The Atlantic Wall (1): France

Coastal defense had been assigned to the Kriegsmarine (navy) since the reforms of Kaiser Wilhelm in the late 1880s. This mission focused on the defense of Germany’s ports along the North Sea and Baltic coasts. By the time of World War I, German naval doctrine saw coastal defense as a series of layers beginning with warships and submarines at sea as the initial barrier, followed by coastal forces such as torpedo boats and small submarines as the inner layer, and finally fixed defenses such as minefields and shore batteries as the final defensive layer. Fortification played a minor role in this doctrine. During World War I, this doctrine was found inadequate when Germany occupied Belgium. The Kriegsmarine did not have the manpower or resources to create an adequate defense along the coast of Flanders, and the dominance of the Royal Navy in the English Channel undermined the traditional tactics since German warships stood little chance of challenging the British on a day-to-day basis. The Kriegsmarine was obliged to turn to the army to assist in this mission, particularly in the creation of gun batteries along the coast to discourage British raiding or possible amphibious attack. These gun batteries were employed in elementary Kesselbettungen (kettle positions) so named for the pan-like shape of the fortification. The Kreigsmarine began to pay more attention to needs of fortification in the late 1930s after Germany’s re-militarization under Hitler’s new Nazi government. One of the first major coastal fortification efforts took place on the islands in the Helgoland Bay, along the North Sea coast.

At the start of World War II, the Kriegsmarine retained the traditional coastal defense mission. There was no dedicated coastal defense force, but rather the mission was simply one of those assigned to the regional naval commands. The North Sea coast was defended with a scattering of coastal batteries and newly installed naval flak units, but there was little modern fortification construction prior to 1939. Following the defeat of France in the summer of 1940, the Wehrmacht began preparations for an amphibious assault on Britain, Operation Seelöwe (Sealion). On July 16, 1940, Hitler issued Führer Directive No. 16, which called for the creation of fortified coastal batteries on the Pas-de-Calais to command the Straits of Dover and to protect the forward staging areas of the German invasion fleet.

Since it would take time to erect major gun batteries, the first heavy artillery in place were army railroad guns that began arriving in August 1940. To provide these with a measure of protection against British air attack, several cathedral bunkers (Dombunker) were created near the coast at Calais, Vallée Heureuse, Marquise and Wimereux. At the time, the army had nine railroad artillery regiments with a total of 16 batteries and the Kriegsmarine had a pair of 150mm railroad guns known as Batterie Gneisenau. The army created a coastal artillery command to manage this new mission and the army artillery along the English Channel was put under the command of Army Artillery Command 104. There was some dispute between the army and Kriegsmarine over the direction of the coastal artillery, with an eventual compromise being reached that the navy would direct fire against naval targets while the army would direct fire against land targets and take over control once the invasion of Britain began.

^{The army preferred heavy railroad guns over massive fixed guns for long-range firepower. This is a Krupp 203mm K(E) of battery EB.685 stationed near Auderville-Laye in the Cherbourg sector shortly after its capture in June 1944. (NARA)}

^{The heights of Mont de Coupole, located to the southeast of Wissant, provided an ideal observation point between Cap Gris-Nez and Cap Blanc-Nez for the heavy artillery batteries nearby. As a result, the hilltop is dotted with observation bunkers like this one. (Author’s collection)}

Following the arrival of the railroad guns, both the army and Kriegsmarine began to move other types of heavy artillery to the Pas-de-Calais. The Kriegsmarine obtained some of these by stripping existing coastal fortifications, while the army obtained some weapons from the Westwall border fortifications or from field army heavy artillery regiments. Four powerful batteries were constructed, starting in 1941, which had the range to actually reach Britain near Dover and Folkestone. These included the Lindemann, Todt, Friedrich August and Grosser Kurfürst batteries. The artillery concentration in the Pas-de-Calais pre-dated the Atlantic Wall and was in reality an offensive deployment intended to support the invasion, and not a defensive fortified position. Even though not a true part of the Atlantic Wall, these batteries would come to symbolize Fortress Europe due to their frequent appearance in propaganda films.

