“Domus single-storey house which was built around a courtyard known as an atrium. Atriums had rooms opening up off of them and they had no roofs. A domus had many rooms including kitchen, bath, dining, and bedrooms.”
The designers offer their thoughts and explanations as to why their design will work for today’s market.
Why a Trimaran?
Van Geest Design has collaborated with Rob Doyle Design on a revolutionary new trimaran which they are calling Domus. 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 have to be doubled for the two hulls, this significantly increase the cost of the vessel, by going the trimaran route we have all the systems and engineering in the center hull just like a normal construction method and the Armas are kept simple.
All the rigging forces are taken by the main hull, thus keeping crossbeam structures simpler and generally the overall structure being more straight forward.
More Space – Due to the fact that 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 better damping effect on the Trimaran than on a catamaran, thus a more solid feeling platform and vastly reduced motions then experienced on monohulls. Since Domus is designed to a heel angle of 2 degrees, guests onboard will experience a level of comfort underway, far superior to any sailing or motor monohull, which can experience high angles roll leading to motion sickness.
The First Truly Zero Emission Yacht over 750 Gross Tonnage
The uniquely designed combination of Solar power, Hydro Regeneration & Hydrogen Fuel cells gives Domus unlimited range with Zero Emissions. An optimised system of Solar Power and Battery Storage, allows the yacht to motor during daylight hours and then transfer over to the Battery system at night. This also means that Domus is fully silent with Zero Emissions while at anchor. Gone are the days of Generator Noise and Exhaust Smells while sitting in your Idyllic anchorage.
Considering the choices regarding technical and performance criteria of multihulls Van Geest says that in the Domus design has double the interior space compared to 40m catamarans.
Besides the larger interior and covered exterior spaces, the fact that the main guest areas are all on one deck without steps give Domus a unique villa/bungalow like onboard experience.
Inside out or outside in?
In the last years Van Geest has 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 interior of the yacht. In Domus they 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 do have view to the outside so not losing the connection with what is happening but, they are all connected to the communal exterior and interior spaces.
Catamaran VS Trimaran
Over the last few years there has been an increased interest in larger catamarans. The reason for this increased interest is 3 main perceptions/ideas why catamarans are better than monohulls. More Space, Higher performance and significantly lower heel angles while sailing.
Looking at these perceptions/ideas in depth, all is not as it seems, and it can get very complicated when we start talking about Superyacht Multihulls greater than 40m. When looking at large multihulls, there are 3 other factors, Cost, System Complexity and Structural Design.
It is true that Multihulls sail at significantly lower heel angles then Monohulls. This is a major attraction to many potential superyacht owners who may not have been bitten by the sailing bug at an early age and are less comfortable walking around a deck heeled at 15 to 20 degrees. The thought of only 2 to 3 degrees heel is well within their comfort zone.
Space and Performance are very much linked when designing multihulls. Van Geest classes Space into 2 areas, interior & exterior. Generally, it is true that Multihulls are designed with more space because they have more beam than the same size monohull. However more space/interior means more weight which is the nemesis of performance. Catamarans will have duplicated systems in each hull which significantly adds to the cost, complexity of the systems and also the weight.
The two hulls generate massive racking forces as they move thorough the water, these types of forces are not experienced by monohulls therefore careful structural design is required. One of the greatest challenges in designing the structure of a catamaran is the mast compression loads. These loads must be taken by very highly loaded cross beams. 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. This reduces wetted surface area (hull drag) while maintaining high stability to generate power from the sails. While this may be OK in a racing setting or for smaller yachts flying a hull in a 50/60m Superyacht Catamaran has many dangers including a significant increase to the risk of capsize. Therefore, we do not allow Superyacht Catamarans to “Fly Hulls”.
You may be asking the question why to bother with multihulls. They are more complex, more expensive and most designer massively underestimate the actual final weights leading to lower performance.
Van Geest and Rob Doyle Design believe that the current trend to design large Superyacht Catamarans is fundamentally wrong. They strongly believe if you want the benefits of Multihulls at 40m plus size the only practical solution is a trimaran. The extensive design research and analysis we have undertaken for an 80/90m and a 40/50m Multihull Superyachts clearly shows that a Trimaran is the best option.
“We have approached the design of both projects from the starting point that the main centre hull will be the main hull for systems, take all the mast & sail loads, be the main area for services (galley, laundry, crew mess etc) and the outer hulls used for storage. We then allow the main deck at full beam for exclusive us of the guest & owner all on one level. 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.
With this approach we are basically designing a monohull with outriggers. Of course, this is a major simplification, however the concept holds, and allows for a much simpler construction process.
With careful design and attention to the weight estimate we 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 hull to fly maintains the full safe operation of the yacht under sail.”
Van Geest / Rob Doyle explain their Collaboration:
“The approach in Domus has been from the start “Why Not”. Just because superyachts are what they are now does 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. We were constantly looking at every aspect of the design and saying, “I know we do it this way normally but is there a better way?” If we did not have to worry about any financial, practical, or technological limitations what would we do, then is that better than what we have and can we now make it work within the context of the limitations of the project. Therefore, we truly believe that this project will redefine what a multihull sailing Superyacht can be, and we also know where we want to and can go next in this development.
We studied what would be the smallest size vessel we could design with the 1 floor layout without making it look too bulky. While RDD has been focussing on the naval architecture, performance, and structural feasibilities VGD developed the styling and layouts. Domus is an amalgamation of ideas we discussed daily over the development period.
The team behind the Domus project been involved in the design of over 60 Superyachts, and have extensive detailed design experience, knowledge and data which allows us the confidence to undertake such a project.”