Royal Huisman’s Project 405: Construction Completed

With her departure from the Vollenhove facility of Dutch shipbuilder Royal Huisman, the installation of her towering rig in Amsterdam, and following sea trials, the new Reichel/Pugh-Nauta 154 NILAYA has achieved a significant milestone. A comprehensive light-weight approach has reduced weight without sacrificing stiffness or skimping on quality, producing a superyacht that is both opulent and capable of podium results at superyacht regattas.

154 Reichel/Pugh-Nauta Reichel/40 Pugh's years of sailboat design expertise and the creation of the best CFD study to evaluate R/most P's recent candidate hull shapes led to the design development of NILAYA. The 147' Visione, the 112' Nilaya, the 200' Hetairos Ketch, and the 130' My Song are just a few of Reichel/famous Pugh's superyacht designs from earlier, ground-breaking times. The Superyacht Regatta's St. Barts Bucket has been won outright by Visione, Nilaya, and Hetairos, respectively.

A long-standing Client hired Reichel/Pugh to finish the naval architecture, hull lines, sail plan, and appendages for the new Reichel/Pugh-Nauta 154. One of the best Computational Fluid Dynamics (CFD) and VPP consultants in the world, Caponnetto Hueber and Giorgio Provinciali, who have more than 20 years of America's Cup expertise, were hired by Reichel/Pugh. Builder Royal Huisman did the engineering. Project management and everyday communications between Royal Huisman, designer Nauta Yachts, and project manager Nigel Ingram were handled by Reichel/Pugh Naval Architects, David Oliver, and Tony Beale. Daily throughout the design and construction phases, Reichel/Pugh collaborated with Royal Huisman and Nigel Ingram to jointly oversee the weight study.

Photo by Tom van Oossanen

With its straight bow, wide transom, low profile, and twin rudders, the new Nilaya echoes the appearance of her owners' earlier, wildly successful 112' maxi-racer, which was also created by Reichel/Pugh and Nauta. In addition to the Superyacht Challenge Antigua, Loro Piana Caribbean Superyacht Regatta, St. Barths Bucket, Maxi Yacht Rolex Cup, and Les Voiles de Saint-Tropez, the 112' Nilaya recently claimed her class at the 2021 Superyacht Cup Palma (shown below). The St. Barths Bucket, Loro Piana Caribbean Superyacht Regatta, Loro Piana Superyacht Regatta, Rendezvous, and Superyacht Cup Palma are among the events she has won altogether.

Nigel Ingram of MCM Newport is the owners’ representative for the Reichel/Pugh-Nauta 154 NILAYA as well as the owners’ previous 112’ Nilaya, which he describes as "a really happy boat." That yacht won nearly every regatta she entered. "The owners wanted a powerful performer with easy-to-helm responsiveness; basically, all the good habits of the last boat, but with more comfort and less noise." Nilaya, after all, means "blissful home" in Sanskrit.

Throughout the year-long design process, the overall plan for the yacht changed little, John Reichel said, except for becoming one meter longer, the length distributed mostly at the ends. "Weight distribution is critical for assuring comfortable motion on a cruising yacht. We gave the shipyard team a weight study early on, not just for the total but for balance and maintaining the proper center of gravity. "Royal Huisman responded with extensive Excel sheets showing the weight of every element. That’s a process typical of the highest end racing program construction."

Photo by Tom van Oossanen

CFD was used to look at Reichel/Pugh's best designs for building with metal and high-tech composites. Using the ORCsy Superyacht VPP (velocity prediction program), the designs were looked at and tested in real time. John Reichel, a naval architect, said that in addition to the standard CFD analysis, they also used a complex RANS code analysis to predict how the hull, keel, rudders, and propellers would affect the turbulence under the water. It is a technique for improving submarine structures. Lastly, to enhance the yacht's seakeeping and motion characteristics, the naval architects gathered extensive wave data from the owners' preferred windy cruising grounds and created new hull shapes to put through the RANS CFD code.

As Reichel/Pugh enhances the performance of their superyacht designs, they are aware of the necessity of enhancing the seakeeping qualities in waves while using either sail or electricity. Running a Velocity Prediction Program (VPP) for the best designs revealed that the yacht was shaping up to be an exceptional performer against top scorers in the maxi yacht fleet as the strong sail plan was evolving in collaboration with Rondal and Doyle Sails. Even in a 10-knot breeze, the VPP forecasts that the yacht can reach upwind faster than the windspeed when using only the main and jib.

Photo by Tom van Oossanen

Finite Element Analysis (FEA), a design methodology with roots in spacecraft technology, is used in the project's comprehensive light weight strategy. FEA is a sophisticated geometric mathematical calculation used to forecast how a component or the complete product will respond to stresses like load, force, heat, vibration, etc. When a part is viewed in three dimensions, it is possible to anticipate how the part will respond when the same stresses are placed on its adjacent parts, which can help designers identify any potential weak or vulnerable areas. Imagine it as a type of digital prototyping that is much faster and more precise. Without creating and putting through testing new physical models, solutions can be implemented.

To optimise hull stiffness while reducing overall displacement, different construction materials, Alustar aluminium plate thicknesses, and frame spacing were chosen thanks to FEA modelling. The strategy was all-inclusive, covering mechanical systems, insulation, and illumination. All internal structural members made use of lightweight foam coring and were the beneficiaries of careful weight analysis. The displacement disparity between yachts made of aluminium and carbon composites was reduced by this all-encompassing strategy.

