The interior arrangement was designed by Reichel/Pugh Yacht Design to accommodate three crew and six guests. The design eliminates the need for non-structural partitions by using the major load paths of the boat. Interior design was completed by Nauta Yachts, who worked closely with the client to develop their vision for living space aboard the SW-RP90. “Our challenge was to design interiors that were intriguing and innovative but with ergonomics that could function within the structural and dimensional constraints that the performance aspects of the yacht’s design imposed,” state Massimo Gino and Mario Pedol, founders and co-heads of Nauta Design. “These constraints led us to show, and not hide, the yacht’s shapes and its main structural elements. The SW-RP90 respects a series of safety parameters typical of a real bluewater cruiser,” says SWS CEO Willy Persico.
The interior paneling and upholstery that veils the structure of the SW-RP90 is held in place with fasteners that allow for easy inspection and maintenance of systems throughout the yacht. Nonstructural interior paneling and furniture is primarily made of light carbon-skinned honeycomb-cored panels, veiled with thin wood veneers. The interior is lit with high efficiency LED lights that consume less power, which in turn means lighter electrical wiring. The end result is a finely crafted interior that reflects the vision of the client while preserving sailing performance.
One of the many examples of innovation aboard the SW-RP90 is the anchoring system. The heavy anchor is deployed with an arm that swings from its locker below deck, out over the bow, keeping the stem free of any visible anchor, chain, or rollers when the arm is stowed. The anchor arm is actuated by two hydraulic rams at the push of a button. Southern Wind Shipyard had previously made production anchor arms out of aluminum. However, to stay in tune with the weight-consciousness of this project, they requested R/P investigate the possibility of crafting it out of carbon. The engineering team at Reichel/Pugh Yacht Design conducted significant Finite Element Analysis to engineer a new anchor arm from scratch that is stronger than the anchor chain. In conjunction with ISOTOP Composites of France, R/P developed a workable construction sequence that would be achieve the deflection targets for the system. The final product is a composite anchor arm that is 53% lighter than its aluminum counterpart.
Just aft of the anchoring system in the sail locker is another feature suited for a multipurpose superyacht such as the SW-RP90: a drop-down bow thruster. At the push of a button, a hydraulically actuated bow thruster deploys underwater to simplify shorthanded docking and harbor maneuvering while cruising. In the retracted position the bow thruster opening is capped with a flush panel to remove any drag in the racing configuration.
For a performance cruiser like the SW-RP90, sail storage is a very important consideration. While the main consideration during the design process is the owner’s enjoyment, some attention must also be given to the professional sailors onboard who need a place to store gear and sails. The design team made sure to preserve enough space for several hundred pounds of gear and sails in an area isolated from the living quarters. Sails and gear can be lowered into this forward compartment by halyards through a large foredeck hatch. On deck, just aft of the sail locker is another unique feature requested by the client: a hidden storage compartment large enough to fit a dinghy or, more important to the racing crew, the Mast Head Code Zero.
At the base of the mast, all halyards are led aft under two composite coamings, leaving the deck clean and uncluttered. The decision to lead all halyards aft also greatly eases shorthanded cruising. While underway, most sails aboard the SW-RP90 are “locked” at the top of the mast instead of hanging on halyards. The use of halyard locks has a few key benefits on a project such as this. From a practical standpoint, they reduce halyard wear that normally occurs on when a sail is flown for days on end during long voyages. Another important aspect of the halyard locks is a reduction in the amount of compression in the rig and mast step, which can save weight in the mast and hull structure. As a robust blue-water cruiser, it was determined that in case the SW-RP90 halyard locks failed far out to sea, the system on deck must be able to withstand the full load of the cruising sails. To meet this need, local deck reinforcements were specified in way of the Karver KJ halyard jammers, located under the coaming aft ends.
