Scheduled Monument: HEAVY ANTI-AIRCRAFT GUNSITE 340M SOUTH EAST OF GARDENS FARM (1019871)

REASONS FOR DESIGNATION 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 340m south east of Gardens Farm is a well- preserved example of an early World War II gunsite. It retains the archaeological remains of the functional core of the station, the command post, gun emplacements, ancillary building and a section of the approach track. DETAILS The monument includes the standing, buried and earthwork remains of part of a World War II Heavy Anti-aircraft (HAA) gunsite known as Station DNH4. The site includes two gun emplacements, an ancillary building and part of the approach track. It also includes the earthwork and buried remains of the command post. It is unclear exactly when Station DNH4 was established but it is known to have been in place by February 1940 when the site is mentioned in an Anti-aircraft Command Letter. In June 1940 the site was manned by 222/68 Bty (222 Battery of 68 HAA Regiment), but by May 1942 control had passed to 498/144 Bty, a mixed sex battery which employed women from the ATS (Auxiliary Territorial Service). The women operated radar, communications systems and other support roles whilst men continued to operate the guns. On the 22nd June 1942 four 3.7in static guns supported by a GL (gun laying) Mk II radar were reported to be at Station DNH4. The site was probably connected with the defence of Derby generally and the Rolls Royce Engine Manufacturers in particular, both of which lie just a few kilometres to the west. The Anti-aircraft (AA) guns were used not only for destroying enemy aircraft but, more importantly, for preventing accurate bombing and for preventing enemy aircraft reaching their objectives, particularly at night. The effect of AA gunfire was, generally speaking, to keep all enemy aircraft at a high altitude and to deter them from flying on the straight and even course necessary for accurate bombing. Another important function of AA guns was to indicate the position of enemy aircraft to their own fighters. Often, when an enemy plane was out of range, the guns would fire one or two rounds to burst as near as possible, simply to draw the fighters' attention to the enemy. The site at Elvaston was selected as one of the 192 HAA gunsites to have been retained after the war as part of the Nucleus Force. On 15th January 1946 an AA Command Letter records that during this time the site was held for care and maintenance, with ordnance and instruments being stored in nearby depots. In 1950 an Anti-aircraft Operations Room (AAOR) was built approximately 100m west of the HAA gun site to control defences for the area. The building was one of 27 such sites throughout the United Kingdom, all built to a virtually standard design. This was built at a time when attack from the Soviet Union was considered a realistic possibility. In this pre-missile era, any attack would have been delivered by bomber aircraft and the defence of the area could have relied heavily on the Anti-aircraft gun system which had been installed during World War II. The AAOR has been burnt out and, although the shell of the building survives, most internal fixtures and fittings have been removed. For this reason the building is not included in the scheduling. The monument survives as a series of standing, buried and earthwork remains. The two gun emplacements and the ancillary building are constructed out of concrete and breeze block and broadly follow standard designs. The Command Post survives as earthwork and buried remains which lie beneath a circular area of grass now used as a roundabout. Early post war and later aerial photographs show the command building as a standing structure and indicate the size, shape and position of the building. From the available evidence it appears that the Command Post followed the standard Directorate of Fortification Works 55402 design with an additional room added to the rear for a central heating boiler. The building measured approximately 20m by 8m with its long axis orientated north to south. The Command Post would have been divided into two main parts with a series of semi-sunken rooms forming a wide horseshoe around the raised frontal area, which would have been enclosed but open to the sky. The bases of various instrument mountings would have been located in the area at the front of the building. In operation these mountings would have housed an identification telescope, the predictor (a mechanical computer), and height finder. These fed information to the plotting room, a long room in the covered part of the command post where the bearing, elevation and range were calculated and relayed to the guns. The other rooms acted as offices, stores and communications rooms. The building faces to the east so that the Gun Position Officer (GPO), who was in charge of the command post, could control the firing of the guns, watch the effects of the fire and take responsibility for the identification of enemy aeroplanes. The two surviving gun emplacements lie to the south east of the command post but, originally, four emplacements were arranged in a semicircle around the east side of the command post. The two northernmost emplacements have been removed and there are no indications to suggest that remains survive beneath the ground surface. The gun emplacements broadly match the March 1938 pre-war pattern which were octagonal in plan and had twin axial entrances with internal ammunition recesses and shelters. This type of emplacement was designed for both 3.7in and 4.5in guns. At Elvaston the ammunition recesses and shelters do not survive but the positions of these are indicated on the internal walls of the emplacements. The gun holdfasts, which are generally octagonal concrete pads set level with the ground surface and with a standard ring of holding down bolts for fixing the gun mounting, would have been positioned in the centre of each gun emplacement. At Elvaston these are no longer evident on the ground surface although the raised ground level within the emplacements suggests they may survive as buried features. The gun emplacements are surrounded by earth and turf embankments; these would not only reinforce the structures, but would also help to camouflage the site from the air. The ancillary building lies approximately 4.6m south west of the circular grassed area, beneath which lies the Command Post. It is the only surviving one of a pair, the second of which was situated a similar distance north of the grassed area. The building survives as a ruin without a roof, is constructed from breeze blocks and measures approximately 12.8 sq m but is not enclosed around the north eastern corner. The building appears therefore to have had open access from the direction of the Command Post. The external face of the east, south and west walls of the ancillary building are embanked with earth and now support shrubby vegetation. As with the gun emplacements this would reinforce the structure and help to disguise the building from the air. Attached to the northern side of the ancillary building and adjacent to the opening in the north east corner, is a small structure measuring approximately 2.05m by 3.67m. The structure is built of a single layer of breeze blocks, has a flat roof and a doorway on the northern side. Approximately 1.2m from the structure and running around its northern and eastern sides is another breeze block wall. This forms an enclosed corridor which leads into the main ancillary building. The exact purpose of the building is unknown but buildings of this type would have been a necessary part of the HAA complex, functioning as part of the operational core of the site or as support in the form of storage or shelter. Gun stores, officers quarters and motor transport garages and workshops are all buildings often associated with HAA gun sites. From the summer of 1941, many HAA Regiments used women to operate equipment. Station DNH4 was designed to accommodate mixed sex batteries and had a large domestic camp to the west of the protected area. The layout and design of the camp is evident from an aerial photograph taken by the RAF in 1945 but, by 1971, most of the structures had been removed and are not therefore included in the scheduling. The HAA battery complex would, originally, have included a radar platform and a magazine for storing ammunition. A pair of buildings are recorded on the Ordnance Survey 1:10,000 map and on the early post-war aerial photographs. These are situated approximately 90m east of the Command Post and one at least may have functioned as a magazine but these no longer survive and are not therefore included in the scheduling. In 1942 a GL Mk II radar was reported to be at Station DNH4 but its exact position is unknown. The monument also includes a section of the approach track and service roads associated with the HAA gunsite. When compared to aerial photographs taken before the site was converted into a camp site, it is clear that the existing system of tracks is, in general, based on the original World War II site layout. All modern fences and track surfaces are excluded from the scheduling although the ground beneath these is included. SELECTED SOURCES Other Reference - Title: MAL/71034/206 02/05/71 1:10,000 - Date: 1971 - Type: AERIAL PHOTOGRAPH Book Reference - Author: Dobinson, C - Title: Twentieth Century Fortifications in England - Date: 1996 - Page References: 112-160 - Type: DESC TEXT - Description: Volume 1.1 and Appendix II Book Reference - Author: Lowry, B - Title: Twentieth Century defences in Britain. An introductory guide - Date: 1995 - Page References: 50-57 - Type: DESC TEXT