In 1943, at the height of WW2, the Brits built some "sea forts" in the broader thames estuary. The plan was to protect London from the Luftwaffe
raids. Fortunately, the raids were over, by time the sea forts were installed.
It seems like a couple destroyers, anti aircraft equipped, would have been a better choice...with their mobility.
Perhaps they should have listened to Gen Patton, who said.. "Fixed fortifications are a monument to the stupidity of man."
THe Persian Gulf had numerous abandoned oil drilling platforms when my nephew was serving there wiith our Navy, during the Iran/Iraq war.
It seems some of those Iranian fanatics installed some guns on those platforms..and waited until they figured some of our ships were in range,
when they fired upon them.
Our Navy gave them warning and waited for them to abandon the platforms..some did..some didn't. the stubborn ones found their Valhalla !
Below, see the "sea forts"..they still stand today..without crosswalks, etc.
