Fortress Europe- European Fortifications Of World War II

by J E Kaufmann

  OBW Rundstedt tried to find a middle ground between Rommel's ideas and those of his opponents like General Geyr von Schewppenburg of Panzer Group West. Thus Rommel was allowed to proceed with the construction of the Atlantic Wall even though he was prevented from pushing all available units as close as possible to the beaches. Rommel ordered his forces to lay down millions of mines, more than tripling the number placed before 1944, and set up thousands of obstacles at possible landing sites. He also closed the vulnerable gaps between fortress areas.

  Every significant coastal port was fortified. The ports of Ijmuiden, Hoek van Holland, Dunkirk, Calais, Le Havre, Cherbourg, St. Malo, Brest, Lorient, St. Nazaire, and La Rochelle-La Pallice and the Channel Islands were declared fortresses by March 1944. Small fishing harbors were defended but not heavily fortified.

  Even though French citizens were barred from the construction sites, information leaked out, including a German map showing the major positions. In addition, Allied reconnaissance flights detected many of the defensive structures. However, bombing had little effect on the great submarine pens until the huge block-buster bombs came into use.

  In 1943 a new offensive element made its debut on the Atlantic Wall: the V-1 missiles. Their launch sites, consisting mainly of concrete installations, were strung out from the Channel Islands to the Calais area. In 1944 V-2 missile sites were added to the V-1 rocket bases. Some of these locations, like the complex at Wizemes which was built into a hill, were quite impressive. The only site for the secret V-3 longrange gun was in Minoyecques, not far from Wizernes in the Calais area, and was not finished in time for D-Day.

  By May 1944, the OT had completed another 5,000 concrete structures on the French coast, including in southern France. These positions were in addition to 8,500 existing structures on the Atlantic and Channel coasts. The fifteenth Army occupied the most heavily defended sectors located between the Seine estuary and the Dutch border. It had more than twice the number of heavy and medium artillery pieces of the seventh Army, which held the much longer coastline of Normandy and Brittany.

  On the home front, the defenses of the German Bight or Helgoland Bay, were not built until late 1944. Some gun batteries had been shifted from Germany to France between 1940 and 1941.

  In the Eastern Mediterranean, the Germans set up some coastal defenses on the Greek mainland. In addition, OKW sent officers of the Fortress Engineers and Coastal Defense Staff South to advise the Bulgarians on coast defense, and the Italians on the fortification of the Aegean Islands. After Italy surrendered in September 1943, the Germans occupied many of their coastal fortifications.

  In June 1944, the Atlantic Wall was still incomplete. Troops and civilian workers were still toiling over many of the obstacles. In addition, only 6.5 million of the projected 40 million mines had been laid. By the spring of 1944, OKW and OBW had completed only 10,500 of the 15,000 fortified installations Hitler had ordered (not including Norway). According to Colin Partridge, almost 6,000 smaller positions were also completed. This number included over 3,700 Tobrucks and 780 tankgun platforms and bunkers.

  Thus in 1944, the critical areas of the Atlantic Wall presented a formidable challenge indeed. Any assault directed at the defenses of the major or minor ports would have been tantamount to suicide, which is why the Allies did not seriously consider such a move. It is true that emergency plans such Plan Rankin A through C called for airborne troops and other units to capture Le Havre, but they were only to be set in motion in the event of a German collapse, when resistance would be minimal.

  DESCRIPTION

  The German-Norwegian coastal fortifications covered the coasts of Norway and Denmark. In Norway, the Germans defended fjord entrances and associated islands. The inner rims of the fjords were lightly fortified or guarded by field works. Strong points protected bases and blocked access routes to the interior; Narvik, Lofoten, Langoy, Tromso, Bodo were designated as fortresses in the northern sector; Mo, Vega, Rorvik, Trondheim, Kristiansund, Alesund, and Solund in central Norway; and Stavanger, Fleekefjord, Kristiansand, Arendal, Tensberg, and Oslo in southern Norway. The defenses of Narvik were given priority over all the others in the north. Bergen, the key air and naval base of southern Norway, was second to Narvik in importance. The third most important base was Trondheim, with its sub pens.

