While she is Feadship’s first biofuel cruiser, she likely won’t be the last. The sea trial results for the Feadship yacht Obsidian have, according to the shipyard, bested the already-stringent carbon-emission-reducing requirements from the owner. She’s also the first of more contracts to come where advanced electric propulsion, biofuels, and better hull designs combine to make a difference.
The owner’s brief specified a superyacht with a higher level of energy efficiency and carbon reduction than Feadship’s first hybrid yacht, Savannah. That 2015 delivery relies upon hybrid propulsion to burn 30 percent less fuel than traditionally powered projects. Technological advances since then were important both to the owner of the 276-foot (84-meter) Obsidian and Feadship.
Firstly, Feadship’s De Voogt Naval Architects analyzed not only potential carbon-dioxide emissions, but also the overall impact of Obsidian’s materials, including interior finishings. The work, organized by the studio’s senior designer, Bram Jongepier, set the groundwork for what’s now the Yacht Environmental Transparency Index (YETI) of the sustainability non-profit Water Revolution Foundation. Through YETI, the Foundation, of which Feadship is a member, gathers data on shore power, fuel, and more from shipyards, engine manufacturers, and other stakeholders. The tool predicts a yacht’s environmental impact during a typical operational year. Jongepier says that YETI currently captures 90 percent of a yacht’s lifecycle. As for the operational profile of the Feadship yacht Obsidian, she’ll have a 27-percent lower impact than a same-size superyacht from within the past five years. Furthermore, her impact with be even more noteworthy, around 60 percent lower, when she runs on HVO.
HVO is a biofuel, which the superyacht substitutes for diesel fuel. She further eschews traditional main engines, rudders, and shafts. Instead, her propulsion system uses four tailored Caterpillar C32s with permanent magnets, operating as gensets. They work in conjunction with two Veth contra-rotating thrusters for propulsion and steering. The lack of appendages and the Veth units’ efficiency lessen vibration, yet another owner directive. Additionally, a massive battery bank with four and a half times the electrical-storage capacity of Savannah’s is aboard. Specifically, it’s a 4.5-MWh battery bank, with charging handled by the Caterpillars when needed. The batteries take on the hotel load (air conditioning, lighting, hot water, and more), with YETI helping determine the best peak shaving.
Significantly, YETI determined that 60 percent of an average superyacht’s energy consumption directly relates to hotel load. With that as a target to reduce, waste-heat recovery became a solution, from not only the gensets but also the A.C. chillers and further systems. Ultimately, more heat recovery comes from more systems, plus sea water, too, than any previous Feadship. A computer system selects the most efficient combination depending on whether the yacht is at anchor, on shore power, or underway.
Additional details about the propulsion and operational system are worth noting. For instance, a dedicated cool room on the tank deck houses the 560 battery modules. Therein lies yet another advantage of the Feadship yacht Obsidian. Propulsion-related equipment need not be in one central area. Therefore, the thrusters, gensets, and batteries are each where weight distribution and access for the 27-person crew are optimal. Related to this, the engine room itself is just one level, something Feadship hasn’t done on a large project in several years. Finally, while long-range cruising taps the Caterpillars, the batteries alone should allow 35 nautical miles at 10 knots. Anchored, meanwhile, they’ll provide silent power for 10 to 15 hours.
Of course, the De Voogt studio had to design Obsidian’s hull for more efficiency, too In fact, it designed the hull for cruising-speed efficiency (12 knots), rather than top-speed efficiency (17 knots), the latter the customary practice. Tank tests confirmed a low, slim hull worked best, as did carbon fiber to reduce weight for louvered aft-deck overhangs. As the image above reveals, that in turn allowed for more creative design solutions.
Speaking of creative design, the Feadship yacht Obsidian gained more space for guest accommodations due to the one-level engine room. Two design studios, RWD and Monk Design, collaborated on creating seven guest staterooms and several unexpected areas to delight them. For example, an asymmetrical atrium stairway connects to a lower-deck dining room. A wall in that dining room opens to reveal views less than one inch (75 centimeters) above the water. Another hidden staircase takes guests to a study and a sunken lounge on the main deck. Yet another sunken lounge aft, a.k.a. an Aqua Lounge, has windows beneath the water’s surface. The lounge can be a cinema or classroom, too. Further rooms and foyers situate off, not on, fore-to-aft and side-to-side arrangements, again contrary to tradition. And, other than the staterooms, no guest area has 90-degree angles, either. Lots of asymmetry characterizes alfresco areas as well.
Of all the areas sure to elicit smiles, the Feadship yacht Obsidian saves one of the best for the bow. Tucked inside it is an observation lounge, with double-curved, full-height glass. Guests access it from their stateroom foyer, through the tender garage—where fast-charging stations power up the custom Tenderworks boats.
Monk Design monk-design.com
More About the Yacht Obsidian
LOA: 276’3” (84.2 meters)
Beam: 44’9” (13.65 meters)
Draft: 12’4” (3.75 meters)
Guests: 14 in 7 staterooms
Engines: diesel-electric system with 4/Caterpillar C32 gensets and permanent magnets
Range: 8,000+ nautical miles at 12 knots
Stylist: RWD, Monk Design
Naval Architect: De Voogt Naval Architects
Interior Designer: RWD, Monk Design