Shipyard report: Vitters wants to go from zero to emission-free with 69-metre ketch
Sören Gehlhaus
· 22.03.2025
Cable harnesses here, cordoned-off cabins there and the occasional flash of finished veneer. Apart from tripping hazards and bumping heads, there is a marvellous hustle and bustle of trades on large floating projects during the outfitting and construction phase. Vitters' 69-metre aluminium construction "Project Zero" feels like yacht building with an open heart.
In Zwartsluis, not far from the IJsselmeer, the shipyard employs 85 people and welds hulls in its own halls if capacity permits. The one for "Project Zero" was subcontracted due to the full order books and has been in its own hall since August 2023. The goal should now be within sight in winter 2024, but there is not even a deadline for the launch of this project. It is complicated - and not in the usual sense for one-offs. The degree of difficulty is increased by the owners' desire for sleek, more classic lines that do not show the wealth of innovation above the waterline.
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Below deck, yes. "This is the system room," says sales and marketing man Bas Peute, taking a rhetorical pause. "No combustion engine comes in here, hence the name." Shaking his head in disbelief. Really not? No emergency generator or range extender either? "No, no, no, there's no generator and no fuel on board." Peute smiles contentedly. Instead of diesel bunkers, there will be four enclosed rooms full of batteries in the underwater hull, which will provide a total of almost five megawatt hours of electricity. The equivalent on the road would be 77 Tesla cars (with an average of 65 kWh).
On the water, it's all about buoyancy. And the aim was to keep "Zero's" hull narrow so that there is room below for the ballast of 35 tonnes of batteries, which contribute to the righting moment alongside the lifting keel. This is the undisputed battery record in superyachting. By way of comparison, the largest batteries on board a motor yacht, at 4.5 megawatt hours, are on board the 84-metre "Obsidian"; 150-metre-long ferries have a capacity of ten megawatt hours.
Two pods for drive and hydrogeneration
What happens if at some point the batteries run out on the high seas? The entire sailing plan has been optimised so that the mega ketch starts to move even in light winds - and then energy is to be generated by turning the front propeller from a speed of eight knots. This would cover the targeted minimum energy requirement of just under 30 kilowatts, which the team determined from consumption studies with values from other yachts. The aim is to make rapid progress under sail. "The Dykstra team analysed 30 years of wind data for the usual routes and developed the sailing plan based on this," says Peute. However, there is also an upper limit for regeneration. The 69-metre ketch can sail at up to 16.5 knots in hydrogenerator mode due to the speed limit of the gearbox. Up to 250 kilowatts can then be generated. "That's 50 times as much as with solar cells," says Mark
Leslie-Miller from Dykstra Naval Architects.
Leslie-Miller consulted the Dutch research institute Marin for the hydrodynamic optimisation of the propulsion and regeneration system. "Zero" relies on two pod drives: a smaller forward-facing unit in front of the keel, which is optimised for energy recovery and provides support during harbour manoeuvres. The larger propeller pod - diameter: 1.50 metres - behind the lift keel primarily generates propulsion and is rotated 180 degrees to generate additional power. CFD simulations have shown that a propeller that is primarily used for power generation works more efficiently and cavitates less. The result for the front folding propeller is three narrow blades reminiscent of turbine blades. During hydrogeneration, low drag was prioritised over increased yield. As a result, "Zero" should only lose around one knot of speed when sailing at high speed and with the front propeller turning.
Strict energy savings at all levels
Inevitably and true to the motto "It makes no sense to produce something you don't need", the team concentrated on making savings and focused on the largest energy consumers, which account for almost 50 per cent of energy consumption: Air conditioning and heating. Peute draws attention to the hull, which is covered in melamine foam, originally developed for sound insulation and with excellent insulating properties at low and high temperatures. The absence of rock wool insulation also means that there are no hull connectors and therefore no thermal bridges. In addition, thick Tufnol discs separate all interior panels from the raw exterior material to prevent heat from penetrating into the guest areas. The resin-impregnated hard fabric also hangs between the stainless steel supports to the floor of the deckhouse of the aft owner's cabin.
The superstructures are not made of carbon for weight reasons, but have better insulation values than aluminium. Despite the powerful propeller turbine, 100 square metres of solar panels will shine on the roofs. The reason for this is that they also serve to heat the solar fluid. This is because the interior is heated or cooled via wall panels through which hot or cold fluid flows. The deck is also about low heat transfer coefficients: Here, a three-centimetre-thick layer of cork milled onto the metal substrate lies beneath the bars, which also saves on filler. Tesumo is laid - the alternative to teak made from natural, fast-growing wood.
Vitters shares results on innovations with interested parties
"Project Zero" is scheduled to come out of the hall at the end of the year, with Vitters aiming for delivery sometime in 2026. Bas Peute: "Normally, we start with finalised specifications. We still don't have that here. That's the biggest difference compared to conventional projects, which require us to plan for 70 weeks." It has not yet been decided what type of batteries will be on board. During construction, the innovations lead to delays, but will certainly lead to imitators in the future: The "Zero" project team is committed to the open source concept and shares all its findings with interested parties on the website foundationzero.org. The front pod propeller used specifically for power generation has already attracted attention. It is offered for supersailors as a supplement to existing drives.
A few weeks before the - meticulously planned - day of the first launch, "Magic" appeared. The 44-metre-long aluminium slipway relies on a conventional shaft drive and 435 kilowatts of diesel as its power source. A battery bank caps load peaks and keeps all on-board systems running for up to eight hours when the boat is stationary. All deck winches, furling systems, tensioning devices and capstan winches for the genoa, staysail, main halyard and mainsheet are operated by hydraulic units that Vitters developed and built himself. Two anchors drop from flaps in the forward underwater hull.
Thick deck for long-lasting enjoyment of Burma teak
Characteristic features of the Reichel/Pugh crack are the deckhouse with large glass surfaces, a very high bulwark and a fixed keel that reaches 4.50 metres deep. On deck, Bas Peute points out the staves, some of the last from Burma. They are 19 millimetres thick and not the usual 14 millimetres. The advantage: the deck lasts longer, as it can be sanded down more frequently during refits. "Magic" has an interior volume of 304 gross tonnes and is therefore not much inferior to motor yachts of a similar length. Below deck, Design Unlimited was responsible for the design together with Pieter Laureys, while the interior was fitted out by the Austrians from List GC. The client wanted the largest guest cabin aft, where it extends over almost the entire width of 9.66 metres.
After 30 months of construction, Vitters pulled the 43-metre-long aluminium slipway out of the hall on 3 January. "Magic" then travelled by self-propelled heavy-duty module onto a pontoon and was towed to Amsterdam. There, the 250-tonne vessel was finally lowered into the water by floating crane and received its 62-metre-long carbon mast from Southern Spars. After the handover in February 2025, "Magic" will set course for the Mediterranean, perhaps with a second owner by then: the client is offering the brand-new 44 metres for sale via Burgess Yachts; price on request.
Vitters expansion as a result of full order books
Founded in 1990, the shipyard celebrated the ground-breaking ceremony for the construction of a new hall in Zwartsluis in the old year. The extension will be 80 metres long, 30 metres wide and 16 metres high and will house a 68-metre ketch with classic lines by Andre Hoek for outfitting as early as this April. Vitters salesman Bas Peute also spoke of another order that is in the process of being landed. The supersailor segment is clearly doing well.