The role of the Pas-de-Calais artillery batteries gradually evolved due to changing German war plans. As the possibilities for Operation Seelöwe dimmed in the winter of 1940, the role of the batteries gradually shifted to the naval interdiction role, challenging British shipping in the Channel. The railroad guns were gradually removed, especially once Hitler shifted his attention to Operation Barbarossa, the invasion of Russia scheduled for the summer of 1941. Construction of some of the large gun batteries initiated in the summer of 1940 continued, but without any particular priority and most of the larger Pas-de-Calais batteries were not completed until well into 1942. The only area to receive special attention was the Channel Islands, which attracted Hitler’s personal interest. He wanted the islands to be heavily defended to prevent their recapture by Britain and, in October 1941, authorized the heavy fortification of the islands as a key element to this process.

^{280mm K5E Railroad Gun Dombunker}

^{Among the first type of fortifications built along the French coast was the Dombunker (cathedral bunker) so-called because of its resemblance to the arched shape of Gothic cathedrals. These were intended to protect three batteries of 280mm K5E railroad gun deployed to the Pas-de-Calais in the summer of 1940 and construction began in September 1940. This bunker was a simple reinforced tunnel, usually 80m in length and about 10m tall, though some bunkers such as the one at Hydrequent were shorter. Sites with these bunkers included Pointe aux Oies (EB.712), Fort Nieulay near Calais (EB.765), and Hydrequent (EB.713). Besides these bunkers, many of the railroad gun sites also were fitted with Vögele turntables to permit traverse of the weapon. (Artwork by Lee Ray)}

^{A good example of a kettle gun emplacement typical of the initial construction in 1940–42, still part of the Cherbourg defenses in June 1944. The gun is a Saint-Chamond 155mm K220(f), a French World War I type widely used in the Atlantic Wall defenses. Most but not all of the kettle emplacements were rebuilt with full casemates by 1944. (NARA)}

Coastal defense began to attract the attention of the Wehrmacht’s occupation forces in France due to Britain’s initiation of Commando raids along the Norwegian and French coasts. In February 1941, the army began proposing a policy directive which argued that a unified defense of the coast be established, with the army rather than the navy taking the lead role. This attempt was rebuffed by the OKW (Wehrmacht high command). which left the navy in charge of coastal defense artillery and the Luftwaffe in charge of flak protection of the coast, including naval flak batteries. Until the invasion of the Soviet Union in June 1941, there was a general policy against extensive fortification of the French coast for fear that it would confirm that the Wehrmacht’s intention had shifted from the invasion of Britain to the invasion of Russia.

British Commandos staged attacks against the Lofoten Islands off the northern Norwegian coast in March and December 1941. These prompted another Führer directive on December 14, 1941, which ordered the construction of a “new Westwall.” This order recognized that the western front was seriously short of troops due to the war in Russia, and it was proposed to substitute fortification for manpower. Light fortifications were authorized along endangered coastlines and permanent strongpoints at key points. Priority was given to the Norwegian coast, which Hitler felt was more vulnerable to such raids. Second priority went to the French coast, followed by the Dutch coast and Helgoland Bay in that order. Hitler also ordered the reinforcement of the coast defense with flak batteries that were assigned the dual role of anti-aircraft defense and potential use against landing craft. As a consequence of this order, the commander-in-chief West (OB West), Generalfeld-marschall Erwin von Witzleben, began to designate some of the key French ports as fortified areas (Festungsbereichen) to assign priorities for the eventual fortification effort. The Kriegsmarine was primarily responsible for the defense of the port itself, but the army was assigned the task of ensuring landward defense against possible airborne attacks.

British Commando raids continued in early 1942, including the daring raid on Bruneval to secure a Würzburg Radar. With the Wehrmacht bogged down in Russia, it seemed likely that the Western Front would remain on a defensive posture for some time to come. The evolving strategic situation led Hitler to issue Führer directive No. 40 on March 23, 1942, which laid the groundwork for the Atlantic Wall. The directive provided few specifics about the actual nature of the fortification, and it reaffirmed earlier priorities, with Norway and the Channel Islands being singled out for special attention. The ink was hardly dry on the new directive when it was followed a few days later by the dramatic raid on St. Nazaire, which managed to severely damage the vital dry docks there. This led Hitler to refocus the attention of the earlier directive, with a new emphasis on the defense of ports to prevent a repeat of the St. Nazaire raid. The first serious planning meeting for the Atlantic Wall occurred in May 1942 at Wehrwolf, the Führer headquarters at Vinnitsa, and attending the meeting was the new Reichsminister for Armaments Albert Speer, who had taken over the Organization Todt following the death of Fritz Todt in an airplane crash in February.

