 4.5 inch guns in a NW to SE arc. All well preserved octagonal enclosures are approximately 13m in diameter with opposing entrances approximately 4m wide. Of reinforced concrete with six flat-roofed lockers (2m long, 1.8m wide and 1.6m high). NW emplacement: entrances to the NW and SE, a central holdfast for the gun approximately 4m in diameter with surviving fittings (other emplacements have central dumping so this is the clearest example). Evidence of drainage, camouflage fixings on the enclosure wall and an external earth bank. The lockers have cavity walls with air vents, and rubber seals to the metal door frames but are missing their doors. NE emplacement: as before but with N-S entrances. E emplacement: W-E entrances with remnants of solid wooden plank gates. Sand bags protect the S gate E pier. SE emplacement: NW-SE entrances. Also surviving metal sight mounted between a pair of lockers (the only emplacement which has this feature).
COMMAND POST: Irregular semi-sunken building of reinforced concrete but broadly with flat roofs to the north and open courtyard zones to the south. Oriented NW to SE with an extension to the NE possibly for light anti-aircraft guns or radar. External fixtures and fittings include fixings for camouflage, a triangular roof mount and a metal plotting table. Access via entrances to the SW with steps down. Interior flooded at the time of inspection but plan and internal divisions, where visible, appear largely intact.
NORTHERN PILLBOX: A type 24 hexagonal pillbox of stock brick and reinforced concrete. Concrete 'porch' protecting low entrance to SE with patching above suggesting modifications to the same. Concrete cills to embrasures. Internally a straight ricochet wall.
SOUTHERN PILLBOX: A further type 24 pillbox of the same form and fabric as that to north. Also with concrete 'porch' protecting low entrance, this time to the NW with patching above suggesting modifications to the same.
AIR-RAID SHELTER: Broadly rectangular flat-roofed air raid shelter but with two projecting porches to the S protecting entrances at the SW and SE corners. Of brick and reinforced concrete. Externally plain other than two unusual diamond-shaped openings in the N elevation with brick header surrounds. These light the two N-S entrance corridors internally which allow access to two parallel W-E rooms.
BOFORS GUN EMPLACEMENT: Now very overgrown and difficult to discern but aerial photographic evidence indicates a polygonal concrete enclosure with central gun holdfast.
HISTORY: One of the most significant developments in the evolution of warfare in the C20 was the emergence of strategic bombing during the Second World War, 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 Auxiliary Territorial Service who served on batteries from the summer of 1941, and the Home Guard who manned many sites later in the war.
Heavy Anti-aircraft (HAA) batteries housed large guns to engage high-flying enemy bombers, hence their location around the south and east coasts and close to large cities and industrial or military targets. Of all of the Second World War batteries built, these were the most substantial with provision for either static or mobile guns or varying sizes (3.7, 4.5 or 5.25 inch guns). As well as the gun emplacements, which were usually in groups of either four or eight, anti-aircraft sites had other related structures such as a command post, sometimes radar, on-site magazines for storing reserve ammunition, gun stores (for infantry use) and power generation huts. There were also domestic buildings with huts, ablution blocks, offices and stores. Sites were also provided with structures for their close defence with pillboxes being the most common.
Slade's Green Heavy Anti-aircraft Battery is one of a number of HAAs designed to create a protective ring around London. All were allocated identifying codes as part of the London Inner Artillery Zone with the site code here being ZS1. Possibly it was built as a prototype. It was the most easterly of the London IAZ HAA's with its position just south of the River Thames ensuring that it played an important role in the early stages of any attack on London from the east. In addition there were local military targets such as the Vickers-Armstrong factory in Crayford. Although first mentioned in documentary sources on 22 January 1940 (Dobinson, 1996), its layout indicates that it is of late 1930s origin. Records indicate that it was manned in January and May 1940 by the 54th Regiment (160 Battery) and in July 1942 by the 164th Regiment (446 Battery) and was built for 4.5 inch guns. The site was protected by two pillboxes and later in the war by the addition of a Bofors gun emplacement.
SOURCES:
Dobinson, C, 1996, Anti-aircraft artillery: England's air defence gunsites 1914-46. Twentieth Century Fortifications in England series. Vol. 1.1 & 1.3, Council for British Archaeology
Dobinson, C, 2001, AA Command: Britain's anti-aircraft defences of the Second World War. English Heritage/Methuen, particularly plates 4 and 28
Greater London Sites and Monuments Record reference: 300036/00/00 : ML0682
Defence of Britain Database, records S0013563; S0002646; S0002648; S0002647 and Non Anti-invasion record 3073 at http://ads.ahds.ac.uk/catalogue/collections/blurbs/324.cfm (accessed 25 September 2009)
National Monument Record Aerial Photographic Collection, particularly RAF/26K/UK1455 frame 2090 (library no 6555), 14 March 1941;
RAF/106G/LA/26 frame 4018 (library no 8312), 4 August 1944;
RAF/106G/UK/1356 frame 5048 (library no 208), 2 April 1946;
RAF/540/1543 frame 61 (library no 1638), 4 March 1955;
REASON FOR DESIGNATION:
Slade's Green Heavy Anti-aircraft (HAA) battery, of late 1930s date, is designated at Grade II for the following principal reasons:
* A well-preserved Heavy Anti-aircraft battery of the Second World War which retains its core structures including a command post, gun emplacements, air raid shelter and perimeter defences;
* Of historic interest as the most easterly battery of the London Inner Artillery Zone with a strategic Thames-side location on the Crayford Marshes such that it was well placed to engage enemy bombers attacking the capital.
