The mainsheet traveller went through several design iterations, from a circular solution to an oceansheet concept, before finally becoming a straight and more traditional traveller. This chapter explains the reasoning behind that choice and documents the complete construction of the traveller base.
Mainsheet traveller
The original idea was to build a circular mainsheet traveller, with a radius approximately equal to the length of the boom. When constructing the roof of the aft cabin, I had already replaced the foam core in that area with high-density foam in anticipation of this solution. The relevant photos can be found in the album related to the preparations for the deck laminate.
In the end, however, this solution proved to be too complex, too labour-intensive and too expensive, especially when weighed against the relatively small performance gain. It simply did not feel justified.
The next idea was to drastically simplify the system by using a so-called “oceansheet”: an inverted V-shaped arrangement with a three-block tackle on each side of the cockpit. This solution is successfully used by several multihull sailors, but it does come with compromises in ease of trimming.
For quite some time I assumed that I would accept those drawbacks and go with the oceansheet. However, the loads under such deck-mounted blocks are substantial. When I saw how the laminate under a comparable block on an F-36 trimaran was already deforming, it became clear that additional reinforcement would be required. That meant extra work I had not planned for.
Eventually, the decision was made to build a straight and more traditional mainsheet traveller. For the base, I purchased seven Red Cedar planks measuring 18 × 140 × 3050 mm. This provided sufficient material to construct the traveller base for the high-aspect jib as well.
The cross-section was drawn as a pyramid shape: wide at the base and narrower towards the top. Further down, the required width exceeds that of a single plank, but by carefully re-using material removed from the upper layers, the full width could be built up efficiently.
The track itself is a Ronstan Series 30 traveller with a standard length of 300 cm. I deliberately kept this full length, allowing part of the traveller to extend beyond the aft cabin roof. Please click here or on the image to open the full photo report. (~25 photo's)
