Reichel/Pugh-Nauta 154’ Nilaya - Royal Huisman’s Project 405
Photography By Tom Van Oossanen
Reichel/Pugh’s Design # 283, the 154’ Nilaya was R/P’s first and very welcome opportunity to work with Royal Huisman whose Tradition for Excellence goes back to 1884 with a passion for perfection that matches Reichel/Pugh’s. The new Reichel/Pugh-Nauta 154 NILAYA has reached a major milestone with her departure from the construction hall at Dutch builder Royal Huisman’s Vollenhove facility, the installation of her towering rig in Amsterdam and subsequent sea trials. A holistic light-weight method has reduced weight without sacrificing stiffness or cutting corners on quality — delivering a most luxurious global cruising yacht that will also be capable of podium finishes at superyacht regattas.
Reichel/Pugh-Nauta 154 NILAYA’s design development is a result of Reichel/Pugh’s 40 years of yacht design experience and designing the optimum CFD study to analyze R/P’s latest candidate hull shapes. Earlier Superyacht designs by Reichel/Pugh are groundbreaking and include the iconic yachts, the 147’ Visione, the Reichel/Pugh-Nauta 112’ Nilaya, the 200’ Hetairos Ketch and the Reichel/Pugh-Nauta 130’ My Song. Visione, Nilaya and Hetairos have each won overall the Superyacht Regatta the St Barts Bucket. Reichel/Pugh was contracted by a long-standing Client to accomplish the naval architecture and complete the hull lines, sail plan and appendages for the new Reichel/Pugh-Nauta 154. Reichel/Pugh enlisted one of the world’s best Computational Fluid Dynamics (CFD) and VPP consultants, Caponnetto Hueber and Giorgio Provinciali, who have over two decades of America’s Cup experience. Engineering was completed by builder Royal Huisman. Reichel/Pugh Naval Architects, David Oliver and Tony Beale managed the project and daily communications between Royal Huisman, designer Nauta Yachts and project manager Nigel Ingram. Reichel/Pugh worked with Royal Huisman and Nigel Ingram on a daily basis throughout the design and build process jointly monitoring the weight study.
The new Nilaya’s low profile, straight bow, wide transom and twin rudders echo the look of her owners’ previous highly successful 112’ maxi-racer also designed by Reichel/Pugh and Nauta. The 112’ Nilaya recently won her class at the 2021 Superyacht Cup Palma (pictured below), and has previously won the Superyacht Challenge Antigua, Loro Piana Caribbean Superyacht Regatta, St Barths Bucket, Maxi Yacht Rolex Cup, and Les Voiles de Saint Tropez. She has won overall the St Barths Bucket (pictured below), Loro Piana Caribbean Superyacht Regatta, Loro Piana Superyact Regatta and Rendezvous and Superyacht Cup Palma. 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.”
Reichel/Pugh’s top performing candidate designs of both metal and hi-tech composite construction were tested in CFD. The designs were analyzed in real and rated time under the ORCsy Superyacht VPP (velocity prediction program). Beyond conventional CFD analysis, naval architect John Reichel explained that they layered on a sophisticated RANS code analysis to predict underwater turbulence generated by the hull, keel, rudders and propellors. It is the method used to optimize submarine hulls. Finally, the naval architects collected extensive wave data from the owners’ favorite windy cruising grounds and developed new hull shapes to run through the RANS CFD code to improve the seakeeping and motion characteristics of the yacht. As Reichel/Pugh improves the performance of their superyacht designs, they know it is critical to also improve the seakeeping characteristics in waves both under sail and power. As the powerful sail plan was developing in concert with Rondal and Doyle Sails, running a Velocity Prediction Program (VPP) for the top designs showed that the yacht was shaping up to be an exceptional performer against top scorers in the maxi yacht fleet. The VPP predicts the yacht is capable of exceeding windspeed when reaching upwind with main and jib alone, even in a 10-knot breeze. The project’s holistic light weight approach makes use of Finite Element Analysis (FEA), a design methodology rooted in spacecraft technology. FEA is a complex mathematical geometric computation used for predicting how a part or an entire product will react under stresses such as load, force, heat, vibration, etc. Being able to look at a part in three dimensions also predicts how the part will react as the same stresses are being applied in its neighboring parts, thus identifying potential weak or vulnerable points that can be corrected in design. Think of it as a kind of digital prototyping but far more accurate and much faster. Solutions can be applied without having to build and test new physical models.
FEA modeling enabled the selection of various construction materials and varied Alustar aluminum plate thicknesses and frame spacing to maximize hull stiffness while minimizing total displacement. The approach was comprehensive, extending to lighting, insulation, and all mechanical systems. All interior structural members benefited from careful weight analysis and utilize lightweight foam coring. This holistic approach narrowed the displacement gap between aluminum and carbon composite yachts. “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.”