Fortress Europe- European Fortifications Of World War II

by J E Kaufmann

  Nestos Defensive Position for Heavy MG.

  Greek Bunker for 75-mm field gun and observation.

  Greek position for two rifle grenade launchers.

  Chapter 13

  FINLAND

  BACKGROUND

  Sandwiched between Germanic and Slavic cultural areas, the Finns have been caught in a tug of war between the Swedes and Russians for centuries, probably faring better under Swedish than Russian rule. They spent the majority of the nineteenth century under the domination of Russia and many of them, including Carl Gustav E. Mannerheim, served in the Russian army during World War I. When the Russian Civil War tore the Empire asunder, both Red and White forces fought to dominate Finland in late 1917. The arrival of German troops brought victory to the White forces of Mannerheim and soon the bloody struggle ended, leaving the Finns independent at last. Although Finland was the state with the largest land area to achieve independence from Russia, its population barely consisted of a couple of million people.

  When it gained its independence, Finland inherited old and abandoned Russian equipment and naval vessels from the Russians. However, they shortly received some aid from the French, who sent them aircraft and Renault FT-17 tanks. The fact that the Soviet Union recognized Finland's independence by signing the Treaty of Tartu in October of 1920 did not reassure the Finns. So, during the 1920s they attempted to build some form of defensive system against future Soviet aggression. They concentrated most of the work on the Karelian Isthmus and on the coast defenses in southern Finland.

  The creation of a barrier across the Karelian Isthmus was a new enterprise for the Finns since few places in their homeland, besides Viipuri, had been fortified over the centuries. The new government of Finland forced Mannerheim, an opponent of democratic ideals, to retire, and spent almost a decade attempting to protect the country from a possible Soviet invasion. In addition to coastal defenses, the Finns fortified the landward approaches from the Soviet Union on the Karelian Isthmus, the most direct invasion route. Here the terrain consisted of forests, lakes, and marshes, and was crisscrossed by an adequate road system.

  The only route to the north, the new Arctic Highway linking Petsamo and its nickel mines to Oulu, traversed one of the most desolate areas of Finland in the Arctic Circle. It was about 10 meters wide, and probably graveled but nonetheless it presented a tempting invasion route for Soviet troops coming out of Murmansk. However, it was not secured with fortifications because the Finns did not have enough resources to defend their Arctic outpost. In this area the determination of the Finnish soldier would effectively have to replace fixed defenses.

  MAJOR FORTIFICATIONS

  Mannerheim Line

  Salpa Line

  Coast Defenses

  LOCATION

  1. Mannerheim Line

  The Mannerheim Line stretched approximately 130 km across the Karelian Isthmus, which consisted of some hills and rocky areas between Viipuri and the prewar border. Birch forests, interspersed with open fields covered large parts of the isthmus. There were also small swampy areas that ranged from a couple of hundred meters to 2 km in length and had few, if any, trees and a great deal of moss.

  The Mannerheim Line included an intermediate position and the Back Line or Stop Line further to the rear. The main line ran from the Gulf of Finland to Lake Ladoga about 20 to 50 km behind the border, taking advantage of the numerous watercourses and wooded areas, and followed the Kuolemajarvi (Death's Lake)- Muolaa-Sakkola-Taipale route. According to some experts, it consisted of a western and eastern section.

  The Western Section stretched about 54 km from the Gulf of Finland to Vuoksi and consisted of two lines 3 to 5 km apart. The Eastern Section extended from Vuoksi to Lake Ladoga, a distance of about 46 km, following the Vuoksi River, which would channel any invasion force. The area around the town of Summa was one of the key points to controlling the isthmus. The defended sectors covered all possible lines of advance along the isthmus but did not form a continuous line of bunkers and trenches. Many of the positions blocked roads, covered river fords, or occupied the spaces between small lakes that dominated the central part of the isthmus.

  Lake Ladoga's shoreline was rocky for most of its length, and was most vulner able in winter when the lake froze, allowing troops and vehicles to cross it. The Karelian Isthmus was mainly low-lying terrain south of Viipuri to the Soviet border with clay-like soil and occupied by much farmland between the forested areas.

