October 16, 2012 at 10:19 am

The Maunsell Sea Forts of WWII

by twistedsifter

WWII Sea Forts - Red Sands

Photograph by Neil Brown on Flickr



At the outbreak of World War II, the Port of London was the busiest port in the world. The German Navy recognized the Thames as an important shipping route and sought to disrupt its usage through the use of a new secret weapon — the magnetic influence mine. Essentially these mines were detonated by the presence of a large metallic object, like that of a steel-hulled ship. This meant that the mines could detonate with ships in close proximity, not having to actually make physical contact to be effective.

Hundreds of ships were sunk by these innovative mines and the Allies needed a solution, fast. Knowing the mines were laid by aircraft, Guy Maunsell (1884-1961), a British civil engineer, produced plans for offshore defences. After some modifications his plans were approved and the Maunsell Sea Forts and Army Towers were born. [Source: Project Redsand]



Knock John Naval Fort



Fort Knock John



The Maunsell Sea Forts

The design was a concrete construction; a pontoon barge on which stood two cylindrical towers on top of which was the gun platform mounting two 3.75-inch guns and two 40 mm Bofors guns. They were laid down in dry dock and assembled as complete units. They were then fitted out — the crews going on board at the same time for familiarization — before being towed out and sunk onto their sand bank positions in 1942. [Source: Wikipedia]

Each fort accommodated approximately 120 men, housed mainly within seven floors of the 24’ diameter (7.3m) twin reinforced concrete legs. These forts were under the control of the Navy, and were individually known as HM Fort Roughs Tower, Sunk Head Tower, Tongue Sands, and Knock John. They were all placed in position between six and twelve miles (9.6km – 19km) offshore between February and June, 1942. [Source: Project Redsand]



Knock John fort 8118

Photograph by Tony Crowe on Flickr



Knock John Navy Fort



The Maunsell Army Sea Towers

Maunsell also designed forts for anti-aircraft defence. These were larger installations comprising of seven interconnected steel platforms (army sea towers), five carried guns arranged in a semicircle around the control centre and accommodation while the seventh, set further out than the gun towers, was the searchlight tower. Three forts were placed in the Mersey and three in the Thames estuary between May and December, 1943. [Source: Wikipedia]

Each tower was built off a reinforced concrete base of ‘Oxford picture frame’ design. Four hollow reinforced concrete legs of 3’ diameter supported the 36’ x 36’ (11 x 11 meters) steel house of two floors, with the military equipment installed on the top deck. Each fort accommodated up to 265 men. [Source: Project Redsand]



WWII Sea Forts - Red Sands

Photograph by Neil Brown on Flickr



WWII sea forts - Red Sands

Photograph by Neil Brown on Flickr



Redsands WWII Maunsell Sea Forts



Redsands WWII Maunsell Sea Forts



Redsands WWII Maunsell Sea Forts



Pirate Radio and the Principality of Sealand

After the war the forts were decommissioned in the late 1950s and used for a variety of activities. Various forts were re-occupied for pirate radio in the mid-1960s.

In 1964, a few months after Radio Caroline went on air, Screaming Lord Sutch set up Radio Sutch in one of the towers at Shivering Sands. Sutch soon became bored with the project and sold the station to his manager Reginald Calvert who renamed the station Radio City and expanded operations into all of the five towers that remained connected. Calvert’s killing in a dispute over the station’s ownership (found to be self-defence rather than murder) contributed to the Government passing legislation against the pirates in 1967. [Source: Wikipedia]

In 1967, former British Army Major Paddy Roy Bates occupied the HM Fort Roughs Sea Fort, claiming it as an independent sovereign state. Bates seized it from a group of pirate radio broadcasters, establishing the Principality of Sealand as a nation in 1975 with the writing of a constitution and establishment of other national symbols. Bates moved to mainland Essex when he became elderly, naming his son Michael regent. Bates died in 2012 at the age of 91.

While it has been described as the world’s smallest nation, or a micronation, Sealand is not currently officially recognised by any established sovereign state. Although Roy Bates claimed it is de facto recognised by Germany (since they have sent a diplomat to the micro-nation), and by the United Kingdom (after an English court ruled it did not have jurisdiction over Sealand) neither action constitutes de jure recognition as far as the respective countries are concerned. [Source: Wikipedia]



The Maunsell Forts



redsand maunsell sea forts The Maunsell Sea Forts of WWII



Project Redsand

As the only complete structure built in wartime, Redsand Fort is the focus of attention by Project Redsand, a group of enthusiasts with the aim of reinstating the Fort to its original built condition. Having had an underwater survey carried out by the Port of London Authority, work has progressed to installing a new access system to the G1 tower thanks to the generosity of Mowlem Marine (now Carillion) of Northfleet. Built at a cost of approximately £40,000, the access system enables project members to board the tower to commence restoration.

A new survey of the above water structures is being conducted by Taylor Woodrow and once this is complete, a museum and other installations will enable the Fort to take its place as a monument to the ingenuity of Guy Maunsell, who used the Army Fort design to pave the way for oil and gas exploration rigs in the North Sea in the 1950s. [Source: Project Redsand]



Thames Forts

Photograph by Rich C on Flickr



WWII sea forts - Shivering Sands

Photograph by Neil Brown on Flickr







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