Gi09 Bon Anse 'Cosel' , M.K.B.Coubre-Ost, Batterie (South site).

Also known as Rest Adler, this section covers everything south of the road, which constitutes the main batterie position.

This list details the unit 2./M.A.A.284 and its associated fortifications and armaments:

• 1 x M272 Casemate (120deg)
• 3 x M170 Casemate (90deg)
• 4 x R622 Twin group bunker
• 1 x R661 Bunker for casualty assembly
• 1 x M145 Ammunition depot
• 1 x M162a Fire control post for light batteries
• 2 x R669 Casemate for field guns (60deg)
• 1 x Vf67 Tobruk for tank turret
• 1 x R629 Anti tank gun bunker
• 2 x V134 Light AA emplacement with commissariat bunker
• 1 x R638 Small dressing station
• 4 x 13.8cm K.M./10 (f)
• 2 x 7.62cm F.K.295 (r)
• 4 x 2cm Flak 28
• 2 x 2cm Flak 38 Vierling
• 1 x 5cm KwK L/42
• 1 x Tank turret Pz.T. R35
• 1 x 3.7cm KwK 144(f)

A 1957 air photo of the batterie position on the hill above the beach. The guns had a range of about 18km. The four canon de 138mm guns were in four open emplacements here, as a French batterie, placed here in the Maginot period as an extension. After the capture of most of France, the port of Bordeaux and its new U-Boat pens had to be defended. The Heer (army) were too busy fighting on other fronts, so the Kriegsmarine stepped in and started building batteries of casemated artillery covering all the ports along the whole front, which a year later would be called the Atlantikwall. So, here as the casemates were built, the French guns were dismantled, re-designated 13.8cm K.M./10 (f) and placed in the casemates.

In the 60s and 70s, the whole area was under French Naval jurisdiction. They turned it into a campsite for naval personnel and their families. That is why some bunkers look as though they were converted inside into discos or bars.

This list provides the SHM details for the site structures:

• 1: Poste de direction de Tir
• 2a-5: Casemate pour canon de 138mm
• 6,7: Casemate pour canon de 77mm
• 8: Tobruk avec tourelle de char
• 9,10: Abri pour personnel
• 11: Soute à munitions
• 12a-16: Baraquement
• 17: Projecteur
• 18: Abri personnel
• 19: Abri soute
• 20a-26: Tobruk pour mitrailleuse
• 28: Water reservoir (Wasser)

Allied intelligence reports regarding the batterie indicated that the casemates and bunkers were built on sand, rendering the structures highly unstable.

Allied intelligence gathering of the batterie did state that the casemates and bunkers were built on the sand and were very unstable.

We start at the Turm 3 M170 casemate.

Set up on the bank above the road, you can see the rear of the bunker. The rear has a second lump built over the entrance, which is not standard to the plan.

We start at the Turm 3 M170 casemate, which provides a full view of the rear of the bunker.

This is the Turm 3 M170 casemate, which features a dedicated close combat defence room designed to protect the bunker against infantry attacks.

Turm 3 M170 casemate.

This is the frontal view of these large casemates.

Turm 3 M170 casemate.

A set-up photo after capture; the poor bloke was made to stand there for the camera, though he was probably never a member of the batterie. Note also the cases strewn around. There was quite a lot of shooting from the batterie, and it also received a lot of shot back, as you can see on the casemate.

Turm 3 M170 casemate.

This is one of the other casemates pictured following the action.

Turm 3 M170 casemate.

Gun room with, from left to right, access to the ammunition room and slots in the back wall to receive shells and cases from the stores. Note the open manhole cover to the spent-case ammunition store underground, and the stairs leading to the ammunition rooms.

Turm 3 M170 casemate.

The 68P9 Niedergangsklappe translates to 'companionway flap' or manhole cover. It is interesting that although there were two slots provided to put spent cases down, the gunners often just threw them out of the front of the casemate.

Turm 3 M170 casemate.

Looking into the spent case store, which is the space under the gun room for spent shell cases to be stored. When the gun fires, the shell is expended out of the breech. The gunner removes the case and throws it down one of two holes in the side walls. The case clatters down into the space and can be collected after the battle. When they were actually engaged in a battle in 1945, the lazy gunners just threw the cases outside, as you can see in one of the photos.

Turm 3 M170 casemate.

This bunker is marked Gi09 M 33 1944. It features a rear steel door with radio aerial slots on either side of the passage.

Turm 3 M170 casemate.

This is the large cartridge ammunition room. The rear door provides access to the close combat defence room.

Turm 3 M170 casemate.

Large cartridge ammunition room. L to R: entrance to shell store, a hole to pass the cases through the wall to the gun room, doorway down to gun room.

Turm 3 M170 casemate.

Close combat defence room. Sometimes this room could be used for a small standby petrol generator to run the gun's electrics. Ventilation was a problem, though, as was the question of where to put the exhaust pipe.

Turm 3 M170 casemate.

Looking at the bricked-up gun embrasure.

Turm 3 M170 casemate.

Part of the DEFE 44/98 JIB report, a British intelligence report on heavy batteries in Europe.

Turm 1 M272 Casemate.

This is the roadway leading to the M272 casemate.

Turm 1 M272 Casemate.

The bunker features a double entrance protected by an armoured cover.

Turm 1 M272 Casemate.

Access is fun; looking out of the entrance, yes, I managed to scramble down.

Turm 1 M272 Casemate.

Rear entrance; to the right is the control cabinet space where information would come down armoured cables to dials on the wall, and the information transferred to the guns.

