Currently, under construction at Castagnola Yacht in Lavagna, Italy, a 24m motor boat Zattera began with an idea from Renzo Piano and Olav Selvaag. Renzo Piano OMRI OMCA is an Italian architect whose notable buildings include the Centre Georges Pompidou in Paris, The Shard in London, the Whitney Museum of American Art in New York City and Stavros Niarchos Foundation Cultural Center in Athens, and Olav Selvaag is a Norwegian property developer. Nauta Design and Francesco Rogantin shaped to that idea and Siemens Energy created its propulsion system.
Zattera is inspired by the idea of being able to live life at sea in silence and in harmony with the natural environment. Made using sustainable yet durable wood, its design is characterized by modern, clean, and simple hull lines. The purity of its forms is achieved through a design that features a raft-like low freeboard and wide beam. The hull’s clean lines are emphasized by a glass superstructure that almost seems to float.
The motorboat is relatively lightweight with a displacement hull that can navigate at up to 12 knots with a 10,5 knot cruising speed. CFD testing allowed for an optimized bow shape with good sternwards flow and reduced resistance.
Siemens Energy’s hybrid propulsion system plays a key role in reducing emissions and careful attention was dedicated to eliminating vibration and sound pollution in the surrounding environment. The vessel has lithium-ion batteries and can navigate in the silent mode under electric power only. The propulsion system and the boat’s functions run on two180 kW variable RPM diesel generators and a 95 kWh battery pack connected to a 700 Volt continuous distribution system.
Zattera has a traditional shaft drive run via twin 135kw permanent magnet motors that are directly connected to the shafts without the use of inverters. The diesel generators were purpose-developed by Mase Generators for Siemens Energy with Volvo Penta D4-300 motors using speed technology with permanent magnet alternators in order to minimize consumption and emissions.
The generators are installed on a double anti-vibration pad and the underwater exhaust system is undergoing careful soundproofing testing. To create a zero impact and no-cost renewable energy source, the yacht will incorporate solar panels will.
The Castagnola shipyard has constructed the hull, the deck and the superstructure in solid wood that have been treated with silica-infused epoxy resin for optimal adherence, and marine grade plywood. All frames are made using solid ash while hull planks are in marine grade plywood. The deck is in lightweight marine grade okoune’, while the interior structural bulkheads are in wood lined with rubber and cork.