In the early 20th century, Siemens electrified the most important railway line for transporting iron ore in Sweden’s Arctic Circle. It was not only a technological masterpiece but also a milestone for the Swedish economy.
Iron ore still transported with steam locomotives – but electricity would soon take over
Sweden is rich in mineral resources. Its northern Norrbotten County has massive deposits of iron ore that began to be mined toward the end of the 19th century. The ore mined in the Kiruna district has been transported by rail to the Atlantic coast of Norway for shipping since 1902. Even though Narvik lies north of the Arctic Circle, the Gulf Stream keeps its harbor ice-free all year long — making it an excellent base for shipping out Swedish iron ore. Initially, steam locomotives were used to transport the ore. In the early 1910s, Siemens electrified the Kiruna–Riksgränsen line. Once the railway line — the “Malmbanan” in Swedish — was completed, industrial iron ore mining could begin.
Coal consumption rose in parallel with the amounts of iron ore produced, since the rail line, roughly 180 kilometers long, operated entirely with steam locomotives. Running a single steam locomotive just between Abisko and Riksgransen – a distance of nearly 40 kilometers – consumed 7,200 kilograms of hard coal a day and represented a major financial burden for Sweden, which had to import almost all its coal. So the government was all the more alert to European advances in rail electrification, especially because more than enough energy was available locally from water power. Luossavaara-Kiirunavaara Aktiebolag (LKAB), a company that had been mining ore in the region since 1890, had contracted with the Swedish government to produce a certain continually rising amount of ore every year. But after only a few years it was already evident that the required production quotas would soon exceed the single-track steam railway’s estimated capacity of three million metric tons.
Faster, cheaper and more powerful – with electricity!
After extensive preliminary studies on the Tomteboda–Vartan route, company officers concluded that there was now enough experience with the technology to start electrifying the Swedish state railways. This was the only way to expand the railway’s capacity as much as was needed — while cutting operating costs at the same time. In May 1910, Parliament decided as an experiment to convert the Kiruna–Riksgransen line to single-phase AC electric power at 15,000 volts.
The contract to electrify the 129-kilometer route was awarded jointly to Siemens-Schuckertwerke and Allmanna Svenska Elektriska Aktiebolaget (ASEA). The Swedish government was especially attracted by the two electric firms’ comprehensive guarantees and warranties. Because it had more experience with complex infrastructure projects, Siemens took on the overall management of the project. All work was planned and executed in close cooperation with Siemens’ Swedish partners. Power for the railway was delivered by a hydroelectric plant built near Porjus. From there, electricity at 80,000 V was carried northward along the railway line, by way of Kiruna. A total of four substations on the section to Riksgransen transformed the voltage from the long-distance power lines to the overhead lines’ 16,000 V. Three of the four substations along the Riksgransen line also served as rail stations.
The work is now complete, and the guarantees have been not only fulfilled, but indeed exceeded in a number of important points.General Directorate of the Swedish State Railway, 1917