  The Norwegian defenses included 225 batteries with over a thousand medium and heavy pieces of which 42 guns were 240-mm or larger. In the area of Narvik the Germans set up batteries at Trondenes and Engeloy to protect the ore route from Sweden. The Danish coast had 70 batteries with 293 guns. The largest two batteries mounted 380-mm guns and were found near Oksby and north of Esbjerg. Construction of field fortifications on the coastal dunes required large quantities of material.

  In addition to the gun batteries, the Norwegian defenses included fifteen torpedo batteries of various calibers that used single, double, triple and quadruple trainable launchers. The old fixed launchers of Fort Kvarven and Oscarsborg were part of the total. Two of these were near Narvik, one at Namsos and the rest south of Agdenes (near Trondheim). Except for those at Narvik, most were housed in concrete bunkers or sheds. The Danish sectors also included torpedo batteries.

  The German Bight included the pre-war fortifications on the North and East Frisian Islands and the defenses of Heligoland that comprised twenty-two batteries, including twelve guns over 240-mm.

  Along the Dutch, Belgian and French coasts the Germans concentrated their main defenses around the fortress areas. In these sectors the Atlantic Wall included 343 batteries with 1,348 guns of 150-mm or more. Between North Cape and Bayonne on the Spanish border there was a total of 700 coastal batteries belonging to the army or the navy. In a few places torpedo batteries existed, the most significant being at Vlissingen (Flushing) on the Dutch coast, and in a large bunker west of Brest, France. In the spring of 1944, the Germans planned to create about 200 torpedo batteries in Western Europe with the new wire guided T10 Spinne torpedoes. They would have been placed in concrete splinter-proof sheds, but only one battery was set up at Ostend before the Allied invasion.

  Toulon, Marseilles, and Sete became the core of the German defenses on the French Mediterranean coast. However, their defenses were far from complete by the summer of 1944.

  Parts of the Atlantic Wall were classified as Verteidigungsbereich or Defense Areas. A typical area in 1943 consisted of several kilometers of coastline with both perimeter and strongpoint defenses. The perimeter defenses comprised barriers such as anti-tank ditches, walls, trenches on land and minefields out to sea. The strongpoints, situated within the perimeter defenses, were almost independent positions composed of infantry fortifications surrounded by barbed wire and mines. Their entrances were heavily guarded. The heart of these strongpoints usually consisted of an artillery battery armed with weapons with calibers of 150-mm or more.

  A Verteidigungsbereich included positions known as Stiitzpunktgruppen that consisted of several strongpoints occupied by a unit of battalion strength or less. Each Stiitzpunkt or strongpoint comprised all around defense, several weapons positions, crew quarters, communications and munitions bunkers, and, usually, a power source. Its garrison was up to company strength. Its weapons, mounted in the various types of concrete positions, included machine guns, anti-tank guns, old tank turrets, and flame-throwers. Some of the later positions included the small Goliath remote-controlled explosive tank.

  The smaller positions of the Uerteidigungsbereich included the Widerstand or resistance point designed for a well-armed platoon or smaller unit. Widerstand, found either on heights overlooking beaches, on the beaches, or between strong points in fortress areas, supported the stronger Stiitzpunkte.

  Ports designated as fortresses were surrounded with Stiitzpunkte and included gun batteries, many of which were in casemates. Gun batteries were also placed at points outside the fortresses wherever there was a need to cover a section of coastline beyond the range of the fortresses.

  Many of the heavy gun b
atteries mounted naval guns served by naval crews. The army manned some heavy rail-g-an positions. During the war, the army took over from the navy the task of defending the coasts and organized about 800 batteries, many with captured weapons. By late 1943, the navy's hundred or so coastdefense battalions were outnumbered by about 140 army coastal-defense battalions (three or more batteries each) and a large number of coastal artillery regiments (two to three batteries and independent battalions).