The Organization Todt was a paramilitary construction organization created in the 1930s to undertake major state projects including the autobahn and the Westwall defensive fortifications. Since the Wehrmacht had very modest construction capabilities, the Organization Todt was responsible for nearly all of the major fortification and military construction programs in France and the neighboring countries, including the gun batteries on the Pas-de-Calais, the new U-boat bunkers on France’s Atlantic coast, and the fortifications on the Channel Islands. The Wehrmacht’s Festungspionere Korps (Fortress Engineer Corps) under the Inspector of Engineers and Fortifications was responsible for designing and supervising the construction of fortifications by Organization Todt.

Serious construction efforts on the Atlantic Wall began in June 1942, and this was the first time that concrete consumption for the new fortifications exceeded that for the U-boat pens. On August 13, 1942, Hitler held a meeting with Reichsminister Speer and the senior OB West engineer staff to outline the strategic aim of the Atlantic Wall: “There is only one battle front [the Russian Front]. The other fronts can only be defended with modest forces… During the winter, with fanatical zeal, a fortress must be built which will hold in all circumstances… except by an attack lasting for weeks.” Hitler planned to defend the 3,800km (2,400 miles) of coastline from Spain to Norway using 15,000 bunkers and 300,000 troops with completion by May 1943, the earliest time an Allied invasion was likely. Hitler placed the emphasis on the defense of ports that were viewed as the most likely Allied objectives while the open beaches in between ports were assigned a lower priority. Hardly had this meeting been concluded when on August 17, 1942, the Allies struck at Dieppe with Operation Jubilee.

^{MKB Graf Spee of 5./MAA. 262 in Lochrist near Brest was armed with the Krupp 280mm SKL/40 M06 originally built for the old Brauschweig class of warships and previously located on one of the Friesian islands off the northern German coast before being transferred to Brittany in 1940. Three of the four guns were in open pits like this one, and only one in a large casemate. (NARA)}

^{Among the massive coastal artillery casemates on the Pas-de-Calais was Turm West of MKB Oldenburg MAA.244, armed with a 240mm SK L/50, originally a Tzarist 254mm gun captured in 1915 and re-chambered by Krupp. The two casemates of this battery were specialized SK designs built to the heavy Standard A with 3m-thick walls and ceilings. In the foreground is one of the associated H621 personnel shelters. (Author’s collection)}

This large-scale raid was a fiasco and demonstrated that even a modestly fortified port could be defended. Dieppe was held by two under-strength battalions of Infanterie Regiment 571, 302.Infanterie Division, a typical second-rate occupation unit. The seacoast town was partially fortified with some concrete bunkers plus machine guns and other weapons in field entrenchments. While the fortifications were not especially numerous by later standards, the cliffs on either side of the 1.5km-wide beach provided a natural overwatch position for enfilade fire along the coast. A pair of naval artillery batteries were located on either side of the town, armed with a total of ten 105mm guns, but they played little role in repulsing the main attack. Once the raid began the German commander rushed the divisional anti-tank company to the town which played a role in stopping the Canadian Churchill tanks trapped on the beach by the seawalls, tank traps and treacherous shingle. For the Wehrmacht, the Dieppe raid re-affirmed the value of coastal defenses in enabling badly overextended units to defeat amphibious attacks. It also reinforced the Wehrmacht’s belief that the main Allied invasion would be directed against a port.

Some German officers felt that the success in repelling the Dieppe raid was exaggerated, distorting later plans for the defense of France. General Freiherr Leo Gehr von Schweppenburg, who later led the Panzer forces in France during the Normandy campaign, argued that:

^{In some cases, the Germans integrated existing French coastal defense positions into the Atlantic Wall. This triple-tier fire-control post was part of MKB Seeadler located on Pointe du Brulay near Cap Lévy east of Cherbourg, armed with French 194mm guns in kettle emplacements. (NARA)}

For the Allies, Dieppe provided valuable lessons into the realities of assaulting fortified ports, even one as weakly protected as Dieppe. It convinced British planners that it would be wiser to stage future assaults away from ports against more thinly defended beaches. These lessons were at the heart of the plans for Operation Neptune, the D-Day amphibious assault in Normandy two years later.

