Tunnel / Bowthrusters
Tunnel thrusters are generally used to improve manoeuvrability. Mooring and entering the docks will be much easier and even the influence of the wind can be compensated too. Those newly designed thrusters meets the demands for the safe and fast response manoeuvring systems, allowing precise ship control even under extreme environmental conditions.
To minimize bowthruster noise, the drive shaft is connected to the drive motor utilizing an elastic coupling. The gearweels of the thruster are provided with high-grade Gleason type teeth. The advanced propeller design minimizes cavitation effects under all operational conditions. This is an important issue since cavitation may cause noise and vibration as well as remarkable loss of thrust. Cavitation also can cause damage to the propellor and tunnel.
Tunnel thrusters with a fixed pitch propeller, provided with a high quality right angle bevel gear, fully immersed in oil and special propeller shaft seals with low maintenance requirements.
Retractable thrusters
Present-day's, ships are requested to be always fast to shorten time actually, however by means that modern keels needs specific characteristics, as reduced immersion at the bow, with consequent risk of cavitation of thrusters propeller, suction of air, and worst influence of irregular water lines on the hull resistance.
Such aspects will create difficulties to install proper thrusters, in terms of power and dimensions. To this, PROMAC felt the needs to settle a new system, able to allow high capacities in manoeuvring, without penalize the keel shape.
