As explained in our background page, the four
Navy forts were the first Maunsell platforms to be placed in the
mouth of the Thames. They included Roughs Tower, Sunk Head,
Tongue Sands and Knock John and, between February and August of
1942, they were positioned in an a broad arc that mapped the
coastline between Felixstowe and Margate. At this point is worth
taking another look at our estuary map....
The forts were brought into service in the following
They were more compact than their army descendants,
occupied positions much further seaward and formed a North-South
(rather than East-West) line of protection on the outer perimeters of the estuary.
Each fort comprised a substantial steel platform
mounted on two massive concrete legs....
The platform carried two 3.7"
anti-aircraft and two Bofors guns. The hollow legs contained a
number of storeys and provided living quarters for the navy
personnel. Power was supplied by generators.
The Navy Forts
The forts have met with mixed fortunes and only two
can really be said to have survived. The table below summarises the
||Survives and now has a heli-pad located on its
||Officially Demolished by explosives in
||Destroyed by a storm in 1996.
||Survives and is probably the
best preserved in terns of original appearance.
As mentioned in on our background page, the Knock
John can just be seen from Tankerton Slopes on a clear day. It's
orientation means that you can make out the distinctive 'pi-sign'