Maunsell Forts


The Maunsell Forts are towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom. They were operated as army and navy forts, and named after their designer, Guy Maunsell. A total of four navy forts were built, off the east coast of England, and six army forts were built - three in the Thames estuary, and three in the Mersey estuary. The forts were decommissioned during the late 1950s and later used for other activities including pirate radio broadcasting. One of the forts is managed by the unrecognised Principality of Sealand; boats visit the remaining forts occasionally, and a consortium named Project Redsands is planning to conserve the fort situated at Red Sands. The aesthetic attraction of the Maunsell forts has been considered to be associated with the aesthetics of decay, transience and nostalgia.
During the summers of 2007 and 2008, Red Sands Radio, a station commemorating the pirate radio stations of the 1960s, operated from the Red Sands fort on 28-day Restricted Service Licences. The fort was subsequently declared unsafe, and Red Sands Radio has moved its operations ashore to Whitstable.
Forts had been built in river mouths and similar locations to defend against ships, such as the Grain Tower Battery at the mouth of the Medway dating from 1855, Plymouth Breakwater Fort, completed 1865, the four Spithead Forts: Horse Sand Fort, No Mans Land and St Helens Forts which were built 1865–1880 and Spitbank Fort, built during the 1880s, the Humber Forts on Bull & Haile Sands, completed in late 1919, and the Nab Tower, intended as part of a World War I anti-submarine defence but only set in place in 1920.

Maunsell naval forts

The Maunsell naval forts were built in the Thames estuary and operated by the Royal Navy, to deter and report German air raids following the Thames as a landmark, and prevent attempts to lay mines by aircraft in this important shipping channel.
There were four naval forts:
This artificial naval installation is similar in some respects to early "fixed" offshore oil platforms. It consisted of a rectangular by reinforced concrete pontoon base with a support superstructure of two tall, diameter hollow reinforced concrete towers, walls roughly thick; overall weight is estimated to have been approximately 4,500 tons. The twin concrete supporting towers were divided into seven floors, four for crew quarters; the remainder provided dining, operational, and storage areas for several generators, and for fresh water tanks and antiaircraft munitions. There was a steel framework at one end supporting a landing jetty and a crane, which was used to hoist supplies aboard; the wooden landing stage itself became known as a "dolphin".
The towers were joined above the eventual waterline by a steel platform deck upon which other structures could be added; this became a gun deck, on which an upper deck and a central tower unit were constructed. QF 3.7 inch anti-aircraft guns were positioned at each end of this main deck, with a further two Bofors 40 mm anti-aircraft guns and the central tower radar installations atop a central living area that contained a galley, medical, and officers quarters.
The design of these concrete structures is equal to a military grade bunker, due to the ends of the stilts, that are locked into the ground. Many species of fish live near the forts because the forts create cover. They have provided landmark references for shipping. They were laid down in dry dock and assembled as complete units. They were then fitted out—the crews going aboard at the same time for familiarization—before being towed out and sunk onto their sand bank positions in 1942.
The naval fort design was the latest of several that Maunsell had devised in response to Admiralty inquiries. Early ideas had considered forts in the English Channel able to combat enemy vessels.
During World War II, the Thames estuary Navy forts destroyed one German E-Boat.

Rough Sands Fort (U1)

Rough Sands fort was built to protect the ports of Felixstowe, Harwich and the town of Ipswich from aerial and sea attack. It is situated on Rough Sands, a sandbar located approximately from the coast of Suffolk and from the coast of Essex. Fort Roughs or the "Rough Towers" was the first of the four naval Maunsell Forts to be deployed. It was constructed in dry dock at Red Lion Wharf, Gravesend, and was commissioned "H.M. Fort Roughs" on 8 February 1942. After an eventful journey, its grounding was supervised by Maunsell at 16:45 on 11 February 1942. With "almost 100 men" having earlier embarked at Tilbury docks, the fort began service immediately.
In 1966, Paddy Roy Bates, who operated Radio Essex, and Ronan O'Rahilly, who operated Radio Caroline, landed on Fort Roughs and occupied it. However, after disagreements, Bates seized the tower as his own. O'Rahilly attempted to storm the fort in 1967, but Bates defended the fort with guns and petrol bombs and continued to occupy it. The British Royal Marines were alerted and the British authorities ordered Bates to surrender. He and his son were arrested and charged, but the court dismissed the case as it did not have jurisdiction over international affairs: Roughs Tower lay beyond the territorial waters of Britain. Bates took this as de facto recognition of his country and seven years later issued a constitution, flag, and national anthem, among other things, for the Principality of Sealand.

