Ship design and development

Occasional Paper 83: Current Australian Ship Naval Building Projects

July 27, 2020

This story, which was first published in the Australian Naval Architect, Volume 24 Number dated 2 May 2020 is reproduced with thanks to the Australian Division of the Royal Institution of Naval Architects.

More Patrol Boats for the RAN

The Commonwealth Government announced on 1 May that it will spend around $350 million to build six new Cape-class patrol boats for the Royal Australian Navy.

The vessels will be built by Austal in Western Australia, securing Australian shipbuilding jobs and maintaining strong border protection.

The Australian Border Force currently operates eight Cape-class patrol boats, while the Navy operates two leased vessels.

The six new Cape-class patrol boats will grow the patrol boat force to 16 vessels, while the new, larger Arafura-class offshore patrol vessels are introduced into service.

The Minister for Defence, Senator the Hon. Linda Reynolds CSC, said that the new vessels will play an important role in keeping Australia’s borders safe, while Navy’s new capability is brought online.

“These vessels will not only enhance national security, but will provide important economic stimulus and employment continuity during the COVID-19 pandemic,” Minister Reynolds said.

“The ability to build more of these vessels in Australia will deliver Australian industry content of more than 65 per cent, providing significant opportunities for Australian industry and Defence, as well as more than 1200 workers in the broader Australian supply chain.”

Austal Chief Executive Officer, David Singleton, said that the new contract both reaffirmed the Cape class as Australia’s pre-eminent patrol-boat platform and represented a clear commitment by the Australian Government to strengthen Australia’s sovereign shipbuilding industry during a challenging global environment, brought on by the COVID-19 pandemic.

“Since its introduction by the Australian Border Force (ABF) in 2013, the Cape class has proven to be a high-performing, reliable and effective maritime asset, utilised for a wide variety of constabulary and naval missions, playing a critical role in Australia’s national security,” Mr Singleton said. “With ten Capes currently in operation with the ABF and RAN, it is a smart, logical step to build upon the existing fleet with additional vessels which will enhance the nation’s ability to protect and secure our maritime borders.

“These new, evolved Capes add even greater national security at this critical time during the COVID-19 pandemic, by ensuring that at least 700 jobs are maintained at Austal, and supply chain opportunities continue for Australia’s shipbuilding industry.”

Austal is to build six evolved Cape-class patrol boats for the Royal Australian Navy (Image courtesy Austal)

Based on Austal’s proven 58 m aluminium monohull design, the new RAN evolved Capes will include a number of enhancements which further extend the capability of the vessel and the fleet. These evolved Cape-class patrol boats include modifications determined through the extensive in-service experience of the RAN and ABF Capes currently operating throughout Northern Australia.

Crew capacity has been increased by 10 people, to now total 32, and quality-of-life provisions have been enhanced, ensuring that those who operate the new Capes have connectivity to the outside world regardless of the operating environment. Further improvements have been incorporated into the new RAN Cape-class design, developed during the design and construction of two Cape-class patrol boats for the Trinidad and Tobago Coast Guard, an export contract awarded on 16 August 2019 and won with the strong support of the Australian Government and Export Finance Australia.

The Trinidad and Tobago Coast Guard Capes are currently in an advanced state of construction and are scheduled for delivery later in 2020. Construction of the six Capes for the RAN will commence immediately at Austal’s Henderson shipyard, with deliveries scheduled from September 2021, then successively through to mid-2023.

Progress with the Offshore Patrol Vessel Program

On 9 April the National Shipbuilding Program reached another milestone with the ceremonial keel laying of the second Arafura-class offshore patrol vessel (OPV) in Adelaide.

The Minister for Defence, Senator the Hon. Linda Reynolds CSC, said that the keel laying reinforced the continued progress and ongoing success story of Government’s continuous shipbuilding endeavour in Australia.

“The Arafura-class offshore patrol vessels are larger than the Armidale-class patrol boats currently in service with the Royal Australian Navy, and will offer greater endurance and capability for patrolling Australia’s maritime borders,” Minister Reynolds said.

“Over the past 10 months, Luerssen Australia and ASC Shipbuilding have contributed an enormous effort to build and commence consolidation of the keel blocks which, when complete, will be part of a 1600 t ship.

“Defence and industry are working closely together to support our sovereign shipbuilding programs and Australian jobs in these challenging times, in a way which is safe for employees and the community.”

The Minister for Defence Industry, the Hon. Melissa Price MP, said that the OPV program is creating jobs right across the supply chain.

“This project is estimated to create around 600 jobs involving more than 300 small and medium businesses, reinforcing the Morrison Government’s commitment to maximising Australian industry involvement in our $90 billion shipbuilding program,” Minister Price said.

“The project also highlights Australian industry’s ability to deliver on schedule, with construction of the first offshore patrol vessel to be built in Western Australia commencing ahead of schedule.

The forward and aft hull modules of NUSHIP Arafuracoming together at Osborne recently (Defence photograph)

The Chief of Navy, VADM Michael Noonan AO RAN, announced that the second OPV will be commissioned as HMAS Eyre when it comes into operational service in early 2023.

“The next four OPVs will be named HMAS Pilbara, HMAS Gippsland, HMAS Illawarra and HMAS Carpentaria,” VADM Noonan said.

The OPVs being built by ASC Shipbuilding at Osborne Naval Shipyard are setting the foundation of continuous shipbuilding prior to prototyping commencing on the Hunter-class frigate program this year.

Construction of the first offshore patrol vessel (OPV) to be built in Western Australia began at the end of March. The future HMAS Pilbara will be the first to be built at the Civmec shipyard in Henderson, Western Australia.

After the first two vessels built by Luerssen Australia and ASC in Adelaide, the remaining ten vessels will be constructed by Luerssen Australia and Civmec at Henderson.

Luerssen Australia is the prime contractor working with key shipbuilding partners Civmec in Western Australia and ASC OPV Shipbuilder in South Australia to deliver the OPV capability for the Royal Australian Navy.

Evyenia Kontakos, fourth-year apprentice welder and boilermaker and Larry Lavallee, Offshore Patrol Vessel Block Construction Manager, ASC Shipbuilding, after hammering in wedges to secure the Chief of Navy’s ceremonial coin in place during the keel laying ceremony of Offshore Patrol Vessel 2, NUSHIP Eyre (RAN photograph)

Last Air-warfare Destroyer Delivered

In a ceremony in Adelaide on 28 February, the Royal Australian Navy’s third air-warfare destroyer, NUSHIP Sydney, was officially handed over to Defence. NUSHIP Sydney is the last of the three ships being delivered by the Air Warfare Destroyer Alliance which includes the Department of Defence, Raytheon Australia, and ASC Shipbuilding supported by Navantia Australia.

The Minister for Defence, Senator the Hon. Linda Reynolds CSC, attended the acceptance ceremony at the Osborne Naval Shipyard in Adelaide. “Today’s milestone demonstrates the success of the Government’s Naval Shipbuilding Plan,” Minister Reynolds said.

