Fortress Europe- European Fortifications Of World War II

by J E Kaufmann

  With no other recourse, the Finns allied themselves with the Axis, and embarked on the Continuation War in June 1941. They recovered all their lost territories, including the isthmus and Hanko, and advanced no further. By that time, the Salpa Line was already in progress. However, the retreating Soviet forces destroyed most of what was left of the Mannerheim Line. The Finns set up new installations, including on Lake Ladoga.

  As the German Eastern Front began to collapse in 1944, Mannerheim hastened the work on the Salpa Line and some advanced positions to conserve manpower. In the latter part of 1944 Finland found itself in yet another conflict with the Soviet Union. Finnish forces began to take increasing casualties as the Soviets advanced. Knowing the Finns would resist against the odds, as they had done during the Winter War, and apparently not anxious to test the new Salpa Line, the Soviets allowed their war with Finland to end. The new fortifications may well have saved Finland from the type of brutal occupation that the nations of Eastern Europe would soon have to endure.

  When the war was over the Finns had to remove the 12-inch gun turret from Fort Kuivasaari, which fired only once during the war to harass the Russian troops evacuating Hanko in 1941. It was returned and restored to its position in 1960. The army still maintains many of the bunkers of the Salpa Line.

  Model Finnish Bunker.

  Standard Finnish Bunker for flanking fires.

  Map of Mannerheim Line showing sectors

  Map of Hanko sector.

  Chapter 14

  SOVIET FORTIFICNIONS

  BACKGROUND

  The Russian army was no stranger to fortifications, especially after the defense of Sevastapol during the Crimean War, and the unsuccessful defense of Port Arthur in the Russo-Japanese War half a century later. By 1914 the Russians had erected relatively modern fortifications along their borders and coastlines, including the Gulf of Finland and the Polish shores. When Poland regained its independence, reclaiming some of its former territories in the east, and Finland and the Baltic States broke away, the Soviet Union lost many of these fortifications. Only Kronstadt and the associated forts protecting Leningrad gave the Soviet Union a last "Window on the Baltic." However, the Red Army managed to hang on to the Ukraine despite its unsuccessful bid for independence, thus retaining control over the Black Sea defenses. As a result of these changes, the Soviet Union's western frontier stood open to invasion, and northwestern Russia south of the Baltic remained without defenses.

  MAJOR FORTIFICATION

  The Stalin Line

  The Border Defenses or Molotov Line

  The Coast Defenses I

  LOCATION

  The general layout of the terrain of the Soviet Union in itself constituted a formi dable defensive feature, consisting of large rivers, extensive forests, swamps, and sandy regions criss-crossed by a poor road system. The railroad system, which had carried over 80% of all Soviet traffic in 1937 according to the July 1941 issue of Time magazine, was the key form of transportation in this area. The railroads gave the Soviet Union a tremendous defensive advantage because their non-standard broadgauge rail lines differed from the standard gauge used in Germany and most European nations. An invading army would be forced to change the gauge of the tracks or capture enough rolling stock and locomotives to support its own operations inside the Soviet Union.

  In the territories they occupied in 1939, the Soviets converted the standard gauge railroads to the Russian broad gauge. This required Soviet engineers to have one rail moved approximately 9-cm outward on each of nine rail lines in occupied Poland. One additional railroad, by agreement, remained standard gauge. This line ran from Przemysl to Lvov and on to Rumania through Cernauti, so Germany could have a direct rail link to Rumanian oil.' The Russian rivers also formed substantial obstacles because they were large and difficult to ford. However, since most of them had a higher west bank than eastern bank, they put the Russian defenders at a disadvantage, giving the enemy the commanding position. Fortunately, most of the rivers had swampy banks on both sides, which effectively hindered assaults and bridging operations. In addition, bridges had to span most of the river's flood plain to avoid being destroyed by spring floods or winter ice floes. For instance, one bridge over the Desna spanned about 600 meters even though the river was only 100 meters wide and the Volkhov, south of Leningrad, was a swamp flowing through a marshy wilderness of woods and brush. The Dnepr3 River, which became the main defensive line in 1941, was up to 200 meters wide and even wider in the Zhlobin area where the Germans encountered considerable problems. Its swift current added to the problems caused by its swampy banks that became quickly impassable in a rain. So, naturally, the Soviets concentrated their defenses on existing bridges.

