Centre for Marine Science and Technology

Australia's Marine Science and Technology Plan: An Overview
Technology Highlights
page 32

Ocean Leveller Fast Ferry Ride Control System

The Ocean Leveller Ride Control System was developed by the Australian Maritime Engineering CRC (AME CRC), in conjunction with Austal Ships Ltd. This innovative system reduces the motions of fast ferries operating in waves by up to 50% and has been installed on 19 vessels to date, ranging in length from 37m to 86m. The benefit to Australia has been export orders for the ferries fitted with Ocean Leveller to the value of $350m, and direct import replacement of nearly $20 million.

The Problem

Fast ferries operate on many passenger and vehicle routes around the world. Unfortunately, waves can cause the motions onboard a fast vessel to be very unpleasant - causing discomfort and even seasickness. Large motions also make the working conditions of the crew difficult and can lead to unacceptable levels of wear and tear on the vessel.

The Project

In 1992 Austal Ships Ltd, of Western Australia, approached the AME CRC to assist in developing a ride control system for their high speed aluminium ferries. AME CRC designed, built and tested the computer programs for the system executive, the controller algorithms and the user interface. The electronic circuits take the measured signals from the instrumentation, transmit them to the central computer and then receive the signals back for onward transmission to the hydraulics. The hydraulics were designed, built and tested by Austal Ships. Austal Ships also designed the actuator system, including the underwater fins and flaps that create the stabilising force.

A computer simulation was developed as a test bed for different controller algorithms and for extensive testing of the final program. It has also been utilised in the development of controllers for other ride control configurations, for example monohulls.

Full- scale sea trials are conducted on each vessel in a variety of sea conditions. The heave, pitch and roll of the vessel are measured and subsequently analysed to determine the performance of the system. Motion reductions are usually in the range of 35 - 50%.

Through this project AME CRC and its industry partner Austal Ships have developed a close working relationship that has facilitated the transfer of technology between the organisations.

Austal Ships has used the services of AME CRC for several other projects, including the computer prediction of motions of patrol boats operating in a seaway.

[This work was conducted by CMST staff. Corrections to the article are shown in italics.]

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