“While the delivery of NUSHIP Sydney marks the end of this program, it represents an exciting time for the National Naval Shipbuilding Enterprise, as we continue to build upon the unique skills developed at this precinct and transfer them across the whole shipbuilding ecosystem. “I congratulate the 5000 workers who have worked directly on this program over the past decade, from the design phase through to the construction, integration and delivery of these magnificent ships.

NUSHIP Sydney entering Sydney Heads on 27 March at the end of her delivery voyage from South Australia (RAN photograph)

“The significance of this success cannot be understated and is reflected in the truly world-class capability of these warships, and the naval shipbuilding and combat system integration skills that have been developed at Osborne.”

NUSHIP Sydney arrived at her home port at Fleet Base East in Sydney on 27 March 2020 and commissioned into the RAN on 19 May 2020.

Further Reading

The Government of Australia’s Naval Shipbuilding Plan, released on 16 May 2017, outlines the Government’s vision for the Australian naval shipbuilding enterprise and the significant investment required in coming decades. It is available at https://defence.gov.au/NavalShipbuilding/Plan/

Royal Australian Navy, Arafura Class OPV, available at https://www.navy.gov.au/fleet/ships-boats-craft/future/opv

Royal Australian Navy, ADV Cape Fourcroy, available at https://www.navy.gov.au/adv-cape-fourcroy

Occasional Paper 60: Naval Gigs: Past and Present

August 22, 2019

August 2019

By Dennis J Weatherall JP TM AFAITT(L) LSM, Volunteer Researcher, Naval Historical Society of Australia

Subsequent to the recent recovery of an HMAS Australia (1) Gig from bushland at Coles Bay, Tasmania, reported in Issue 28, March 2019 edition of Call the Hands, Naval Historical Society researchers attempted to determine where the gig was built. They also examined the history and use of gigs which dates back to the 17th century. This paper provides more information on the history of that particular gig and an overview of the use and development of gigs from e 17th century to the present.

Fortunately, the history of the Australia (1) gig was researched by Mr Mike Web of the Maritime Museum of Tasmania. Mike provided the following history.

Two gigs were brought from Sydney to Tasmania in 1922 by HMAS Australia. It appears they were used by HMAS Huon (naval base) in Hobart. The 1st Derwent Sea Scouts based at HMAS Huon bought them in 1931 for one pound each. They were named Bass and Flinders. Both were sold in 1966 to the late Alan Emanuel, Lindisfarne, who was going to use them to make a catamaran.

In the 1967 bush fire Bass was ashore and was lost, Flinders was afloat and survived. The Flinders was given to Maritime Museum of Tasmania in 1984. As the Museum was then on a site at Battery Point with little space, it was stowed upside down at the work site of Philip Fowler. It then went to the Augusta Road Primary School propped up by rocks. There as it can imagined it received most of her damage. She was then sold to a fisherman in 1996, Peter McGee, who took it from Margate to a site north of Coles Bay. It was to be used to develop an oyster farm in November 2005.

Gig active with Sea Scouts at HMAS Huon in 1959

A neighbour of the property where the gig lay reported that there was an old inshore whale boat down in the bush at Coles Bay. As Mike Web regularly visited Coles Bay he went to see this boat. As a former Chief Officer of HMS Worcester (training ship on the River Thames) which had two gigs identical to the reported boat near Coles Bay identification was not difficult. Further research found the gig was of an 1860 design which superseded the Captain’s Galley.

The Design was based on the West Country (UK) pilot gig that was normally about 32’ and had two masts, standing lug on the main mast and a dipping lug on the Mizzen mast and 6 oars. Further contact with UK authorities indicated that the number 271 on the forward thwart of Flinders did not tally with their records.

28’ Gigs from HMS “Worcester, Mike Webb image

It has been suggested that the gig is built of Kauri. Hence Mike believed she was built in Sydney to naval plans. The register of boats when HMAS Australia sailed from the UK did not include gigs. This being the case there were only two possible yards where the gig could have been built, either the Commonwealth Naval Dockyard at Cockatoo Island or Garden Island, Sydney.

A check of records of the Commonwealth Naval Dockyard at Cockatoo Island which built many small craft; cutters, whalers, skiffs, dinghies etc. for Naval Stores and specific ships between 1914 and 1921 showed that the registered number for the Australia (1) gig was not included in the records.

The Cockatoo Island Dockyard built two 30 foot gigs in 1914-15 for Naval Stores, but their numbers were 367 and 368. A 24 foot gig was built in 1916 for HMAS Franklin (at a cost of £108), No. 369. Several more from 18 feet to 24 feet were built for various ships, including transports which were generally not numbered.

There was no record of a gig with a length of 28 ft 4 inches or any boat numbered 271.

Having eliminated its construction in both the UK and Cockatoo Island it is quite likely to have been built at Garden Island and possible the ‘Boat Shed’ which is now home to the Naval Historical Society of Australia.

At the time, gigs were managed as a stores pool item as is the case with ships boats today. Boats were not dedicated to any particular ship.

The heritage significance of the Australia (1) Gig is that it is the last of its type in Australia.

HMAS Australia 1 with ships boats slung on very high davits adjacent the main mast and funnel. RAN Image

By definition gigs are lightweight ships boats of varying length rowed by four, six, or eight long oars. Traditionally, they were reserved as the captain or commander’s personal boat. This being the case there is no surprise that the saying “A ship is known by her boats” developed. The appearance of a gig was a matter of ships company pride. This also applied to the crew’s appearance, handling, management and bearing.

Layout Plan of a GIG shown in Service Rig, Image from; The Pilot, Autumn 2007 edition No.291

When the Royal Australian Navy was established there were some seven types of boats carried in Royal Navy and RAN ships. The mix of boats carried in a warship varied with the size and Class of the warship. The range of boats used during the early years of the RAN included;

Pulled or Sail Powered

Launch 42ft,

Pinnace 30 or 36 ft,

Cutter 25 or 34 ft,

Galley 32 ft,

Gig 28 or 30 ft,

Whaler 24 or 27 ft,

Dinghy 13.5 or 16 ft.

Steam Powered

Pinnace 40 or 56 ft,

Barge 40 ft

(for Admirals),

Cutter (various lengths, 23, 25, 27 and 32 ft.)

With the advent of steam powered warships and their boats and phasing out of sailing ships as “men of war” in the late 19^th and early 20^th centuries, pulling boats remained important for seamanship training and as a means of maintaining physical fitness. Pulling events were also an outlet for competitive spirit amongst ships of the fleet. “Away all boats, pull around the fleet” or “Man and Arm boats”, “Away duty sea boat” where piped for various drills. Racing under oars or sail weren’t just for fleet regatta days. Gig crews manned single-banked oars with the stroke pulling a starboard oar and the rest of the crew pulling port and starboard alternatively.

