Mannerheim Line

Name

During the first construction phase of 1920-1924 the Finnish press often called the position the "Enckell Line", after chief of staff Oscar Enckell. The name "Mannerheim Line" appeared only after the complex had been built, in December 1939 at the start of the Winter War. A group of foreign journalists had toured the works in the autumn of 1939, and Jorma Gallen-Kallela, who accompanied them, called the fortifications the "Mannerheim Line" in conversation. It was never an officially designated name; at the time the European press wrote much about the French Maginot Line and the German Siegfried Line.

Construction

Planning began in 1918, soon after Finnish independence, on Mannerheim's initiative. The first plan was drawn up by Lieutenant Colonel A. Rappe, and German Colonel Otto von Brandenstein then proposed using the lake isthmuses as defensive positions; his plan was approved in August 1918. In October 1919 chief of staff Oscar Enckell sited the line, with design work by Major J. Gros-Coissy of the French military commission and Lieutenant Colonel Johan Fabritius. About a hundred small bunkers were built in 1920-1924, of unreinforced concrete for reasons of cost, which gave only partial protection. After Enckell resigned in 1924 construction was interrupted for a long period. A second phase ran from 1932 to 1939, and from May 1938, as the European situation worsened, funds and resources increased considerably. The line was still incomplete in November 1939, when the Winter War began, and many of its defences were already outdated.

Structure and character

The line ran from the coast of the Gulf of Finland through Summa to Taipale on Lake Ladoga; the western flank was covered by Fort Saarenpaa and the Ladoga side by Fort Jariseva. It had 157 concrete machine-gun positions and eight artillery positions, with the Summa area most heavily fortified. Unlike the Maginot Line, it relied on natural terrain rather than huge bunkers and dense obstacle lines, incorporating felled trees and boulders. Its purpose was to delay rather than repel an invasion, and it applied "flexible defence": trenches and obstacles instead of large bunkers. Concrete bunkers were mostly troop shelters, and few had embrasures. Russian accounts count 28 defensive nodes by December 1939, 21 of them on the main line, with 35 works left unfinished.

Winter War

During the war the line halted the Red Army for about two months. In December 1939 three Finnish divisions on the isthmus faced five Soviet rifle divisions of the 7th Army. On 11 February 1940 a general offensive opened after a massive artillery preparation, and the Summa area was broken at very heavy cost to the attackers. By 13 February the Soviet 123rd Rifle Division had pierced the main defensive line to its full depth, and the Summa node, with 12 concrete bunkers and 39 wood-and-earth works, was destroyed. By mid-February Khotinen and other key nodes had fallen in turn.

Aftermath and assessment

After the war Soviet combat engineers blew up the surviving installations, and some fragments became exhibits in Moscow and Leningrad museums. Finnish troops retook the area in August-September 1941 and restored the line over three years, but in June 1944 the Vyborg operation broke through it in ten days. Wartime propaganda on both sides greatly exaggerated the line's strength: the Soviet side to explain the slow advance, the Finnish side to sustain the morale of the army and the public. Mannerheim himself wrote that the myth of the "Mannerheim Line" was spread by the Russians, and that in reality there were only scattered permanent machine-gun nests, about two dozen new bunkers built on his proposal, and trenches between them, with no depth. Russian historian A. Isayev notes that the isthmus is largely flat terrain and that the image of powerful granite fortifications is far from reality. Anastas Mikoyan later wrote that Stalin invented the claim that a well-equipped Mannerheim Line had been "suddenly" discovered, to justify the failures of the Finnish war.