Two 23-meter (about 75-foot) long lightships are to be built at Ocean Shipyards, Fremantle, Western Australia, for the Australian Department of Transport at a cost of 2.4-million Australian dollars.
On completion, scheduled in 1982, one will be stationed at the Carpentaria Shoal, Torres Strait, and the other at Breaksea Spit at the southern end of the Great Barrier Reef. There is an option for a further two vessels for use in the Bass Strait, where a traffic separation scheme is planned.
The vessels will be built to the design of the naval architectural firm of Sir J.H. Biles & Co., Ltd., who were responsible to AGA Navigational Aids, Ltd., Brentford, England, for the lines and specification for two similarly designed vessels for the U.K.'s Trinity House. The Australian vessels will carry the same AGA 17-mile-range acetylene lighting system which will maintain the lightbeam on a horizontal plane, regardless of pitch and roll. They will also be fitted with radar responders to help location and identification by ship-borne radar.
These vessels will have the same service life of two years on station without attention. Differences in design include the addition of a diesel hydraulic windlass for mooring, no bulwarks on the foredeck for easier maintenance, and no recessed boarding ladders amidships. Stainless steel will be extensively used for ladders, rails and fittings. The hull will be painted with a chlorinated rubber system. At 22.72 meters LOA, these vessels will be about a meter longer than the AGA vessels bought by Trinity House.
Lighting equipment will be made at Brentford and supplied through AGA Products Australia Pty. Ltd., Melbourne.