World War II Heavy Anti-aircraft gunsite (P2) at Sinah Common, 570m south east of Sinah Farm


Heritage Category: Scheduled Monument

List Entry Number: 1020961

Date first listed: 16-Jul-2003


Ordnance survey map of World War II Heavy Anti-aircraft gunsite (P2) at Sinah Common, 570m south east of Sinah Farm
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The building or site itself may lie within the boundary of more than one authority.

County: Hampshire

District: Havant (District Authority)

National Grid Reference: SZ 69991 99404


Legacy Record - This information may be included in the List Entry Details.

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 World War II Heavy Anti-aircraft gunsite (P2) at Sinah Common, 570m south east of Sinah Farm is well preserved and will contain a wealth of archaeological evidence relating to the construction and usage of the site, which spanned two main periods: World War II and the early Cold War. Its remains, which bear the marks of bomb damage, provide a testimony to a crucial period in British history, which has been largely erased elsewhere. Its significance is futher enhanced by its association with the bombing decoy south of the gunsite, as well as World War II defences along the southern coast of Hayling Island, such as pillboxes and anti-tank defences.


Legacy Record - This information may be included in the List Entry Details.


The monument, which includes a World War II Heavy Anti-aircraft (HAA) gunsite and its associated domestic camp, is situated at Sinah Common approximately 700m north of Hayling Bay. The gunsite, known as Sinah or P2 (Portsmouth 2), formed part of a chain of batteries positioned to defend the industrial and military targets of Portsmouth. As the size and shape of Hayling Island closely resemble that of Portsmouth, the island was set up as a decoy to distract enemy aircraft from the city. In April 1941 Hayling Island received over 200 bombs and parachute mines, and the gunsite was hit directly, killing six of its crew members. The gunsite remained out of action until December 1941. It was then equipped with a GL Mk II radar and in April 1942 was amongst the first to be fitted with a paraboloid aerial replacing the Ground Laying mat. 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 four 4.5 inch gun emplacements are situated at the western end of the site along a semicircular road with direct access from Ferry Road. They surround a control building, which has been mounded over, but which will survive as a buried feature. Sources indicate that the gun emplacements were numbered 1 to 4 from south to north. They were octagonal in shape with six ammunition recesses fitted along the concrete blast wall surrounding the holdfasts. Emplacement number 1 is well preserved, despite its southern tip subsiding into the adjacent pond as a result of quarrying. At its centre securing bolts protrude from the holdfast, while all six ammunition lockers are present, equipped with internal recesses in which wooden shelfs were fitted. Contemporary stencilling on one of the lockers reads the angle measurement 75 degrees, indicating the position of the gun at this angle. Immediately north of emplacement number 1 is a generator room, which was damaged during the 1941 attack, leaving a large hole in the roof. Original cables remain embedded in its northern wall. Emplacements numbers 2 and 3 have been substantially altered to provide sheltered seating; the back gates have been filled, the adjoining storage bunkers were closed off, and all ammunition lockers removed. Surfaces were plastered or paved over and benches were placed along the blast walls. Emplacement number 2 was heavily damaged in 1941 and a small plaque, installed in 1994, commemorates the men of the 219 battery, 57th Heavy Anti-aircraft Regiment, who were killed in action. Emplacement number 4 was infilled in the late 1960s, but will survive as a buried feature underneath the mound. The emplacements were served by two ammunition stores; one at the northern end of the site along Ferry Road and the other at its southern extremity near emplacement number 1. These five-bay magazines were protected within blast walls, which proved effective during the 1941 attack. Although the blast wall at the southern end of the site was damaged, the magazine remained unscathed and the glass in its windows survives. About 100m east of the magazine on Ferry Road is a red brick flat-roofed gun store, which has been refurbished with new doors, ramp, guttering and roof, and is now in use as a powerhouse. A track connects the emplacements and the domestic camp at the eastern end of the site. The general layout of the domestic quarters is apparent from the concrete roads, which come off the main entrance at Ferry road. Along the southernmost track is a concrete standing which probably functioned as a parade ground. In the north eastern corner of the site a concrete air raid shelter is preserved, which has been bricked up. On its roof are two small domes covering air vents. The gunsite was surrounded by a fence, of which some of the original posts survive. The following items are excluded from the scheduling: all later surfaces, fences, gates and structures (including bollards, bins, interpretation boards and Pay and Display machines), and all later materials and equipments stored within the site. However, the ground beneath these features is included.

MAP EXTRACT The site of the monument is shown on the attached map extract. It includes a 2 metre boundary around the archaeological features, considered to be essential for the monument's support and preservation.


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

Legacy System number: 33402

Legacy System: RSM

End of official listing