Fortress Europe- European Fortifications Of World War II

by J E Kaufmann

  The basin in the Nevrokopion section was encircled by fortifications such as the fort of Pisse (Ochiron-Lisse) that occupied an isolated conical peak. Fort Pisse (Ochiron-Lisse) and three others in the sector were covered by a large anti-tank ditch. Like most of the Greek fortifications, they were difficult to spot from the Bulgarian frontier. According to a 1941 German report on the main positions:

  The nearly completed works Usita and Paljuriones constituted the main defenses.... Field-type fortifications replaced a few missing bunkers at the southern front of the Usita works. Each work of the Usita group was staggered, from east to west, 20 meters above the next work. The western part also dominated the outpost area of the Paljuriones works. These works flanked the Kelkaya Group. The Kelkaya group, in turn, rose 700 meters above the Paljuriones works. A continuous anti-tank trench ran in front of the northern edge of the Usita and Paljuriones works, and on the northwestern rim of the Kelkaja works. The Istebei and Popotlivica fortifications were situated only 200 meters from the border. The Istebei works were completed; reinforced obstacles protected them against surprise attacks. Popotlivica was not yet half finished and presented only a linear fortification facing northwest (from Ger- nian Attacks on Fortified Positions).

  A Greek fort usually consisted of as many as twenty combat blocks or as few as a dozen or less. The blocks might be classified as small infantry casemates. They were mostly uni-functional, rather small, and devoid of cloches or turrets. However, according to a German report, there were blocks with an armored cloche. Most held machine guns, but some mounted mortars or searchlights. Anti-tank gun casemates guarded the more easily accessible approaches. Some of these casemates housed two mortars or anti-tank guns. Most blocks also served as observation positions, although there were special observation blocks. Some forts included a howitzer casemate and anti-aircraft gun blocks and, apparently, a few positions mounted 75-mm and 77-mm guns.

  Fort Istebei is an example of a very large Greek fort with 400 men. It was entirely surrounded with barbed wire and had two entrance blocks and a large tunnel complex that covered an area of about 250 x 300 meters. The entrance blocks of most forts were usually rather simple structures usually lacking external defenses. Istebei's subterranean system included concrete-lined tunnels 1.0 to 1.4 meters wide and 2.4 meters high. The tunnels were generally about 15 meters below the surface and in some forts they ran for a few hundred meters, but in the larger ones like Istebei there were over 4 km of galleries. Since they were small, these tunnels were not curved, but formed sharp angles to create interior defensive positions. Interior defenses were reported to have been present in most of the major forts and these included air locks, blockhouses, and mined sections of the tunnels. Many of the tunnels ended in a block that served as a sally port. These well hidden exits were intended for use against enemy troops on the fort and also as an entry for a relief force. The underground facilities, located near the center of Fort Istebei and close to its entrance, consisted of command centers, a caserne, a usine, ventilation equipment, food stores, and an infirmary. The magazines were situated near the combat positions. Surprisingly, these small tunnels also included a narrow-gauge track for manually operated wagons that hauled artillery ammunition.

  Although no large anti-tank ditch appears around the mountain top position of Istebei, some forts like the large one of Rupel had an anti-tank ditch running around their front.

  Fort Istebei consisted of twenty-eight combat blocks, mostly for machine guns. A couple of these positions had light mortars in addition to machine guns. Two of the Istebei blocks housed 81-mm mortars. Mortar blocks in the Metaxas Line usually had an open firing position similar to the famous Axis "Tobrucks" with an armoured lid to cover the position. One block near the entrances mounted a howitzer and another, that stood nearby, anti-aircraft guns. The anti-aircraft blocks consisted of a light revolving cupola which opened by splitting into two halves. These positions mounted 20-mm machine guns. The specialized positions included three observation blocks and a machine gun casemate with a searchlight. One block in an iso lated position with no underground connection was used for observation, and included machine guns and an anti-tank weapon.

  Fort Istebei's interval positions held various types of weapons of German and French origin, most of which were already considered obsolete. Some of the smaller were forts like Pisse (Ochiron-Lisse) which consisted of three machine gun, three artillery and one anti-tank gun casemate.