In 1943–44, OB West designated several port areas as fortresses (Festung) included Dunkirk, Calais, Boulogne, Le Havre, Cherbourg, St. Malo, Brest, Lorient, St. Nazaire, the Gironde estuary and the Channel Islands. The US invasion of French North Africa in November 1942 prompted the Germans to occupy Vichy France, adding another coastal region to the list. The Mediterranean coastal fortifications were dubbed the Südwall and are outside the scope of this book. In the event, the Mediterranean ports of Marseilles, and Toulon retained the lesser and earlier designation as “fortified areas,” as did some Atlantic ports such as La Rochelle and Bayonne. The Festung ports were to be fortified on both the seaward and landward sides and were to be provisioned to be able to hold out for at least three months.

Kriegsmarine defenses in France

German naval forces in occupied France in 1943-44 were under the command of Marine-Gruppekommando West based in Paris, led by Admiral Theodor Krancke since April 20, 1943. MGk-West in turn was divided into regional sector commands of which the most important was Admiral Kanalküste (Channel Coast Admiral), which replaced the earlier Marine-Befelshaber Kanalküste (Channel Coast Naval Command) in April 1943 and which was led by Vizeadmiral Friederich Rieve. The other sectors of the coast were the Marbef Bretagne for Brittany and the Admiral Atlantikküste for the sector from St. Nazaire to Spain. These regional commands were in turn sub-divided into nine Seekommandant (Seeko) of which seven were along the Atlantic Wall:

The Seeko headquarters in turn controlled a variety of naval units in their sector. The most important were the harbor commands with a Hako (Hafenkommandant: port commander) in the larger ports and a Haka (Hafenkapitän: harbor captain) in the smaller ports. These commands usually included a port police force (Hafenüberwachung). The Kriegsmarine had an active program for using naval mines for coastal defense, but this subject is largely outside the scope of this book. Of somewhat more relevance are controlled mines for harbor defense. The raids on St. Nazaire and Dieppe made it quite clear that existing net and boom harbor defenses were inadequate and led to further examination of controlled mines for harbor defense, a tactic previously shunned by the Kriegsmarine in France. Controlled minefields were left inactive to permit friendly vessels to pass, but could be made active in the event of a raid to protect the harbor. The standard types in German service were modifications of existing naval mines such as the RMA, RMB, RMH and KMB but fitted with a remote activation device and tethered by a submarine cable which led back to a mine control station in the port. These mines were eventually deployed in a number of French harbors, but a shortage of mines led to the local development of the so-called Franz WB (Französische Wasser-Bombe: French depth charge) using captured stocks of French depth charges. These controlled mine units were also responsible for the deployment of harbor demolition mines, which were used in several ports, such as Cherbourg, St. Malo and Brest, to wreck vital equipment prior to the surrender of the ports to the Allies.

German coastal defense doctrine placed considerable importance on light coastal forces such as torpedo boats and small submarines and these were under the control of Defense Command-West (Befelshaber der Sicherung West) with three defense divisions (Sicherungs Division) in French waters, the 2.Sicherungs Division on the Channel, the 3.Sicherungs Division from Brittany to the Loire estuary, and the 4.Sicherungs Division on the Atlantic coast. These naval forces are outside the scope of this book.

From a coastal fortification standpoint, the most significant units were the coastal artillery battalions. There were three principal types, the Marine-Artillerie-Abteilung (MAA), the leichte Marine-Artillerie-Abteilung (leMAA: light naval artillery regiment) and the Marine-Flak-Brigade (MaFl-Br). Each naval artillery regiment consisted of several gun batteries, each battery deployed at a single coastal artillery post with several guns, a fire-control bunker and associated defensive and support positions. There were 14 regiments along the Atlantic Wall in France plus two more (MAA.604 and 605) on the Channel Islands. The light naval artillery battalions were peculiar to the Atlantic coast islands and were hybrid formations consisting of a few gun batteries and a few companies of naval infantry for island defense. The navy Flak brigades, as their name implies, controlled major port anti-aircraft sites. There were three of these: III.MaFl-Br at Brest; IV.MaFl-Br at Lorient; and V.MaFl-Br at Saint-Nazaire.

