Stealthy Optionally Crewed Catamaran for Australian Navy

HMAS Stradbroke Island.
Stealthy Optionally Crewed
Catamaran for Australian Navy
Diagram by Tom Worthington,
CC-BY 21 February 2024

The Australian Government released a fleet plan for the Navy yesterday which included designing and building six large optionally crewed missile carry ships. Australian companies Austal and Incat have both made catamaran high speed transports for the US military, derived from their car ferry designs. Austal have also make trimarans with stealthy tumble-home hulls for the US navy. Both companies offer high levels of automation. They could either (or both) produce vessels for the Australian requirement. I suggest any such design should be designed for these features (but with not all fitted to very vessel):

1. Tumblehome hull: The hull would slope inward above the waterline, and the superstructure would be free of railings, masts, cranes, and other items, to reduce the radar cross-section. All equipment needed on deck would be covered. 

2. Vertical Launch Cells: Rows of vertical launch cells would extend down into each of the catamaran hulls.

3. Drone Hangar:  A covered hangar forward of the flight deck would accommodate UAVs. Automated systems would launch, recover and service the drones.

4. XLUUV Bay: A travelling gantry with cradle between the hulls would pick up Extra-Large Unmanned Undersea Vehicles (XLUUV), while the ship is underway. The bay would be equipped with  ECLIPS robots for automated rearming & refueling, before dropping the XLUUVs back in the water.

5. USV Bay: A bay at the back of the vessel, would allow Uncrewed Surface Vessels (USV) to be launched and recovered. Automated systems would service the USVs.

6. Self Defense Auto-cannons: The four corners of the ship would each have a small caliber auto-cannon similar to the EOS Slinger, for self defence from missiles, drones, and small boats. Each cannon would be equipped with an electro-optical sight, radar, backup power supply, and operator station. This would allow the ship to be defended even if all other power and systems failed.

While the media has made much of the "optionally crewed" feature of the vessels, of more significance is that the ships are highly automated and so only need a small crew, about one quarter of a conventional military vessel, when they are aboard. 

ps: John Birmingham's book "Weapons of Choice" featured highly automated ship warfare. One of the ships was an Australia high speed catamaran HMAS Moreton Bay, apparently inspired by the real HMAS Jervis Bay. This was an Incat built high speed catamaran, which transported troops to East Timor. I wrote a review of the book, and as was John's custom, I hoped he would use my name for a sister ship "USS Stradbroke Island", but unfortunately not. ;-)

Offshore Combatant Vessel

Australian Defence project SEA 1180, proposes to replace patrol, mine and survey ships with one design of "Offshore Combatant Vessel" (OCV). Containerized equipment would be placed on the ships temporarily to suit the mission. The obvious design for this would be the Austal Multi Role Vessel (MRV 80). This is a trimaran, which looks like a patrol boat at the front and a car ferry at the back. The proposed MRV 80 is about 50% longer and heavier than the current Armidale class patrol boa,. Due to the trimaran design the MRV 80 is twice as wide as the patrol boats, providing room for a helicopter flight deck and hangar, as well as 500m2 of covered space to accommodate cargo, vehicles, or containerized equipment.

The MRV 80 resembles the US  Independence class littoral combat vessel from the same designers. But the MRV 80 is smaller and leaves out the high tech weaponry and complex systems of the LCS.  The LCS has a stern door for launching boats and sensors at sea, with a side ramp for loading equipment in port. In contrast the MRV 80 has boats stored in open areas on each side and a stern ramp for loading equipment. The stern ramp is based on a proven design used on car ferries and might be used to launch sensors at sea and transfer cargo while underway, as well as in port.

High Speed Resupply for New Australian Submarines

Work has commented on VIGILANT JHSV 2, the second Fortitude class Joint High Speed Vessel being constructed by Australian company Austral for the US military. The first, Spearhead JHSV-1, was started in July.

The JHSV is adapted from Austral's civilian high speed ferry design. One of the civilian ferries, MV Huakai , is part of the United States National Defense Reserve Fleet and was used to carry equipment and personnel to open Haiti's mail port after the 2010 earthquake.


The JSHV could be used by Australia to resupply the Collins class submarine replacement, allowing fewer, smaller, less expensive submarines to be acquired (such as the Spanish S-80 Class from Navantia).

Common electronic system for multi-hull Australian warships

In Naval Systems (Proceedings of the US Naval Institute, June 2009) Edward J. Walsh describes the electronic core mission system to be used on the Australian designed USN Navy littoral combat ship Coronado (LCS-4). The Coronado will be the second trimaran LCS for the UN Navy, following the USS Independence (LCS-2), which began sea trials recently. He reports at a simplified version of the same electronic system will be used for the Joint High Speed Vessels (JHSV). The JHSVs are designed by the same Australian company, Austral, as the LCS-2 and LCS-4.

Austal are using a similar trimaran hull for the lower cost Multi-Role Vessel and so the same core mission system would be an option for these vessels. If the MRV was purchased by Australia, that would provide some commonality with UNS systems, as well as between different classes of Australian ships.

The Austral design for the LCS is competing with the Freedom class mono hull design by Lockheed Martin. The Israel Navy has abandoned plans to acquire Freedom class ships and is now reported to be looking at the more conventional German Kedah class ships, as used by Malaysia.

Austal Multi-Role Vessel

Austal have proposed a long range, high speed, patrol ship called the Multi-Role Vessel (MRV). This is essentially the Independence-class littoral combat ship (LCS), which was designed for the US Navy, but with the expensive weapons and electronics removed to make a lower cost, long range multi-purpose ship for military and policing purposes.

The MRV is a trimaran with one large hull in the middle and two outriggers. This gives a wide area accross the three hulls at the rear for cargo and a large helicopter flight deck on top. The wider hull projecting at the front provides good sea keeping and space for weapons and sensors. The slim outer hulls allow for high speed.

The Austal Multi-Role Vessel can provide offshore and littoral war fighting roles, border protection tasks, long range counter-terrorism and counter piracy operations, support to special forces and missions in support of security and stability in the immediate neighbourhood surroundings.

The Austal Multi-Role Vessel (MRV) utilises the unique and proven Austal Trimaran platform coupling high speed and superior seakeeping performance with unparalleled deck space.

From border patrol to ASW to humanitarian relief missions the Austal Multi-Role Vessel (MRV) is the truly reconfigurable seaframe.

See Also:

• Austal Trimaran Technology Brochure
• View the Multi Role Vessel Image Gallery
• Austal Defence News - July 2008
• Austal Defence News - March 2008
• Austal Defence News - May 2007

Features

Multi-mission helicopter capability
Large flexible mission / logistics deck
Open architecture systems network
Systems packaged mission modules

• EEZ border patrol
• Command & control
• Surveillance
• Humanitarian support
• Theatre hospital
• At sea replenishment
• Force transportation
• Special forces support
• Amphibious operations
• SAR
• ASW

From: Multi-Role Vessel, Austral, 2009