Events

Repair round-up: largest suction sail retrofit

Largest suction sail installation completed

Bound4blue has completed the installation of the world’s largest suction sails, with four 26m-high eSAILs being fitted to Atlantic Orchard. Chartered by Louis Dreyfus Company (LDC) and owned by Wisby Tankers of Sweden, the specialised juice carrier had the sails fitted in a single stop already scheduled for its 10-year special survey at Astander Shipyard in Spain.

The four eSAILs were installed in under a day per unit. This installation marks the third so far this year for bound4blue and is the latest in a series of installations that has seen the DNV type-approved suction sails fitted to vessels ranging from MR tankers to general cargo and RoRo vessels.

Drydocks World and Cochin Shipyard to explore ship repair opportunities

Dubai’s Drydocks World has entered into a memorandum of understanding (MoU) with Cochin Shipyard Limited, with the aim of developing ship repair clusters within India. The aim is to bring global best practices to the ship repair sector in the country and add significant new capacities for this type of work, to meet local demand.

Two locations, Kochi and Vaidinar, have been identified for special focus, as having the potential to become new ship repair centres to be developed under the terms of the new MOU.

Steelpaint secures multiple vessel contract

German coatings firm Steelpaint has secured an order to supply its Stelpant system to 20 dry bulk vessels operated by one of the world’s largest shipping companies. An additional 19 bulkers are scheduled for application next year.

The Singapore-based shipping group, which manages a fleet of large bulkers totalling 16 million dwt, has opted to apply the coating to 39 ships as part of a fleet maintenance initiative focused on steel preservation, reduced downtime and operational efficiency. Vessels ranging from 70,000-200,000dwt will undergo coatings work at Chinese shipyards Youlian (Zhoushan), Youlian (Shekou) and Qingdao Beihai. Application will focus primarily on tank tops and lower hopper regions, where frequent impact from grabs and bulldozers can cause wear and damage to conventional coatings. It is anticipated Stelpant will also be applied to hatch coamings and inner bottom plating.

High-tech AUVs to hit Madeira Island

Madeira Island’s Regional Agency for the Development of Research, Technology and Innovation (ARDITI) has ordered two Autosub Long Range-branded AUVs from the UK’s National Oceanography Centre (NOC) to aid its research and ocean scientific activities off the coast of Portugal, and further afield.

The AUVs are designed for multi-month endurance without the need for research vessel back-up, and both come equipped with scientific sensors. One of the vehicles, a 3.6m unit rated for depths of 1,500m, will undertake oceanographic and biogeochemistry-related surveys of the water column, using a turbulence probe. Equipped with rechargeable batteries, this AUV has range of up to 1,330km. 

The other AUV, measuring 4m in length and rated for depths of 6,000m, will focus on seabed mapping. Also powered by batteries, this vehicle has a range of up to 600km. 

Located in the middle of the Atlantic Ocean, Madeira Island’s waters deepen to approximately 1,000m within 10km of the shoreline, while water depth exceeds 3,000m beyond 15km. 

Rui Caldeira, principal scientist at ARDITI, comments: “The data [the AUVs] gather will support our and our partners’ research and help regional and national governments enforce EU Directives. Combined with USVs and traditional ships, they will also help to make Madeira Island an attractive ultra-deep-sea location for testing for international partners.”  

NOC says it is also building additional AUVs for its own fleet and expects to have eight Autosub Long Range vehicles at its disposal by the end of 2026.

'Iryna' leads the way for B.Now 67 yacht family

Benetti’s Livorno yacht factory has delivered the first model in the builder’s B.Now 67 series, christened Iryna, to her unspecified owner. Co-designed by RWD, the 66.2m x 11.2m, six-deck vessel has a steel hull, an aluminium superstructure and a maximum draught of 3.1m, and displaces 1,150tonnes at full load. 