  Great forests almost encircled the Pripet Marshes along the post-1939 border, continued northward to Minsk on the Dnepr. On the east bank of the Dnepr they extended southward, to a point north of Kiev. Other massive forests stood south of the swampy area near Leningrad in the Valdai Hills, and between Smolensk and Moscow, making an effective barrier against invading armies. In addition, the Pripet Marshes were treacherous since they dried out under the hot summer sun, but quickly became a muddy mire as soon as it rained. The Soviets took advantage of all of these natural features when they revised their defensive plans early in 1941, reserving these areas for partisan operations in support of the main line of defense on the Dnepr.

  The farmlands of the steppes of the Ukraine south of the Pripet Marshes remained largely devoid of forests, but were cut by major rivers such as the Dnepr and Dniestr. In the far north, on the Finnish border, Nature provided great expanses of taiga and barren tundra as barrier.

  1. The Stalin Line

  The Stalin Line passed through four Military Districts (MD): Leningrad,; Western, Kiev, and Odessa. It included the thirteen original ukreplinnyje rajony (UR or fortified districts) begun in 1928: Kingissepp, Pskov (Pleskau), Polotsk, Minsk, Mozyr,Korosten, Kiev, Novogrod-Volynski (Zwiahel), Letichev, Mogilev-Podolski, Rybnitsa, Tiraspol. Some sources consider the Karelia UR part of the Stalin Line, or the thirteenth UR, but others do not include it because it faced Finland. Each of these URs covered 50 to 150 km and included a forward position of obstacles and outposts with a depth of up to 12 km, and a main line about 4 km deep. Each UR, its flanks secured by natural obstacles whenever possible, was intended to dominate an approach route.

  The URs of the Leningrad MD covered the approaches to the city and included the Baltic coastal defenses. The district was heavily wooded, mostly marshy and interlaced with numerous watercourses and many lakes such as Lake Ilmen, Pskov and Peipus. The URs of the Western MD occupied Belarus, forming a salient around Minsk, and resting on the Pripet Marshes. The dense woods of this district around the Pripet Marshes, and the great marsh, served as an effective barrier against modern invaders. They guarded the approaches to the Smolensk-Moscow Land Bridge, the main route to Moscow from the west, which passed between the upper courses and head waters of the Dvina and Dnepr Rivers. The URs of Kiev MD occupied the western part of the Ukraine and closed the gap between the Pripet Marshes and the Dniestr River. Here the terrain was more open than in the north. Finally, the URs of the Odessa MD rested along the Dniestr all the way to the Black Sea. The river formed the most effective natural barrier facing the Rumanian border. As the river neared the Black Sea and began to meander, its valley widened, forming a large marshy area.

  In 1938, the Soviets began to fill the gaps in the line with the eight new URs. The URs of Ostrov and Sebezh in the Leningrad Special Military District (SMD), closed the gap between the old URs of Pskov and Polotsk along the Latvian border. The new UR of Slutsk extended the defenses of the Minsk UR southward. The other five URs advanced the main defenses in the Ukraine west of the Letichev UR to the Polish border, and included the URs of Shepetovka, Staro Konstantinov, Ostropol, and Kaments-Podolski. This gave the Stalin Line a total of twenty-one URs in 1938.

  2. The Border Defenses or Molotov Line

  The border of 19
39-1940 required new defensive positions, which led to the creation of additional military districts and the expansion of older ones. The term "special," which had already been applied to the border districts in July 1938, was also assigned to the military districts on the new border. Since the Czech Crisis, this designation was added to indicate that more than normal defensive measures would be undertaken in such districts. The Kiev SMD and the Belarus (changed to Western in July 1940) SMD each were occupied by an army group. The Baltic SMD was created after the occupation of Lithuania, Latvia, and Estonia in the summer of 1940.' The Western SMD and Kiev SMD were expanded westward into Polish occupied territory. The Odessa SMD took over the Bessarabian territory annexed from Rumania in 1940, but there was no time to prepare new URs in it.