  Boulogne is probably one of the best examples of a fortress. It was surrounded by over forty Stiitzpunkte and Widerstande that included several with gun batteries. Almost half of these satellite positions were Widerstande and fifty percent were located on the coast or in the harbor. They included 75-mm, 88-mm, 94-mm, 105-mm, 138-mm, and 155-mm weapons and the usual assortment of anti-tank guns, mortars, and other infantry weapons.

  Fortress Boulogne was home to a garrison of two battalions of a Luftwaffe regiment, three battalions of Luftwaffe Flak, and an undetermined number of fortress engineer units. The navy was represented by a flotilla of R-boats or small mine sweepers that were sheltered in concrete pens, and a naval garrison. The whole fortress was under the command of a colonel and was divided into six sectors. Naturally, the other fortresses were not exact duplicates of Fortress Boulogne for there was a certain amount of organizational variability.

  Rommel changed the orientation of the defenses by turning the high water mark into the main line of defense. As a result of his decision, many new features were added, including a huge number of mines. Rommel also ordered the installation of many dummy minefields and positions and fore-shore obstacles that filled the gaps between the Widerstand and the Stutzpunkte. In addition, three to six rows of underwater obstacles were placed between the high and low tide marks. Some consisted of wooden and concrete stakes placed at an angle, sometimes mounting mines, others consisted of old artillery shells anchored to metal structures. Finally, there were also pyramids, tetrahedrons, and Belgian Gates. The obstacles on the Channel beaches alone reached a total of over 500,000; more than 30,000 held mines. Tall pointed stakes, known as "Rommel Asparagus," were installed in open fields to prevent glider and parachute landings.

  The OKW's Regulations Governing the Army's Standard Design as of Autumn 1942, set the standard for most of the construction on the Atlantic Wall. The designs and specifications set out in this document were, to a great extent, developed on the East and the West Wall. There were too many variants of fortifications on the Atlantic Wall to cover in the present work. However, there are a number of fundamental types, such as troop shelters, ammunition magazines, weapons bunkers, positions for machinery and searchlights, supply and kitchen positions, infirmaries, command posts, observation and fire direction positions, command posts for anti-aircraft units, combat bunkers with cloches or turrets, combat bunkers with frontal embrasures and others with flanking embrasures, combat positions for naval artillery turrets, open concrete artillery positions, and command posts with communications equipment. Most of these types usually had ten or more variants that included the design Series 100, 200, 300, 400, 500, 600 and 700 bunkers. The casemates for the huge artillery batteries, and the concrete positions for the artillery turrets were not usually standardized. One of the most unusual positions was a special concrete turret built for Battery Waldham at Fort Vert, in the vicinity of Calais, which was not approved for use until April 1944. Another unusual position consisted of several larger domed turrets in Norway that were not approved until 1944.

  Many of these bunkers had protected entrances, air locks, and, in some cases, Tobruk positions. The Tobruck was a circular open machine gun position, sometimes placed on the roof of, or adjacent to, a bunker designed for local defense. Some of the first Tobruk positions to appear on the Atlantic Wall were the Series 100 of 1939 that included Czech 4.7-mm anti-tank guns and M-19 automatic mortars. Series 400 and 500, which required less armor, replaced Series 100 in 1942 and were used with coastal batteries.

  Coastal positions used the standard protection that consisted of as much as 3.5 meters of concrete and 600-mm to 350-mm of armor thickness in Type A structures, and as little as .3 meters of concrete and 60-mm to 30-mm of armor thickness in the small Type D.

  The Kriegsmarine and Luftwaffe, who developed their own designs, began setting up radar positions during 1942. They used concrete positions for the radar masts, and communications and command blocks. The navy's gun casemates faced the coast for maximum range, while the army's tended to be concealed. As a result the naval range-finding positions operated more effectively than the army's, against naval units. The radars that were deployed along the coast in concrete positions, and even atop large concrete observation posts, yielded disappointing results.