The megayacht incorporates Benetti’s Oasis Deck concept, which spans 190m2 of surface area and features open-out wings to extend the deck’s width, while offering “an unobstructive 270° view towards the stern”, Benetti says. Overall, Iryna boasts 500m2 of useable outdoors space, while interior features include a 65m2 main salon and a full-beam owner’s suite on the upper deck. Two VIP cabins are arranged on the main deck, and four on the lower deck, enabling the vessel to accommodate up to 15 guests. 

The hull and superstructure colouring takes in three different shades of grey. “The boat is also characterised by extensive, mainly curved glazing that covers up to 70% of the overall vertical surface area,” Benetti adds. 

Powered by twin Caterpillar 3512E engines, Iryna has a range of 5,000nm at a cruise speed of 12knots. The vessel is also equipped with a Naiad 200kW bow thruster. Onboard capacities include 115,000litres of fuel oil and 33,000litres of fresh water. The project took around three years to complete, Benetti says, with classification having been handled by Lloyd’s Register. 

Turkish tugbuilding sector on a roll

Turkey’s tug output is showing no signs of a let-up, whether for domestic or overseas customers – and with Robert Allan Limited’s designs very much at the forefront for the steady stream of newbuilds.

A report published on Statista, titled Export value of tugs and pusher craft from Turkey between 2012 and 2023, claims that Turkey exorted new tugs and pushers to the value of just over US$416 million in 2023, representing an increase of nearly 36% on the previous year. The country has also been pioneered a number of eco-friendly tug firsts, designing vessels capable of running on alternative fuels. Examples include the 2014 launch of the twins Borgøy and Bokn, hailed as the first two pure-LNG-fuelled tugs in the world, and the 2020 delivery of the 18.7m ‘zero emissions electric tug’ (ZEETUG) by Navtek: a vessel powered by lithium-ion batteries.

One major Turkish player is Uzmar, originally founded in 1972 as a pilotage and towage services firm, before coming to build tugboats for its own requirements from 1993. In February this year, the builder delivered the 32m x 13.2m tug TIGER to Italy-headquartered tug and barge operator Ocean SRL. This vessel will be used for operations including towing, pushing, firefighting, vessel escort, ship rescue and stand-by duties. Uzmar says that it managed to complete TIGER just eight months after the contract with Ocean SRL was signed.

TIGER was built to the specs of the RAstar 3200 class, provided by Canadian naval architect Robert Allan Limited (RAL). RAL’s tug designs – including the RAstar, RAmparts and VectRA series (and their offshoots) – have proven popular with Turkish shipbuilders such as Uzmar, Sanmar and Med Marine, covering a range of applications, from harbour towing to offshore support.

TIGER features a depth of 5.5m and has a the capacity to store 199m3 of fuel and 40m3 of fresh water. The tug is powered by twin Caterpillar 3516E main engines, each rated 2,350bkW at 1,800rpm and featuring IMO Tier III-certified aftertreatment systems. Propulsion-wise, the vessel is fitted with two Kongsberg US255 Z-drives with 2.8m fixed-pitch propellers, while deck equipment includes an Ibercisa split drum escort forward winch, an aft towing winch and a towing pin, supplied by Data Hidrolik, to support vessel escorting and towing operations. Uzmar reports that TIGER has a bollard pull capacity of 80tonnes and carries the class notations Escort Tug, Recovered Oil Second Line (FP>60°C) and Firefighting 1.

Uzmar is now working on a battery-methanol tug for port and terminal services supplier Svitzer, scheduled for handover in the second half of 2025. The tug will incorporate a 6MWh battery, manufactured by AYK Energy, to assist it in providing zero-emissions escort tug duties in the Port of Gothenburg. This vessel is based on Svitzer’s TRAnsverse design – which, as the name implies, features additional design input from RAL. AYK Energy explains: “The battery will be supported by dual-fuel methanol engines for back-up and range extension. The escort duty tug is expected to conduct more than 90% of its operations using its battery-electric powertrain.”

