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The Permanent Magnet tunnel thruster is a new addition to the Kongsberg Maritime family of thrusters, building on a completely new approach to thruster design and motor integration. The TT-PM meets operational requirements with focus on performance and reliability.

Reliable, efficient and low through life cost

The Permanent magnet tunnel thruster (TT-PM) is our latest tunnel thruster design and has been engineered with reliability and through life costs as the focus. Using permanent magnet motor technology increases efficiency and makes the installation more compact, only the variable frequency drive unit is housed in the thruster room, freeing up space on board.

It also simplifies maintenance as the patented mount means units can be removed and replaced without drydocking. PM thrusters are currently available in two sizes with powers of 1,000 and 1,600 kW. These thrusters have been developed for the most demanding applications such as dynamic positioning.

Key features

  • Efficient and space saving PM technology
  • Fast response times to full power
  • Rugged design with high reliability
  • Equal thrust in both directions
  • Patented resilient mounting system reduces noise and vibration, simplifies tunnel fabrication and removal/installation
  • Oil filled stator for superior cooling and protection
  • Robust centre shaft carries all propeller loads


TT-PM thrusters are resiliently mounted in the tunnel to minimise noise and vibration. Installation and removal can be carried out without drydocking the vessel.

Space saving installation

PM space saving comparison
These two pictures illustrate the significant space savings delivered by PM technology.

Due to its symmetric design the permanent magnet tunnel thruster provides increased flexibility for the ship designer to achieve a more optimal and space-saving installation.