Swedish iron-ore industry during World War II

Swedish iron ore was an important economic and military factor in the European theatre of World War II, as Sweden was the main contributor of iron ore to Nazi Germany. The source of iron ore for Nazi Germany 1933–43 give the following average percentages when added together: Sweden 43.0 Domestic production 28.2 France 12.9. Within the German military the Navy was most dependent on Swedish steel as an absolute necessity to the German war effort, according to their grand admiral. It has also been argued that the Swedish export helped prolong the war.

Both the Allies and the Axis were keen to gain control of the mining district in northernmost Sweden, surrounding the mining towns of Gällivare and Kiruna. The importance of this issue increased after other sources of iron were cut off from Germany by the Allied naval blockade during the Battle of the Atlantic. Both the planned Anglo-French support of Finland in the Winter War, and the following German occupation of Denmark and Norway during Operation Weserübung were to a large extent motivated by the wish to deny their respective enemies iron critical for wartime production of steel.

Winston Churchill, then First Lord of the Admiralty, was particularly concerned about Swedish exports of iron ore to Germany, and pushed for the British government to take military action to end the trade. From the beginning of the war Churchill tried to persuade his cabinet colleagues to send a British fleet into the Baltic Sea to stop Swedish iron reaching Germany from the two Swedish export ports, Luleå and Oxelösund. The planned incursion was termed Project Catherine and was planned by Admiral of the Fleet William Boyle. However, other events overshadowed the incursion and it was canceled. Later, when the Baltic ports froze over and the Germans began shipping the iron ore from the Norwegian port of Narvik, Churchill pushed for the Royal Navy to mine the west coast of Norway to prevent the Germans travelling inside neutral territorial waters to escape Allied Contraband Control measures.

Background

At the outbreak of hostilities on 3 September 1939, Britain and France having vastly more powerful naval forces at their disposal swiftly enacted a repeat of the German naval blockade used to great effect throughout the previous war. Germany, had limited natural resources and was reliant on large scale imports for a wide range of goods and raw materials, including iron ore, a steady supply of which was imperative in the creation of steel to sustain its war effort and general economy.

In the year before the war, Germany received 22 million tons of iron ore from various sources. Although it was able to produce around 10m tons of its own iron ore each year, it was of low grade quality and needed to be mixed with high grade material from other countries such as Sweden, which annually supplied it with 9 million tons: 7 million from Kiruna and Gällivare in Lapland and 2 million from the central Swedish ore fields north-west of Stockholm.

With the declaration of war and the start of the blockade, many sources of these foreign supplies were lost to Germany, and although it retained access to 3 million tons per annum from neutral Norway and Luxembourg, the supplies from Morocco and Spain were lost to it, and so the remaining supplies from neutral Scandinavia became of crucial importance. Grand Admiral Raeder, head of the German navy, declared that it would be "utterly impossible to make war should the navy not be able to secure the supplies of iron-ore from Sweden".

Britain, who itself imported large quantities of iron ore, was fully aware of the Swedish exports to Germany and through its system of Contraband Control was routinely stopping ships of all nations to ensure they were not delivering important supplies to the Germans. To counter the allied blockade, Germany embarked upon a system of unrestricted submarine warfare whereby Allied and neutral ships could be attacked without warning. As a result, during the first nine months of the war a large number of neutral ships were sunk with considerable loss of life by the Germans.

While the Allies were keen to maintain the moral high ground and stressed at every opportunity the difference in impact between their approach compared to their enemy's, they were mindful that many neutral mariners (including those of Sweden) relied upon the trade with Nazi Germany for their livelihoods, and so during the opening stages of the war they were careful not to be too strict with non-combatant vessels for fear the blockade would alienate neutral nations into joining the war on the side of Germany.

Iron ore routes

There were two main routes by which iron ore was shipped to Germany from Sweden.

The Eastern Route

Annually from May to November, ore from the Northern region was shipped from the port of Luleå down the Gulf of Bothnia to the German north Baltic ports at Lübeck, Swinemünde, and Stettin. Outside these months, the Gulf of Bothnia froze over, severely restricting supplies, and although an alternate port was available at Oxelösund, south of Stockholm, for the transport of iron ore from the mines in Bergslagen, this facility was unable to supply the full amount required by Germany, and in any case froze over from January to March each year. Luleå remained outside the reach of Royal Navy's patrols but it was estimated that when Luleå and the Baltic ports of Oxelösund and Gävle were open it could only supply around 8m tons, or less than half pre-war imports.

This meant that during the early winter months of the war, due to the thick ice, Germany had no choice other than to transport the majority of its ore by rail to Narvik and then by ship along Norway's heavily indented Western coast to Germany, a much more circuitous route than the one available during warmer months.''The Rise & Fall of the Third Reich''. William L. Shirer. 1959

The Western Route

The port of Narvik, high above the Arctic Circle was open for iron ore shipments all year round. But the stormy Atlantic coast of Norway also provided another extremely useful geological feature for Germany in its attempts to continue shipping the ore and beating the allied blockade.

Immediately offshore from Norway's western coast lies the Skjaergaard (Skjærgård), a continuous chain of some 50,000 glacially formed skerries (small uninhabited islands) sea stacks and rocks running parallel to the shore. A partially hidden sea lane (which Churchill called the Norwegian Corridor) exists in the area between this rocky fringe and the coastal landmass proper. Inside this protected channel it is possible to navigate the entire 1,600 km length of the Norwegian coast from North Cape to Stavanger. Such coastlines, sometimes known as Leadsa rough English translation for the common Norwegian nautical term Ledene (shipping lane) are common around ScandinaviaSkjaergaard also exist along the Swedish and Finnish Baltic coasts and off Greenland.

The Germans made great use