Finnish propulsion specialist Steerprop has received an additional thruster order from German shipbuilder TKMS for the new German research vessel Polarstern. The contract covers two SP 40 TT ARC tunnel thrusters, completing a fully integrated propulsion thruster package for one of the world’s most advanced research icebreakers.
The new order builds on Steerprop’s earlier contract to supply two SP 160 Pull azimuth thrusters and deliver hydrodynamic shaftline integration. As a result, Polarstern will become the first Polar Class 2 (PC2) icebreaker project where main propulsion, tunnel thrusters and hydrodynamic integration are awarded to a single supplier.
Polarstern is being built for the Alfred Wegener Institute (AWI), with close technical cooperation between AWI, TKMS and Steerprop throughout the design process. According to TKMS, Steerprop’s ability to meet stringent ice-class and low-noise requirements was a key factor in the decision.
The gridless SP 40 TT ARC tunnel thrusters are engineered for heavy ice conditions and optimised to minimise underwater radiated noise, in line with strict ICES 209 acoustic limits for polar research vessels. Flexible mountings and optimised tunnel design further reduce vibration and cavitation.
“This project marks a defining milestone for Steerprop,” said Riku-Pekka Hägg, CEO of Steerprop. Deliveries are scheduled for 2027.