Sunk Head Fort (U2)

Sunk Head fort was situated approximately from the coast off Essex and was grounded on 1 June 1942. The fort was decommissioned on 14 June 1945 though maintained until 1956 when it was abandoned. Unlike some of the other forts, Sunk Head was clearly well outside territorial waters, and when the Marine, &c., Broadcasting Act 1967 came into effect in August 1967, the Government was anxious to ensure that it would not be taken over again by an offshore broadcaster. On 18 August 1967, Sunk Head was boarded by a contingent of the 24th Field Squadron, Royal Engineers from Maidstone from the tug Collie, commanded by Major David Ives. The Fort was weakened by acetylene cutting torches and 3,200 pounds of explosives were set. On 21 August 1967, Sunk Head was blown, leaving 20 feet of the leg stumps remaining.

Tongue Sands Fort (U3)

Tongue Sands Fort was situated approximately from the coast off Margate, Kent and was grounded on 27 June 1942. On the night of 22/23 January 1945, fifteen German E-boats were seen on radar, with five close by. The S.119 or S.199 operating out of IJmuiden, Holland was just over 4 miles away and came under heavy fire from Tongue Sands Fort's 3.7-inch guns. The German E-Boat's captain was unsure of where the attack was coming from and manoeuvred to avoid being hit, ramming another E-Boat in the process. The captain scuttled his badly damaged vessel.
The Tongue Sands Fort was decommissioned on 14 February 1945 and reduced to care and maintenance until 1949 when it was abandoned. The fort had settled badly when it was grounded and as a result became unstable. On 5 December 1947, the Fort shook violently and sections began falling into the sea. The caretaker crew sent a distress call and were rescued by HMS Uplifter. Divers later established that the foundations were solid, but in a later storm the fort took on a 15 degree list. During the mid-1960s, under-scouring had further distorted the fort: large holes had appeared in the east leg, sea water had flooded the lower levels and the platform had become detached with huge gaps between the deck. Tongue Sands Fort finally collapsed into the under-scouring hole during storms on 21/22 February 1996, leaving only a single 18 foot stump of the south leg remaining visible above sea level.

Knock John Fort (U4)

Knock John fort is situated approximately from the coast off Essex and was grounded on 1 August 1942. It was decommissioned on 14 June 1945 and evacuated on 25 June 1945. The platform was maintained until May 1956 when it was abandoned. In 2009, it was observed that there was a slight distortion of the legs when viewing the tower from west to east. It is thought that underscouring is the cause of this.

Maunsell army forts

Maunsell also designed forts for anti-aircraft defence. These were larger installations comprising seven connected steel platforms. Four towers arranged in a semicircle ahead of the control centre and accommodation each carried a QF 3.7-inch gun, a tower to the rear of the control centre mounted Bofors 40 mm guns, while the seventh tower, set to one side of the gun towers and further out, was the searchlight tower.
Three forts were placed in Liverpool Bay:
  • Queens AA Towers
  • Formby AA Towers
  • Burbo AA Towers
and three in the Thames estuary:
  • Nore,
  • Red Sands
  • Shivering Sands
The Mersey forts were constructed at Bromborough Dock and the Thames forts at Gravesend. Proposals to construct forts off the Humber, Portsmouth & Rosyth, Belfast & Londonderry came to nothing. During World War II, the Thames estuary forts shot down 22 aircraft and about 30 flying bombs; they were decommissioned by the Ministry of Defence during the late 1950s.

Nore Fort (U5)

Nore fort was the only one built in British territorial waters at the time it was established. Other forts were in international waters until the three-mile limit was extended to. The fort was damaged badly in 1953 during a storm, then later in the year a Norwegian ship, Baalbek, collided with it, destroying two of the towers, killing four civilians and destroying guns, radar equipment and supplies. The ruins were considered a hazard to shipping and dismantled in 1959–1960. Parts of the bases were towed ashore by the Cliffe fort at Alpha wharf near the village of Cliffe, Kent, where they were still visible at low tide.