Sanlorenzo developing 50Steel with fuel-cell system


The Italian luxury motor yacht builder is building a two-pool, 50m superyacht that houses a green methanol fuel system and ‘hidden engine room’ architecture.


Sanlorenzo, 50Steel, Siemens Energy, Zuccon International Project, Piero Lissoni


Sanlorenzo is developing the 50Steel, which it has described as the first yacht to house the green methanol fuel cell system, developed in collaboration with Siemens Energy. Zuccon International Project designed the exterior of the 499GT steel-and-aluminium yacht, while Piero Lissoni, Sanlorenzo’s Art Director, handled the interior of the first unit.


The 499GT yacht has an overall length of 49.99m (164ft) and a beam of 9.40m (30ft 10in), with accommodation for 10 guests and nine crew. Featuring twin MAN engines and a 55,000-litre fuel capacity, the yacht has a predicted top speed of 16 knots and a range of 4,000nm at an economical speed of 11 knots.


The 50Steel will be the world’s first superyacht project to accommodate the modular ‘Reformer – Fuel Cell’ system, capable of transforming green methanol into hydrogen and then into electricity to power all the yacht’s hotel systems, and eventually recharge the batteries, without storing the hydrogen on board.


The solution allows the vessel to generate electricity up to a maximum of 100kW, with no need for the propulsion engines and diesel generator. The carbon-neutral system significantly extends the time spent at anchor without consuming diesel fuel, covering around 90 per cent of the typical utilisation time of a superyacht in zero emissions.


Sanlorenzo, 50Steel, Siemens Energy, Zuccon International Project, Piero Lissoni


Sanlorenzo is also introducing the Hidden Engine Room (HER) system on the 50Steel, creating a horizontal layout for the propulsion equipment and a new distribution of the technical area on the lower deck. Instead of occupying two levels for the engine room, the new naval architecture creates additional space by modifying traditional layouts, yet keeps the yacht’s volume below 500GT.


The 50Steel features four ‘staggered’ levels, with considerable volumes and minimising partitions and barriers, although the new interior architecture is imperceptible from the clean external profile.


Bernardo Zuccon of Zuccon International Project said: “The real challenge was to be able to interpret a boat that was extremely complex in terms of design while maintaining balance and simplicity of lines, a study aimed at simplifying features which gives harmony and balance to the eye of the beholder.”


The new internal design has enabled the creation of a lower-deck saloon, the ocean lounge, which connects aft with the 120sqm beach club with swimming pool and forward with the guest area, where the cabins are joined by areas for a gym and spa.


Sanlorenzo, 50Steel, Siemens Energy, Zuccon International Project, Piero Lissoni


Five steps from the Ocean Lounge leads to the main deck and main saloon. The stairs, designed to let the light filter through, run through the interior of the yacht, connecting the different areas, from the gym and spa area on the lower deck to the second saloon on the upper deck. In the middle is the dining room, with ceiling heights ranging from 2.1m to 3.35m. The sun deck has a swimming pool, which complements the one in the beach club.


Lissoni’s interior elements include coffered ceilings and dark timber panelled walls, while for the first time he also benefited from 3D technology that allowed the technical model to be superimposed on the architectural model, ensuring a high degree of control over every detail.


“The 50Steel was entirely designed in 3D and this was really effective from a design point of view. It was as if we had used a super parametric. Everything that came out of the engineering and architectural side reverberated without any unwanted surprises in reality,” Lissoni said.

“In fact, we physically worked within a virtual model that radically changed the final effect of the project. We left tradition behind to build a real object using virtual technology.”