  The group located along the Struma Valley, a typical group position, is described in a 1942 German document. It consisted of three forts identified as A, B, and C. Fort A had twelve machine gun. casemates, two observation positions, and a casemate with anti-tank guns. Fort C stood to its rear, and consisted of twelve machine gun positions, a mortar blocks, and two observation positions. Fort B, also behind Fort A, comprised twenty-five machine gun casemates, four artillery casemates, four mortar positions, eleven observation positions , and one anti-tank emplacement. The 1942 document does not identify the group, but it may well have been either the Karatas or Kali Group,'

  In the intervals between forts were some 500 of the remaining combat blocks, which are the equivalent of French casemates or blockhouses with facilities. They included machine gun and artillery casemates, which, in some cases, occupied isolated positions. Some of these blocks were made of stone. Many artillery positions were located to the rear of the line.

  There were three types of concrete thickness for the Greek fortifications that could resist 105-mm, 155-mm, or 220-mm shells. The highest category, used in most of the machine gun and anti-tank gun casemates, could also resist a 300 kg bomb. Depending on the type of positions, the roof thickness varied from 0.6 to 2.0 meters. The walls were usually between 1.0 to 1.5 meters thick with a standard of about 1.2 meters.

  The obstacles not only included barbed wire and anti-tank ditches, but also anti-tank rails and concrete pyramids similar to the German "Dragon's Teeth." They blocked the approaches to strong points. In places, several rows of concrete antitank obstacles alternated with a couple of lines of anti-tank rails. Many anti-tank ditches were water-filled.

  The army garrisoned the coastal defenses, except for the naval bases. Some of these positions built by Metaxas during the 1930s included concrete shelters and even gun turrets. The Greek coastal defenses of Athens-Piraeus included the positions on the islands of Fleve, Psitalia,, and Salamis. A naval arsenal protected by three batteries of 88-mm anti-aircraft guns was located on Salamis. A battery of 150-mm guns stood at Punta, on the southeast end of the island. Psitalia Island had two batteries of 150-mm guns and three of 76-mm anti-aircraft guns positioned to protect Piraeus harbor. At Cape Tourla, on Aegina Island to the south of Salamis, there were two batteries of 305-mm guns, one of 150-mm guns, and anti aircraft gun batteries. Near Perdica, on the same island, stood another 305-mm gun battery and an anti-aircraft gun battery. Fleve Island mounted a battery of 305-mm guns, two batteries of either 120-mm or 150-mm guns, and two antiaircraft gun batteries2.

  Cape Papas, west of Patra, was home to four 305-mm guns in two batteries, two of which were emplaced by the end of 1938. Two more batteries of 305-mm guns were located near Cape Scropha, opposite Cape Papas. In addition, Cape Papas and Cape Scropha held four gun batteries of 75-mm anti-aircraft guns and 47-mm guns. At Cape Rion, on the Gulf of Corinth, there were machine gun bunkers and a pair of 76-mm and 47-mm gun batteries. In addition, a submarine net stretched from Cape Rion to Anirion. Fortifications also covered a naval base in the Gulf of Amvrakia.

  Two fortified groups were built on the coast of the North Aegean. The 1st Group, East, at Cape Karabournu consisted of pre-war installations with a battery of four 270-mm Krupp guns in two twin gun turrets and a similar battery with 240-mm Krupp guns. It also had an ancient battery of three 190-mm guns that may have been deactivated in 1938, during the installation of a 305-mm gun battery. The 2nd Group, West, at the mouth of the Vardar River, consisted of old, pre-World War I installations that include
d a battery of four 100-mm guns and another of anti-aircraft guns.

  The coastal defense positions were equipped with artillery weapons, all of which, except the anti-aircraft guns, were mounted in armored turrets linked by underground concreted tunnels that held the magazines. The heavy and medium caliber artillery, which came from the obsolete battleships Leninos (ex-U.S.S. Idaho) and Kilkis (ex-U.S.S. Mississippi), consisted of:

  8 - 12-inch (305-mm) guns

  16 - 8-inch (203-mm) guns

  16 - 7-inch (178-mm) guns

  The following weapons came from other ships:

  16 - 3-inch (76-mm) guns

  9 - 273-mm guns

  15 - 152-mm guns

  The anti-aircraft guns, which were mounted so they could also cover the minefield and engage small vessels, included 47-mm, 76-mm, and 88-mm guns of recent German manufacture.