  2. Salpa Line

  Theoretically, the Salpa Line covered the border with the Soviet Union from the Gulf of Finland west of the Karelian Isthmus and to the north of Lake Ladoga. In practice, however, its main positions lay west of the Karelian Isthmus. The heavily forested area along the Soviet border,, from north of Lake Ladoga to the Arctic circle, consisted of less than 500 km of hard-surfaced roads and required hardly any defenses. Beyond the isthmus, in the heavily glaciated and wooded lake region of the southern half of Finland, the road system became more extensive, giving the Finns the advantage of interior lines. The terrain of the Karelian Isthmus, on the other hand, offered many advantages to the defender.

  North of Viipuri, the land was more hilly than the isthmus and included more birch forest, fewer fields, more rocky areas, and about the same expanse of swamps. The line began near the coast, entering an area of numerous swamps and lakes.

  In the south, the Salpa Line actually consisted of several lines although there is some question on whether they should all be lumped together under the same appellation. The first line, an advance position for delaying the enemy, began on the coast about 25 km west of Ristiniemi (southwest of Viipuri). Between this first line and Hamina were other lines that extended to the northeast and north and ended about 20 km southwest of Nuijamaa (south of Lappeenranta). The main line was set up almost directly behind the first line. About 30 km north of the coast it veered to the northwest towards Kivijarvi, at a distance of over 20 km behind the delaying line. In the summer of 1940 a new main line was set up about 20 km east of Hamina and on the coast, running from Sydankyla northward to Kivijarvi. This new line was preceded by another advance position located about 5 km in front of it.

  The remainder of the Salpa Line was not a continuous line of bunkers stretching north from the vicinity of Lappeenranta. The central section of the line ran along the lakes northward to Lake Pielis (Pielisjarvi). These lakes created an almost continuous barrier, at which the Finns set up positions at a number of key points, including islands. The line of concrete bunkers ended in the vicinity of Joensuu (northwest of Lake Ladoga). To the north of Pielisjarvi, the "Wilderness" served as the defense.

  3. Coast Defenses

  The Finnish Navy and Coast Artillery put the old Russian forts, except for Ino, back into operation. Much of the coastline consisted of rocky promontories separated by beaches, and, in some cases, swamps. In addition, there were numerous islands just off the shore. The Lake Ladoga side was rocky while the coastline on the Gulf of Finland had a low elevation and was covered by sandy beaches near Viipuri. Coast defense positions were set up on many islands adjacent to the Karelian Isthmus. In addition, an attempt was made to space out sufficiently the new gun positions along the coast. The preferred distance was a minimum of about 500 meters. Where possible, the gun battery positions were placed far enough inland to be out of the direct line of fire of naval vessels. Observation positions, on the other hand, occupied well camouflaged sites near the coast.

  HISTORY

  During the 1920s the Finnish armed forces were reorganized because many units, which had been indoctrinated in the old Russian system, had to be retrained. Many officers were schooled by the Germans. Furthermore, adjustments had to be made to much of the military and naval equipment, which was Russian. Finland's government and military establishment, who were certain that any future threat would come from the east, oriented all their planning and preparations in that direction.

  However, the Mannerheim Line was the creation of both Finnish and Soviet
propaganda. The Finns tried to fend off aggression through misinformation and exaggeration concerning their defenses. The Soviets, on the other hand, found it expedient to blame their initial failure and exaggerated their victory by inflating the importance of the obstacle they had to overcome. In reality, the Mannerheim Line was no Maginot Line, nor even an obstacle as formidable as the German West Wall.

  The construction of the Mannerheim Line began between 1920 and 1921 when many of its positions known as korsu or dugouts-wooden bunkers in Finnish-were built. These wooden structures sometimes included machine gun positions and were covered with earth and stones.

  The permanent structures, known as bunkkeri, could be constructed of either concrete or stone, above or below the ground. A large number of weak concrete bunkers were built during the 1920s. It was not until 1931, during the second building phase, that construction began on concrete bunkers of sufficient strength to resist at least 150-mm (6-inch) guns. The first of these heavier bunkers were not completed until 1932. The bunkers rarely mounted weapons heavier than a machine gun and were not intended to serve as the main fighting positions. Indeed, the Finns preferred to fight outside the bunkers.

