Originally 49 sea forts were planned to be built on the Thames estuary and 38 on the Mersey.
The forts were built on land and transported out on the sea.
Right after they were planted there, they became operational and took part in the British effort to defend the much-so important Thames Estuary.
After the war was over the forts lost their strategic importance and were soon decommissioned.
The Nore Army Fort had to be dismantled between 1959 and 1960 after two of the towers collided with a ship and the ruins were considered unsafe.
Possibly the other towers would have been forgotten as well but musician and troublemaker Screaming Lord Sutch founded Radio Sutch in 1964.
The pirate radio started in a fishing boat but in May it relocated in the ruins of Shivering Sands fort. Although Sutch soon sold the radio station to his manager, many other pirate radios moved in to other forts and started broadcasting from there.
Some of these pirate radios include Radio 390 on Redsands, Radio Essex on Knock John or Tower Radio on Sunk Head. Soon after the Marine Broadcasting Act passed and offshore pirate radios were outlawed. As a response BBC started Radio 1 and Radio 2 in 1967.
Aspects of the forts’ design were used in the early 70’s for offshore oil and gas rigs and they are considered as the predecessors of modern offshore rigs.
The Roughs tower is occupied by the Principality of Sealand since 1967, a micronation that is described as the world’s smallest country.
In 1996 following a heavy storm, Tongue Fort collapsed.
Currently the Redsands Project aims to restore the Redsands Army Fort.
Among the renovation plans are an on-site museum devoted to the war and the pirates, a recording studio, and possibly a broadcasting studio.