Tuesday, February 1, 2011


The preparation for the nationals was very much a rush job considering the late completion of the boat and the fact that uni studies where pulling me a away from tuning and finishing the boat.

The rig was tested in the front yard for the bend characteristics of the mast under different leech loads using wire, digital scales and a block and tackle. A tight string was then run from tip the goose neck and measurements every 1/8th of the luff length taken. This gives useful information to the sail maker for determining the luff curve.

The data in the graph above shows the curves produced for different leech loads and lower stay positions e.g. (tight or loose). From the graph you can see that the difference between tight and loose lowers is quite substantial giving approximately 20-30mm difference in the point of max deflection and the position at which this point occurs. This data alone for me suggests that easily adjustable lowers on the water would give quite an advantage on days where the weather is quite unstable. This idea will be explored later on. Note: Data is for the 40mm ID series High modulus "Stiff" rig from CST made in late 2010.

After this it turned out that the rig performed rather closely to the older rig off Heart Shaped Box and it was therefore decided that due to the lack of time left and the close fitting of the main we would leave it as it was and not build a new one. This is certainly an area that can be improved on this boat though.

Overall the boats performance at the nationals was reasonable and certainly developed significantly at the end of the regatta, but our major downfall was lack of training/tuning and sailing in the new boat. Our sailing skills where not up to scratch, which cost us a lot of places and prevented us from getting the most from the boat. In terms of the performance of the hull, it appeared to nose dive no more or worse than the current Matthews hull design and held good pace downwind. Upwind pace was good but to combine this speed with height proved to be difficult. By the end of the regatta the boat had good upwind height and pace but it wasn't exceedingly quick, so i feel there are still plenty of improvements to be found.

Pushing the boat hard to the wind mark in a large chop and 25 knot winds

approaching the mark

Cruising along it the lighter breezes

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