^{The heights of Cap Blanc-Nez overlooked the cliffs of Dover across the English Channel and so were the site of several observation posts like this one and two other examples further down the slope. (Author’s collection)}

One approach to coastal defense rarely used on the Atlantic Wall in France was the shore-based torpedo battery. The Kreigsmarine was made painfully aware of the capabilities of such batteries with the loss of warships in the 1940 Norwegian campaign, and developed a shore-based version of the standard TR 53.3 Einzel launcher from the S.Boote torpedo boat, which fired the 533mm G7a torpedo. However, these weapons were expensive and not as well suited to the open coastline of France as the constricted fjords of Scandinavia. The only significant use of shore-based torpedo stations in France was around the harbor of Brest where batteries were installed in 1942 near Crozon Island at Fort Robert and Cornouaille Point.

^{Batterie Lindemann}

^{The Schleswig-Holstein battery armed with three Krupp 406mm SKC/34 guns was originally installed on the Hel Peninsula near Danzig but in early 1941 the Kriegsmarine decided to redeploy these guns to the Pas-de-Calais. The site selected for the new battery was Noires-Mottes, located between Cap Blanc-Nez and the coastal town of Sangatte. Each casemate consumed some 17,000m³ of concrete and the guns were mounted in fully armored Schiessgerüst C/39 turrets. They were entirely self-contained with their own power generation and ammunition magazines. The three guns were directed by a massive fire-control bunker based on the S100 type, which included a large Lange optical rangefinder and was supported by a Würzburg See-Reise FuMO 214 surface-search radar located nearby on Cap Blanc-Nez, as well as several other observation and range-finding posts.}

^{These guns had originally been designed to arm a new class of battleship that was never built. The massive casemates for the guns were the S262 types, measuring about 50m in length and 17m in height. The three casemates were named Anton, Bruno and Cäsar. Anton and Cäsar became operational in June 1942 and Bruno in July, but at this stage their full concrete casemate had not been completed. They did not begin any major bombardment of the English coast until November 1942. The battery was initially named Grossdeutschland and was part of StP Neuss. It was manned by MAA.244 and commanded by Kapitänleutnant MA Werner Lokau. In September 1942, the battery was renamed after the captain of the ill-fated battleship Bismarck, Ernst Lindemann.}

^{In total, the three guns of the battery fired 2,450 rounds including 1,242 against coastal traffic, 593 against English ports, 235 against the city of Dover, 186 against British coastal batteries and 194 against unrecorded targets. Batterie Lindemann was a frequent target of British air-raids as well as counter-battery fire by British coastal guns and over 1,600 impacts were recorded in its perimeter, with about 45 hitting the gun casemates. The attacks left the terrain around the batteries a lunar landscape but failed to damage the gun casemates, and only two personnel were killed in the three years of counter-bombardments. The Canadian North Shore Regiment finally captured the battery on September 25, 1944. A half-century later, the casemates were submerged under spoil and an artificial pond created from the construction of the Eurotunnel, which runs directly under the site. (Artwork by Lee Ray)}

^{The most technologically advanced naval fortification on the Atlantic Wall was this experimental turret for a 150mm SK C/28 gun located in the coastal marshes near Fort Vert east of Calais. The turret used stressed steel wire instead of rebar to reduce the weight of the turret and it was fully traversable using a warship-type race. As a result, it was able to turn landward to fire on approaching Canadian troops in September 1944, and the turret remains locked in this position today. The fire-control post in the background served the nearby MKB Oldenburg. (Author’s collection)}

German Army defenses in France

Until 1943, the areas between the ports were much less heavily defended than the ports. The naval coastal artillery batteries tended to be clustered around the key ports, leaving significant expanses of coastline without any protection. These were gradually covered by army coastal artillery batteries deployed along the coast like “a string of pearls” to provide a basic defensive barrier. Coastal artillery was viewed as an excellent expedient since a single battery could cover about 10km of coastline to either side of the battery. In addition, the resources needed were fairly modest since most of the batteries were created using captured French, Russian or other weapons. As in the case of other defenses, the army’s coastal batteries were most heavily deployed along the Pas-de-Calais and Upper Normandy in the Fifteenth Army sector, with an average density of one battery every 28km, while in the Seventh Army sector from Lower Normandy around the Cotentin Peninsula, the density was only one battery every 87km. As can be seen from the charts below, the Fifteenth Army had nearly double the density of artillery of the other two sectors, averaging nearly one gun per kilometer. This certainly did not live up to the propaganda image of the Atlantic Wall. German tactical doctrine recommended a divisional frontage of 6 to 10km, implying a density of about five to eight guns per kilometer, substantially more than average Atlantic Wall densities.

