5:The Fate of the Navy Towers: Rough, Sunk, Tongue, Knock John

U1 Roughs Tower

Roughs Tower celebrated its 80th anniversary in 2022. In action, Roughs engaged 96 enemy aircraft and expended 1,784 3.7″ rounds, 1,217 Bofors rounds: six aircraft and six V1 kills were claimed¹.

The tower’s career as Sealand is well documented elsewhere. Sadly, most of the superstructure has been removed over the years but the structure still appears sound. The towers sit on a seabed of 9.2m below CD.

U2 Sunk Head

Sunk Head sits on a seabed at 12.6m below CD and so was the deepest installation of the four Naval Towers.

Attempts were made to occupy the tower by radio pirates, but they failed to maintain a presence.

Sunk Head 1965 occupied by pirate radio station.
From Principality of SeaLand Official Community, original author unknown.

To prevent this U2 Sunk Head was partially demolished in 1967 to deny it to future occupiers. To misquote the Italian Job, made two years later:

“You’re only supposed to blow the bloody doors off!”.

Probably the Navy was also having some fun. This short video shows the event.

Demolition of Sunk Head – ignore title it’s not Roughs.

The stumps of the towers were left standing above sea level. This resulted in a vessel being damaged by colliding with them in 1991. Presumably, the job was finished not long after this.

In order to find out what remains a survey was made using a yacht depth sounder in 2023. This was developed into a rough 3D image to be produced showing the base and tower stumps.

U3 Tongue Sand

Tongue Sands sits on a seabed of around 7m below CD and visibly began to subside in 1947. In action Tongue Fort claimed an ‘E’ Boat kill. After the War, the crew had to be rescued by the RNLI and the fort was abandoned in the 1960s. Only a stump remains. Judging by the chart a visit at LW springs would be interesting. Unlike the other sites where the tide reciprocates, there is a rotary cycle at Tongue Sand which caused scouring and collapse. The Admiralty chose the sites, of which this was the third. Maunsell would have understood the issue so why allow it to be put there? If it had been put on Sunk Sand, it might not have collapsed and would have closed the gap mentioned earlier.

These photographs from around 1973 show the instability of the towers.

1973 approximately - Tongue Sands Tower photographer Nick Catford — 1973 approximately – Tongue Sands Tower photographer Nick Catford

U4 Knock John

U4 Knock John sits on a seabed of around 6m and looks surprisingly good from the photos taken in 2018 by the 28DL group and used in the HM Fort Roughs Tower workings item. There are still traces of the Carbolastic bitumen.

The crew would have been thrilled on June 5th 1944: throughout that day and evening, thousands of bombers passed overhead to bomb France. During the morning the 280 vessels of Force ‘L’ assembled nearby before sailing for Normandy. This was the follow up force that would push into France.

Knock John Photo from 24DL www.28dayslater.co.uk

Tidal Diamonds

Sailors will notice the co-incidence of fort sites and tidal diamonds. This must be because the accurate surveys carried out for the site selection were then re-used.

The Army Towers

When more Towers were required, Maunsell proposed the design that was the basis for the Army Towers. Perhaps the Army had them because they were closer to the shore, or was it their turn? The Army forts are visually more appealing and another tale which is well covered by Frank Turner and others. The first set was positioned in the Mersey and there were plans for many more such as on the Humber.