Since 1969 the ore trains have been using the Soviet SA3 coupler. However, LKAB wanted to try Janney couplers (also known as AAR coupler, used in much heavier trains in USA and South Africa), as the SA3 couplers were not much tested with the new weights. Later LKAB went back to SA3 couplers which now are used on all ore trains. In 2003, the Iron Ore Line from Kiruna to Riksgränsen and the Ofoten Line were finished upgraded to 30 tonne axle load, allowing half the trains to operate with maximum capacity.