Brunvoll delivers ‘silent’ thruster

As predicted by

The Motor Ship

in October 1998, Brunvoll has delivered the first of its resiliently mounted ‘super silent’ tunnel thrusters to Chantiers de l’Atlantique to be fitted to the Millennium class cruise ships. Resiliently mounting the thruster reduces noise levels by up to 15 dBA or 20-25 dBA where a floating floor or other additional methods are used.

The ‘double tunnel’ design has the outer tunnel secured to the ship’s structure while the thruster itself is secured to the inner — between the two are full length air-filled elastic elements. Water fills the voids between the elastic elements with a well-protected seal at the top of the tunnel flanges.