  2. The Carol Lines and Rumanian Fortifications

  Few details are available on the Rumanian fortifications besides their lightest works. It is known that, in some places such as Bessarabia, old forts were reinforced and put back into use wherever they were available.

  By 1938, trenches were dug and underground shelters and over sixty concrete machine-gun bunkers built, mainly in the river valleys along the Hungarian front. The bunkers mounted two machine guns. The purchase of 600 units consisting of machine guns and 47-mm anti-tank guns from the Czechs at the end of 1938, seems to indicate that additional bunkers were being built to accommodate them. Apparently, the Czechs helped the Rumanians design their new positions, which were designed for their own weapons. Supporting positions included emplacements for four batteries of 150-mm Skoda guns. They were located on both sides of the main highways and camouflaged with latticed blinders to conceal them from motorists. Permanent guards helped pinpoint their location.

  It is likely that other fortifications were built in Bessarabia and in the south along the same pattern. Apparently the new bunkers were larger than the older models. A permanent garrison of three special fortress detachments was drawn from three infantry divisions.

  3. The Turkish Straits

  Turkey set up a coastal defense system on the peninsula on the northern side of the Dardanelles. In 1939 it included three batteries of old Russian 8-inch howitzers, five batteries of 6-inch guns, and an assortment of smaller weapons. On the Asiatic side, there were two 210-mm Skodas in the vicinity of canakkale. There were also five batteries of 6-inch guns and three of 6-inch howitzers. A number of concrete emplacements were located on the coast between Kimkale and Guilpinar.

  WEAPONS AND EQUIPMENT

  WORLD WAR II

  1. Greece

  The Italian invasion across the Albanian border forced Greece to alter its defensive plans in 1940. Greek divisions were shifted to the Albanian front-defended only by light field fortifications-to contain and drive back the Italian forces. When Germany attacked Greece and Yugoslavia in April 1941, the Greek forces were off balance and the Metaxas Line was still incomplete. The British contribution was not enough to support the Metaxas Line, and they wanted the Greeks to defend a more central position on rugged slopes. This was where the British took up position. The Greeks were left on their own. However, the Axis powers lacked sufficient knowledge of the composition of the Greek fortifications to develop advanced plans for their elimination partially because of their location and excellent camouflage. The Germans soon found that they could not bypass the key routes and the strong points protecting them. In the end German superiority in weapons and numbers allowed them to force their way through.

  The German 2nd Panzer Division, two mountain divisions, and three infantry divisions faced three Greek divisions in the Struma sector, the only place where the Greek fortifications were clearly visible from Bulgaria. On April 6, after eliminating minor resistance on the border, the German 50th Division ran into the isolated Nimfea group east of the Metaxas Line. Its surprise attack on Nimfea failed, but on the evening of April 7, after a bombardment of an hour and a half, German troops infiltrated the Greek lines, attacking from three directions. After losing several bunkers in close combat, the 400-man garrison surrendered that night. To the west, the partially completed fort of Echinos lasted three days before its garrison withdrew.

  Meanwhile, the German 72nd Division advanced on the Nevrokopion Basin, but intense fire prevented it from bringing forward the artillery. On the afternoon of April 7 the field fortifications in front of Fort Malianga were captured. Two subsequent attacks on Fort Malianga failed and even an attempt to bypass the fort was foiled by the defenders. Only a few outposts of Malianga had fallen by April 9.

  A German battalion was driven back by Fort Perithori and took heavy losses in a second attack on that strong point on April 6. German 88-mm anti-aircraft guns destroyed two bunkers, but Greek artillery drove them off on April 6. Early in the morning of April 7, the German battalion from the 266th Regiment managed to penetrate the position, but after eliminating several bunkers, it was driven out by the Greeks.