  Among the most impressive, if not unusual, positions of the Atlantic Wall were the batteries defending the approaches to Narvik, which included Battery Dietl (three guns) and Battery Trondenes (four guns). These mounted their naval guns in turrets on large two-level concrete installations. The Gneisenau batteries, also quite uncommon, were created with two turrets salvaged from the badly damaged warship Gneisenau. One turret was placed on an island west of Bergen, the other at Austratt, Norway. The guns from the forward turret went to the Fortress of Hoek van Holland. The secondary armament of the ship went to various locations, including Denmark. The emplacement of the 280-mm triple-gun turret of the battery at Austratt, which went into operation in late 1943, was blasted into the rock. The interior rooms were concreted. The battery was complemented by anti-aircraft weapons and anti tank guns that were set up at the fort. Along with other 280-mm batteries and medium artillery positions, the Austr,-itt site played a key role in barring access to Trondheim and its submarine pens through the fjord.

  The area between Calais and Boulogne was home to Batteries Todt and Lindemann, a battery of 305-mm guns, another of 280-mm guns, and a few domed bunkers for heavy rail guns, the heaviest concentration of big guns on the Atlantic Wall. Battery Todt, located near Cap Gris Nez, consisted of four casemates, each containing a 380-mm gun in a turret. The completed positions went into operation in the spring of 1942. Wire obstacles and minefields surrounded the battery, and other bunkers served various types of weapons, including anti-aircraft guns. There were also troop shelters, munitions storage, and other supporting positions to complete this strongpoint.

  Located near Sangatte, Battery Lindemann was the heaviest gun battery on the French coast. Unlike similar 406-rnm guns near Narvik, these weapons were in three single gun turrets, mounted individually in large three-level casemates. Additional bunkers in and around the battery site formed a strongpoint that included anti-aircraft batteries, machine gun positions, a concrete anti-tank ditch with wire obstacles, and an electrified fence protecting each gun casemate.

  Further to the west, atop a hill overlooking the harbor of Cherbourg, old Fort Roule was equipped with defensive positions, including concrete emplacements for anti-aircraft guns. Just below the fort, a rough gallery was excavated in the rock and four concrete 105-mm gun casemates with an observation position between them were built into the side of the hill. In addition to Fort Roule, other positions surrounded the city of Cherbourg, including concrete gun batteries, and reinforced positions on old forts which occupied the jetties.

  The fortress area of the Channel Islands was also unique. The Mirus Battery, located on the island of Guernsey, mounted 305-mm guns salvaged from the old Russian battleship Imperator Alexander, which had been scrapped in Bizerte, Tunisia. The guns had been sent by the Allies to Northern Finland during the Winter War, but were captured by the Germans after they invaded Norway. The weapons were refurbished and sent to the Channel Islands where they were mounted in turrets atop a large underground concrete support area. This massive construction fitted well with the large multi-level observation and range-finding stations on the islands.

  The largest of all the Atlantic Wall concrete structures were the submarine pens. The most unusual of these pens were those of Lori
ent, where only one set was on the water. The other two were only reached by a slipway. The submarines were pulled out of the water on "chariots" and shifted along a set of rails into one of the pens. Another position included unusual dome bunkers for U-boats, where they were also pulled out of the water and moved on to a round table from which a chariot carried them into one of the two shelters.

  Other large submarine pens in France were located at Bordeaux, La Pallice, St. Nazaire, and Brest. Along the Channel coast, concrete pens for R-boats were built at Cherbourg, Le Havre, Boulogne, and Dunkirk. Outside of France, the Germans built submarine pens at Trondheim, Norway and R-boat pens at Rotterdam and Ijmuiden in the Netherlands.

  Most of the artillery was concentrated on the Channel Coast. Only about one third of the artillery allotted to the area was placed in Normandy, between the Seine and the Belgian border. Even the Channel Islands had more super-heavy batteries than the Normandy coast west of the Seine. More importantly, Norway received almost as much heavy artillery as the remainder of the Atlantic Wall.

  Heavy and Super Heavy Gun Batteries of the Atlantic Wall in 1944 included:

  The South Wall's heavy weapons consisted mostly of French guns.

  In addition to these batteries, many others consisted of guns ranging from 75mm to 88-mm (including Flak). Many weapons were mounted in casemates or on concrete platforms with supporting facilities in concrete positions.