The 806gt vessel will feature an overall length of 34.9m, a bollard pull ahead of 85tonnes and the capability to reach speeds up to 14knots. It will also utilise escort steering and braking forces, rated 150tonnes and 200tonnes respectively, measured at 10knots.

Meanwhile, Turkish builder Sanmar Shipyards recently completed the sea trials for the third fully electric tugboat constructed for SAAM Towage. Sanmar has stated that the newbuild effectively constitutes “the first fully electric tugboat to operate in Latin America”, as well as marking the eighth all-electric newbuild produced by Sanmar,

The builder adds that it has another six fully electric tugboats under construction at its facility in Tuzla. The newcomer follows the ElectRA 2300-class tugs SAAM Volta and Chief Dan George, which Sanmar delivered to SAAM Canada in Q4 2023, for operations in the Port of Vancouver (see Significant Small Ships of 2023).

This latest launch is based on RAL’s ElectRA 2500SX design, provided to Sanmar on an exclusive basis. The boat features an overall length of 25.4m, a 12.86m beam and a draught of 5.6m, and has a maximum battery capacity of 3,616kWh. Rüçhan Çıvgın, commercial director of Sanmar Shipyards, says: “It was extremely important, when we were developing the ElectRA series with RAL and [battery manufacturer] Corvus Energy, that the move to electricity and other alternative fuels should not come with any loss of power or performance.” According to the partners, the ElectRA 2500SX exhibits a bollard pull of at least 70tonnes and a speed of 12.5knots – which certainly seems to have pleased the operator.

New IACS recommendation for 3D printing for maritime

The International Association of Classification Societies (IACS) has published a new recommendation, Rec. 186, which has been developed to help determine a standardised approach to integrating additive manufacturing (AM), AKA 3D printing, into marine and offshore applications.

IACS comments: “AM has emerged as an alternative to traditional manufacturing processes by fusing materials to produce objects from a digital 3D model into a series of 2D cross sections for layer-by-layer physical prints, ultimately producing a 3D object.” The association notes that AM’s benefits include “greater design freedom”, along with reduced material waste and a higher degree of flexibility when it comes to on-demand production and customisation.

In particular, IACS adds, ‘Rec. 186: Additively Manufactured Metallic Parts for Marine and Offshore Applications’ establishes a framework for “the qualification, approval and certification of additively manufactured metallic parts”, including guidance on part design, feedstock selection, AM processes, post-processing and inspections and testing. The association adds: “By incorporating recognised international standards such as ISO/ASTM 52900 and AWS D20.1, it aligns AM technology with existing Unified Requirements [UR], particularly UR W for materials and welding, ensuring equivalent reliability and safety.”

Rec. 186 outlines several “key areas” for the “safe and effective adoption of AM in the marine sector”. These include: AM processes such as powder bed fusion, directed energy deposition and binder jetting, as well as detailed parameters for each of these processes; the introduction of tiered testing levels – referred to here as ‘AM Levels 1-3 – for class and certified items; “rigorous qualification processes” and recycling protocols for AM feedstocks (such as powder, wire and binder feedstocks); maritime-specific qualifications for parts, which would also involve pre-build simulations; and non-destructive testing (NDT) methods, such as CT scans.

The recommendation is intended to assist not only shipyards and vessel operators but OEMs in using AM to develop safety-critical marine components. Alexandre Astruc, chair of IACS’ expert group on materials and welding, comments: “3D printing is increasingly becoming a valuable tool for the marine sector, offering a flexible, speedy and customisable solution for environments where the consequences for safety, sustainability or operational uptime can otherwise be significant.

“While [AM’s] potential for rapid production is notable, its true strength lies in its ability to provide innovative, on-demand solutions tailored to complex maritime challenges. In developing Rec. 186, IACS is seeking to safeguard the benefits offered by AM by ensuring it is underpinned by a standardised framework for verification and certification that gives confidence to all parties.”