"Royal Huisman used Finite Element Analysis (FEA) of Nilaya’s 3D model to fine-tune the engineering to "a much higher level," according to naval architect Jim Pugh, adjusting plate thickness in the computer and predicting longitudinal stiffness or deflection without so much as touching that first piece of material. "Bringing in the mast and sail designers early in the process has significant advantages," said Jim Pugh. "From the aero CFD side, Rondal and the sail designers shared high quality data about sail forces and sail loads that we integrated into the hydro CFD studies of the candidate hulls. This markedly improved the quality of the CFD hull testing and the resultant performance prediction. The mast and sail loads were then input into the hull and deck’s structural engineering," said Pugh. "These studies are applicable to any design whether Featherlight™ or heavy, no matter the thickness of the plate or weight of the composite, such a study will yield remarkable results."

Photo by Tom van Oossanen

The Reichel/Pugh-Nauta 154 NILAYA superyacht is the first to make use of Royal Huisman's new FeatherlightTM design and production method, accomplishing the company's goal of shedding 11% of the weight of its normal advanced aluminium cruising yachts. With the newest carbon technology combined with nearly 60 years of experience constructing aluminium yachts, Royal Huisman's FeatherlightTM technique offers the best of both worlds for a hybrid yacht without compromise.

Royal Huisman CEO Jan Timmerman used the occasion to highlight both the innovative construction methodology and the latest milestone for the Reichel/Pugh-Nauta 154 NILAYA: "The success of the innovations with Nilaya paves the way to use this bold new approach for future builds. I am proud of the investment we have made in advanced engineering and of the way teams from Royal Huisman and Rondal advanced new solutions to meet the brief from very knowledgeable clients and designers. The owners as well deserve congratulations for pushing everyone to achieve just a little bit more and for encouraging innovation at every step. Nilaya will be the world’s lightest aluminum sailing superyacht for her length: she rewrites the script for high-performance superyachts." The robust characteristics of an aluminum yacht are now a viable option for owners seeking true sailing performance.

The engineering team at Royal Huisman used this synergy to analyse and forecast which structural components would be best made of composites or aluminium by utilising the carbon fibre knowledge of its sister business Rondal. The complete 17.5m/57-foot curvy coach roof and guest cockpit structure, for instance, are made of carbon composite. Likewise, a watertight bulkhead, crew entry, twin rudders, the keel trunk, and a cockpit bimini hardtop are all made of carbon composite, as is the foredeck's recessed tender well, which can be converted into a seating area for sailing or a flush deck for racing. A carbon fibre mast, boom, and standing rigging are essential for any high-performance cruiser to keep weight as low and centred as feasible for ideal balance. Though Rondal has extensive knowledge of carbon spars, it is a maxi-racer strategy to involve the sailmaker and this component's design during the larger hull design period.

The Doyle Sails-developed structured luff sail design was used for the first time on the Reichel/Pugh-Nauta 154 NILAYA, making the Rondal mast, gear, and components lighter overall, which is important given the boat's Panamax air draught. Rondal developed a radical new curved carbon fibre spreader design that is both shorter and more aerodynamic than anything previously available to take advantage of the very narrow headsail sheeting angles feasible. Rondal also provided different sail handling equipment, new generation hybrid (carbon and aluminium) captive winches, and hatches. Titanium is used for most deck fittings.

Photo by Tom van Oossanen

Nigel Ingram of MCM Newport serves as the owners’ project manager on the build. "While the new Nilaya is meant to take the owners world cruising, they also asked for a boat with all the ‘good habits’ of their previous racer, meaning responsiveness and excellent handling. Alustar aluminum is the right material for an advanced, quality superyacht for global cruising. It deals with noise better and is a better choice for cruising in comfort to remote locations. However, we also thought it was possible to build a lighter aluminum high-performance superyacht. Royal Huisman was not afraid to invest in research to explore and develop all manner of innovative weight-saving possibilities. They really chased the details."

While she may share some handsome profile characteristics with her 34m /112ft Maxi Class racing predecessor, this 12m/42ft longer yacht is designed for luxurious cruising with a good turn of speed, explains exterior and interior designers Nauta Design. In this process we took into account the owners’ priorities, including less noise, the strength of the material, and the possibility of repairs around the world. We set about discovering ways to minimize the difference and look for advantages elsewhere," noted Nauta’s co-founder Mario Pedol.

Historically, increasing weight was necessary to reduce noise and vibration, which is completely the opposite of the intended result. Royal Huisman conducted in-depth sound attenuation studies and created sophisticated composite panels using cork, foam, honeycomb, and other materials to remain within the interior weight budget. In order to enable the owners to choose, the shipyard created interior cabinets that displayed the three levels of execution's appearance, feel, and sound.

Photo by Tom van Oossanen

Developing the deck and cockpit perfectly for the dual purposes of cruising with family and friends and regatta racing was very important to the owners, according to Pedol. "Royal Huisman constructed a 1:1 mockup of the entire aft half of the yacht for finetuning all the aspects from sail controls and steering pedestals to the dining table, seatback angles of sun loungers and the step to the aft deck leading to the swim platform. Checking sightlines over the coach roof from the helm positions received critical attention, even by simulating heeling angles."

"Not only this hybrid use of the two materials but the approach to saving weight while keeping quality and comfort was a great solution for this project." The choice of hull material did not alter the yacht’s interior design except as needed to adjust for framing dimensions, while the carbon composite coach roof preserved headroom," explains Nauta co-founder Massimo Gino. "By developing the complete interiors in 3D and consequently by producing hundreds high quality 3D rendered views, of both general views and details, in several different revisions and options, we were able to fulfill the owners’ expectations for light yet warm and welcoming interiors, which combine a modern look with classic elegance."

The Reichel/Pugh-Nauta 154 NILAYA will be delivered to her owners in the coming months.