The earliest record of a gig dates from 1666 when Gigs from St Mary’s on the Scilly Isles rescued the crew of British East India Company’s Royal Oak which had been wrecked on the Bishop Rock. There’s little documentation to be found on early Gigs but its design evolved over time until it matured in the early 19^th century. Records show a William Peters of Polvarth near St Mawes started building high quality Gigs in 1790. His advanced design became the blue print for the Pilot Gigs that met the sailing ships and offered “pilot service” to inbound Merchant Captains.

In 1812 William Peters received an order for three Gigs to be shipped to Burma (today’s Myanmar). However, due to lack of deck space on the ship transporting them to Rangoon one wasn’t embarked. This Gig was in turn sold to the “Newquay Pilots” and it was named “Newquay”, this same vessel is still raced today by the Newquay Rowing Club UK, some 207 years on.

Most Gigs built for the Royal Navy were 30 foot in length and with a beam of 6 foot, fitted with two masts and a steel (70lb) centreplate, drop keel. The Admiralty Manual of Seamanship states that the 30 ft Gig “was the fastest service boat under sail and oars!”. The crew was six plus a coxswain.

Gigs remain popular today, particularly on the English south coast in Devon and Cornwell. Here there is a large following of Pilot Gig racing with boats built in the traditional manner by local shipwrights. The tradition stems from the race to get a pilot from shore to an incoming vessel in need of a pilot to navigate in confined waters. The fastest gig rowers got the payment.

Cornish Pilot Gig under construction, looking aft. Brian Nobbs image.

Gig under construction in Launceston, Cornwall UK. Brian Nobbs image.

Construction takes from four to six months with the launch of a new Gig a major occasion. Gigs are often launched at the World Championships in Scilly, where the local vicar blesses new vessels. Through this sport traditional shipwright skills are maintained and knowledge of the historic Gig is not lost to history.

References:

The Pilot Gigs of Cornwall and The Scilly Isles, The Pilot, Autumn 2007 edition No.291, available at http://www.pilotmag.co.uk/wp-content/uploads/2008/07/pilotmag-291-final.pdf

Brian Nobbs Cornish Pilot Gig Builder, available at http://www.pilot-gig-builder.co.uk/pilot-gigs.asp

‘Up and Downers’ save the day

June 6, 2019

By Bob Hetherington

This story was first published in All Hands, the magazine for volunteers at the Australian National Maritime Museum (ANMM), and is reproduced with their and the author’s kind permission.

Just when reciprocating steam engines were looking like a dead duck, along came WWII and a new lease of life.

‘Up and Downers’ was the nickname given to the reciprocating steam engines which powered the Industrial Revolution. We have a classic example of one in the Australian National Maritime Museum’s Navy Gallery, but it’s not widely known how they got a second wind and powered the Liberty Ships which changed the course of WWII. And there’s an Australian connection. Up and Downers developed from the single cylinder steam engines which drove machines, ships and locomotives in the early 1800s. It was soon realized that coal consumption could be reduced by using the energy remaining in the steam leaving the cylinder, and triple expansion engines were introduced to feed the exhaust steam from the first (high pressure) cylinder into a second cylinder and then feeding its exhaust into a third (low pressure) cylinder. The pistons in each cylinder were connected to a common shaft which turned the wheels of industry. By the turn of the century triple expansion engines had become standard for marine propulsion. They had the advantage that they could be coupled directly to the propeller shaft and they ran at speeds suited to propeller efficiency.

SS Jeremiah O’Brien, one of 2075 Liberty Ships with good old fashioned steam technology.

However, a rival soon appeared in the form of the steam turbine. Turbines generate a rotary rather than reciprocating (up and down) motion with the advantages of lower vibration, lower weight, smaller dimensions, fewer moving parts and lower maintenance. By the early 1900s turbines were replacing Up and Downers and their low vibration was a big plus for the prestigious passenger liners of the time. Olympic and Titanic were fitted with a combination of both types of engine but a few years earlier Cunard had taken the plunge and chosen all-turbine drive for Lusitania andMauretania.Turbines operate at high speeds and need elaborate precision reduction gearing to drive propellers at efficient speeds, typically 80–120 rpm. Specialist engineering companies grew up to design and build the gear trains needed for marine propulsion. By the 1920s marine diesel engines had made their appearance (they are almost universal today); in 1924 the Swedish-American Line Gripsholmbecame the first diesel powered liner to cross the Atlantic. It seemed to be the end of the line for the Up and Downers.

World War II erupted and it became clear that the Allies would not prevail without a massive supply of materials from the United States to Britain. This required a huge and urgent expansion of merchant shipping capacity and the Liberty Ships program was launched to make up the shortfall.

These ships were designed to be simple, cheap, quick and easy to build and to operate (at relatively slow speeds) under the convoy system. The idea was to have the components built in various locations outside Britain with the ships assembled and launched on the U.S. east coast.

Engines also needed to be simple, reliable and quick and cheap to build. Although steam turbines and diesel were by now the prevailing technology there were two major problems: Diesel fuel was in short supply and there was an acute bottleneck in the availability of the gear trains needed for turbines; new designs would be needed to cater for the slower ship speeds. This engineering capacity was dedicated to production and maintenance of warships. Time was absolutely critical so it was decided to dust off a proven ‘up and down’ design and standardise it so it could be built quickly in existing engineering facilities. The engine chosen was a tried and tested design from the North Eastern Marine (NEM) Company of Sunderland and Wallsend, producing 2500 HP at 76 rpm. These were fitted not only to U.S. built Liberty ships but to Fort, Park and Empire ships built in the UK and Canada. No less than 2075 Liberty ships were to be built, and the choice of the NEM engine proved to be a very good one. In this sense the Up and Downer really did help to save the day.

At the same time a similar story played out in Australia, albeit on a smaller scale, and again Up and Downers proved their worth. They were fitted to the sixty Bathurst class corvettes built here during the War. In 1938 the Australian Commonwealth Naval Board (ACNB) proposed a general purpose local defence vessel which would be easy to construct and operate and in 1939 the RAN completed a design for a 680-ton vessel with a speed of 15 knots to be locally built and, yes, fitted with a triple expansion steam engine which could be constructed in the existing workshops of train locomotive manufacturers. This was a demanding project for the local industry. Cockatoo Island Dockyard became the lead shipyard and in February 1940 laid down the first ship, HMAS Bathurst. Seven other yards were involved in Queensland, New South Wales, Victoria and South Australia. Of the sixty vessels built, fifty six were commissioned into the RAN and travelled a total of twelve million kilometres during and after the war. The last to leave RAN service was HMAS Waggain 1960, taking with her (to the best of the author’s knowledge) the last Up and Downer in the fleet. Only two examples remain: HMAS Castlemaine is a museum ship in Williamstown, Victoria and HMAS Whyalla is a land based tourist attraction in Whyalla, South Australia. If you would like to see a marine Up and Downer in motion in Australia it seems you have limited opportunities. Close to home is the Museum’s SY Ena, but I should point out for the purists that her engine, while still live steam driven, is two cylinder, not triple expansion. To experience a live triple expansion engine you can take a trip on Sydney Heritage Fleet’s SY Lady Hopetoun. More pedestrian but larger examples are our own from the 1926 Sydney vehicular ferry Kara Kara, and in Melbourne you can visit HMAS Castlemaine. Sadly neither is steam powered any longer.