Turm 1 M272 Casemate.

This is the ammunition storage room; the other side houses the shell room, which has a capacity for about 100 rounds.

Turm 1 M272 Casemate.

Inside the gun room, I have placed a gun in position for scale. We are not sure if the existing steps and concrete were designed for a gun or were placed later by the French military.

Turm 1 M272 Casemate.

On both sides are the command and control cabinets with command cable inlets. There is a manhole in the middle for used cases, and the entrance passage in the center features small magazines on either side. All controls, cabinets, and guns were rendered useless just before capture.

Turm 1 M272 Casemate.

Turm 1 M272 Casemate.

The bunker is seen here under construction, appearing very fresh and clean.

Vierlinge [quadruple].

The 2cm Flak 38 Vierlinge provided anti-aircraft defence for the battery, with two such weapons positioned on the site. Each gun would have required an eight-man crew to operate. In this location, it appears the gun was situated in an earth emplacement reinforced with ammunition boxes, which were likely filled with sand to serve as a defensive wall.

13.8cm K.M./10 (f).

These were the original French emplacements that the occupiers found when they arrived in the summer of 1940. A complete set of four guns in open emplacements had been placed here as extensions of the Maginot Line, which covered the north and east of France. As every port in France and its colonies was subsequently upgraded with heavier weapons—in Cherbourg and Marseille, for instance, battleship turrets were to be used—the Kriegsmarine took over the site.

R669 Casemate for field guns (60deg).

Situated on both flanks are two R669 casemates for field guns, each housing a 7.62cm F.K.295(r) ex-Russian gun.

R669 Casemate for field guns (60deg).

A view inside the gun room of this emplacement.

R669 Casemate for field guns (60deg).

Note the flanking wall covering the embrasure from direct fire.

R669 Casemate for field guns (60deg).

A contemporary photo taken just after the capture of the site.

M162a Fire control post for light batteries.

Here you can see the Fire Control Post (FCP) out in front and the two casemates, with French open Ringstands located right next to them.

M162a Fire control post for light batteries.

Here you can see the Fire Control Post (FCP) situated in front, accompanied by two casemates with French-style open Ringstands positioned immediately adjacent to them.

M162a Fire control post for light batteries.

This photograph, taken just after the capture of the site, shows the original camouflage layout for the bunker.

M162a Fire control post for light batteries.

This is the range finder room, which would have had a slit all the way around, allowing 360° of rotation for the range finder. I did not manage to squeeze in, but I did try before giving up.

M162a Fire control post for light batteries.

This is the observation room, where there would have been a slit covering three sides to provide a wide field of view for monitoring the batterie.

M162a Fire control post for light batteries.

Fire orders from here would have been sent down to the computing room in the heart of the bunker. They were then sent via armoured cables to the four guns.

M162a Fire control post for light batteries.

This photograph shows the post after capture, with the French army back in control of the position.

During our survey of the site, we found the Turm 2 M170 casemate to be inaccessible, preventing any closer inspection of its interior.

Air photo after capture showing all the casemates and the Flak positions (D.C.A.).

This is a Flak Ringstand for a 2cm Flak 38 Vierlinge (quadruple anti-aircraft gun). I believe this may be the second of the two 2cm Flak 38 Vierlinge emplacements at this site.

Turm 4 M170 Casemate.

We now move across the road to inspect the fourth emplacement of the batterie.

Turm 4 M170 Casemate.

Inside the gun room, there are hooks on the ceiling to lift the gun into its mount, and two doors with steps leading up into the ammunition rooms, each featuring slots to pass cases and shells through.

Turm 4 M170 Casemate.

Unlike most casemates, this one is built up, not half-buried.

Turm 4 M170 Casemate.

A snapshot of Mike checking his Facebook page in 2012, highlighting how the site has become a focus for modern visitors.

Turm 4 M170 Casemate.

Close combat defence covering the rear entrance, still with its wood shuttering left in place to help deflect ricocheting bullets.

Turm 4 M170 Casemate.

Rear passage with another close combat defence embrasure behind the 19P7 door.

Turm 4 M170 Casemate.

Rear steel door with radio aerial slots on either side of the passage.

Turm 4 M170 Casemate.

This is the shell room where shells would have been piled up either in boxes or even wicker-work cases. The shells would then be passed by a member of the crew, through the slot into the gun room.

Turm 4 M170 Casemate.

The close combat embrasure provides defensive cover for the entrance passage.

Turm 4 M170 Casemate.

Close combat embrasure, 48P8 type.

Turm 4 M170 Casemate.

Case room, featuring the door to the secondary close-combat defense position that covers the rear entrance.

Turm 4 M170 Casemate.

Close combat room covering the rear of the casemate with a 48P8-type embrasure.

Turm 4 M170 Casemate.

This is the main passageway leading forward to the gun room.

Turm 4 M170 Casemate.

Gun room with the gun embrasure bricked up and windows added. This whole area was a French Naval training ground post-war, and the area of the batterie was turned into a summer camp for military personnel and their families. So, every year the place was inundated by campers.

Turm 4 M170 Casemate.

The heavy steel roof structure.

Turm 4 M170 Casemate.

This space contains the control cabinet and cable inlets; you can also still see the wooden fittings on the wall. The pipe fitting on the left is where the exhaust fan was mounted to extract gases from the gun room.

Turm 4 M170 Casemate.

This is the other door to the shell store, comms cabinet on the wall on the right with cable ducts in place.

Two highly professional bunker hunters awaiting instruction on where to go next.