Steerprop Launches Largest Retractable Thruster
May 28, 2025
Finland's Steerprop expanded its range of retractable thrusters with its biggest unit to date. Designed for offshore vessels and workboats that need high-performance station-keeping or thrust boost capabilities, the SP 45 R will be introduced on several offshore, renewables and special purpose vessels.
Working with vessel operators and designers, Steerprop identified that the sealing and locking mechanisms are often a weak point for retractable designs. The R series minimizes downtime, maintenance demands and space required onboard while delivering the high-performance propulsion and dynamic positioning capabilities needed by today’s offshore vessels.
The patent-pending seal design minimizes downtime by actively managing water ingress, with low maintenance requirements that can be performed from inside the vessel during normal operation. A floating housing moves with the stern tube to keep the seals in contact even at high speeds and sea states, and a simple scraping solution reduces marine growth on the stern tube—a primary cause of seal damage.
A hydraulic locking and lifting mechanism ensures maximum reliability and addresses another common challenge for traditional retractable thruster designs—available deck space. The compact, zero-clearance solution fits entirely below the main deck of most standard vessel designs, ensuring that the prime real estate onboard can be fully utilized for the ship’s main mission.
The fixed-pitch propulsion concept further reduces maintenance demands, while delivering the propulsion performance for which Steerprop’s existing range of thrusters is renowned. Like the other thrusters in the R series, the SP 45 R is available in L-drive, permanent magnet or induction electric motor configurations—fitting a range of vessel power configurations. Electric steering gear ensures the precision needed for dynamic positioning, while power and propeller size can be adapted to meet the specific requirements of each application, within a power range of 900 to 4,000kW.