Bathurst class corvettes at Williamstown Naval Dockyard January 1946 – Allan C Green

Footnote: See www.hmascastlemaine.org.au for a good description of this Bathurst class corvette. As explained above the engines were sourced from existing local manufacturers, in this case Thompsons Engineering and Pipe Co. Castlemaine, Victoria.

An Essay on Autonomous Ships

June 6, 2019

By Lieutenant M. De Angelis, RFD, RANR

Mario De Angelis enlisted in the Royal Australian Naval Reserve, Melbourne Port Division on 22 January 1974. Initially joining as a Cook, he later qualified as a Seaman Quartermaster Gunner and was commissioned as a Seaman Officer in 1976; he continues to serve as an Active Reservist.

Mario served in various ships including Patrol Boats, Landing Craft, Destroyers and the Aircraft Carrier HMAS Melbourne. In 1985, he changed to the Supply Branch with subsequent promotion to the rank of Lieutenant in 1987.

In recent times he has also used his civilian expertise in communications and logistics whilst serving in various short appointments including the Australian Warfare Centre at RAAF Williamtown, Support Command Australia and HQ Joint Logistics Command.

This essay is a brief review on the status of Autonomous Ships. We discuss the definition of the class, degrees of autonomy and the implications.

The lead countries and companies have high expectations of the economic returns from their investments in this field. To date, there are significant investments in both military and commercial fields.

Players in this industry need to consider a variety of technologies to resolve the risks and issues in communications, control and propulsion. These have a direct bearing on the levels of human involvement and the degree of automation.

The uptake of autonomous shipping has similarities with the uptake and development of autonomous land vehicles. The significant difference is that sea craft generally have a longer half-life than land-based vehicles. Technology take up is also slower. Interactions between autonomous vessels and their crewed counterparts will also affect the uptake timeline. Vehicle and vessel servicing also share similarities given the mix of technologies.

Each degree of automation up to complete autonomy requires increases in sophistication, data and redundancy. In the military context, damage control can mean the difference between mission success and mission failure.

The piracy risk is also increased. Not only are there pirates on the water to consider there are pirates in the data environment. From industrial sabotage to state sponsored hacking the new electronic environment offers a fresh hunting ground. With greater strategic reach, there is a proportional increase in risk.

The industry uses various scales to define automation and autonomy. The Technical University of Denmark (DTU) developed their scale for ship automation using the Society of Automotive Engineers (SAE) automation scale for land vehicles.

Table 1 illustrates the five-step classification of automation leading to full autonomy for land-based vehicles. DTU used this in their 2016 A Pre-analysis on Autonomous Ships. Funding from the Danish Maritime Authority helped publish the report. It describes how to define the various levels of autonomy and the potential of autonomous ships.

DTU developed a nine step series of classification terminology for merchant ships achieving full autonomy.

DTU used the terminology summarised in Lloyds Register 2016, to determine the classifications in Table 2. This resembles the SAE codes used for land vehicles.

Tables 1 and 2 show that greater levels in automation and autonomy require more complexity in the solution. There will be a close relationship between massive databases and the automation algorithms.

DTU details are below, including the address of their website.Technical University of Denmark: DTU Electro, Elektrovej 326 and DTU Management Engineering, Produktionstorvet 426, DK-2800. Kongens Lyngby www.dtu.dk

Commercial and Military Leaders

Commercial groups are primarily interested in the logistics side of cargo carrying autonomous vessels. Military elements are primarily interested in weapons delivery against military targets.

Label	Level of Automation	Description
SAE 0	No automation	The driver performs all driving and navigation without any aids.
SAE 1	Driver assistance	The car can keep a distance to other similar cars.
SAE 2	Partial automation	The car can perform simple tasks on its own, such as driving in the road system where it is located.
SAE 3	Conditional automation	The car can drive on its own in specific situation (e.g. on motorways). The driver does not need to control the car actively or to keep a lookout, but must be able to intervene at short notice.
SAE 4	High automation	The car can drive on its own in specific surroundings, but the driver does not need to be ready to take over control.
SAE 5	Full automation	Driverless cars in all surroundings and in all potential situations.

Table 1: SAE scale of land vehicle levels of automation up to complete autonomy

Code	Description	Operator Role
AL 0	Manual steering. Steering controls or set points for course, etc. are operated manually.	The operator is on board or performs remote control via radio link.
AL 1	Decision-support on board. Automatic steering of course and speed in accordance with the references and route plan given. The course and speed are measured by sensors on board.	The operator inserts the route in the form of “waypoints” and the desired speed. The operator monitors and changes the course and speed, if necessary.
AL 2	On-board or shore-based decision support. Steering of route through a sequence of desired positions. The route is calculated so as to observe a wanted plan. An external system is capable of uploading a new route plan.	Monitoring operation and surroundings. Changing course and speed if a situation necessitates this. Proposals for interventions can be given by algorithms.
AL 3	Execution with human being who monitors and approves. Navigation decisions are proposed by the system based on sensor information from the vessel and its surroundings.	Monitoring the system’s function and approving actions before they are executed.
AL 4	Execution with human being who monitors and can intervene. Decisions on navigation and operational actions are calculated by the system which executes what has been calculated according to the operator’s approval.	An operator monitors the system’s functioning and intervenes if considered necessary. Monitoring can be shore-based.
AL 5	Monitored autonomy. Overall decisions on navigation and operation are calculated by the system. The consequences and risks are countered insofar as possible. Sensors detect relevant elements in the surroundings and the system interprets the situation. The system calculates its own actions and performs these. The operator is contacted in case of uncertainty about the interpretation of the situation.	The system executes the actions calculated by itself. The operator is contacted unless the system is very certain of its interpretation of the surroundings and of its own condition and of the thus calculated actions. Overall goals have been determined by an operator. Monitoring may be shore-based.
AL 6	Full autonomy. Overall decisions on navigation and operation are calculated by the system. Consequences and risks are calculated. The system acts based on its analyses and calculations of its own capability and the surroundings’ reaction. Knowledge about the surroundings and previous and typical events are included at a “machine intelligent” level.	The system makes its own decisions and decides on its own actions. Calculations of own capability and prediction of surrounding traffic’s expected reaction. The operator is involved in decisions if the system is uncertain. Overall goals may have been established by the system. Shore-based monitoring.

Table 2: Autonomy levels (AL) extract from DTU ‘A Pre-analysis on Autonomous ships’.

