German WWII Coastal Artillery, Longues Sur-Mer, Normandy
Le Chaos battery at Longues sur Mer was only just ready for action on D-day, construction having started in September 1943. It comprised four gun emplacements type 272, and a two story observation post type 262. which at the time of the invasion had not been completed.
The cliff face in from of the post still had to be cleared, this was done for the making of the film "The Longest Day". The battery was also equipped with anti aircraft guns and searchlights.
The site is unique in having its guns still in situ. The guns are 152 mm, made by Skoda, rapid firing naval guns and were intended to be fitted to ships. These guns had a range of 13 miles and had been built in 1928 and were the most modern on the Atlantic Wall. They were protected by 10 mm of steel around the gun, and with a well trained crew they could fire six shells per minute.
Each Casemate needed 600 cubic meters of concrete and over 100 tons of steel in its construction.
The guns that protected the Atlantic Wall were commandeered by the Germans from many of the countries overrun by them, French, Russian, Czechoslovakia, Polish & Swedish guns of 28 different calibres. The guns also varied in age many coming from the first world war, in many Casemates you can still see the calibre of the gun painted on the wall. Spare parts were scarce and had to be manufactured when required, and this often meant that one gun was out of service being robbed to keep the others in action. There was no radar connection to the site, all the sightings were made from the observation post. The square hole still visible in all the Casemates would have had plants in them to help camouflage the guns from the air.
source: info board at the location