Heavy Anti Aircraft gunnery relied on large calibre guns intended to combat high flying aircraft. During WW2 this work was shared between five main types of weapon, ranging from a 3 inch 20 cwt gun, (the standard HAA waeapon during WW1 and used well into WW2) which could fire a shell to a height of 23,500 ft, up to a 5.25 inch Mk 2 gun, which could fire a shell up to 43,000 ft. Some of the first 5.25 inch batteries were positioned on the coast and had a dual coastal defence/anti-aircraft role. Until late 1940 virtually all HAA sites were temporary, consisting of earthwork gun pits and tented accomodation. Guns were generally mobile. As war progressed, these were replaced by permanent structures and static guns. A typical HAA gun site consisted of a command post (rectangular concrete or brick semi-sunken structure, often protected by earth banks), this was usually located at the centre of a 39.6m radius semi-circle of gun pits. There would also be one or two shelters, one for gun maintenance (limber gunner's shelter) and the other for the gun detachment. Ammunition was stored in magazines. Instruments and spare parts were kept in the gun store. Domestic HAA sites also had Nissen and timber huts, workshops and garages and often a sewage treatment plant.A concrete service road led from main gate via the magazine around the command post, with offshoots to each gun pit. In plan this gave the site a "four leaf clover" shape {"20th Century Defences in Britain, An Introductory Guide, Handbook of The Defence of Britain Project, 1995, pp 48-59}.

Heavy Anti Aircraft gunnery relied on large calibre guns intended to combat high flying aircraft. During WW2 this work was shared between five main types of weapon, ranging from a 3 inch 20 cwt gun, (the standard HAA waeapon during WW1 and used well into WW2) which could fire a shell to a height of 23,500 ft, up to a 5.25 inch Mk 2 gun, which could fire a shell up to 43,000 ft. Some of the first 5.25 inch batteries were positioned on the coast and had a dual coastal defence/anti-aircraft role. Until late 1940 virtually all HAA sites were temporary, consisting of earthwork gun pits and tented accomodation. Guns were generally mobile. As war progressed, these were replaced by permanent structures and static guns. A typical HAA gun site consisted of a command post (rectangular concrete or brick semi-sunken structure, often protected by earth banks), this was usually located at the centre of a 39.6m radius semi-circle of gun pits. There would also be one or two shelters, one for gun maintenance (limber gunner's shelter) and the other for the gun detachment. Ammunition was stored in magazines. Instruments and spare parts were kept in the gun store. Domestic HAA sites also had Nissen and timber huts, workshops and garages and often a sewage treatment plant.A concrete service road led from main gate via the magazine around the command post, with offshoots to each gun pit. In plan this gave the site a "four leaf clover" shape {"20th Century Defences in Britain, An Introductory Guide, Handbook of The Defence of Britain Project, 1995, pp 48-59}.

Heavy Anti Aircraft gunnery relied on large calibre guns intended to combat high flying aircraft. During WW2 this work was shared between five main types of weapon, ranging from a 3 inch 20 cwt gun, (the standard HAA waeapon during WW1 and used well into WW2) which could fire a shell to a height of 23,500 ft, up to a 5.25 inch Mk 2 gun, which could fire a shell up to 43,000 ft. Some of the first 5.25 inch batteries were positioned on the coast and had a dual coastal defence/anti-aircraft role. Until late 1940 virtually all HAA sites were temporary, consisting of earthwork gun pits and tented accomodation. Guns were generally mobile. As war progressed, these were replaced by permanent structures and static guns. A typical HAA gun site consisted of a command post (rectangular concrete or brick semi-sunken structure, often protected by earth banks), this was usually located at the centre of a 39.6m radius semi-circle of gun pits. There would also be one or two shelters, one for gun maintenance (limber gunner's shelter) and the other for the gun detachment. Ammunition was stored in magazines. Instruments and spare parts were kept in the gun store. Domestic HAA sites also had Nissen and timber huts, workshops and garages and often a sewage treatment plant.A concrete service road led from main gate via the magazine around the command post, with offshoots to each gun pit. In plan this gave the site a "four leaf clover" shape {"20th Century Defences in Britain, An Introductory Guide, Handbook of The Defence of Britain Project, 1995, pp 48-59}.

Gasholders or gasometers are large vertical cylindrical storage vessels for holding town gas at constant pressure prior to distribution to consumers. The oldest design of gasholder, made from wrought-iron plates dates from an 1824 patent. It telescoped vertically by means of grooved wheels on vertical guide rails. Later design by W. Gadd in 1890. Small gasholders were used in factories and mills which had their own gas manufacturing plant for providing lighting. By the 1870s a typical gas manufacturing works comprised of: a retort house containing rows of retorts where the gas was made, a hydraulic main to provide a water seal to prevent explosive gas blowbacks when a retort was opened, a condensor to cool the gas and allow liquid tar to drain out, an exhauster to draw out the gas from the retorts, a scrubber in which water removed ammonia from the gas, purifiers to remove contaminants, a meter to measure the volume of gas, one or more gasholders, a governor to control the pressure at which gas was distributed to customers, covered storage for coal and coke, a boiler and steam engine to drive the exhauster and a water pump for the scrubber (William Jones, 1996, Dictionary of Industrial Archaeology, EG Stewart, 1958, History of the gas, light and coke co. 1812-1949, T. Williams, 1981, History of the British Gas Industry).