The major commercial entities investing in autonomous ships are Kongsberg Marine (Norway), Rolls-Royce (UK), MUNIN a European based consortium, a UK consortium comprising the University of Southampton, QinetiQ and Lloyd’s Register.

National entities include the Danish Maritime Authority, the US Navy, China, the United Kingdom, Norway, Japan and the European Community. There is a mix of driving influences as all nations have both economic and military interests.

The following quote from the Port Technology website, (Maritime Information Services Ltd) demonstrates the level of state and commercial interest in autonomous vessels.

This week, Bloomberg reported that Japan’s largest container shipping company, Nippon Yusen Kabushiki Kaisha (NYK Line), is planning to test a remote-controlled vessel across the Pacific Ocean in 2019.

The Monohakobi Technology Institute, NYK Line’s research and development unit, is reportedly considering using a large container ship for the test from Japan to North America.

Interest is widespread and as diverse as the countries investing in the technology. Commercial interests centre on cost savings and increased profitability. Military interests centre on weapons delivery and interdiction of enemy sea assets, all with minimal risk to trained personnel.

Anything short of full autonomy is, in reality, a drone. This is similar to the USAF drones currently flying military missions. The pilot sits in a control centre and the drone transmits data from its sensor arrays to provide the pilot’s cockpit view.

A drone vessel would relay data from its sensor array to the shipping control centre to provide the bridge crew with the watch keeper’s view. This applies equally to the commercial or military application.

The main investment effort in drone and autonomous shipping is in the northern hemisphere. The main players are in the United States, Europe, Russia, Japan and China. The American, Japanese and European entities are in the public domain. Very little information is available from the Sino-Soviet sphere.

Figure 1. The US Navy’s Sea Hunter autonomous anti-submarine platform

Autonomous communications, control and propulsion

Military applications for autonomous vessels require real time communication and control. Real time communication and control for merchant marine autonomous vessels is critical at points of departure and arrival. Long passages would mean quiet time with little or no change for a control centre to deal with. Greater autonomy requires more computing power. The minimum requirements are:

Maritime Rules of the Road
charts for all the oceans a vessel can expect to travel
port information
weather
winds
tides

This data needs correlation with the ship’s sensor array to confirm its status:

fuel
cargo condition
sensor performance
power availability
speed through the water
position by GPS, radar and sonar
winds and tides experienced

Figure 2. The Rolls Royce autonomous or drone vision for cargo transport

The size and mission of the autonomous vessel determine if data can be stored centrally ashore with the ship feeding information as it moves through an area or fully downloaded before departure. Coastal freighters need different data to that needed by a trans-Atlantic or trans-Pacific vessel. At departure and arrival points however, their data needs will coincide.

Propulsion options have a bearing on design and effort to maintain vessels operating efficiently. Fossil fuels require mechanical transfer of energy and management of toxic wastes. Electronic control and propulsion minimises energy loss through mechanical transfers but in a marine environment can be susceptible to electrical failure. Biofuels have the same issues as fossil fuels. Hydrogen fuel can operate in both mechanical and electronic environments.

Fossil fuels require tanks close to the engines and present an explosive or incendiary risk. Failures have catastrophic results.

Electronic propulsion relies on efficient battery power, and military diesel-electric submarines already use this technology. The Royal Australian Navy’s new Landing Helicopter Dock ships use electrical direct drive pods that remove the need for rudders. These have also demonstrated the critical risk of electronic failures during sea trials. Commercial shipping interests will baulk at risking valuable cargoes in this way. Reliability is a key economic consideration.

Biofuels, unlike fossil fuels, are renewable to the extent that production diverts crop growth from food to fuel production. Transport, storage and calorific values are much the same, and the same risks apply.

Hydrogen has more than twice the calorific value of carbon-based fossil fuels. NASA used it to propelthe Saturn 5 Apollo missions to the Moon. The tanks were huge and the hydrogen was under high pressure. At sea, this kind of storage is counterproductive as it displaces valuable cargo. The viable answer is a storage system at normal temperature and pressure utilising an electrical signal to release the fuel.

This works equally well for gas turbines, internal combustion or fuel cell technology. The tanks use metal-hydrides to soak up the hydrogen in a chemical lattice, much as a sponge absorbs water. These tanks hold more hydrogen by volume than an equivalent volume with hydrogen in gas or liquid form.

Ships on passage could refuel themselves in the same way that solar cells recharge batteries. Solar power could be used to trickle charge metal hydride tanks with hydrogen from the water resulting from its own combustion.

Economic arguments for autonomous ships

The economic argument is an offset of investment in technology against removal of human involvement in shipping. Autonomy simplifies ship design by removing the need for life support. No accommodation, food storage, bio-waste management, passages or environmental management are required. This leaves more ‘space’ for propulsion and cargo, increasing profitability by volume. Ships’ sea endurance is longer and they can traverse inhospitable environments, all without the cost burden of heating, cooling and life maintenance for humans.

In battle, autonomous ships can operate individually or as a pack to interdict or overwhelm enemy capability. Losing a few drones is politically easier to losing lives. Military tasking could also include hazard and explosives removal, hydrography and use in emergencies. Again, it comes down to cost effectiveness and risk compared with crewed ships currently performing those tasks.

Fuel type and propulsion systems are critical to the economic argument. These directly affect running costs and maintenance liabilities. Maintenance translates to human intervention. Autonomy seeks to eliminate this basic cost.

Autonomous capability, data and redundancy

Autonomous capability for a ship at sea translates to the manipulation of huge amounts of data. Ship handling characteristics are the starting point, along with the sensors and control systems to manage the ship. Automated radar and GPS readings require analysis and correlation with electronic copies of charts and positioning data. In addition, the shipping control centres require regular progress and situation reports, much as crewed ships do today.

Propulsion and data management need reliability and redundancy on a ship out of reach of human intervention. Mechanical or electronic systems need to perform at optimum levels. Equipment failures require self-diagnosis and repair or redundancy. Switching to the backup systems and business continuity is critical. This contributes to the economic argument.

In the event of complete failure, the autonomous vessel must have enough residual power to send a distress call to its home control centre. Equally, when help arrives, there must be enough power to authenticate access to the ships sensitive areas. Simple recognition of friend or foe.

Specific types of cargo fit into the calculations for power requirements. Sensitive cargoes that may spoil in the event of power failure need redundancy. Insurance companies will be very specific about cargo insurance where there is no repair or backup system in place.

Port facilities also need upgrading. Autonomous ships need to understand anchorage points and wharf designations. The autonomous ships will need security access by stevedores to both load and unload the various cargoes. Refuelling and other port services also require secure access.

Risks with autonomous ships

Risk exists for autonomous ships in the same way that it does for crewed ships. One exception is the risk posed by and to a live in crew. Autonomous ships will not need life support systems so there are no risks to a crew. Other risks range from interactions with crewed vessels, with military vessels, other autonomous vessels, sea and virtual piracy.

