Reichel/Pugh Leverages Latest CFD Hydro Technologies to Advance Performance Superyacht Design with Improved Seakeeping and Motion Characteristics Both Upright and Heeled. 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 construction 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 Leverages Latest CFD Hydro Technologies to Advance Performance Superyacht Design with Improved Seakeeping and Motion Characteristics Both Upright and Heeled.
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.
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.
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 construction 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 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 is a leap forward from the look of her owners’ previous highly successful 112’ blue water cruiser 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.
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.”
The Reichel/Pugh-Nauta 154 NILAYA superyacht is the first to utilize Royal Huisman’s new Featherlight™ design and production method, achieving its goal of reducing 11% off the weight of its typical advanced aluminum cruising yachts. Royal Huisman’s Featherlight™ method is an evolution of nearly 60 years of aluminum yacht-building experience melded with the latest carbon technology, providing the best of both materials for a no-compromise hybrid yacht.
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.
Capturing the carbon fiber expertise of its sister company Rondal, Royal Huisman’s engineering team used this synergy to analyze and predict which structural components would be best made of composites or aluminum. For example, the entire 17.5m / 57-foot curvaceous coach roof and guest cockpit structure are carbon composite. Likewise, the recessed tender well on the foredeck (that transforms to a seating area for cruising or a flush deck for racing) is also carbon composite as are a watertight bulkhead, crew entrance, twin rudders, the keel trunk and a cockpit bimini hardtop. For any high-performance cruiser, a carbon fiber mast, boom, and standing rigging are critical to keeping weight as low and as centered as possible for optimal balance. While Rondal has considerable carbon spar expertise, bringing the design of this component — and the sailmaker – into the process during the larger hull design phase is a page out of a maxi-racer’s playbook.
The Reichel/Pugh-Nauta 154 NILAYA is also the first yacht of this size range designed to take advantage of the structured luff sail design pioneered by Doyle Sails, a choice that allowed the entire Rondal mast, rig, and components to be lighter — a key point considering her Panamax air draft. To take advantage of the very narrow headsail sheeting angles possible, Rondal created a radical new curved carbon fiber spreader design that is both shorter and more aerodynamic than anything previously available. Rondal also supplied new generation hybrid (carbon and aluminum) captive winches, hatches and various sail handling gear. Most deck hardware is titanium.
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.
Traditionally, reducing noise and vibration required the addition of weight—strictly the opposite of this desired outcome. To stay within the interior weight budget, Royal Huisman made extensive sound attenuation studies and developed sophisticated composite panels utilizing cork, foam, honeycomb and other materials. Accordingly, the shipyard made interior cabinets demonstrating the look, feel and sound of three levels of execution and allowed the owners to make the choice.
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.
Main Specifications
- Yacht name: Nilaya
- Type: High-performance cruiser sloop
- Length overall: 46.8m / 154ft
- Beam: 10m / 33ft
- Draft: 4.5 - 6.9m / 15 - 23ft
- Accommodation: 8 - 10 owners / guests + 8 crew
- General concept, exterior & interior design: Nauta Design
- Naval architecture: Reichel/Pugh Yacht Design
- CFD – Caponnetto-Hueber SL
- VPP – Georgio Provinciali Srls
- Owners’ representative: Nigel Ingram, MCM Newport
- Owners’ race team: Bouwe Bekking
- Builder: Royal Huisman Project 405
- Construction: Aluminum and carbon composite
- Classification: Hull structure & superstructure according to the rules & regulations of Lloyd’s Register Special Service Craft Rules, eligible for the class notation: X100A1, SSC, Yacht, Mono, G6
- Rig + handling: Rondal carbon Panamax rig + Integrated Sailing System
- Year of delivery: 2023
Photography and text courtesy of Royal Huisman/Tom van Oossanen/Mike Tesselaar