The Grand Blockhouse is a renovated 5 level fortification build by organization Todt and part of the Atlantic Wall. It is located in Batz-sur-Mer, France, and part of the fortress around Saint-Nazaire (about 30 km) the last liberated part of France.
After the Luftwaffe lost the battle of Britain and the just started attack on the Soviet union, the Germans loaded their submarines to set up a blockade of the Britische Isles. Huge submarine bases where build by Organzition Todt in order to protect the submarines after returning from missions.
Around 1944 major Atlantic ports had to become fortresses fighting till the last man, so Marshal Erwin Rommel, who was the inspector for fortifications at that time, appointed each major port a responsible for building its defence around it. For Sain-Nazaire Generalmajor Maximilian Huenten was appointed. The defense should be able to prevent an allied landing for taking these ports by building a wall of steel and concrete to protect them. In the lower Loire area about 1000 fortifications where built. Most of them facing the ocean, other for protection more inlands.
These fortifications had to serve with strong artillery, many units of the German Navy and troops entreched in the fortress behind minefields on the coastline.
This Blockhouse was built on a rocky promotory. Because of its visibility at this location it was camouflaged with paintings looking as was it a regular house/building. Even false balconies were built. The camouflage was made by a group of young Germans by the sixth Arbeitsabteilung of Arbeitstruppe 304 (RAD Abteilung 6/304) a bavarian unit formed in Burtenbach. The defence was done by Marine-Artillerie-Abteilung 280, which in fact were reserve personnel, aged 30 till 45 years.
Five batteries of MAA where deployed in the North and South of the estuary. in the South of the Loire on two old Frensch coastal navy locations at Pointe Saint-Gildas and Needle. They had
four old Frensch 75 mm. The battery in Needle is modernized in 1943 with quick loading German guns of 10.5 cm. The third battery is posted in the French Navy Fort of Eve.The had 4 17cm quick loading guns and the fourth was located in neighbourhood (Kermoisan) of Batz-sur-Mer. It was equiped with two French cannons 240 mm 1893-1896 Schneider Miss M “Colonies” seized in 1940 from the general reserve artillery park of the French army. After being tested in Germany the were installed near Batz-sur-Mer at the Atlantic coast. These huge cannons placed on rails where defended by flaks. A such cannon can be seen in a macquette inside the Blockhaus or for real in Organisation Todt museum in the Nort pas de Calais.
The Blockhaus, some figures
It is about 25 meters long and a max height of 17 meters. It required 1800 m3 of concrete, about 300 truck mixers. Its interior mesh has about 110 tons of round steel and 15 tons of iron I. Its interior space is 285 m².The outside and ceilings are about two meters thick. It is occupied by 20 soldiers and a battery manager
The building started on October 22, 1942 and ended 8 February 1943, camouflage included.
The type of fortification is a type S 414. It is build on the rocky promontory of Dilane, 16 meters above sea level . On the upper level ,the fifth, about 30 meters up, you can see a rangefinder. It was used to identify potential enemy ships, whith help of the curvature of the ocean at this point.
What can be seen?
In the lower part: sleeping place, infirmary and machineroom.
On the main floor you can see how the operational part looked like, including some scale models and simulated events in history of the blockhous and surroundings.
On the other floors you can see a goniometer telescope which allows you to calculate the magnetic azimuth (magnetic North) of a target at sea, observation posts of which one has a range finder.
The Blockhaus has some nice fresco’s recovered and restored. Outside the Blockhaus next to the shop you can find the recoverd and restored fresco of the U96, better known as Das Boot (the movie).
Some Pictures taken
Visit the Grand Blockhaus
For more info and openinghours visit the Grand Blockhaus website.