^{Batterie Todt}

^{Construction of Batterie Siegfried began in August 1940, armed with four 380mm SKC/34 in B-Gerüst C/39 turrets, near the village of Haringzelles. The battery was located close to the sea and within sight of Cap Gris-Nez where several supporting observation posts were located. The four turrets were of a special design consisting of a main circular gun casemate with a smaller multistory bunker for ammunition and support located to the left of the gun pit. Each casemate consumed 800 tonnes of steel and 12,000m³ of concrete.}

^{The battery was declared operational on January 11, 1942, and it was renamed later in the year in honor of the head of the Organization Todt, Fritz Todt, who died in a plane crash on February 8, 1942. Unlike Batterie Lindemann, the four gun turrets were not named, but simply numbered from 1 to 4, with Turret 4 being the one located closest the sea and Turret 1 being the furthest inland and the site of today’s Musée de Mur de l’Atlantique.}

^{This battery was part of MAA.242 and was commanded by Kapitänleutnant MA Klaus Momber. The battery was part of StP 186 Saitenspiel, which included numerous support facilities, defensive positions and anti-aircraft batteries. The associated surface search radar and optical rangefinder for the battery was positioned along the cliffs near the village of Cran-aux-Oeufs about 1km to the northwest.}

^{Like Batterie Lindemann, Batterie Todt was engaged in bombardment of Channel shipping in 1942–44 as well as periodic campaigns against English ports, coastal towns, and coastal artillery batteries. The battery’s most active combat took place in the summer of 1944 when in took part in a campaign against Dover and Folkestone along with Batterien Lindemann and Grosser-Kurfürst. As Canadian troops closed in, it fired for the last time on September 29, 1944, hours before its surrender. (Artwork by Hugh Johnson)}

^{Some of the ports along the Atlantic Wall were protected by controlled minefields. To supplement German mines, the Franz WB was developed based on surplus French depth charges. These mines were also used to demolish harbor facilities prior to their surrender. (NARA)}

^{One style of camouflage for the shoreline casemates was trompe l’oeil painting, intended to make the bunker look like a harmless civilian home. This example is certainly more elaborate than most, complete with a cart in the false garage. This Canadian soldier is looking into the gun embrasure of the casemate, which had been covered with a false wooden cover now on the ground. (NAC PA-131229 Ken Bell)}

Although the coastal artillery batteries were an economical way to cover large areas of coastline with minimal coverage, they could do little against Commando raids. The task of patrolling the coastline was assigned to the infantry divisions stationed near the coast. These sectors consisted of divisional KVA (Küsten Verteidigung Abschnitt: coast defense sector), further broken down into regimental KVG (Küsten Verteidigung Gruppen), battalion-strength strongpoint groups (Stützpunktgruppe), company-sized StP (Stützpunkt: strongpoints) and finally platoon-sized WN (Wiederstandnest: resistance points). Since the Kriegsmarine received the bulk of the construction work in 1943, these positions were often little more than field entrenchments with a small number of fortified gun pits and personnel shelters. Except on the Pas-de-Calais, there was little fortification of the infantry coastal defenses until 1944. The bunkers and defensive positions were intended to compensate for the severe shortage of troops. German tactical doctrine recommended that an infantry division be allotted no more than 6–10km of front to defend, but the occupation divisions in France were frequently allotted 50 to 100km of coastline to defend, sometimes even more in the remoter locations of Brittany or the Atlantic coast.

^{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.

During 1943, fortification engineers began to experiment with an advanced type of reinforced concrete using wire under stress instead of the usual steel reinforcing bars. This promised to be significantly lighter, leading to plans for a fully traversable concrete turret to get around the limitations of traverse in fixed casemates. An experimental example was completed outside Paris in early 1944, and the first concrete turrets began to be built on the Atlantic Wall. starting with one near Fort Vert to the east of Calais. However, the technology appeared too late in the war to be widely used.