Further details on Rec. 186 can be accessed at https://iacs.org.uk/resolutions/recommendations/181-200/rec-186

CII: Striking the right balance

The IMO Carbon Intensity Indicator (CII) gives ship operators wide freedoms on how to reduce their vessel and fleet carbon intensity. However, according to recent analysis carried out by Wärtsilä Marine, 47% of the global merchant fleet will need to upgrade its emissions performance to avoid slipping into the C to E CII bands across their expected lifetime.

Companies can choose to change the fuels they use, implement operational measures such as reducing speed, or install one or more of the 44 energy-saving measures listed in IMO’s fourth Greenhouse Gas Study. The key challenge for owners and operators, then, is not just to familiarise themselves with these measures – a daunting task given the number available – but also to decide when it makes sense to invest in them.

According to Peter Hanstén, director for business development at Wärtsilä Marine: “The question of timing is key because CII compliance requires only a few percentage points in improvement each year. That means, for many vessels, the targets could be met by installing new technologies or employing operational solutions every year or few years, to deliver incremental gains.

“Alternatively, several years’ worth of targets could be banked in a single jump – for example, by switching to clean fuels.”

Which options work best for a company will depend on many factors, says Hanstén, not least the vessel’s current carbon intensity, its remaining lifetime and the operator’s ability to invest. Considerations will also need to include fuel availability and market expectations. It is clear, for example, that reducing reliance on fossil fuels and substituting them with alternative fuels will be the big change needed for vessels to meet the long-term carbon intensity reductions required by CII. But that shift will be expensive and its timing uncertain, as the widespread availability of alternative fuels remains unsettled.

Similarly, reducing vessel speed may be an effective way of conserving energy for some vessels, but will be impractical for the many that rely on speed to fulfil contracts and remain competitive. Hanstén suggests: “On the other hand, stacking marginal energy gains from other measures can keep ships compliant with short- and medium-term targets. These can be planned in advance so that investments are made in line with the required stepped improvements.

“Beyond compliance, these measures cut current fuel costs and give operators an optimised baseline of vessel efficiency that will minimise future fuel costs once vessels do make the leap to cleaner power. This also needs to be factored into calculations of return on investment [ROI].”

The starting point for developing a longer-term CII investment plan needs to involve a rigorous analysis of the existing fleet. “This is the approach adopted by Wärtsilä Decarbonisation Services when supporting shipowners including Princess Cruises, Dubai-based Tristar Eships and Brazilian energy company Raizen,” says Hanstén. “Together, we build a complete picture of the current state of play by gathering data from a variety of sources, including vessel operational profiles, technical characteristics and fuel consumption reports, or from Wärtsilä data collection units installed onboard. Machine-learning techniques are then used to process this data and predict how vessels’ emission performance will degrade over time.” Once processed, the data can be used to build a digital model of each vessel, which is used to simulate the effects of different energy saving measures, or different combinations of technologies and how they interact with each other.

Big efficiency gains can come from some surprising areas, which are sometimes overlooked, Hanstén points out, one example being the propeller. He says: “Propellers are typically designed at newbuild stage to meet a single speed point that may not remain optimised to the vessel’s operating profile in later years. A new propeller design, along with reduced vessel speeds and engine power, can lead to combined propulsive efficiency improvements of up to 15%.” Another high-gain area that Wärtsilä believes is often overlooked is the harnessing of wind power to assist propulsion. Rotor sails, for example, can reduce a vessel’s fuel consumption and associated GHG emissions by up to 30%, based on Wärtsilä’s experience through its license and cooperation agreement with Anemoi Marine Technologies for the latter’s Rotor Sail system.

Repair round-up: LNG retrofits on the up

EGCS retrofit combines carbon capture technology

Value Maritime (VM) has installed its combined exhaust gas cleaning system (EGCS) and carbon capture unit aboard the 75,000dwt Nexus Victoria, an LR1-type product tanker owned by Mitsui O.S.K. Lines (MOL).

