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©2004-2019 F. Dörenberg, unless stated otherwise. All rights reserved worldwide. No part of this publication may be used without permission from the author.


Latest page update: September-October 2019 (added ref. 245A-245D, added & used ref. 179)


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BERNHARD INSTALLATION BE-7 AT ARCACHON (France, dept. 33)

Map

On 19 July 2012, I visited the remnants of the Bernhard installation at La Teste-de-Buch, just outside Arcachon. It is located some 2 km south of the south-shore of the Bay of Arcachon, 50 km southwest of downtown Bordeaux. More precisely: in the Camicas-dune area .The local altitude is 40 meters above sea-level (see this interactive topographic map). There is no higher terrain . The Dune de Pilat, Europe's tallest sand dune (about 100 m ASL), is about 7 km to the southeast.

It was actually the site of an old maritime radio station "Arcachon Radio", with the call-sign FFC. The station dates back to the early 1900s, and originally operated in the LF-MF frequency range. It may already have had its own power generator capability. The station was active until 1997 or 1999. In 1985, the maritime station at Brest/Le-Conquet took over the night-time operation of FFC via remote-control, and all operations in 1993. These days, the site has an 88 m (290 ft) tall cell-phone tower, with the antennas of several FM radio stations.


The area of the Arcachon Bay (Bassin d'Arcachon, including the Cap Ferret spit and Dune de Pilat area) was occupied by the 159th Infantry Division of the Wehrmacht. The Kriegsmarine had a Hafenüberwachungsstelle (HÜST) in Arcachon. On the south side of the town (in the Eden dune area outside Pyla-sur-Mer), it also operated a Kriegsmarine Flak-Schule (subsidiairy of the one at Dax) for training with FLAK-searchlights, radar, and sound-locating systems (FLAK Horchgeräte). They had a FuMG80 "Freya" early warning radar and two gun-laying (fire-control) radars: a huge FuMG 65 "Würzburg Riese", and a small FuMG 39T "Würzburg" (ref. 245A-245D). West of Arcachon, near Plage de l'Horizon beach (Bélisaire) on the Cap Ferret spit, another Würzburg and two Freya radars were installed. This corresponds to a standard level-3 Luftwaffe/Luftnachrichten radar site ("Funkmeßstellung 3. Ordnung").

The nearest Luftwaffe airfields were Bordeaux-Merignac, 40 km to the east-northeast, and Cazaux, 12 km to the south. The latter was built in 1914 as a training field for the French Air Force, and used by the Luftwaffe from May 1940 through June 1944. It was used by several training, fighter, and night fighter squadrons. The French Air Force resumed operations there in April of 1945 as Airfield R.51, renamed Base Aérienne 120 "Commandant Marzac" in 1962. The nearest U-boat base was located just a couple of kilometers to the northeast of the center of Bordeaux, off the Garonne river. From the fall of 1940 until early 1943, this was the BETASOM base of the Italian Royal Navy (Beta = "B" for Bordeaux, SOM for "sommergibili" = submarines). This was in the German occupation zone, and the BETASOM subs operated under German command. Construction of German U-boat pens at Bordeaux was completed early 1943. After the Italian surrender in September of 1943, BETASOM was used by the Germans.

The "Bernhard" station was constructed during 1942/43. Analysis of aerial photos taken by RAF 192 Squadron in February of 1943 showed the turntable had been constructed and the superstructure erected. Ref. 173D. The report mentions that photos from June and December 1942 showed no signs of any new construction being prepared. Operational buildings and quarters consist of "two large, nearly square huts and a long narrow hut, all more or less symmetrically situated to the south of the array". No. 192 Squadron also went on two recce flights mid-November 1943, to search for sweeping signals [ = rotating beam] emanating from a radio-navigation beam station near Arcachon. No "Bernhard" signals were detected during those flights.

The installation was dismantled by the retreating Germans after the Allied invasion of France. The dismantling was ordered on 22 June 1944 (ref. 179). Ref. 99 suggests on the one hand that the (entire) installation was moved to Buke, but also states that (only) the equipment from Arcachon was re-used at Buke. The latter is corroborated by the post-war picture below of the installation at Arcachon: it shows a dismantled, damaged, and de-railed installation. So the antenna system was definitely not moved!

Bernhard station

Fig. 120: The Archachon "Bernhard" after the war - damaged, dismantled, de-railed

(source: p. 21 in ref. 90)

Bernhard station

Fig. 121: RAF aerial photo of the Arcachon site (18 February 1943)

(source: ref. 173D; three huts on south side of station (mentioned in the report) are marked in yellow)

Bernhard station

Fig. 122: Aerial photo of the Arcachon site (19 December 1946)

(source: geoportal.gouv.fr; full-size photo C1337-0071_1946_CDP2341-4517, 37 MB!)


