A bow thruster or stern thruster is a transverse propulsion device fitted to the bow or stern of a vessel to assist with manoeuvring. Bow thrusters allow the vessel to turn to port or starboard side, without using the main propulsion system, which requires some forward motion
ATZ with our partner, Aegir Marine, have the parts, service and experience to overhaul most thruster types.
Large vessels usually have one or more tunnel thrusters built into the bow, below the waterline. An impeller in the tunnel can create thrust in either direction which makes the ship turn. Most tunnel thrusters are driven by electric motors, but some are hydraulically powered. A bow thruster, also known as a tunnel thruster, may allow the ship to dock without the assistance of tugboats, saving the costs of such service. Ships equipped with tunnel thrusters typically have a sign marked above the waterline over each thruster on both sides, as a big cross in a red circle: (x).
Tunnel thrusters increase the vessel’s resistance to forward motion through the water, but this can be mitigated through proper fairing aft of the tunnel aperture. Ship operators should take care to prevent fouling of the tunnel and impeller, either through use of a protective grate or by cleaning.
Maintenance of tunnel thrusters can typically be described as a minor overhaul or major overhaul.
During a planned dry dock, a minor overhaul can be carried out with the thrusters still attached to the thruster tunnel in the hull or removed and taken to a workshop.
The type of works carried out during a minor overhaul could be:
A major overhaul normally requires the removal and transportation of the thrusters to a workshop. To do this the thruster is disconnected from its main drive unit (normally an electric motor) and cut from its mountings to the thruster tunnel itself.
The type of works carried out during a major overhaul could be:
ATZ with our partner Aegir Marine have extensive experience with most bow thruster and stern thruster types and are in position meet your thruster parts and service needs.
Thruster repairs are normally carried out at the shipyard, but we can offer all options:
All our repair procedures are set up in close partnership with the classification society and are followed by detailed reports.
Vital equipment that require testing is normally gears, blades, blade carriers and hubs
This is largely dependent on the components that are most likely to be affected by the bio oil (particularly when mixed with seawater), and are normally elastomeric (gaskets, o rings, lip seals etc). It is essential that they are of a compatible material.
Many thrusters are bio compatible or can easily be upgraded to be so.
Yes, pay attention to the input shaft seals as they are known to wear, particularly on the liner. Sometimes, shimming to re-position the liner will eliminate leakages.
Also, check any flexible couplings on the input shaft. They transmit a lot of torque and a little misalignment rapidly wears them out.
Our team of technical experts offer industry-leading consultation services, equipment sales and support and with a wealth of project management and technical experience, we plan and deliver. We work with you to ensure a smooth project from design specification to onsite installation. Our impartial guidance and multi-supplier approach mean we are focused on finding you the best solution meaning you can be confident in both our services and products.
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