VM’s 15MW next-generation EGCS Filtree system can filter sulphur and ultra-fine particulate matter, and can capture 10% of the vessel’s CO2 emissions, with the potential to further increase this to 30% if needed. The retrofit installation of the technology was completed in Singapore under the supervision of VM’s technical team.

LNG retrofits surge 

Lloyd’s Register’s (LR’s) Engine Retrofit Report 2025 highlights a resurgence of LNG retrofits in 2024, as shipowners sought immediate carbon reductions to navigate regulatory requirements. However, while LNG offers a near-term compliance solution, the report warns that deeper emissions reductions will be necessary beyond the next decade.

Supply chain readiness is another important factor highlighted in the report. It warns that, without improved coordination between engine manufacturers, fuel system suppliers and shipyards, lead times for conversion projects could stretch beyond 18 months.

Another significant issue identified in LR’s initial report, published in 2024, was the limited capacity of shipyards capable of undertaking alternative fuel conversions. While the number of capable yards has increased, the latest report identifies that current retrofit capacity is still only approximately 465 vessel conversions annually, well below the projected peak requirement of more than 1,000 conversions a year.

The LR Engine Retrofit Report 2025 can be downloaded from www.lr.org

FPSO refurb contract secured by Drydocks World

Drydocks World Dubai has been awarded a contract for the refurbishment and life extension of the FPSO Baobab Ivorien by Modec Management Services. Scheduled to commence in May, the eight-month project will involve 1,000tonnes of steel renewal, 250,000m² of tank coating, and 11,500m of new piping.

The work scope also covers enhancements to crew living quarters and the integration of technologies to enhance its operational efficiency and reliability. Upon completion, the vessel’s lifespan will be extended by 15 years on its return to deployment offshore West Africa.

REACH for a remote-controlled future

Demand for dependable research, survey and intervention vessels is booming, positioning this sector as one of the fastest-growing in the maritime industry. This demand is being driven by numerous factors, including: a surge in offshore wind farm projects, necessitating detailed seabed mapping and environmental impact assessments prior to turbine installations; ongoing exploration needs within the oil and gas sector; and the growing requirement for vessels capable of supporting research projects focused on ocean health, climate change and biodiversity.

Formed in 2008, Norwegian operator Reach Subsea specialises in deploying work-class ROVs to gather ocean data for clients. “We were looking for something that could make us a bit more competitive in this market,” Bjørg Mathisen Døving, VP for the REACH REMOTE fleet at Reach Subsea, tells The Naval Architect, “and we also wondered why we were utilising a big vessel for what were quite easy ROV deployment tasks.” An encounter with Kongsberg Maritime in 2015 led Research Subsea to consider the use of a remote-controlled USV.

This uncrewed craft would not only taxi a work-class ROV from site to site, but also act as an ‘energy carrier’, providing the power required by the ROV for its offshore tasks. The USV and ROV would be operated from remote operations centres (ROCs), on land or on another ship. This concept would evolve into Reach Subsea’s REACH REMOTE 1 USV, which was launched in January 2025.

“We started off with a pilot programme, using a pool at the Norwegian University of Science and Technology in Trondheim, where we tested the vessel’s hull and the ROV, and their movements,” says Døving. “From there, we worked with Kongsberg on a field study. At Reach Subsea, we have years of experience and knowledge of ROV operations, so we were able to add a lot of details for the final concept, especially regarding the onboard ROV launch and recovery system [LARS].”

For Døving, the vessel offers numerous benefits compared to traditional crewed vessels. For instance, the smaller overall vessel size (think no need for heads, crew berths, fresh-water tanks or a galley), combined with the use of hybrid electric propulsion, spells lower rates of fuel consumption per operation, minimising the boat’s environmental impact. Reach Subsea and Kongsberg restricted the USV’s length to just under 24m, to meet the UK Maritime & Coastguard Agency’s (MCA’s) Workboat Code 3 requirements.