  The German 266th Regiment was also repulsed in an attempt to capture the fortified mountain position east of Pisse (Ochiron). Two attacks on April 7 inflicted heavy losses on the Germans who found it impossible to climb the steep slopes below the bunkers. The 105th Regiment succeeded in taking the fortifications on the ridge of Kresti after heavy fighting. However, Greek counter attacks on April 8 almost recaptured the ridge.

  Also in the eastern sector, German troops forced their way into one of the three tunnels of Pyromidoides. The garrison no longer capable of mounting a counterattack, detonated the mines in the tunnel sealing it off and continued to resist until the armistice. On the western sector of the Metaxas Line the 125th Regiment, a veteran from operations on the Maginot Line, was reinforced during its attack on the Struma positions. Its path was barred by the almost completed forts of Rupel (Usita) and Paljuriones, the completed Istebei group, and the half-finished fortifications of Poptlevitsa about 200 meters from the border. On April 6, artillery and air attack heralded the beginning of the attack, which failed. The Struma River could not be crossed. The Germans also suffered heavy losses in three fruitless attacks on Fort Usita on April 6. The German attacks continued to fail until April 9.

  The 5th Mountain Division succeeded in taking a couple of positions in a surprise attack on April 6. Dive-bomber attacks on Hill 1941 at Rupesco (probably refers to Rupel), Istebei, and Popotlevitsa failed. The Rupesco position held out against the German mountain troops until April 9 when Popotlevitsa also surrendered after heavy fighting.

  Another German mountain battalion attacked Istebei's western slope before the fall of Popotlevitsa, reached the heights, and eliminated a few of the bunkers early in the afternoon. However the remaining bunkers continued to resist, inflicting heavy casualties on the attackers, who had to be relieved by another battalion on the afternoon of April 7. A German assault team blasted through a cloche and attempted to enter the tunnels, but was repulsed by the Greeks. Finally the defenders surrendered after the ventilation system was damaged by explosives and they were overcome by smoke.

  On April 6, a battalion of the 100th Mountain Infantry Regiment attacked the fort of Kelkaja, but was repulsed by the flanking fire from Istebei. That afternoon, using infiltration tactics, the Germans reached the fort but had to take the bunkers one by one. On the morning of April 7, they located the main entrance. But first they had to demolish parts of the fort, use flame-throwers against it, and finally damage the ventilation system before the garrison would surrender. The central part of the fort was taken later that day. The next day, the Greeks evacuated the southeastern part of the fort before the Germans attacked, even though most of the positions were still intact. From here the German 125th Regiment joined the mountain troops in the attack on the western sector of Paljuriones.

  Further east, the 6th Mountain Division broke through the Krusia Sector by April 8 after crossing what the Greeks believed an impassable 2100 meter high snow covered mountain range, while the 2nd Panz
er Division continued to envelop the Metaxas Line.

  The forts of the Nevrokopion Sector held out until ordered by the Greek high command to surrender. The Struma Sector fought to the bitter end and its forts were eliminated one by one. The Germans attacked twenty-four forts and managed to take only five in their brief campaign.

  The Germans best summarized the results of the victory over the Greeks by stating that their enemy was numerically inferior and lacked the troops to eliminate penetrations despite their tough determined resistance.'

  2. Rumania

  Rumania lost all of its pre-war defenses to territorial annexations in 1940. Its only remaining defenses, the FNB Line, went into action in August 1944 against the Soviets. It was Rumania's last ditch effort before its government collapsed and defected to the Allies.

  3. Turkey

  Turkey's defenses were more impressive on paper than in reality. In actuality it had no effective defenses against the Soviets or the British and French in the 1930s. Its army was relatively weak compared to other military forces and not capable of mobile defense. Thus Turkey found itself negotiating with the Axis during the war because its lack of major fortifications could not provide security. Nonetheless, the rugged terrain of the country should have made defense relatively easy beyond the Straits.

  Example of a Rumanian bunker for heavy MG.

  Drawing of Greek Fortified Position

  Metaxas Line (Greece) - Several Fortified Groups

  Greek Strong Point Block for AA Gun.

  Strong Point Block linked to underground system and mounts 81-mm in cupola.