Naval forts of WW2

A link from Castle Argghhh! led to this fascinating tour of the Maunsell Towers, anti-aircraft positions built on artificial islands to protect the Thames Estuary:

The Thames Estuary Army Forts were constructed in 1942 to a design by Guy Maunsell, following the successful construction and deployment of the Naval Sea Forts. Their purpose was to provide anti-aircraft fire within the Thames Estuary area. Each fort consisted of a group of seven towers with a walkway connecting them all to the central control tower. The fort, when viewed as a whole, comprised one Bofors tower, a control tower, four gun towers and a searchlight tower. They were arranged in a very specific way, with the control tower at the centre, the Bofors and gun towers arranged in a semi-circular fashion around it and the searchlight tower positioned further away, but still linked directly to the control tower via a walkway. All the forts followed this plan and, in order of grounding, were called the Nore Army Fort, the Red Sands Army Fort and finally the Shivering Sands Army Fort. All three forts were in place by late 1943, but Nore is no longer standing. Construction of the towers was relatively quick, and they were easily floated out to sea and grounded in water no more than 30m (100ft) deep.

There was also a link to a page on the Navy version:

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.