From a safety perspective, moving operations to onshore ROCs also removes the dangers faced by human crews in rough offshore environments. Additionally, as smaller, quieter vessels, USVs significantly reduce underwater noise, minimising disturbance to sea life.

There is also the benefit of reducing unplanned downtime by using shipboard predictive maintenance technologies to keep tabs on the performance of vital equipment and systems. Moreover, remote-controlled operations open up new job opportunities for a more diverse workforce, including people who may be restricted from travelling offshore, due to disabilities or family commitments, for example.

Kongsberg then contracted shipbuilder Trosvik Maritime to fabricate the USV. This was an unusual arrangement for Kongsberg. As Marthe Kristine Sand, Kongsberg senior project manager, explains: “Normally, Kongsberg would supply the systems directly to the yard for outfitting – but this time, the yard acted as our subcontractor. This meant we were able to offer REACH REMOTE 1 as a complete package, including the vessel, its systems and navcom package.” Sand, Døving and Kongsberg senior ship designer Erik Leenders (who headed up the USV’s design) oversaw the development of the newbuild from the earliest design phase to the fabrication stage.

REACH REMOTE 1 isn’t just dependent on its ROV for underwater tasks; the USV can also perform its own surveys, using two Kongsberg EM2040 multibeam echosounders and a Topas PS120 sub-bottom profiler, which can gather data up to 500m-deep. The ROV is an electric work-class ZEEROV model, produced by Norwegian tech specialist Kystdesign. Rated 150hp (112kW), the vehicle measures 2.75m x 1.7m x 1.69m, weighs 3,800kg and can carry up to 600kg of sensors and scientific equipment. The ZEEROV can descend to depths of 2,000m, and has been specially developed for 30 days’ worth of prolonged immersion, matching the USV’s range.

Described by Leenders as “the heart of the vessel”, the ROV LARS has been customised for crew-free operations, deploying the ROV beneath the surface through a 5m x 3m moonpool. Døving adds: “The umbilical that runs with the ROV is also a lifting umbilical with a SWL of 8.6tonnes. So, in principle, it acts like a winch. We could use the LARS with any drone or underwater vehicle that fits.”

The engine room houses two Volvo Penta diesel engines with permanent magnet motors, which provide power for both the vessel and the ROV. Kongsberg supplied the USV’s two lithium-ion battery banks, which can be used for peak shaving and added redundancy in the event of engine failure, or to power the vessel in pure-electric mode. Running solely on batteries would limit the vessel’s endurance somewhat – perhaps to between half a day and a day, Leenders estimates – but this is an important feature should the boat have to enter eco-sensitive areas. The USV uses two ZF azimuthing thrusters, one fore and one aft, to maintain its DP2 dynamic positioning capability.

Rise of the reactors: could commercial ships benefit from nuclear power?

One of the most significant shifts in the maritime sector has been the consideration of nuclear energy as a potential fuel for commercial vessels. In just six to seven years, this idea has transformed from an unlikely prospect to one gaining considerable support in various circles.

A fuel energy comparison produced by class society Lloyd’s Register has concluded that uranium and thorium, both potent nuclear fuels, can generate over 80.6 million MJ and 79.4 million kilojoules (KJ)/kg respectively, compared to 142KJ/kg for hydrogen, 46KJ/kg for diesel fuel and 19KJ/kg for liquid ammonia. In the energy stakes, nuclear power clearly has a lot to deliver to an industry that’s up against fast-approaching emissions deadlines and, in many cases, tight budgets.

One expert watching these developments closely is Jonathan E. Stephens, professional nuclear engineer and manager at BWX Technologies (BWXT), who delivered a presentation, Nuclear Technology for Commercial Maritime Propulsion, at the RINA President’s Invitation Lecture in London in November 2024. For Stephens, it’s not a case of whether the wider maritime sector embraces nuclear power, but when.

