Customers within the leisure cruise, naval and passenger ferry industries, are heavily reliant on correct operation of stabilisers to assure the safety and comfort of their passengers and crew. They are also a vital contributor to effective use of other ship systems requiring the most stable platform in a variety of sea conditions.
Ships have 6 degrees of freedom, Pitch, Heave, Surge, Sway, Yaw and Roll. Past techniques to combat these motions have been met with limited success, with modern propulsion systems helping to control Yaw and Surge but with Sway still remaining an issue. For operators where customer comfort is of the utmost importance, tackling the Pitch, Heave and Roll is imperative for a smoother more comfortable on board experience, along with creating a safer environment for crew and cargo.
Stabilisers are designed to tackle the rolling motion of a ship. Typically stabiliser fins protrude from both port and starboard sides of a vessel and are able to produce lift in an upward or downward direction. The lift generated is a function of the fin aerofoil shape, the speed of water flowing around it, and its angle of attack. Reducing or eliminating the rolling motion of the vessel is possible by generating opposing rotational forces to the hull. These forces are generated by the fins rotating in opposite directions as they pass through the water.
Sensors mounted within the ship provide position and acceleration data to a central control system. Based on these inputs, the system calculates the required orientation of both fins and adjusts them continuously through a series of electrical and hydraulic systems.
Dependent on vessel size and design, the stabilisers and associated systems vary significantly with the largest parts easily reaching thousands of kilogrammes in some cases.
Some of the components that would be maintained as part of a stabiliser overhaul include: main shaft seals, hydraulic seals, wear rings, pipes, gaskets, lubricants, oils, greases and filters. Key interfacing components are also checked for wear, and if necessary refurbished or replaced.
Customers looking to make the most of ever tightening docking schedules and budgets benefit from AtZ services which offer full management of a variety of repairs– often using the same technical team reducing both time and cost incurred. AtZ work closely with customers to understand their particular requirements in order to structure a suitable service and repair package.
Most recently AtZ, in conjunction with AEGIR Marine has supported stabiliser maintenance on board various ships within a large cruise line fleet and passenger ferries working in and around the British Isles.
AtZ are experts in marine engineering and offer a full consultative service to multiple aspects of above and below the waterline components. With a comprehensive product portfolio and an excellent service and repair capability, AtZ have been serving the marine, power generation and petrochemical sectors since 1998. Boasting not only industry leading technology, the skillset and knowledge of AtZ has been gained with over 50 years’ operating within the marine sector.