The army did not favor fixed guns like the navy and preferred to use conventional field artillery. This was based on the premise that the batteries could be moved from idle sectors to reinforce the defenses in sectors under attack. The army pointed to previous examples of British amphibious attack, such as Gallipoli, where the amphibious assault became a protracted campaign. At first, the army preferred to use simple kettle mounts patterned on the World War I style, which were simply circular concrete pits with protected spaces for ammunition. The gun itself was completely exposed, but the gun pit was supported by fully protected crew bunkers, ammunition bunkers and a fire-control bunker. This was the predominant type of army coastal battery configuration on the Atlantic Wall from 1942 into early 1943. However, as Allied air activity over the French coast increased in intensity, the vulnerability of these batteries to air attack became the subject of some concern. Intuitively it seemed that the navy’s casemates offered better protection from air attack than the kettle positions. However, based on actual combat experiences, some of the fortification engineers argued that this was not the case. The confined casemate tended to concentrate the blast of any bomb that landed near the gun opening, and it was found that guns in open pits were almost invulnerable to air attack except for the very rare direct hit on the gun itself. In the wake of the Dieppe raid, however, the policy shifted to full protection of the army coastal batteries in casemates. These resembled the navy casemates except that they generally had a large garage door at the rear to permit easy removal of the gun for transfer to other sectors if needed.

The army fortification engineers had established protection standards during the Westwall program based on steel-reinforced concrete (Beton-Stahl). Category E fortifications were based on walls and ceilings 5m thick but this standard was uncommon and used mainly for strategic command posts such as the Führer bunkers. The highest level for tactical fortifications was A, which used a 3.5m basis, and this was confined to large, high-priority structures such as the U-boat bunkers and some key facilities such as the heavy gun batteries on the Pas-de-Calais and special military hospitals. Most Atlantic Wall fortifications were built to the B standard, which was 2m thick, proof against artillery up to 210mm and 500kg bombs. Many minor bunkers, such as the ubiquitous tobruks, were built to the slightly lower B1 standard of 1 to 1.2m since these structures were partially buried. The designers attempted to minimize the amount of steel necessary in construction, so aside from the steel reinforcing bars (rebar), steel plate and especially steel armor plate was kept to a minimum. A standardized family of small armored cupolas, doors, and firing posts had been developed during the Westwall program and these were used on the Atlantic Wall as well. Most personnel bunkers and other enclosed bunkers built in 1942–43 were also provided with protection against gas attack both by systems to seal the structure from outside air, as well as filtration systems. Obviously, this was not possible with large gun casemates, but the associated crew bunkers typically had gas protection.

The Fortification Engineer Corps in Berlin designed a family of standardized bunkers for typical applications. Some of these were based on the earlier Westwall program but the majority were newer designs. The original Westwall fortifications had been designated in the OB or Vf series for Offene Bettung (open platform) or Verstarkfeldmässig (reinforced field position). Although some of these designations were retained during the construction of the Atlantic Wall, a new series of designations emerged. There is some disparity in how these designs are identified so for example, the “611” bunker design is variously called Bauform 611 (construction plan 611); R611 (Regelbau 611: construction standard 611) or H611 (Heer 611: Army 611) to distinguish army bunkers from air force (L: Luftwaffe) and navy (M: Kriegsmarine) bunker designs. There were about 700 of these standard designs of which about 250 were used on the Atlantic Wall. It should be mentioned that these designs were often modified in the field to better match local terrain contours. Besides the standardized designs, there were localized variations of standard plans as well as entirely new designs, sometimes identified with an SK suffix for Sonderkonstruktion (special design).

The standard plans covered a variety of functional types. These are by no means the only categories of defensive fortifications, but cover the main types.

The table opposite lists the army bunkers deployed under the three army headquarters (AOK) in France in June 1944. The common types are listed by their designations while less common types are lumped together under their function. This list does not include the category of “reinforced field position” such as tobruks, and open gun pits such as the Vf600 types, which were not considered “bombproof”.

^{Coastal erosion has left many bunkers stranded on the beach, like this H120 artillery observation bunker on Platier d’Oye east of Calais. It is an interesting example since it is still fitted with its 27P01 armored cupola, a feature that was removed from most bunkers after the war due to its scrap value. (Author’s collection)}