“We’ve seen a definite shift in civil maritime, driven by the IMO decarbonisation mandates,” Stephens tells The Naval Architect. “A lot of shipping companies are looking at ways they can meet the 100% decarbonisation target and concluding that there are no other viable options.

“The only ways operators can meet that target is either with e-fuels, such as hydrogen and ammonia, or an onboard nuclear plant. With the former, you need to show that you’re generating those fuels with emissions-free sources of energy – and that’s an entire other challenge. So, many ship operators are concluding that it’s at least worth looking at onboard nuclear plants, especially as this technology has been installed on vessels before.”

Nuclear power at sea is nothing new, of course. Navies have been tapping this energy source to fuel submarine and aircraft carrier operations since the 1950s. It’s not as simple as transferring submarine reactor tech to the ferry, cruise ship, yacht and container ship sectors, though. Stephens explains: “Naval vessels can run on nuclear plants for a very long time without refuelling – up to 20 years, typically – but that’s because they are using highly-enriched uranium [HEU].” In fact, he adds, most of these military ships use what we might call ‘weapon-grade’ uranium, having been enriched to contain more than 90% of the uranium-235 (U-235) isotope. “That’s the type of stuff that, if you have the wherewithal to do so, you can use to build a bomb,” Stephens says, “so, for proliferation reasons, it’s not really on the table for commercial use.”

In contrast, most commercial powerplants on land use low-enriched uranium (LEU), which usually features U-235 isotope content as low as 5%. For commercial vessels, though, Stephens sees highassay low-enriched uranium (HALEU) as the most viable option. This is uranium that has a U-235 content higher than 5% but lower than 20%, which can be added to the ‘Gen-IV’ range of advanced reactors and small modular reactors (SMRs).

“HALEU is enriched to just under 20% because that’s the threshold at which it’s considered a proliferation issue,” says Stephens. “So, most of the advanced reactor concepts out rely on the use of HALEU. The downside is that HALEU features one-fifth of the enrichment of HEU, so you’re also going to get shorter cycle lengths out of it.” While not widely used commercially yet, HALEU is steadily being adopted by various industries; to produce medical isotopes, for example.

A major advantage of nuclear power for ships is that once a nuclear reactor has been installed on board, the ship has enough fuel to last for the entire operational lifespan of the reactor’s design cycle, Stephens says. This contrasts with sourcing e-fuels such as ammonia and hydrogen at regular intervals, as the supply chains for these alternative fuels are still underdeveloped in places. “For the earlier reactors that are out there, I would guess we’re talking five-year cycles,” he adds. “Ideally, you would line that up with the vessel’s overhaul schedule anyway, and either replace the reactor’s entire core or refuel the core – but you wouldn’t need to do anything fuel-wise in the interim.”

Stephens is especially excited about some of the opportunities that the emergent Gen-IV reactors may offer. “Some of the advanced reactor concepts out there aren’t quite ready for prime time yet,” he says, “but we envision that one day we’ll have reactors capable of continuous online refuelling.” This is a design feature where the operator can keep the reactor running at full power while adding new fuel and removing spent fuel, thereby avoiding downtime. It would also enable users to extend the reactor’s operational cycle – just as one tops up a car with diesel as required, without first draining the whole tank.

“These reactors would either take fuel in the form of billiard-ball-sized pieces, or in a liquid form,” Stephens predicts. However, he concedes, continuous online refuelling at sea would be a technically challenging process, and comes with safety and training issues. “I think we’re years away from that at the moment,” he says.

Another key issue for shipowners considering nuclear power is deciding from where they would obtain the nuclear reactors or fuel. As Stephens points out, this would largely depend on each shipowner’s location and their country’s government policy, in the absence of an international regulatory framework. “There are still a lot of unanswered questions,” says Stephens. “This is why we’re trying to push this first inside the US or UK; it’ll be easier than trying to figure out how this will work internationally, especially when you start talking about countries that don’t even have a nuclear regulator.”

