World War II Heavy Anti-aircraft gunsite, 100m west of Princes Cottages


Heritage Category:
Scheduled Monument
List Entry Number:
Date first listed:


Ordnance survey map of World War II Heavy Anti-aircraft gunsite, 100m west of Princes Cottages
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The building or site itself may lie within the boundary of more than one authority.

South Hams (District Authority)
National Grid Reference:
SX 50782 49117

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 site at Down Thomas, 100m west of Princes Cottages, is considered to be one of the best preserved examples of those HAA sites which protected Plymouth during World War II. It is one of only three such sites to survive in the Plymouth area and it provides a significant and visible reminder of the nature of home defence during World War II; its function being to combat German bombers heading towards the city and naval dockyards of Plymouth.

The importance of the site lies in the survival of all of its gun emplacements and its well-preserved command post and magazine, all linked by a contemporary trackway. As such it provides an exceptional insight into anti-aircraft measures in the region.


The monument includes a World War II Heavy Anti-aircraft (HAA) gunsite located some 650m inland from the coast on the western side of Wembury. The battery was known as Down Thomas and this name persists into the early years of the 21st century. It was built in 1940, as part of the defences for the city of Plymouth, with four 3.7 inch gun emplacements and was manned by 210 HAA Battery in August 1941. Subsequently, two other emplacements were added for 3.7 inch and/or 4.5 inch guns. During the period of use the battery was divided into two parts. The living area to the east (alongside Spring Road) contained the accommodation and general administration buildings. This area is not included in the scheduling. The operational area, the subject of the scheduling, lies to the west. This formed the combat element of the site and included the gun emplacements, a command post and a magazine. The gun emplacements are approached by a concrete access road leading from the accommodation site. The final 15m length of this road is included in the scheduling. The gunsite comprises an array of six gun emplacements arranged around a loop at the end of the access track. The gun emplacements are of two different types: four are octagonal and are of a standard type for 3.7 inch guns. These are believed to have been constructed as part of the original battery of 1940, whilst two are rectangular and are believed to been constructed a little later, possibly for 4.5 inch guns. The four octagonal emplacements form an arc to the south of the command post whilst the two rectangular additions sit at the northwestern end of the array. The octagonal emplacements each have six brick-built, internally rendered, ammunition lockers (some retaining wooden fixtures and fittings) built against the 1.5m high concrete block walls which are embanked with earth for extra protection and which surrounded the guns. Concrete `holdfasts', some of which retain metal fixtures, mark the positions of the guns, which were manoeuvred into place via a single access gateway in each emplacement. The rectangular emplacements are similarly enclosed by concrete block walls embanked with earth and with a single entrance. They are however provided with only two ammunition lockers, one at either end against the shorter walls. The semi-sunken command post is situated within the access loop towards its southern end. The building is protected by earth banks and has a standard suite of rooms including a plotting room, telephonists' quarters, and offices. Built into the top of the building are protected positions for spotting equipment, observation platforms, and a pillar for a range finder. Also within the access loop is a 5-bay magazine protected by blast walls; each bay (known as a recess) retains its stencilling for detailing numbers and types of shells stored. The magazine is accessed by its own concrete track which has embedded rails to facilitate the movement of shells to the access road. A semi-sunken building to the south of the magazine, but still inside the access loop, may be a shelter. To the exterior of the access loop and just north of the easternmost gun emplacement is a concrete block building which may represent a shelter. On the northern side of the loop is a further concrete block building which, although it has been altered and its entrance widened in the post-war period, is believed to be the remains of a contemporary World War II stores building.

All modern fencing and fenceposts are excluded from the scheduling, although the ground beneath them is included.

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


The contents of this record have been generated from a legacy data system.

Legacy System number:
Legacy System:


Books and journals
Pye, A, Woodward, F, The Historic Defences of Plymouth, (1996), 232-33


This monument is scheduled under the Ancient Monuments and Archaeological Areas Act 1979 as amended as it appears to the Secretary of State to be of national importance. This entry is a copy, the original is held by the Department for Digital, Culture, Media and Sport.

End of official listing

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