  New URs were organized in all these special districts, except in Bessarabia, to cover the new border with Germany. Curiously, the Niemen River, a dominant feature near the border of East Prussia in the Baltic district, was not fortified. Instead, the fortifications were placed almost on top of the border. The same happened in other frontier sectors, but this does not mean that additional positions were not sited to the rear, in more defensible sites. A salient around Bialystok in the expanded Western SMD, extended to the Pripet Marshes. Only the Bug River along the southern shoulder of the salient formed an easily defensible position in this mostly level and wooded terrain. The expanded district of Kiev included the foothills of the Carpathians to protect the frontier with Hungary. Its northern sector used the Pripet Marshes and Bug Rivers to help the URs to close the frontier. Between the Bug and the Hungarian border, the Soviets found few natural defenses and had to set up URs to close the gap.

  3. The Coast Defenses

  As a result of the occupation of the Baltic States, the coastal defenses stretched out along the Baltic from Leningrad to East Prussia, forming the Leningrad and Baltic districts. The Russo-Finnish (Winter) War gave the Soviet Union additional Baltic bases, including Hanko (Hanko). The coast of the Black Sea was defended mainly by the special military district at Odessa, and defenses at Sevastopol and a few other bases.

  HISTORY

  The headline, "STALIN CREATES A'LINE OF MAGINOT' IN THE U.S.S.R.," must have created quite a stir when it appeared on December 9, 1936, in Sevodnya (Today), a news publication produced in Riga, Latvia. The story was released by a Warsaw-based English correspondent for the Daily Express, so it could travel quickly across the continent. The article stated that, at a meeting of the Soviet Congress, Joseph Stalin had submitted the new program for armament whose "first part pro vides for the construction of a 3,000 km line of fortifications along the western and eastern frontiers of the USSR, similar to the famous 'Line of Maginot'." Stalin also called for the creation of a 3,000,000 man "shock" army in two years and the tripling of the air force. He added further that a Commissar for War Industry would be appointed and placed under the authority of Voroshilov, the Commissar of Defense. In addition, as key to future Soviet defense plans, war industry plants would be transferred from exposed areas in the west to the interior. Finally, concluded Stalin, the Soviets would begin building a fortification line within the next fortnight.

  Admittedly, the work on the Soviet defenses was no secret since listening posts in the Baltic states had reported on them for years. The American military attache who received the Sevodnya article was not certain whether Stalin meant to strengthen the existing fortifications or create a new line altogether.

  During the Russian Civil War, the Red forces created fortified areas or URs that consisted mainly of field fortifications used both for defense and as bases for offensive operations. Early in the 1920s Fedor Golenkin, a former Russian general, proposed the creation of URs to cover the frontier while the army mobilized. The Military Engineering Inspectorate drew up the plans for a major set of fortifications late in the 1920s. The plan was similar to those of the Civil War and the ideas of Golenkin, in that certain areas would be covered by small positions and obstacles. The army established the first thirteen URs between 1924 and 1938, and initially began to work on the Polotsk and Karelian URs in 1928. By 1938, almost two years after the Estonian article, they had established eight new URs in the west.` Work stopped on eleven of thirteen URs by 1940.

  A group of seven engineers was responsible for creating the defenses, employing rather antiquated concepts and methodologies. General Nikolai Petin, Inspector of Engineers in 1930 and Chief of Engineers in 1934, was responsible for much of the work until his execution during the 1937 purge. Mikhail N. Tukhachevsky, Director of Armaments since 1931, who helped formulate the role of the fortifications, wrote in 1934 that air power would impede the forward movement of forces and that it would be a mistake to commit large forces to the defense of the frontier. It would be necessary, he claimed, to develop defense in depth instead of a linear defense. The fortified regions on the frontier were to act as shields, covering the concentration of the next echelon of armies which would smash the enemy's flanks. Interestingly, the French, who were building the Maginot Line at the time, would have agreed with much of his doctrine. Mikhail V. Frunze, Commissar for Military and Naval Affairs, had stated earlier that "no war, be it highly maneuverable, would ever be waged without fortified zones. The carrying out of maneuver requires to some extent the existence of fortified zones that can be used as a base of operations"(Excerpt from Fugate Thunder on the Dnepr).

