The propulsion system on board the icebreaker Sisu have been modernized by ABB Marine and Ports as a turnkey project carried out in the autumn of 2015. The vessel, owned and operated by specialized ice breaking company Arctia Icebreaking Oy, was originally delivered in 1976 and have been in operation since.
The ship, including its four DC driven propulsion motors, has not seen any major modernization since 1976. In fact, Sisu was still equipped with Ward Leonard Drive system, widely used DC motor speed control system at that time. With the experienced service team, ABB Marine and Ports upgraded the maneuvering components and implemented them as part of the 40 years old system, instead of changing the whole system. This extends the lifetime of the vessel significantly and improves both maneuverability and safety of the vessel with less investment costs for the customer.
Whole project from contract to delivery was executed in 7 months and wet docking was done in 8 weeks. Due to the precise planning phase and strong knowledge of the systems, ABB Marine and Ports was able to meet the tight schedule and expectations. Specific open water trials were done before the project as a reference to be able to compere the performance before and after the upgrade. Seatrial for Sisu was planned with same phases and tests as a seatrial to a new built vessel with adding all the original tests from 1976. Successful seatrial took less than two days.