Crewed vessels range from pleasure craft, sailing vessels and crewed fishing vessels. These craft may not have the level of sophistication inherent in an autonomous vessel. The first time an autonomous vessel collides or interferes with a crewed ship will cause many reactions. Litigation over such an event will certainly affect the take-up of autonomous technology at sea.

Military vessels routinely board crewed merchant vessels. How will the military manage the interrogation and verification of cargoes carried by an autonomous vessel? Electronic records and cargo codes would need upgrading to avoid unnecessary interference with an autonomous vessel. Interrogation Friend or Foe (IFF) and data transfer facilities may need development for all territorial navies through which an autonomous vessel passes.

Pirates have a long, illustrious and ignominious history in the oceans of the world. The romance has faded and most piracy today involves smuggling illicit cargoes, armed interception of luxury craft and in some areas, boarding and ransoming of bulk carriers who stray within range of their usually smaller craft.

Criminal and State sponsored cyber warfare poses the next piracy threat against autonomous ships. Opposition military assets must be neutralised and commercial assets are valuable. Temptation will find new ways of extending bad behaviour.

Imagine holding an entire fleet of carriers to ransom. Pirates could congregate them or keep them moving. Worse, they could redirect them to a State where their cargoes would disappear.

Conclusion

Technological developments will continue to progress the advent of autonomous ships. The economic equations make investment in this field inevitable.

Figure 3. Artist’s impression of Yara and Kongsberg’s Yara Birkland proposal

Land-based vehicles can have model turnarounds of as little as one year. Ships generally have a life span measured in decades. Some military forces refit their existing fleets to extend their service life. Autonomous vessels also follow this life cycle due to the investment they represent to their builders, owners and operators.

The risks to the take up and operation of autonomous ships will not stop their development. A combination of technologies with physical and software defences will keep the economic equation in favour of the market.

Military initiatives will probably involve both drones as well as autonomous fleet units. Autonomous ships will change the nature of convoys and revamp military manoeuvres as these new units come on line.

Autonomous ships will cause changes to Port facilities and maritime regulations. Their technological advances will also change the development of crewed vessels.

Occasional Paper 51: The Attack Class Patrol Boat

April 12, 2019

April 2019

By Dennis J Weatherall JP TM AFAITT(L) LSM

Volunteer Researcher, Naval Historical Society of Australia

Patrol boats have proven to be the most flexible and versatile elements of the Australian Defence Force (ADF) since World War 2. Every day they are at sea patrolling Australian waters and protecting our national interests. They play an active role in the enforcement of Australian legislation pertaining to; illegal immigration, fishing, quarantine and smuggling.

Between World War 2 and 2019 the Royal Australian Navy has operated five classes of patrol boats commencing with the Bathurst class built between 1940 and 1942. Then followed the Ton class, Attack class, Fremantle class and in current service, the Armidale class.

Experience during the period of Indonesian Confrontation (1963-6) with the Ton class demonstrated the value of small vessels for patrol and interdiction tasks. However, the Ton class propulsion system was not suited to loitering and they were expensive to maintain. This experience led the RAN to introduce the Attack class to conduct patrol work in Australian territorial waters.

This paper examines the design, construction and operations of the Attack class and provides some insight into their habitability.

HMAS ADVANCE launched 16th August 1967,
commissioned 6 February 1968. ANMM image

User Requirement

The requirement for a new Royal Australian Navy Patrol Boat design commenced in May 1963 with an official request from Navy for a preliminary feasibility study for a boat of simple characteristics, around 70-80 feet in length with a speed of approximately 12 knots, and accommodation for a minimum of 2 Officers, 2 Petty Officers and 10 Junior Sailors.

From these initial and additional requirements, the final design developed by Department of Navy naval architects resulted in a vessel that could carry out; general duties, harbour defence, pursuit and interception tasks.

The final design required the following;

Capabilities:

• Search & rescue

• Seaward defence

• Coast Watching

• Target towing

• Boarding operations

Navigation:

· Radar, transistorised light weight commercial unit

· Gyro compass, similar to Arma Brown commercial units

· Magnetic compass,

· Echo sounder of a type similar to Ferrograph, a Trident Log with a bridge repeater

· Training: for Junior Officers and sailors (PNF and Reserve) in ship handling

Training

for Junior Officers and sailors (PNF and Reserve) in ship handling

Communications

A package for both external and internal use for control and navigation.

Speed

Maximum, 23 knots

Cruising, 15 knots

Weapons

A power-operated single Bofor gun on forecastle immediately forward of superstructure with similar mount aft. Provision for small arms and ammunition

Endurance

At maximum continuous speed: 500 miles

At cruising speed: at least 1500 miles

Water & victuals: 14 days

Accommodation

to approved standards, fitted with air-conditioning for tropical area operation

Dimensions

length 100-120 ft and

draught of 5-8 ft

Life-saving equipment

RAN standard

Propulsion

Twin screw, simple and reliable in operation

Ships Boat

14 ft dingy (approximately)

Delivered Capabilities and Specifications

The boat ‘as delivered’ generally met the required specifications, e.g. length 107.5 feet (32.76M), draught 6.2 feet (1.9M) and a speed of 24 knots. Full details of the boat as delivered are at Annex A.

Service Life and Disposal

The original plan was to build twenty boats, although the class type was designated the Attack, the boat bearing the class name was the tenth pennant number allocated, fifth launched and second commissioned four days after Aitape # P84. Pennant numbers ran from 81-95 and 97-101, (20 numbers) but Pennant number 96 was never allocated, nor could I find a reason for skipping this specific number.

HMAS *Archer* in Jervis bay showing her original thin style pennant number

The Attack class (A) Boats were built at two Queensland engineering works; Evans Deakin (Brisbane) built 13 and Walkers Ltd (Maryborough) built 7.

Five Patrol Boats were purpose built for New Guinea service and named accordingly. They were used for patrol and general duties in Australian and surrounding waters before transfer to the PNG Defence Force. The boats destined for New Guinea service were HMAS Aitape, Samarai, Ladua, Lae and Madang. These vessels, after Independence, were retitled HMPNG Ships. The table provided in Annex B lists all twenty vessels built; by whom, pennant numbers, dates laid down and dates launched and commissioned.

The Attack class gave good service over more than two decades. HMAS Bayonet, built by Walkers Ltd was the last boat launched (6 November 68) and commissioned on 22 February 69. The last boat to decommission was HMAS Aware on 17 July 1993.

Five boats were gifted to the PNG Government; Aitape, Samarai, Ladava, Lae and Madang. Nine were either gifted or purchased by Indonesia. These were:

RAN Name	TNI Name
Acute P81	KRI Sikuda # 863
Archer P86	KRI Siliman # 848
Ardent P87 sold privately, then bought by Indonesia.	KRI Tenggin # 865
Assail P89	KRI Sigurot # 864
Attack P90	KRI Sikuda # 863
Bandolier P95	KRI Sibarau # 847
Barbette P97	KRI Siada # 862
Barricade P98	KRI Sigalu # 857
Bombard P99	KRI Siribura # 859

Two boats were sunk as targets, Adroit on 8 August 1994 and Buccaneer on 8 October 1988.

