ROV Support Vessel Designed for the Brazilian Offshore
By Andrew Safer: Because it’s too deep for divers, the 2,000- to 3,000-metre depths in the pre-salt Brazilian offshore require that ROVs perform inspections, maintenance and light construction, says Robert Moulton, a 23-year-old Ocean and Naval Architectural Engineering undergraduate at Memorial University. This is what inspired him and three team members to develop a design for an ROV Support Vessel (ROVSV) for their final project before they graduate.
“We did an economic analysis,” he says, “and over the next 10 years, they will need 10 new ROV support vessels. That’s their prediction.”
Mike Manuel, Nathan Smith, and Ryan Sampson rounded out the team that worked on the ROVSV design for 16 weeks between January and March—each bringing expertise to the project that they developed during their work terms over the past six years of their degree program. Manuel, the project manager, arranged the machinery for the propulsion system, Smith created the specifications for the ROVs and determined what support would be required, Sampson did the weight estimate and structural calculations, and Moulton did the hull form development and the stability and resistance analysis.
The ROVSV is a mothership for four work-class ROVs and two smaller inspection-class cameras. It is 96.5 metres long, has a beam of 21 metres and a draft of 6 metres, displaces 6900 tons, and has a diesel electric and propulsion system with two Azipod thrusters. The team’s research indicated that ROV operators work much more efficiently when they are comfortable which translates to increased profitability for the owner, so comfort became a key focus. To ensure privacy, there are solo 12-square-metre cabins for up to 65 people. Moulton is quick to point out that their design exceeds ABS’s most exacting Habitability Standard (HAB++), which indicates that the operator is providing enhanced living and working conditions. There are rec rooms, Internet rooms, and a large kitchen and galley. Assisted by Dr. Scott MacKinnon, a professor of Human Factors in the School of Human Kinetics and Recreation at Memorial, they learned about what contributes to motion-induced sickness on deck. “We took into account where workers would be standing when operating equipment,” explains Moulton, and they optimized the orientation of the workstations so that workers would be standing in positions of maximum stability. “The way people are oriented makes a difference,” he says. “Hull features of the ROVSV, such as bilge keels and anti-roll tanks, also help reduce ship motions.”
Comparing this ship to the half-dozen that were used to deploy ROVs for the Deepwater Horizon oil spill cleanup, Moulton says the ROVSV would be much more efficient because it can launch four ROVs in rapid succession.
If the ship were built today, it would cost approximately $150 million. Efficiency of operations would make up for the significant capital cost, Moulton says. The ship’s service speed is 15 knots (maximum is 18), compared to its competitors’ at 10 to 12 knots. “If something goes wrong with a pipe riser,” he says, “that’s money the operator isn’t making, so if you can go out there and fix it faster and spend less time at the job site, or if you’re doing maintenance and you don’t have to take equipment offline, that’s a lot of money for them (the operator). If you spend $20 million more for the boat, the cost can come back.”
Reflecting on the ONAE course, Moulton says, “It’s not easy, but it’s rewarding. It’s a lot of work. It’s a small program, but it’s top quality compared to others around the world.” He talks about the ocean technology cluster in St. John’s with great appreciation. “Across the street you have a $100 million facility that’s top flight in the world. There are not many programs where you can literally walk next door and have access to that,“ adding the 56-metre tow tank in the Faculty of Engineering and Applied Science building is another rarity.
Armed with his degree, he figures he’ll land a job with a design firm in Canada—possibly at the Irving Shipyard in Halifax. “They’re hiring thousands of people in the next several years,” he says. “Maybe one of those will be me.”