In the cockpit, the design team specified powerful Harken hydraulic racing winches for sail trimming. The winches aboard the SW-RP90 have carbon fiber drums to save weight while withstanding significant loads. Opting for hydraulic powered winches instead of man powered was a simple decision, led by the desire to keep the cockpit uncluttered by grinding pedestals. The extensive hydraulic system for sail handling is powered by generator, but can alternatively be powered off the house battery bank while cruising.
Southern Wind Shipyard partnered with Van Cappellen Consultancy to reduce engine sound pollution aboard the SW-RP90. Engine noise is kept to a minimum through the use of insulation and anti-vibration mountings on all potential sources of sound pollution on board.
Further aft, just forward of the helm, is a secondary companionway. This arrangement allows the crew access to their own living space without intruding on the guests. The crew companionway also offers direct access to the galley, where refreshments and meals can be easily brought on deck to guests enjoying a sail. Forethought on features in tune with how clients and professional crews use their yacht is central to R/P’s philosophy.
With a full draft of 20 feet, the SW-RP90 would have great difficulty finding suitable harbors without her lifting keel. Three hydraulic rams lift the keel to a draft of 12.5 feet, significantly increasing the number of harbors available to her. The keel trunk and lifting system was designed by APM Keels of Italy. Reichel/Pugh Yacht Design has conducted significant research on lifting keel designs. Many lifting keels on superyachts have straight fin profiles, in which the bottom section is as long as the top, to reduce bearing loads on the keel trunk. On the SW-RP90 a tapered fin profile was designed to increase the lifting surface efficiency. This keel design required special attention to engineering the keel trunk and fin structure. The tapered keel of the SW-RP90 was fabricated by APM Keels out of high strength steel. All in all, the 20-ton keel can be raised and lowered at the touch of a button in under a minute.
North Sails provided the sail wardrobe for the SW-RP90. Her sail area is almost 500 m2 upwind and more than 1000 m2 downwind. The mast towers 40m above the deck and is supported by EC6 continuous carbon rigging. The mast and boom were designed and manufactured by Southern Spars at their facility in Cape Town, not far from the Southern Wind Shipyard. The boom on the SW-RP90 features “wings” on the top face that cradle the mainsail when stowed, while providing the crew space to safely perch themselves to assist while raising or lowering the sail. The incredible power provided by the rig can propel the SW-RP90 in excess of 25 knots of boat speed.
The hull was infused in a female mould with carbon skins over a low-density foam core. The deck and primary structure was manufactured out of light Nomex honeycomb core laminated with prepreg carbon fiber. The incredibly light and stiff carbon construction of the SW-RP90 will help to shave off precious time on the racecourse while supporting the immense loads of the keel and mast. A stiff hull is paramount to reducing mast and headstay deflection and maintaining efficient sail shape. All aspects of the SW-RP90, from beam design to winch placement were carefully considered and engineered with incredible attention to detail to achieve the aggressive weight targets of the project.
It’s this attention to detail that keeps the design team working late at times, feverishly searching for the lightest solution on each component in an effort to save mere grams of weight. They keep at it with the knowledge that every seemingly inconsequential gain will add up to significant weight savings. Any weight saved on the structure can in turn be added to the bulb, deep below the surface, to contribute additional performance. While the design team explores any way to save weight on the project, the builder is left with even more extensive challenges. To undertake the build of a modern superyacht like the SW-RP90 is an incredible achievement since lightweight solutions to engineering challenges often result in complex laminates which require immense precision to build.
Conversion to race mode
In preparation for racing, a few key modifications are made to the SW-RP90 before she heads to the starting line. First, the conservatively sized pinhead mainsail is traded for one with a powerful square top. The centerline cruising backstay at the transom is disassembled and twin running backstays are installed. The cruising anchor and chain is removed to save critical weight at the bow. The bowsprit and supporting bobstay are installed, requiring only 4 bolts and one pin to hold it in place. After any remaining cruising amenities are removed, she is ready to race.