Loss of HMAS Arrow

HMAS Arrow floundered alongside Stokes Hill Wharf during Cyclone Tracy on 25 December 1974 with the loss of two lives, Petty Officer Leslie Catton and Able Seaman Ian Rennie. Arrow and Attack had attempted to sail Port Darwin and ride out the cyclone at sea, but neither vessel made it out of the port. Arrow was unlucky and was blown under Stokes Hill Wharf and wrecked. Attack was driven ashore at Doctor’s Gully without sustaining any casualties. Arrow was re-floated by DT1 on 13 January 1975 by attaching pontoons to her hull and, with the assistance of tugs, the wreck was towed underwater to the shallows of Frances Bay, where she was surveyed, written off as a wreck and put up for sale.

HMAS Arrow, lost in Darwin during Cyclone Tracy, 1974 RAN images

A local businessman purchased what was once a proud patrol boat, his idea was to restore her, but it proved far too expensive, therefore a decision was made to break her up where she lay.

HMAS Advance was the third boat in Darwin at the time. She escaped damage at sea. One of HMAS Arrow’s name boards is proudly displayed in the Mess at HMAS Waterhen, once her home base.

HMAS Advance is the last remaining Attack class patrol boat maintained as an operating exhibit by the Australian National Maritime Museum in Darling Harbour, Sydney. Advance is a proud reminder of the twenty boats built between 6 July 1967 and 6 November 1968 to protect Australia’s 200nm economic zone, fishing rights and just about any other task directed. They welcomed fleeing South Vietnamese after the Fall of Saigon in April 1975, and towed many a craft safely to our shores. They were work-horses with more sea time than many major fleet units. Once a “boat-man”, you always wished to stay in what was often referred to as “McHale’s Navy”. There wasn’t much of our extensive coastline that we didn’t pass or “drop the pick” in some secluded bay or river entrance, from Cooktown into the Gulf and down the West Australian coast.

Life in an ‘A’ Boat

The combination of a small, relatively junior crew, remote area operations and cycle of 6 weeks on patrol and 2 weeks in home port resulted in close-knit self-reliant ships companies very proud of their boat. Dress standards in the tropics were relaxed with the ships ‘T’ shirt, shorts and sandals frequently dress of the day. Multi-tasking was essential for the conduct of evolutions such as boarding operations and during leave periods. Young and inexperienced hands quickly learnt under guidance from the CO and senior sailors. Training in an ‘A’ boat occurred naturally.

Habitability was adequate but some design shortcomings created frustrations. ‘A’ boats were not designed for crew comfort in heavy sea states! Operations in conditions above sea states 4 and 5 (moderate to rough seas) curtailed many activities particularly boarding operations. They rolled uncomfortably in moderate conditions often creating havoc due to design issues. As an example, the galley range door which was oriented longitudinally would fly open in heavy seas. Local modifications such as attaching a gate bolt to keep what was cooking in the oven were necessary. As an aside, one day before the modification was carried out, I found our LSCK chasing half-baked chickens across the deck after we hit some rather heavy seas! You can imagine the mess of oil (from the chickens), the baking tray and one rather irate cook chasing scran across the deck!

The senior sailor’s bathroom located in the peak of the bow presented another challenge. It was some real fun sitting on the heads when underway heading into a forceful sea state, and an impossibility to shower without a very wet deck when the shower curtain swung to starboard at 40-plus degrees. Laundry facilities were ‘Heath Robinson’ with a washing machine lashed to the mast for use alongside when adequate fresh water was available. The engine room doubled as a drying room.

Throughout their service Attack class boats developed a proud and respected reputation so much so that the Australian Broadcasting Commission produced a television series based on actual events with which they dealt. They certainly lived up to their short sharp mottos which are listed in Annex C.

Attack Class Successor: The Fremantle Class

Planning for the new Fremantle class patrol boats commenced in 1970. Experience gained from operating twenty Attack class boats identified numerous areas for improvement in the new design. By September 1970 the Navy proposed construction of ten additional new patrol boats to commence entering service between 1976 and 1980. These additional vessels would augment the Attack class and also replace the two General Purpose Vessels HMAS Bass and Banks.

The acquisition of replacement patrol craft was announced in April 1975 with eleven shipbuilders invited to tender. On 22 September 1977 the Minister of Defence (James Killen) announced the PCF450 design had been selected and fifteen boats would be built at a cost of AUD 115 million.

The lead vessel HMAS Fremantle was built in the UK by Brooke Marine of Lowestoft. The remainder were built in Australia by North Queensland Engineers and Agents. Fremantle was allocated pennant number 203 and following commissioning, 17 March 1980 made one of the longest duration delivery voyages in RAN history taking 82 days. Fremantle arrived at her home base, HMAS Waterhen on 27 August 1980. She had sailed 14,509 nautical miles, probably the longest voyage undertaken by a single RAN patrol boat.

With HMAS Fremantle came the new class of patrol boats and additional duties as they were integrated into the Fleet. Attack class boats progressively handed over the reins to the Fremantles until they were all decommissioned. In turn, the Fremantles were superseded by the Armidale Class, but that is another story!

Annexes

Attack Class Patrol Boat: Delivered Capabilities and Specifications
Attack Class Patrol Boat: Key Dates
Attack Class Patrol Boat: Mottos

References:

Personal experience from boats on which I served (Dennis Weatherall)
Design of Patrol Boats for RAN – J.J. Follan M.R.I.N.A. (Royal Institution of Naval Architects Australia)
Australian Ships of War – John Bastock Published 1975 Pages 372-382
Welcome to the Armidale Class, Semaphore February 2006, Issue 4
Australian Patrol Combatants, April 2010, Semaphore 2010 Issue 3,
HMAS Arrow, Sea Power Centre Australia Website, accessed 30 March 2019

Annex A

Attack Class Patrol Boat: Delivered Capabilities and Specifications

The following describes the Attack class as delivered to the RAN

Displacement: 100 tons standard, 146 tons fully loaded, length 107.5 ft (32.8m), beam 20 ft (6.1m), draught 7.3 ft (2.2m) at full load, propulsion 2×16 cylinder Paxman YJCM diesel engines 2 shafts, speed 24 knots (44 km or 28 mph), complement 3 Officers/4 Senior Sailors/12 Junior Sailors, armament 1×40 mm Mk 7 Bofor gun, 2 x .50 calibre machine guns, sufficient SLR and AR mix of rifles and hand guns.

Hull: The Attack class main hull was constructed of steel frame, bulkheads, deck beams were designed in mild steel of all-welded construction. The superstructure, funnel and masts were constructed of aluminium alloy of all-welded construction and “huck-bolted[1]” to the main hull structure.

