The Bay class Minehunter Inshores were a class of catamaran

Catamaran

A catamaran is a type of multihulled boat or ship consisting of two hulls, or vakas, joined by some structure, the most basic being a frame, formed of akas...

-hull mine warfare vessels operating with the Royal Australian Navy

Royal Australian Navy

The Royal Australian Navy is the naval branch of the Australian Defence Force. Following the Federation of Australia in 1901, the ships and resources of the separate colonial navies were integrated into a national force: the Commonwealth Naval Forces...

 from 1986. Also referred to as the MHCAT (MineHunter CATamaran), the class was an attempt to produce a locally designed inshore mine warfare vessel. Two prototype ships were ordered in 1981, with the first ship, Rushcutter, commissioned in November 1986. The two ships experienced delays in construction, and the RAN resorted to acquiring six minesweeper auxiliaries (MSA) to provide an interim mine-warfare capability, while also keeping Ton class

Ton class minesweeper

The Ton class were coastal minesweepers built in the 1950s for the Royal Navy, but also used by other navies such as the South African Navy and the Royal Australian Navy...

 minesweeper HMAS Curlew

HMAS Curlew

HMAS Curlew was a Ton class minesweeper operated by the Royal Navy from 1953 to 1961, and the Royal Australian Navy from 1962 to 1991. During her Australian service, the ship operated off Malaysia during the Indonesia–Malaysia confrontation during the mid 1960s, then was modified for use as a...

 in service until 1990, well beyond her intended decommissioning date. The ships did not enter service until 1993, due to problems with the sonar.

Design

One of the identifying features of this class is that vessels have a fibreglass

Fiberglass

Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...

 hull constructed with a multi-layer foam sandwich core. No metal is contained in the hull.

Construction

The ships were built by Ramsay Fibreglass, a subsidiary of Carrington Slipways located in Tomago

Tomago, New South Wales

Tomago is a combined industrial/semi-rural suburb of the Port Stephens Local Government Area in the Hunter Region of New South Wales, Australia. It is located just north of the Hunter River and west of the body of water known as Fullerton Cove...

, New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. They were constructed in a purpose-built facility and then carried by crane a short distance south to be launched into a small man-made lunching basin off the Hunter River. (Construction site 32°49′44.3"S 151°42′22.4"E) Construction of a third hull was commenced before cancellation of the project occurred. However, this was never completed. It remained at the rear of the facility until the early 2000s.

Deployment restrictions

The small size of the ships limited their ability at sea, and prohibited deployment outside of the Sydney area. The ships were removed from operational service, and the RAN instead focused on acquiring four to six coastal minesweepers (the Huon class

Huon class minehunter

The Huon class Minehunter Coastal ships are a group of minehunters built for the Royal Australian Navy . Following problems with the Bay class minehunters, a request for tender was issued in 1993 for a class of six coastal minehunters under the project designation SEA 1555...

), and maintaining the MSAs as an as-needed inshore mine-warfare force.

Fate

Both ships in the class were decommissioned on 14 August 2001. Four additional ships, to be named Westernport, Discovery, Esperance, and Melville, were planned but never constructed.