During the First World War, two guns (a 3-inch and a 6-pounder Hotchkiss) were emplaced at Lower Hope Point, for the defence of the explosive works. During the Second World War, an anti-aircraft battery (designated TS14) was established within the Study Area in a field at Redham Mead. This was part of a network of such defences on either side of the Thames to defend the river approaches to London. From contemporary records it certainly existed by February 1940 but few details are known about it. It was probably a battery of 3.7-in. or 4.5-in. guns on mobile mountings. Eyewitnesses refer to problems with unstable marsh which, on the firing of the guns, sometimes caused their mountings to sink into the ground. There is said to have been another anti-aircraft battery existing for a time on the marsh but this needs further investigation. There are also memories of a mobile unit of Bofors light anti-aircraft guns having operated in the area.
The threat and sometimes the reality of air raid during the Second World War led to a need for the building of air raid shelters for the protection of people, including those working in industry. On the north side of Salt Lane such a shelter was created for the workers in the cement factory on the south side of the road (66). This concrete structure, protected under a mound of chalk, still exists. There may have been other shelters for this factory. Caves in the chalk cliffs on the east side of Quarry Road are said to have been used as air raid shelters by those living in nearby, and now vanished, houses. At least one cave still exists. The formerly existing coastguard cottages at the western end of Redham Mead were, according to an eyewitness, provided with two surface air raid shelters – one an Anderson type and the other a small brick one.
As part of a national strategy for air defence, some hundreds of decoy sites were established across Britain as part of strategic planning for diverting the attention of German bombers away from factories, docks, air fields and other sites important to the British war effort. In 1940 one of these ‘Q’ sites, manned by RAF personnel, was created on Cliffe Marshes for RAF Gravesend, 7 km SW, (with another decoy 9 km south of the airfield at Luddesdown). At night, lights simulating the flarepath of a runway could be briefly exposed to suggest that the site was an operational airfield. The deception was controlled from a still extant concrete blockhouse, just south of Boatrick House. Some puzzlement was expressed by the Station Master of Cliffe railway station who questioned the reason for the regular arrival of boxes of condoms to be delivered to the RAF personnel. He was advised (but told not to reveal) that these were needed to cover elements of the decoy airfield array which it was important to keep rainproofed. These coverings had to be frequently renewed. The airfield may have drawn at least some bombing attention from Gravesend, although a study of aerial photographs appears to reveal few traces of bomb impacts or cratering of the marsh. The decoy airfield is also remembered by some local residents to have been, for a time, the tethering site for a barrage balloon.
Ground air observation 1938-1968
With its fine views of the sky approaches to London, the elevated ground of the Allen’s Hill area on the 20m contour above the marshes, just west of Cliffe village, was chosen in 1938 for the siting of one of a national network of observation posts for spotting and reporting hostile aircraft. At least for a time during the Second World War there was also an anti-aircraft searchlight on Allen’s Hill, thought to have been sited in its NW corner. The observation post was replaced in 1953, during the early part of the Cold War, by an updated post formed of a prefabricated concrete. This was called an Orlit post, and resembled a coal bunker on stilts. In 1961, it was removed and replaced on the same site by an underground bunker –one of 1500 nationally - for plotting radioactive fallout in the event of a nuclear attack. It was closed in 1968 as part of a national reduction of the numbers of such posts. Its surface features are still visible.
by Victor Smith