Accommodation was located forward in the bow for 4 Senior Sailors. Senior Sailors’ bunks were two up port and starboard. Officers were accommodated in 2 cabins; Executive officer and Navigator, in a 2-off cabin forward opposite the radio office before entering the Senior Sailors’ Mess, starboard-side. The CO had a single cabin aft of the forward ladder to the lower deck and adjacent the magazine. All three officers shared a bathroom and heads directly opposite the forward ladder, accessible from the wardroom flat. These spaces were lined, with a white laminate and insulated, joins were neatly covered with natural timber trim. The Junior Sailors’ Mess was located aft immediately behind the engine room and forward of the tiller flat. Bunks were steel constructed, 3 up on the port side and 3 on the starboard side, split 6 forward and 6 aft, with a coat locker dividing sleeping area from the general mess.

Fuel Tank Capacity: Diesel, 6 main tanks of 20 tons capacity; 2 ferrying tanks of 2.5 tons;

Fresh Water Tank Capacity: normal capacity 4 tanks of 6.5 tons. Fresh water maximum capacity was 7.5 tons. These fresh water tanks were built into the hull. In order to conserve fresh water, an alternative salt water supply (if needed) could be operated in all three bathroom shower heads. When fresh water was scarce and top-up was impossible due to location, passing rain squalls were a welcome shower alternative on the quarter deck.

Steering Gear was fitted as a “Mathway” light weight power-assisted unit. It could be operated from either the Bridge, Wheelhouse or the emergency steering position in the Tiller flat, also known as the Bosun’s Store aft, directly over the ship’s rudder area. In the event of any hydraulic failure, this equipment could function without any power assistance but extremely hard on the arms.

Deck Machinery on the forecastle consisted of an anchor windlass of one cable lifter and two warpends driven by a 4.5 hp electric motor through an enclosed worm reduction gearbox. The windlass was also arranged for emergency hand operations.

Anchor was a 180 pound (81.8 kg) “Danforth” type fitted with 11/16 inch chain cable.

Galley was located immediately aft of the Wheelhouse on the main deck before exiting the forward superstructure. All equipment was electric and consisted of one single oven range with four hot plates and a grill plate. A 15 cubic feet upright refrigerator, one 7.5 gallon hot water urn for brews (always ready for use 24 hrs/day) and one use-all mixer/mincer.

Provisions Room – located at the bottom of the aft ladder into the Junior Sailors’ Mess directly opposite their bathroom, it took up the entire compartment, 21 cubic ft capacity in which we stored all meats, frozen milk, bread and the beautiful, pre-packed “guinea pig” vegetables such as broccoli, sweet corn and peas. Each Mess (x 3) also had a 5 cubic ft ready-use refrigerator – they also suffered from the same fore & aft placement onboard ship as our galley stove/range and often the fridge lock would spring open and whatever was inside quickly deposited itself on the deck!

Annex B

Attack Class Patrol Boat: Key Dates

The following table provides key dates (builder, pennant number, date laid down, launch and commission) for all twenty boats.

Name	Pennant Number	Builder	Launch Date	Commissioning Date	Decommissioning Date	History Post RAN Service
Acute	P81	Evans Deakin	26/8/67	26/4/68	6/5/83	Indo KRI Sikuda # 863
Adroit	P82	Evans Deakin	3/2/68	17/8/68	28/3/92	Sunk as target, August 1994
Advance	P83	Walkers Ltd	16/8/67	24/1/68	6/2/88	Museum, ANMM Sydney
Aitape	P84	Walkers Ltd	6/7/67	13/11/67	14/11/74	Transferred to HMPNGS, scuttled 1995
Samarai	P85	Evans Deakin	14/7/67	1/3/68	14/11/74	Transferred to HMPNGS
Archer	P86	Walkers Ltd	2/12/67	15/5/68	21/5/74	Indo KRI Siliman # 848
Ardent	P87	Evans Deakin	27/4/68	26/10/68	6/1/94 and Reclassified as TRNG NAV # A243. Paid off Dec. 1998	Sold to Pvte Indo 2002 KRI Tenngeri #865
Arrow	P88	Walkers Ltd	17/2/68	3/7/68	Lost in Darwin, 25/12/74 Cyclone Tracy
Assail	P89	Evans Deakin	18/11/67	21/7/68	18/10/85	Indo KRI Sigurot # 864
Attack	P90	Evans Deakin	8/4/67	17/11/67	21/2/85	Indo KRI Sikuda # 863
Aware	P91	Evans Deakin	7/10/67	21/6/68	17/7/93	Sold Pvte, scrapped 2011
Ladava	P92	Walkers Ltd	11/5/68	13/11/67	14/11/74	T/fs to HMPNGS
Lae	P93	Walkers Ltd	5/10/67	3/4/68	14/11/74	Transferred to HMPNGS
Madang	P94	Evans Deakin	10/10/68	28/11/68	14/11/74	Transferred to HMPNGS
Bandolier	P95	Walkers Ltd	2/10/68	14/12/68	16/11/73	Indo KRI Sibarau # 847
Barbette	P97	Walkers Ltd	10/4/68	16/8/68	15/6/84	Indo KRI Siada # 862
Barricade	P98	Evans Deakin	29/6/68	26/10/68	20/5/82	Indo KRI Sigalu #857
Bombard	P99	Walkers Ltd	6/7/68	5/11/68	12/9/83	Indo KRI Siribura # 859
Buccaneer	P100	Evans Deakin	14/9/68	11/11/69	27/7/84	Sunk as target 8/10/88
Bayonet	P101	Walkers Ltd	6/11/68	22/2/69	26/6/88	Scuttled 21/9/99 in Victoria

Annex C

Attack Class Patrol Boat Mottos

The following is a list of mottos allocated to each boat.

P81 Acute “Swift to the Point”

P82 Adroit “Quick and Secure”

P83 Advance “Never Look Back”

P84 Aitape “Tread Warily”

P85 Samarai “United We Stand”

P86 Archer “Swiftly Sure”

P87 Ardent “Flame and Fury”

P88 Arrow “Straight as an Arrow”

P89 Assail “Cut Deep”

P90 Attack “Never Waver”

P91 Aware “Forever Alert”

P92 Ladava “Fight the Good Fight”

P93 Lae “Dare All”

P94 Madang “Our Ship Your Shield”

P95 Bandolier “Dressed to Kill”

# 96 not allocated. Reason unknown

P97 Barbette “Taut and Trim”

P98 Barricade “They Shall Not Pass”

P99 Bombard “Hit Hard”

P100 Buccaneer “Seek and Find”

P101 Bayonet “We Fix”

[1] Huck-bolting is a patterned fastening, similar to a rivet, used frequently to fasten unlike metals together such as mild steel and aluminium. It’s a screwed thread with a clamp nut.