  Trenches like those made famous at Verdant became a key defensive element. Anti-tank obstacles were also set up. However, the army had virtually no anti-tank guns before the Winter War and only a small force of ineffective tanks. The strength of the line did not lie in its concrete emplacements, but in the soldiers who defended it. Unlike the Maginot Line or West Wall, the fortifications played a minor role compared to their defenders.

  Security was not tight around the Finnish fortifications. Before the war, civilians were not denied access to the fortified areas, which, more often than not, were surrounded by private property. Before the war the work on the defenses was done by troops, reservists, and special construction units that were disbanded once the war started. After the war began, the work force was reorganized, but the recruitment of workers turned out to be a slow process. During the Winter War of 1939-1940 Belgian engineers assisted in building some new and smaller bunkers. Despite this effort, however,, Finland was practically defenseless at the end of the war.

  Only a week after the armistice concluded the Winter War, the Finnish commander-in-chief authorized work on a new and more heavily fortified position between the Gulf of Finland and Lake Kivi (Kivijarvi), which was given the name of Klamila-Luumaki Line (Luumaki Line) and was renamed Salpa Line, or Lock of Finland (Suomen Salpa) by Marshal Mannerheim on July 10, 1944. This line was built with the cooperation of 900 Swedish volunteers, who arrived during the Winter War and went to work about 18 km north of the coast.' Over half of the Swedish workers left for home by June and were replaced by Finns in September, which brought the number of workers up to 5,000. Additional work teams formed that summer, and by the spring of 1941, 30,000 men and 2,000 female volunteers labored on the new line, supported by soldiers.

  The first construction phase on the Salpa Line ended in June 1941, when the Continuation War (as the Finns called World War II) broke out. It was followed by the next phase that lasted until September 1944, although some artillery positions were not set up on Lake Saimaa until December 1944. The line slowly worked its way northward, encompassing a larger area.

  In June 1944, during the Continuation War, when the Finns reoccupied some of their former territory the line was readied for action as the Soviet threat increased and casualties mounted. Instead of extending the original line, the army leadership decided to shorten it in order to reduce the number of troops needed to defend it. The right flank was moved forward to a position running Virolahti- Hakalanjarvi-Tyllinjarvi. With 35,000 men on the job, construction progressed rapidly. The majority of the men worked on the Salpa Line between the Gulf and Lake Saimaa. By October 1944 the work was largely done and troops took up positions.

  The Salpa Line involved a much greater effort than the Mannerheim Line. While the Mannerheim Line consisted of about 300 positions according to the Soviets, a number that probably included every korsu and bunker, the Salpa Line comprised closer to 3,000 positions.

  In addition to the fortified line, the Finns salvaged and upgraded what they could of the old Russian arsenal on their territory. In 1918 the Finns quickly took over the Russian installations, putting them back into service wherever possible and building new ones. Not all of the Russian fortifications were viable however. For instance, Fortress Ino, only about 30 km distant from the first of the forts protecting the approaches to Leningrad, had to be abandoned because the retreating Russians had blown it up in May 1918. What remained of the fortress was destroyed by the Finns in accordance with the Treaty of Tartu. Nonetheless, the Finns managed to salvage one of the four 12-inch guns in twin turrets, four gun barrels, and sections of a turret. They also recovered two of the fort's eight 152-mm guns, four 8-inch gun barrels, and other sundry material. Little of value remained from the fort's four 11-inch howitzers, eight 10-inch guns and four 9-inch guns. The 12-inch gun was modified to increase its range from 30 km to perhaps over 40 km.2

  In 1918 the Finnish coast defense forces also inherited the unfinished Fort Makiluoto which had been badly damaged by the Russians. The armament, which had included two twin gun 14-inch Vickers-built turrets, probably intended for Borodino Class battleships, was also damaged.

