Construction of the first of 12 Arafura-class Offshore Patrol Vessels (OPVs) for the RAN is proceeding slightly ahead of schedule, with detailed planning expected to obviate any risks involved in the build program being split between SA and WA.

German shipbuilder Luerssen was named in November 2017 as the preferred tenderer under Project Sea 1180 Phase 1 to replace the RAN’s 13 hard-working Armidale-class patrol boats at a cost of up to $4 billion. A contract was signed on 31 January 2018 with the company’s new Australian subsidiary.

ASC OPV Shipbuilding (ASCOPV), a subsidiary of ASC Pty Ltd under contract to Luerssen Australia, is undertaking construction of the first two OPVs at the Osborne naval shipyard near Adelaide. ASC Shipbuilding, now owned by BAE Systems, is supplying the workforce to ASCOPV as part of a plan to provide workforce continuity between air warfare destroyer, OPV and Hunter-class frigate construction.

The OPV program then transfers to the Henderson Maritime Precinct in WA where Luerssen has subcontracted construction and heavy engineering company Civmec to build the other 10 OPVs.

The first steel for the Arafuras was officially welded by Luerssen and ASCOPV at Osborne on 15 November last year that steel, supplied by Wollongong-based Bluescope, had been cut by Civmec in WA the previous month and then trucked across the Nullabor to Osborne in specially-designed pallets to maintain quality of the contents.

Peter Croser, Assistant Secretary Ships Acquisition - Specialist Ships at CASG, confirms that Arafura construction is being closely monitored at several levels – by a team headed by Commodore Steve Tiffen, Director General Naval Construction; by Luerssen as the program prime; by ASC quality assurance and by the international certification society DNV-GL.

“Luerssen are there to impart the knowledge,” Croser explained to ADM. “This ship is relatively different in build strategy to the AWDs on which the ASC guys have been working, and the success Luerssen and ASC have achieved early on is amazing.

“The ASC Shipbuilding team and ASCOPV have produced very good, accurate blocks – a far cry from early experience with AWD when another contractor, who will be nameless, produced blocks that were sub-standard size and quality. With the first of the AWDs we put the first two blocks together and had to adjust structural beams and put in strips between the hull to fill the gaps when the blocks were offered up to join, causing much rework and adjustment.

“These issues were resolved and later blocks for ships 02 and 03 were to a much more acceptable standard.”

Build methodology
Croser points out that for the first OPV, the Osborne team is faced with a new methods of build (the Luerssen way) and quite complex structures.

“But through delivery of accurate 3D model cutting files from Luerssen, good quality steel from Bluescope (demanding tolerances), accurately profiled steel from Civmec and high quality work from the ASC workforce and supervisors, these blocks are taking shape fast, accurately, and of a high quality.

“The Osborne team was scheduled to do 50 tonnes of steel in the keel by 25 February and they achieved that two weeks early. We were ahead of schedule in WA for preparing the steel and we were ahead of schedule for start production, and that wasn’t a prototype, that was a real cut and a real first build.”

Croser refers to the benefits of centralisation and the presence of about 25 Luerssen personnel in Adelaide where the design model is located, as are design and build experts who can reach back to Germany and rapidly resolve – maximum overnight – any technical queries from the construction team.

“Plus, they’re on the floor watching the work along with Naval Construction Branch surveyors and picking up on any issues and introducing better methods and practices. There will be more than three blocks in parallel around April so Luerssen is ramping up with more personnel to support the increased production activity,” Croser notes.

Launch of the first OPV is scheduled for May 2021 with delivery in December 2021 after trials and verification. Construction of the second ship starts this August with launch anticipated in February 2022, while work will begin on Ship Three at Henderson in April 2020, with launch scheduled for November 2023.

Ship acceptance for the 12th and final OPV is scheduled for 2028/2029.

Starting construction in WA would not involve any Adelaide resources being moved to Henderson, where the Civmec workforce was already staffed at a level sufficient to undertake the same construction currently underway at Osborne. Some learning would be transferred between the SA and WA team during the build of the first OPVs.

“They have the resources at Civmec and the people; they work in the mining, the energy, the civil sectors, they already have steel workers with the skills to roll, cut, prepare and jig steel to get the accuracy required and construct OPVs under Luerssen supervision in addition to preparing the steel,” Croser said.

Between 200-300 people would probably be required at Henderson to build the ships, in addition to support staff and the supply chain. However, the precise number would come out of the ASC experience after taking into account the fact that the first ship would take longer to complete than the second ship and the learning curve for third and fourth ships at a new facility, and planning for potentially a slightly smaller pool of experienced people from ship 04 onwards. Civmec has two future roles, Croser suggests. The first is supplying the cut steel and secondly fabricated sub-assembles, and will be involved in the construction of the 10 OPVs at Henderson with the support of prime contractor Luerssen.

Also involved is its part in the Luerssen-Civmec Australian Maritime Shipbuilding Export Group (AMSEG) joint venture which currently has no contractual role in the OPV program.

However, its future intent is to combine Civmec’s steel manufacturing capability and infrastructure with the shipbuilding and design expertise of Luerssen, to develop a new world-class sovereign shipbuilding capability.

