The Maunsell Sea Forts.

These forts were constructed to protect the Thames Estuary during W.W.2.

 Between 1942-1943 two types of fort were constructed & placed on the sand banks towards the entrance of the Estuary. The reasons why the Forts were required are as follows;                    

The Thames Estuary was a major shipping area with both merchant shipping & Naval shipping using the Estuary to obtain access to various docks located around the Estuary.

With this being the case it was a target for German mine laying planes who would fly in low over the mouth of the Thames out of range of any existing anti-aircraft weapons & used as floating batteries it was decided that these were not effective enough.

Another  threat of attack was from surface enemy shipping laying mines or using torpedoes to harass shipping in the Estuary & shore based targets.

Enemy bombers could also use the Thames as a landmark to follow on the way to bomb London & any of the important towns/sites around the Thames.

With the reasons given above in 1940 Mr. Guy Maunsell a Civil Engineer was given the task of producing & constructing the Forts for both the Thames Estuary & the Humber Estuary. 2 designs were finally produced to be used in the Thames Estuary both designs were pre-built fully assembled & towed to their permeate location site. The method chosen for sighting these forts was to have them built on concrete barges, which were used to tow the forts to there chosen location which once in position they were sunk in a controlled sinking. The fact that all of the Forts were located on sand banks helped to ensure that they did not move even in the roughest conditions.

Together the 7 forts that were placed in the Thames destroyed 1 E-boat, 22 aircraft & 31 V1 flying bombs.

Of the 7 forts that were built & placed in the Thames only 4 remain standing today. Bearing in mind that the forts were constructed of only reinforced concrete & plate steel. This in itself is not a bad feat in engineering terms as the forts have been standing for some 55 years. No consideration was made for the disposal of the forts after the war as it was considered at the time by the Ministry of Defence that the combination of weather conditions in the Thames & tidal action would destroy the forts in a relatively short period of time.