Norske Tog and SJ's 43-year-old Di4 locomotives are set for a comprehensive upgrade. Mantena in Trondheim has been assigned the task, which will require both experience and rare parts.
The Di4 locomotives transport passengers day and night on the Nordland Line and have served faithfully since 1981.
In the long term, they will be replaced by new, long multiple-unit trains, but for now, Mantena's maintenance ensures that the 43-year-old locomotives continue to do the job in the north.
The diesel locomotives are now, however, set for a major overhaul to meet the requirements for operation on Norwegian tracks – a task Mantena at Marienborg in Trondheim has been assigned. Norske Tog owns the locomotives, while SJ is the operator.
Long delivery times for parts
– This overhaul is a very extensive job. It involves disassembling everything, inspecting all parts, and replacing whatever needs to be replaced in accordance with the overhaul regulations, says Geir Helge Austberg, contract manager at Mantena.
Mantena's department at Marienborg is now building up its capacity to carry out the major overhaul, both through external recruitment and internal reorganizations.
– This contract means we are developing both capacity and expertise that will be valuable for other assignments. It is extremely important for Mantena to have a unit specializing in diesel rolling stock, notes Austberg.
Benefiting from extensive experience
The locomotives were produced in Germany 43 years ago – which means that parts can be difficult to source.
– Since we have extensive experience with these train types, we have some components in stock ourselves. In addition, we have to order parts from the USA, where lead times can be up to eight months. Therefore, it is important to place orders well in advance, Austberg states.
It has been 14 years since the locomotives underwent a similar overhaul.
– We still have two or three employees with experience from the previous round, who will be important in this overhaul. In any case, we have strong diesel expertise in the department, as well as experienced mechanics and electricians who are truly skilled in their field, he notes.
Austberg states that Mantena has already begun work on some of the overhaul items on one of the locomotives, as part of regular maintenance. However, the major work will begin this autumn, and the first locomotive is scheduled to be completed in spring 2025. There are five locomotives of this type in total, but likely only three will undergo the comprehensive overhaul.
Close and productive collaboration
Halvard Tallerud, Acting Director of Rolling Stock at SJ, praises the collaboration with Mantena and Norske Tog.
– We have a close and productive cooperation that works well. We are solution-oriented and communicate effectively together – and all parties share the same understanding of why we are implementing the various measures, says Tallerud.