Additionally, he sees the reactor installation process as being hassle-free. “The thinking is, you would build the vessel without the nuclear reactor in it, then bring the vessel to either an existing port in the US or UK that has been outfitted to support it – or maybe to a special port built specifically for the purpose of installing nuclear reactors,” he says. “These advanced reactors are largely factory-manufactured, so it wouldn’t take a big construction effort on site.

“The manufacturer would make the package and then you would ‘drop it in’ to where it’s going to go aboard the vessel. So, it’s a relatively straightforward operation, especially given what these vessels and shipyards are used to doing in terms of handling installations. There’s no radioactivity in a fresh reactor core, so there would be no real problem regarding exposure to radiation.”

Performance is key for new 70 knot hotshot

With more than 1,000 newbuilds and decades of high-speed action under its belt, sports boat brand Performance Marine is celebrating its 40th anniversary this year with the launch of the Performance 90X: a design intended to comprise a “perfect fusion of brute force and absolute control”, the company says.

Getting to this stage has been quite the ride; the company and its various designs passed through several hands over the years before reaching its current German owners, Frauke and Stefan von Klebelsberg, who are now restructuring operations to future-proof Performance Marine’s output.

The 90X is heavily influenced by the hull of the group’s previous, 9m-long Performance 907 sports cruiser: a planing design, built in PVC. The revamped 90X was handled by German yacht design and engineering studio iYacht, which was responsible for both the design and the engineering of the new boat. iYacht encountered a few challenges – not least being the deck, an intricate structure comprising nearly 20 moulded parts.

Udo Hafner, iYacht CEO, tells The Naval Architect: “The deck itself is highly sophisticated, incorporating a wide range of functional and comfort elements. To ensure both safety and stability, our team of designers and engineers worked in close collaboration throughout the entire process, synchronising all aspects of the design.

“We were directly involved with the tooling company, ensuring that every detail was meticulously refined to meet the highest standards. This hands-on approach allowed us to optimise the modular construction, guaranteeing precision and structural integrity while maintaining the performance and aesthetic that define the 90X.”

The 90X boat’s propulsion system offers several options, including inboard Mercury MerCruiser engines with power outputs ranging from 430-1,130hp (approximately 320-843kW), coupled with a Bravo One XR drive. The variations include: two MerCruiser V6, 4.5litre-displacement models, with a total output of 500hp; two V8, 6.2litre-displacement models with a total output of 700hp; two V8, 8.2litre-displacement models with a total output of 860hp; or two V8, 8.7litre-displacement units with a total outputof 1,130hp.

The boat’s top speed comes to an eye-watering 70knots. “The Mercury Zero Effort DTS system replaces traditional throttle and shift cables with cutting-edge digital precision, delivering instantaneous throttle response,” iYacht adds. “This advanced technology ensures an unmatched driving experience with ultra-fast performance.” Future customers can opt for a joystick piloting system, integrating engines, gearboxes, steering and thrusters into a single unit,  for greater ease of handling and, especially, docking.

The 90X cockpit was designed with a keyless ignition system that doubles as a wireless engine cut-off switch in an emergency. The onboard infotainment system includes multiple screens across the boat, enabling passengers, the driver and co-pilot to check the vessel’s speed, while a dedicated boat app enables users to remotely monitor battery and fuel levels, or to even change the lighting and start cooling onboard drinks, using smart devices on shore.

As part of its design remit, iYacht also optimised the available onboard space, allowing the designer to  produce a cabin with a net headroom of 1.75m and a king-sized bed. iYacht designer Joachim Benders comments: “I spent a great deal of time focusing on ergonomics—exploring the relationship between function, space, and people. I carefully analyse how guests move onboard, and assess how the design translates into real-world experiences for users.”

TECHNICAL PARTICULARS: Performance 90X

Length, oa: 9.15m / Breadth: 2.6m / Draught: 0.43m / Max power: 832kW / Max speed: 70knots / Fuel capacity: 600litres / Water capacity: 117litres / Passengers: 8 / Design category: B