DOMUS: Redefining Multihull Sailing

The first Zero Emission Yacht
DOMUS: Redefining Multihull Sailing


DOMUS: the single-storey house built around a courtyard known as an atrium. Atriums had rooms opening up off them, and they had no roofs. A DOMUS had many rooms including kitchen, bath, dining, and bedrooms.” 

DOMUS: Redefining Multihull Sailing


Faster – Large Trimarans have proven to be faster than equivalent-sized catamarans. This is well demonstrated in the offshore/inshore racing world and the 2010 Americas Cup, where BMW Oracle (27m Trimaran) beat Alinghi (27m Catamaran). 

DOMUS is designed to heel 2 degrees to allow the weather hull to come out of the water, thus reducing drag and increasing performance. This is impossible to achieve in a Superyacht Catamaran. 

Easier to build – Catamaran systems must be doubled for the two hulls. This significantly increases the cost of the vessel. Going the trimaran route, the yacht has all the systems and engineering in the centre hull just like a standard construction method and the Armas are kept simple. 

The main hull takes all the rigging forces, thus keeping crossbeam structures simpler and the overall structure being more straightforward. 

More Space – Since a hull can be raised out of the water, Trimarans generally have much more beam. This directly equates to more interior volume and deck space. More Comfort – With three hulls in the water at anchor, there is a better damping effect on the Trimaran than on a catamaran. Thus, a more solid feeling platform and vastly reduced motions than experienced on monohulls. As highlighted above, DOMUS is designed to a heel angle of 2 degrees. Therefore, a guest on board will experience a level of comfort far superior to any Sailing or Motor Monohull, which can experience high angles roll, leading to motion sickness. 

DOMUS: Redefining Multihull Sailing

The First Truly Zero Emission Yacht over 750 Gross Tonnage 

The uniquely designed combination of Solar power, Hydro Regeneration & Hydrogen Fuel cells gives DOMUS an unlimited range with Zero Emissions. An optimized system of Solar Power and Battery Storage allows the yacht to the motor during daylight hours and then transfer over to the Battery system at night. This also means that DOMUS is entirely silent with Zero Emissions while at anchor. Gone are the days of Generator Noise and Exhaust Smells while sitting in your Idyllic Anchorage. 

DOMUS: Redefining Multihull Sailing


Lately, the collaboration has been looking at yachts differently. VGD and RDD have been after the holy grail of space management. Our Fury designs have increased interior space by 50% in the monohull sailing yachts. 

Considering the choices regarding multihulls’ technical and performance criteria, the collaboration can say that the designers have doubled interior space in the DOMUS design compared to 40m catamarans. By studying the importance of certain functions and focussing on the main ones, the designers strive to be efficient in the design and overall usage of the yacht. 

In addition to the spacious exterior and interior areas, DOMUS‘s main guest areas are all located on one level without steps, lending DOMUS a villa/bungalow feel.  

DOMUS: Redefining Multihull Sailing

Inside out or outside in? 

In the last years, we have seen the trend in the industry of ‘being want to be part of the surroundings.’ In a way, trying to design to get the exterior surroundings into the yacht’s interior. In DOMUS, VGD and RDD looked at it from an architectural point of view. Family life, in a way, is about protection. So why not build around that, create the protected spaces and maximize the functions of the space available in this 1 level setup. 

All spaces have a view of the outside, so they do not lose the connection with what is happening. Still, they are connected to the communal exterior and interior spaces. 

DOMUS: Redefining Multihull Sailing

Catamaran VS Trimaran 

Over the last few years, larger catamarans have increased interest. The reason for this increased interest is that catamarans are perceived to be better than monohulls on three main grounds: more space, greater performance, and significantly lower heel angles while sailing.

It can get very complicated when discussing Superyacht Multi-hulls greater than 40m. When the designers look at large multihulls, they cannot ignore three other factors: cost, system complexity and Structural Design. Multi-hulls indeed sail at significantly lower heel angles than Monohulls. Space and performance are very much linked when designing multihulls.

DOMUS: Redefining Multihull Sailing

The two hulls generate massive racking forces as they move through the water. One of the most significant challenges in designing a catamaran structure is the mast compression loads. Also, the stability of Superyacht Multihulls can be many times greater than a monohull which increases the mast loads to extreme levels, increasing mast weights, cross beam structural weights and associated costs. One of the main performance benefits of Catamarans is their ability to sail with one hull out of the water. Therefore, the collaboration does not allow Superyacht Catamarans to “Fly Hulls”.

They are more complex and expensive, and most designers underestimate the actual final weights, leading to lower performance. Therefore, VGD and RDD believe that the current trend to design large Superyacht Catamarans is fundamentally wrong. The firms strongly consider if you want the benefits of Multihulls at 40m plus size, the only practical solution is a trimaran.

The extensive design research and analysis they undertook for an 80/90m and a 40/50m Multi-hull Superyachts shows that a Trimaran is the best option. Some accommodation is possible in the outer hulls of the 80/90m design; however, the main systems are in the centre hull, with the outer hulls having the normal technical spaces required to service interior spaces.

DOMUS: Redefining Multihull Sailing

With this approach, VGD and RDD are designing a monohull with outriggers. Of course, this is a significant simplification. However, the concept holds and allows for a much simpler construction process. With careful design and attention to the weight estimate, the designers are designing the Trimaran to fly one hull at 2 degrees of heel. This gives us a significant reduction in wetted surface area with the increase in performance. However, allowing one of the three hulls to fly maintains the full safe operation of the yacht under sail.  

DOMUS: Redefining Multihull Sailing


From the start, the approach in DOMUS has been “Why Not”. Just because superyachts are what they are now do not mean they should stay this way. New, never done before, seem impossible or too complicated when first suggested, are no reasons to rule it out. The designers were constantly looking at every aspect of the design and saying, “I know we do it this way normally but are there a better way?” If they did not have to worry about any financial, practical, or technological limitations, what would they do, then is that better than what they have and can they now make it work within the context of the limits of the project. Therefore, the collaboration believes this project will redefine what a multihull sailing Superyacht can be. The designers also know where they want and can go next in this development. 

The designers studied what would be the smallest size vessel they could design with the one-floor layout without making it look too bulky. While RDD (Rob Doyle Design) has focused on the naval architecture, performance, and structural feasibilities, VGD (Van Geest Design) developed the styling and layouts. DOMUS is an amalgamation of ideas that they discussed daily over the development period. The team behind the DOMUS project has been involved in designing over 60 Superyachts. It has extensive detailed design experience, knowledge and data, which allows us the confidence to undertake such a project.  

(“Article as submitted by the Architects”)

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