The forecabin heads is an optional extra. As standard it’s an equipment store
Matteo Polli explains his latest design
The design brief for the Grand Soleil 40 set the bar even higher than the 44. Fitting three comfortable cabins and two heads in a 40-footer that should be able to win races under different rating systems is a rather tough call. Starting from the experience accumulated on the 44 and considering the effects of a smaller size, improvement has been found in different areas. We are talking about refinements in hull volume distribution, improved form stability, slightly longer bow and stern overhangs and some tweaks to the appendages. Definitely not revolution of a concept but more about evolution. In the design phase there was no
specific focus on offshore passage racing or inshore windward-leeward racing. The idea was to balance the performance profile on the full range of conditions without giving more importance to one single situation. However, the owner can adapt his boat configuration quite a lot by selecting from various options of appendages, sailplans and features that in conjunction will work better for inshore or offshore racing. The boat is also equipped to deal with different sail inventories, asymmetric or symmetrical spinnakers, masthead or fractional code zero, conventional jibs or self-tacking jibs, staysails and so on. The effect on performance of adding
heavy equipment and payload is particularly critical on smaller yachts like the GS40. To minimise the negative effects, it has been paramount to pay attention to the location of heavy optional items, trying to avoid positioning them on the boat’s extremities. In this way, pitching motions are reduced but also unwanted
bow down or stern down trim are minimised across the client selection possibilities. Designing the hull lines, not only the racing sailing trim condition has been considered but also the full load displacement condition making sure that all the shape parameters remain between acceptable values across the whole displacement range. The optimal heel angle will be around
20-22° and this allows a perfect balance between righting moment and aero-hydro efficiency. Beyond that, more power can be achieved and thus more drive force but the compromise on drag would be too high. On a cruise, the optimal heel angle (considering comfort) would be slightly less, about 16-18°. Enough to sail up to 17kts without a reef on the main. Good performance in light airs is
achieved by a combination ofmany parameters – rocker, waterline beam, stern profile and a number of others – but themost important are the low wetted surface vs displacement, the relatively low prismatic coefficient together with absence of transomimmersion. Also the large foretriangle helps quite a lot in light airs. Pitchingmotion in waves is a function
of not only the hull underwater shape, butmost importantly the overall volume distribution, so also including the topsides. The perfect balance between bow and stern volumes allows a comfortable and also effective ride. On the GS40 as on the 44 the bow entries remain quite narrow but the forecabin volume is outstanding for this segment and the stern exitsmatch perfectly, forming an equilibriumthat ensures both comfort and performance. As always there are compromises so a
perfect shape in head seas cannot be a perfect shape when sailing in following seas, and the smaller the size of the boat the more critical this aspect is. Balance is required also in this respect. The GS40 is improved in this direction too; in fact the vertical distribution of the volume in the front part of the hull is steeper than on the 44 and this will prevent burying the bow in reaching conditions. On the GS 40, themast is about 4-5%
further back in terms of LOA compared to a typical cruiser-racer. This percentage is even bigger if we compare to older designs. This allows larger jib area which ismore efficient and has lower centre of effort. If we compare to a traditional sailplan with the same overall sail area, this configuration is faster at a smaller heel angle. It is also more reactive in accelerating after tacks and in choppy seas. The large foretriangle of the GS40 is
even more important when the boat has a self-tacking jib, especially if it’s on an under-deck furler which further reduces the J dimension. With the mast in a conventional position the cruising jib would be very small and surely underpowered relative to the typical full load displacement when starting a cruise. The performance differential between
the Performance and Race versions will be noticeable. The Race version has an almost 1m taller mast, 12% more upwind sail area, 14% more downwind sail area. Its appendages are lighter and the deck layout is more efficient. The Race version’s longer bowsprit allows more spinnaker area and also more separation from the mainsail so the performances gain will be surely remarkable if you go for maximum sail area I would recommend it for racing purposes. When cruising, the standard bowsprit will allow more than enough kite area and downwind performance.
The Race version has another pair of winches on the coamings, transverse genoa car tracks and a longer bowsprit
SEAHORSE 85
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