The Artillery Blocks 3 and 4
Each of them has been provided with a turret, under a 30 cm steel cap, lodging the gunners. On the first level there are two sleeping rooms for 9 men, and a filter room. Built into the turret framework, the 80 ton movable body can be rotated as well as ranked up for its top lodge to emerge on the surface, allowing for the shooting, and then ranked down into shelter again. The men in control stood on the level in-between, on which there are two small magazines, a room with four bunks and a tiny gallery giving access to the 'cloche' above.
The lodge, on the third level, is armed with : - two 7.5 cm shortened guns, pattern 1932, range 6.5 to 9.5 km, rate up to 33 rounds a minute, both.
The empty shells were thrown onto the toboggan for them to slide down to the bottom of the Block, where they were recovered. Five men used to be in attendance on the turret's first level, about 15 on its second level and four gunners on its third level. The surfaces of both these Blocks were designed to withstand hits by 42 cm rounds.
Fresh air was sucked in from outside through an air pipe and then filtered in case of need, whereas stale air, smoke and carbon monoxide were blown out. The air-pressure could be raised to prevent poison-gas or smoke from penetrating into the block.
Block three is topped with one cloche' for spying out and short range automatic rifle coverage fire, whereas Block 4, with two 'cloches', one for the aforesaid purpose and the other for straight periscope vision.
The block 3
The block 4