H667 Kleinstschartenstand für 5cm KwK
The H667 was the most common anti-tank gun casemate built on the Atlantic Wall, with some 651 constructed in 1943–44, of which 443 were built on the French coast. Construction of this type began in January 1943 and each required 165m³ of concrete, 7.5 tonnes of steel rebar and 1.3 tonnes of other steel. These were designed to provide better protection than the common Vf600 open gun pits widely used for the pedestal-mounted 50mm gun. This weapon consisted of obsolete KwK 39 and KwK 40 tank guns mounted on a simple pedestal (Sockellafetten) with a spaced armor shield added in front. During 1944, some of these guns were re-bored to fire 75mm ammunition. Since the gun was mounted on a fixed pedestal, there was no need for a rear garage door as was so characteristic of other Atlantic Wall gun casemates. (See for example the H677 for the 88mm gun on page 26 of Osprey Fortress 37: D-Day Fortifications in Normandy.) Instead, the casemate had a simple armored door at the rear, protected by a low concrete wall.
This bunker, like the H677, was designed to be placed directly on the beach. It was oriented to fire in enfilade along the beach, not towards the sea. The design incorporated a thick wall on one side or other to shield the embrasure from naval gunfire. The interior was very elementary, large enough for only the crew and a few containers of ammunition. (Artwork by Lee Ray)
This shows the initial stage of construction of a gun casemate with the steel reinforcing bars in place along with the steel frame from the embrasure. This H669 gun casemate was being built near Ozouville in the Cherbourg area in June 1944. (NARA)
The allotment of fortifications was by no means uniform along the coast. In 1943, the Wehrmacht was deployed in three major formations: the Fifteenth Army from Antwerp westward along the Channel coast to the Seine estuary near Le Havre, the Seventh Army from Lower Normandy to Brittany, and the First Army on the Atlantic coast from the Loire estuary near Nantes to the Spanish coast near Bayonne. Of the three main sectors in France, the Fifteenth Army on the Channel coast received a disproportionate share of the fortification, and the Seventh Army much of the remainder. Of the 15,000 bunkers envisioned under the 1942 plan, 11,000 were allocated to the Fifteenth and Seventh Armies and the rest to the Atlantic coast of France, the Netherlands, Norway, and Denmark. By way of comparison, the First Army sector, which covered the extensive Atlantic coast facing the Bay of Biscay, was allotted only 1,500 to 2,000 bunkers.
The Organization Todt was responsible for the actual construction of the coastal fortifications, but management of the design and placement of the fortifications was the responsibility of the Wehrmacht’s Festungspionere Korps. The Kriegsmarine did not formally establish a fortification command until May 1943, so the army’s staff was primarily responsible for designing bunkers constructed for the navy; the same was true for the Luftwaffe. The army fortification engineers’ plans for the Atlantic Wall were based in part on previous experience in the 1930s in the development of the Westwall fortifications on the French–German border. However, there were some notable differences.
There were continual tensions between the army fortification engineers and the civil engineers of the Organization Todt. The army engineers frequently complained that the Todt engineers were too concerned about “art for art’s sake,” favoring elaborate construction projects near the ports but shunning more mundane tactical positions on more remote stretches of the coast. The army engineers were more often willing to compromise on building standards in order to get the programs completed on time while the Todt engineers tended to be sticklers for detail, for example insisting on the import of the best grade of German concrete rather than relying on local French concrete. It was the age-old engineering dilemma of “perfection being the enemy of excellence;” the army believing that an adequate structure completed today was better than a superior structure that was never completed.
The initial focus of the Atlantic Wall construction was on coastal artillery positions, a type not widely employed on the Westwall, and so requiring a new family of casemate designs. The initial role of coastal artillery was to stop the invasion force before it reached the shoreline. The configuration of the coastal artillery batteries was a subject of some controversy between the army and Kriegsmarine. The navy had traditionally viewed shore batteries as being an extension of the fleet, and so deployed the batteries along the edge of the coast where they could most easily to take part in naval engagements. As had become evident from attempts to repulse the Allied amphibious landings in the Mediterranean Theater, one of the Allies’ main advantages was heavy naval gunfire. As a result, a growing focus of the navy’s Atlantic Wall program was to deploy enough coastal artillery to force the Allied warships away from the coast and thereby undercut this advantage. Naval coastal batteries were patterned on warship organization. The four to six guns were deployed with a direct line of sight to the sea, and connected by cabling to an elaborate fire-control bunker, which possessed optical rangefinders and plotting systems similar to those on warships to permit engagements against moving targets. The army derided these batteries as “battleships of the dunes” and argued that their placement so close to the shore made them immediately visible to enemy warships, and therefore vulnerable to naval gunfire. In addition, the proximity to the shore also made the batteries especially vulnerable to raiding parties or to infantry attack in the event of an amphibious assault.
The army’s attitude to the coastal batteries was based on the premise that they were needed primarily to repulse an amphibious attack, not engage in naval gun duels. As a result, the army was content to place their batteries further back from the shore, though some were located along the shore if it gave them particularly useful arcs of fire. For example, this was the case with shorelines edged with cliffs, since by deploying the coastal batteries on promontories, the battery could rake the neighboring beaches with fire, avoiding the cover of the cliffs. The army fire-control bunkers were far less elaborate than the naval bunkers, possessing rangefinders and sighting devices but usually lacking plotting devices for engaging moving targets. The army placed more emphasis on wire or radio connections with other army units, depending on artillery forward observers to assist in fire direction against targets that were beyond line of sight. The navy complained that these batteries were incapable of engaging moving ships.
Besides their differences about coastal artillery tactics, the Kriegsmarine and army had very different views on the ideal technical characteristics of the coastal guns. The navy preferred a turreted gun that could survive in a prolonged gun duel with a warship. A few actual warship turrets were available and were emplaced in areas that had a rock-bed deep enough to accommodate the substructure of the turret: a turret from the Gneisenau near Paimpol in Brittany, two turrets from the cruiser Seydlitz on Ré Island, the 380mm gun turret from the French battleship Jean-Bart near Le Havre. Since armor plate was at a premium and fortification too low on the Reich’s priority list, it was impossible to manufacture steel turrets for coastal artillery. This led to the development of casemates to protect the gun against most overhead fire, with a limited armored shield around the gun itself. Such configurations limited the traverse of the gun compared to a turret. This would later prove to be a fatal flaw when the attack came from the landward side since the embrasure seldom permitted more than 120 degrees of traverse, limiting the gun’s coverage to seaward targets. The Kriegsmarine was aware of this problem but since its primary mission was to deal with the seaborne threat, this problem was brushed aside.