VOLLENHOVE – In 2020, Royal Huisman of the Netherlands will deliver the world’s largest aluminum performance sailing yacht. At 81m (266ft), it will rank among the world’s 10 largest sailing superyachts. There is much to admire. An 38m flybridge deck, for instance. And a vast 3-masted carbon rig.
But its truly out-of-sight feature you cannot see. Rudder stocks of large yachts are mostly made of stainless steel. But market demand for more performance drives a search for thinner rudder blades that triggers strength issues.
For its 81m project, Royal Huisman turned to Rondal, its sister company and maker of composite rigs, deck gear and winches. It crafted for the yacht, drawn by Dykstra Naval Architects of Amsterdam, a rudder of UD fiber composite laminates.
In a UD (unidirectional) fabric, most fibers run one way and can be laid exactly where needed and in the right amount. Running parallel to the stock, those fibers make for a strong, rigid light-weight rudder. Rondal says the rudder can have a ‘sacrificial tip’ that breaks off in a grounding, sparing the rudder from damage or tearing off.
Working with Swiss composite specialist Gurit, it equipped the rudder with load sensors – very thin optic fibers. “You cannot see them with the naked eye,” Friso Hylkema, Rondal’s marketing, sales and business development manager, tells DutchYachtBuilding. “Besides, the rudder blade will be painted,” he adds.
For Rondal the rudder is a marquee undertaking.
“It is an ongoing part of our R&D, engineering in general and, specifically, the on-development of load sensing applications,” says Hylkema. “This is our investment in the future. We are convinced many interesting applications are possible. Not only for R&D and engineering purposes, but also for the end user, the owner or captain.”
Rondal sees putting load sensors on rudders, keels, masts, booms, stays, winches and blocks as a boon for performance, onboard safety and preventive maintenance. And that rudder project highlights Rondal’s transformation. In recent years, it has become a prolific maker of composite boat parts: superstructures, canopies, radar masts, doors, hatches and custom applications like that rudder. And in its 850-m2 oven, it ‘bakes’ all-carbon rigs of 70m and taller.