Bernhard station

Fig. 123: Aerial views with red & white truss mast on top of the round Bernhard building (1980s-1990s)

(left image (looking north) source Arcachon-Radio; right image: looking south)

Bernhard station

Fig. 124: Satellite image - perspective view (ca. 2013)


Bernhard station

Fig. 125: Satellite image - overhead view (ca. 2013)

(source: geoportal.gouv.fr)


The following diagram is based on my measurements of the site:

Bernhard station

Fig. 126: Cross-section of the installation at Arcachon


At the center of the ring, there is the standard round building. Almost half of it is below ground level. The ceiling is 3m06 above the below-ground floor level. The building has a 120 cm (4 ft) wide concrete walkway around it. Five concrete steps go down 130 cm (4.3 ft) below ground level, to the entrance door. Unlike, e.g., the installation at Venusberg/Aidlingen, the side-walls of the trench with the steps is attached to the building, and the stair treads are still present. The entrance is on the north side of the building.

Bernhard station

Fig. 127: The north side (with door) and east side of the round building


The original windows measured 120x120 (4x4 ft). The window on the east side has been reduced to 48x48 cm (1x1 ft). The window on the south side has been closed off with 1970s-style glass blocks. The window on the west side has been closed off completely, though the original outline is clearly visible. The door is a modern steel door. A large octagonal box sits on top of the roof. The box and the rest of the roof are covered with tar paper. Clearly these are post-war additions. Perhaps the box covers the original ball-bearing and mounting plate construction.

Bernhard station

Fig. 128: The south side (left) and west side of the round building


Above the east-window, on the side of the roof, there is part of a round porcelain insulator. See photo below. Looking into the opening of the window, we can see three additional porcelain insulators, on the wall just next to the opening. They are mounted on a vertical steel profile (56 cm long, 2.5 cm thick, 7 cm wide). This central building continued to be used, when the maritime radio station resumed its normal operation after the war. The insulators are a post-war addition.

Bernhard station

Fig. 129: Porcelain insulators inside & above the east-facing window - post-war additions


Inside the round building, there are several objects attached to the wall that are clearly post-war: a relatively modern electrical heater and telephone outlet, PVC conduits, and a wall light above the door. Below the east window opening, there is an old 4-prong junction box with triangular shape. It appears to be original. Near this box, several cables enter the building through the wall, just above floor level. I presume that this is where 3-phase AC-power entered from the generator in a nearby building.

Bernhard station

Fig. 130: Junction box with four large prongs (installed below the east-facing window)


A heavy I-beam column has been added at the center of the building. It supports the octagonal plate on the ceiling. At some point in time (post-war) a very tall truss-mast was installed on top of the round building. See the aerial photos at the beginning of this section.

Bernhard station

Fig. 131: Inside the round building: a central support column and the door


The concrete ring at Arcachon has the standard 150 cm (5 ft) width. The top of the ring is 70 cm above the soil, both on the inside and outside of the ring.

Bernhard station

Fig. 132: The concrete ring at Arcachon

(a cable trench made of concrete tiles is visible between the ring and the round building)

The concrete ring is interrupted on the southeast side. The cut has a slight V-shape, and a cable "tunnel" passes through it. It leads to one of the three buildings located to the south of the ring, several meters below. It looks like the cut through the ring is not a post-war modification. On the inside of the ring, the cable-tunnel leads about half way towards the round building's east window. The tunnel is made of large cement/concrete tiles (42 cm wide, 5 cm thick).

Bernhard station

Fig. 133: A cable trench passes through the south side of the concrete ring


Bernhard station

Fig. 134: The concrete ring at Arcachon


The ring appears to have been poured in two steps (see photo below): a lower part, and an upper part. The lower part was poured into a mould made of vertical wood planks - their markings are still clearly visible. The concrete of the upper part has lots of pebbles in it.

Bernhard station

Fig. 135: The concrete ring has two visible layers


Bernhard station

Fig. 136: The rail ties are actually I-beams, embedded into the concrete


At various points around the ring, steel brackets have been welded to some of the ties. See photos below. They stick out above the bolts that were used to fix the rails to the rail-ties. They must have been added post-war, possibly to tie-off guy wires for antenna pylons when the marine station had resumed operation. There are also several small I-beams embedded into the concrete between some rail ties. The concrete around them does not appear to be disturbed. So, they must be original. However, their purpose is not known.

Bernhard station

Fig. 137: Anchor plate attached to a rail tie, and small I-beam between rail ties


Bernhard station

Fig. 138: Brackets and anchor plate attached to the rail ties


My 3D photos of this "Bernhard" station are here.


REFERENCES


Note 1: due to copyright reasons, this file is in a password-protected directory. Contact me if you need access for research or personal study purposes.


External links last checked: January 2019


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