  The Finns also inherited Fort Kuivasaari, protecting Helsinki's outer coastal defenses, which had been turned into a base by the Russians in 1896 and further fortified in 1911. Fort Kuivasaari was renovated at a time when the Russians had decided to extend their coastal defenses along the southern coast of Finland as far as Turku and the Arland islands, to control the approaches to Petrograd (Leningrad) on both sides of the Gulf of Finland. The fort had a four-gun 254-mm battery and was almost completed when the war began. In 1918, when German troops arrived to support the White forces, the Reds evacuated the fort, leaving it intact. In the 1920s, Finnish troops trained there with the fort's remaining guns.

  One of the most important coastal positions Finland inherited from Russia was the fortress of Hanko (Hango in Germanic) and its associated island forts. The Russians had intended mounting 305-mm (12-inch) guns and other heavy artillery pieces at Hanko, but did not have time to do so. One of the most important of the island forts was Russaro with six 9.2-inch (234-mm) guns, three of which were put back into operation, and four 75-mm guns. Batteries of 203-mm (8-inch) or 152-mm (6-inch) guns were located on three other islands. In addition there were two mobile batteries with seven 152-mm British Mk VII guns.

  In 1923 the Inspector of Coast Defense, General K. E. Kivekas, took control of the defense of the Finnish coast, which included all naval ports, coastal artillery units, and naval bases. In 1927, further reorganization placed the coastal artillery and the coastal fleet under a single commander. To man the coastal defenses, in cluding those of Lake Ladoga, three artillery regiments, and an independent coast artillery battalion were formed by the army. In addition, two new anti-aircraft batteries were placed under the control of the navy.

  Coastal artillery positions also protected the main naval bases at Helsinki and Pansio, near Turku. Early in the 1930s the government decided to erect a twin gun turret at Fort Makiluoto and at Fort Kuivasaari. At Fort Makiluoto the foundation of one of the demolished twin 14-inch gun turrets was used to set up a new 12-inch gun turret. The turret at Fort Kuivasaari became operational in 1935. However, between 1939 and 1940 the fort's four 254-mm (M-1895) guns were transferred to other coastal forts. In 1940 the base of Hanko and its associated islands was manned by the Finnish Hanko Coast Artillery Brigade.

  In addition to the artillery, Finland started developing a navy whose main role was to defend the coast and support both ends of the Mannerheim Line. In 1923 a plan to be implemented in 1924 for building up the navy's 1,300 man force, included the acquisition of three coastal defense ships (3,900 ton displacement), two destroyers, two mine layers, six submarines, thirty coastal motor boats, and a couple of support ships. At t
he time, the navy only consisted of a few motor torpedo boats and a number of mine sweepers and mine layers. In the 1930s, the navy received the two coastal defense ships armed with four 254-mm (10-inch) guns in two turrets, completed at Turku. Several other vessels, including submarines and coastal defense craft, were built in Finland before the war. By 1939 the Finnish navy approached a strength of 4,000 men, without counting the coast artillery. A small fleet of twenty vessels operated on Lake Ladoga. In addition, a small submarine was especially designed to patrol the lake, but it was not used.

  In 1940 the Soviets took over the Hanko area as a result of the peace terms of the Winter War, but the Finns removed the 9.2-inch guns. The Soviets once again planned to set up 12-inch guns on the island fort of Russaro (about 5 km south of the tip of the Hanko peninsula), but the largest weapons there were two gun batteries with 130-mm coastal defense guns. On the mainland they did employ a battery of three railway guns 305-mm (12-inch). In 1941, when the Finnish army recaptured the base during the Continuation War (as Germany's ally), they were able to put back into service some of the weapons including one of the 305-mm railway guns. They also repaired five 130-mm pieces.

  DESCRIPTION

  1. The Mannerheim Line

  The Mannerheim Line mostly covered the main lines of advance from Russia across the Karelian Isthmus. The area between it and the border was the zone of destruction that was intended to delay the enemy. In fact, it was not a continuous line of bunkers and man-made barriers. Instead its main fighting positions consisted of wood-lined trenches protected by obstacles in front. These obstacles, which were not well covered, consisted of concrete and stone dragon's teeth. The stone version was the most inexpensive of the two.