The Sea Forts
Following the outbreak of World War II, sea forts were built in the Thames Estuary, for the protection of coastal areas, and London from enemy aircraft and shipping attacks.
They were principally there to give an early warning using their then new radar equipment, to break up aircraft formations and also to prevent minelaying in the important sea route to London.
Two types of fort were built, both designed by Mr. G. A. Maunsell. Four of them were for the Navy, out in the open sea, while the Army had three further inshore. Both types were constructed by Holloway Brothers, at Gravesend in Kent.
The Navy forts comprised a pontoon base supporting
two hollow concrete legs of about 8 metres diameter. These contained seven decks with
accommodation for one hundred men, food, fuel and ammunition supplies. They were topped by
a steel gun platform, that also housed a control tower and radar equipment.
Grounding of Roughs tower in 1942
Each Naval fort, fully manned and ready for action was commissioned at the building yard, then towed out by three tugs. The first Navy fort was sited off Harwich in February 1942. The method of grounding was to flood the hollow pontoon base with seawater, causing the fort to sink into position. The Navy forts were situated at Knock John, Tongue Sands, Sunk Sand and the Roughs.
The Army forts at Shivering Sands, Red Sand and the Great Nore were completely different in style to the Navy forts, being similar in layout to a shore based anti-aircraft site. There were seven towers in each complex, with a central control tower, surrounding by five gun towers, with a searchlight tower at the rear.
Gun towers of Nore army fort
Each tower comprised four concrete legs supporting a steel structure. They were all self-contained with fuel and food supplies as well as living and sleeping accommodation. They were linked by steel catwalks, which also carried fuel and power lines from tower to tower. Specially made barges carried the towers, two at a time, out to their grounding sites, where they were lowered by winches onto the sea bed.
All of the forts were successfully positioned and between them shot down 22 enemy aircraft and about 25 flying bombs. The Tongue Sand fort, off Margate, also captured an enemy submarine that was attempting to torpedo the fort.
After the war, the forts were abandoned. The army fort at Great Nore was demolished in 1958 as it was in the shipping lanes. The Shivering Sands fort lost a tower, when a ship ran into it. Four people were killed then, the only casualties on the forts up to that time.
The forts were to remain disused for nearly twenty years, until one day in May 1964, when pop singer Screaming Lord Sutch sailed alongside.
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