109 a number of software, sensors and electronics powering its marine autonomy. But it was the aluminium hull and structure that took most of Zero’s attention, particularly to solve the riddle of how an autonomous industrial vessel could be certified for maritime operations. Construction standards When Ratsey and his team began developing their first USV, there was no guidance on the right standard codes to adhere to, so advice was sought from the managing director of MECAL, a certifying body for the UK’s Maritime and Coastguard Agency (MCA) with responsibility for boats under 24 m. “From what he could see, in the MCA Workboat Code Edition 3, or other guidelines for ‘remotely operated, unmanned vessels’, there was no real way to code an autonomous vessel, but he confirmed that Oceanus12 could absolutely be certified to Hull Construction standards if we followed the related guidelines,” Ratsey recounts. The Oceanus12 has been designed and built to ISO12215, a standard recognised in the MCA Workboat Code. Its design – including scantlings (a naval term for the geometrical dimensions of the structural system) – has been witnessed by a third-party naval architect and its construction by a third-party surveyor, both appointed by MECAL. “We do a load of non-destructive testing, including dye penetrant testing and X-raying, and based on hull construction standards we’re allowed to do one shot of the latter per metre of boat length, meaning 12 X-rays per unit,” Ratsey says. “It’s quite an expensive thing to do, but it gives us full confidence to look customers in the eye and tell them our boat is tough, and built to a known industrial standard. That’s important because after that almost everything we put in the boat is bleeding-edge tech, vital to it being a high-end, autonomous USV. There’s no accommodation or seating onboard; it’s meant to be a completely uncrewed vessel. “We’ve aimed to meet the regulatory requirements by using established industry standards, and where possible using Typeapproved materials, exhausts, batteries, fuel lines and so on. It’s not easy; not everything being developed for use on USVs today is Type-approved – that’s just a fact.” Fibre glass to aluminium In its original drawings (made in early 2023), Oceanus12 was designed as a glass fibre-reinforced plastic (GRP) vessel. After obtaining quotes on raw materials and tooling for GRP-based production, and finding the tally was significantly more expensive than expected, Zero questioned whether they were using the right material. “Around August last year, we decided to switch to aluminium, which required quite a bit of re-engineering, but we found a partner [undisclosed] who could take the GRP design and remake it into an aluminium, kit-built vessel,” Ratsey recounts. “Getting that to production-level drawings was quite a bit of work, lasting until January, but it’s a truism that spending more time in the design phase – especially for these kinds of boats – saves you absolute tons of money and time in production down the line.” Doing so meant that the vessel kit assembled perfectly at Manor Marine, Zero’s chosen shipyard in Weymouth, UK. Notably, Ratsey adds that Manor Marine described Oceanus12’s components as “one of the best kits they’ve ever had”, including both the first version of the USV and the second, latest one (which incorporated 10 minimally-tuned parts – a low number in boatbuilding). “As well as having a competitive price, Manor are basically just up the road from our facility in Plymouth, which is vital for getting the initial build right, ensuring supply chains are working and getting the regulatory oversight in place as needed,” Ratsey says. Zero USV | Digest It’s quite expensive, but it gives us full confidence to look customers in the eye and tell them our boat is tough, and built to a known industrial standard Uncrewed Systems Technology | October/November 2024 In its original drawings (made in early 2023), Oceanus12 was designed as a glass fibre-reinforced plastic (GRP) vessel
RkJQdWJsaXNoZXIy MjI2Mzk4