  The actual work on the fortifications in the early 1930s did not yield satisfactory results. Robert Tarleton, who wrote a brief history of the Stalin Line, stated that there was a severe shortage of military engineers at the beginning of the decade due to the purges and that, in many cases, civilians took charge of the work. As a result, many positions that were nearing completion were left unfinished because the civilians did not know how to install the equipment and armament. In addition, work was desultory, since the workers were not greatly inspired by the Marxist work ethic. It wasn't until later in the decade that the situation changed.

  In the summer of 1939, reports that the Russians had intensified the work on their fortifications filtered to the west. Meanwhile, more trenches were dug, anti-tank obstacles erected, and artillery emplacements created. It was also reported that a double line of fortifications was under construction along the border with the Baltic states. Other rumors indicated that the defenses along the border formed a non-continuous line, being mostly concentrated at critical points. Reportedly, new and more elaborate positions were also being created. At this time the Soviets were finally able to stop the information leaks, so that intelligence on Soviet fortifications became scant.

  The actual work on the positions was carried out by the Military Labor Directorate, which formed labor directorates known as UNRs. Construction of each UR was under the control of a single UNR which directed all construction units and could also call upon the UR's assigned engineer and rifle battalions as a source of labor when necessary.

  The occupation of Poland in 1939 soon led the high command to reconsider its position. During the autumn the army attempted unsuccessfully to build a line of field positions along the new border before the onset of winter. The Main Military Council decided to abandon the Stalin Line and move the defenses to the new border. Meanwhile, work ceased on all but one of the eight new URs created on the Stalin Line since 1938. It continued only on the Kaments-Podolski UR situated on the Dniestr River border with Rumania. On the other unfinished URs the construction crews packed up their equipment and moved westward, to the border positions of 1940. However, the army did not begin any substantial work on the border defenses until the summer of 1940, as Soviet troops occupied the Rumanian territory of Bessarabia and Bukovina in late June 1940. On June 26 Marshal S.K. Timoshenko, Defense Commissar, directed that the Western SMD and Kiev SMD begin the construction ordered a year earlier.

  The new URs created from 1940-41 included: Murmansk, Sortavala, Keksholm, Vyborg, Hanko (Hanko), Telshiai (Titovo), and Shiauliai (Szauliansk). UNRs set up the URs of Kaunas (Kovno), Aly
tus, Grodno, Osovets, Zambruv, Brest, Kovel, Vladimir-Volynski, Strumilova, Rava-Russkaia, Przemysl, Verknne-Prut, and Nizhne- Prut running along the new border with Germany. Initial work began on the new URs of Chernovsty (Cernauti), Odessa and Danube, but only plans were prepared for the UR of Kishinev (Chisinau) in Bessarabia and Beltsevo. The defensive positions followed the border, and by 1940 there were about 4,500 fortified positions known as DFS (dolgovriemienniye fortifikatsyonnyie sooruzenia or permanent fortified lines). Many of the individual bunkers were weak, lightly armed, and fired forwards. Most lacked internal equipment: such as a power supply, filters, and the like, by the time of the German invasion.

  The engineers had completed 3,196 positions on the Stalin Line before 1938 in the thirteen original sectors, but few were of value because most were small and lightly armed. According to one estimate, only 10% of these fortifications had antitank guns. Barely one thousand new combat positions were built on the Stalin lineor half of the projected number-between 1938-39. Their design had been improved to include flanking fire, but many bunkers still lacked a ventilation system, a usine, and many other key components. The armament, in most instances, consisted of a combination heavy machine gun and a 45-mm anti-tank gun.

  There were special artillery positions for 76-mm guns, and, in some cases, some of the fortifications of the older URs were refitted for these weapons. In some sites with concentrations of combat positions, underground tunnels linked the combat areas with support facilities to create a fortified position that could be classified as a fort. Of the structures completed by 1939 and early 1940 on the Stalin Line, only 409 received fortress artillery, the remainder mounted heavy machine guns.