The key factors of the SRW Familiar set-up – no need to learn how to sail again Simple – few controls and the sail can be stored and reefed as a conventional sail Light – no complex structures are involved and weight is comparable to a conventional arrangement Increased performance – due to the wing sail configuration Allows the use of headsails, jibs, code zeros and spinnakers
How does it actually work
Simplicity is the key; our patented system is based around a specially designed and aerodynamically developed mast section. This section is allowed to rotate and is fitted with twin tracks that support two standard sail membranes. A further custom-designed spreader system, together with tapered battens with custom batten ends, plus a few basic but necessary control lines complete the package.
The two mainsail membranes are hoisted in the normal way, using one halyard that splits into two within the mast and attaches to the head of the ‘sails’. This also allows reefing in the traditional way and at the end of the day the sail can be dropped down and either flaked manually or, if you prefer, into a pair of lazy jacks.
The rotation of the mast section is the key to achieving the correct aerofoil sections. When counter-rotating the mast (forward face pointing off wind), the windward membrane becomes tensioned (hence flattening the surface) while the leeward battens and membrane are compressed (causing the membrane to bulge). See illustration B (below right). Additionally, the outhaul control is used to induce camber as required (illustration C, right). Slip movement between the two membranes delivers twist by controlling thickness and camber, as you can see comparing illustrations D and E (right). In short, the SRW provides a wide range of section shapes while only necessitating a relatively simple set of controls.
Next step
Soon after starting this project we increased the size of our development group, G Yacht Design (ARG) joining forces with Advanced Wing Systems (AUS) and Katabatic Sailing (AUS/ESP), to pursue further development of the prototype semi-rigid wing using an RG650 Mini 650 as our original test platform.
Concept
This enlarged team then put their heads together to develop the design concept in terms of creating a purpose-built boat to both exploit the AWS concept and also get something AWS-based into the marketplace. After conducting a careful examination of current offerings, the K8 Sports was the result: a very modern 8m sportboat suitable for a broad range of sailors, simple yet thrilling to sail and easy to transport. In time the K8 Sports may evolve as a one-design class, but in the meantime it is readily suitable for IRC fleet racing.
It should also make for a great little club racer, slotting into most local handicap systems and promoting the capabilities of a modern yet pragmatic wing rig system. We believe that this flexi- bility of concept and application will deliver maximum technical interest and sailing enjoyment… all at an accessible price.
The K8 Sports
In terms of hull design, the K8 Sports was purpose-designed around SRW performance parameters. This approach contrasts with the usual design spiral where too often a rig is designed to suit pre-ordained hull parameters.
Consequently, our final hull lines differ from other existing boats of this size. The SRW rig delivers more power with less heel and, as a result, the hull has been given greater form stability than would be typical at this size, with relatively flat underwater sec- tions – that run right from the bow – to promote early planing. The K8 Sports has more than met our early expectations during initial testing in Spain in September. Upwind the boat is stable and easy to manage and is continuing to impress all who get hold of
48 SEAHORSE
the tiller. Powerful yet extremely manageable, the K8 Sports is achieving speeds comparable with much larger boats, opening the door for a very exciting product launch at the end of this year. The K8’s exaggerated waterline beam – but with narrow heeled waterlines – drove us immediately to employ twin rudders for optimal control in all conditions and at all (normal) heel angles. Downwind the hull is powerful and planes easily, enabling the helm to catch every little wave. In larger waves and stronger winds the bow lifts quickly, the boat behaving a little like a skiff as it begs to be offered up for the next surf.
K8 SPORTS LOA
The bulb keel lifts for trailing as do the rudders. The bowsprit is also easily removed for transport. The deck design has been created
Beam Draft DSPL Crew
Wing area Jib
7.99m 2.55m 2.1m
1,200kg 3-5
29m2 12m2
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