“That is going to generate a business which is focused on export not only essentially of the Arafura-class but also other ships

under the Luerssen flag,” Croser notes. “Civmec’s 180-metre long shipbuilding shed, their blast and paint facility and the rest of the resources including stores, logistics, warehousing, engineering, and also offices for the Commonwealth, will be great.

“It has the potential of three lanes of ships being built or repaired in parallel which means if they get exports they can have one lane for Arafura and two other lanes for other classes or repairs.”

Design heritage
The Arafura class is based on four OPVs in service with the Royal Brunei Navy as the Darussalem class.

The steel-hulled ships will be 80 metres long with a beam of 13 metres, draught of four metres, and displacement of 1,640 tonnes which could eventually grow to a maximum of around 1,800 tonnes at end of life.

Maximum speed will be around 22 knots and the ships will have a range of more than 4,000 nautical miles and endurance of approximately 21 days with a crew of about 40, although accommodation will be available for a further 20 personnel.

The Arafuras will carry a stabilised 40mm gun and two 12.7mm machineguns, reintroducing the larger calibre to the RAN for the first time since the decommissioning of the last of its Fremantle-class patrol boats in 2007.

The 40mm weapon will be supported by an integrated electro-optic targeting system. A second and independent electric-optic package will provide the OPV with a broader surveillance capability.

Additional sensors will include X band and S band surface search radars, a 2D surveillance radar, and electronic support measures. Data will be handled by a Saab 9LV combat management system similar to that equipping the two auxiliary oiler replenishment (AOR) vessels under construction for the RAN in Spain.

Unlike the Armidales, the OPVs will be equipped with an identification friend or foe transponder and the Link 16 data link system, all adding to the scope of the situational awareness system and the ability if required to contribute directly to the recognised maritime picture in support of task group elements, possibly slightly further afield than the Australian station.

Although a helicopter will not be embarked, an as-yet unnamed full-size maritime tactical unmanned air vehicle (UAV) will operate from what is now called the utility deck and vastly increase the ship’s surveillance area. These are being sought under Sea 129 Phase 5.

The three seaboats carried by the OPVs will constitute its primary weapons system in border protection activities across Australia’s exclusive economic zone. While the in-service Armidales are equipped with two 7.2 metre rigid-hulled inflatable boats (RHIBS), the OPVs will carry two 8.5 metre RHIBS, each capable of carrying a full boarding party, and a third 10-metre stern ramp-launched RHIC (rapid interception craft).

One obvious difference from the Darussalem class is in the weight of armament, with the Brunei ships carrying Exocet anti-ship missiles, a 57mm cannon, two Oerlikon 20mm rapid fire weapons and a helicopter.

“That equipment has not been fitted and we left the foundations, there was no point in removing them. We didn’t put in the cabling so it’s minimum change,” Croser explained to ADM. “Exocet was between the forward superstructure and the aft exhaust stack, it’s high up, so we gained Vertical Centre of Gravity (VCG) benefits by removing it. The total ship is managed by a model around weight and VCG; when you take something out and put in something the difference is noted and the change in displacement and VCG is logged.

“We can put containers on the utility deck and containers below the utility deck for things like the UAV, underwater sensors, accommodation, special services required for visitors – this ship has room for growth in terms of displacement, VCG, power, cooling; it’s not an Anzac where all those things were on the margin”.

One less obvious change from the Brunei configuration is the addition to the Arafura-class of a bow thruster to keep the ship moving towards the wharf in ports such as Darwin and Cairns with heavy tidal movement. There are changes in the keel to accommodate the bow thruster, and fresh water production has been increased.

A different standard of electrical power distribution is also being fitted to better align the ship to Australian shore power and safety requirements, and this involves installing a transformer low down in the hull.

“That is good because it provides us with layered margins to put something higher up in the ship to balance it and maintain growth potential,” Croser said.

Other changes involve environmental compliance, which includes installing a different class of MTU engine – two 4,440 kw MTU 16V units driving controllable pitch propellers - to increase the ability to clean and scrub their exhausts and reduce emissions. MAN diesels are being used for power generation.

The change in engines has in turn necessitated a change in gearbox selection and moving some of the foundations in the engine room, all of which was agreed by the Commonwealth in a review in Germany last August before moving to production.

Systems integration
Each of the three program contenders – Luerssen, Damen and Fassmer – were given the headline requirements for platform elements such as command and control, communications, navigation, gun, and an integrated platform management system, without specific suppliers being mandated.

“We did not chose Luerssen’s design solution, they brought L3 and Saab together as part of their primary and accepted bid together with Taylor Brothers in Tasmania for the accommodation modules and fitout,” Croser explained.

Australian Industry Content (AIC) has reached 60 per cent in contracts that have already been set but this figure is expected to increase over the life of the program.

“Luerssen will try and improve the sustainability of these vessels through the 12-ship build by seeking further Australian suppliers, looking at the assembly of components in Australia, and having local supportability of those systems,” Croser remarked. “They’re also very solid about wanting to deliver on schedule; that’s reputation for the business they’re building.”

This article first appeared in the April 2019 edition of ADM.

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