Windermere 17ft Rig Tuning Guide
Windermere 17ft Yacht Tuning Guide
The following is a guide to the settings for a 17ft yacht rig on the newer yachts. Due to the rig loads, unless the deck and super structure of a classic yacht has been strengthen, it is suggested that the following rig loads are not used, other data applies to both new and classic.
When stepping the mast ensure it is upright and straight sideways in the yacht. You can check the straightness of the mast by looking up the luff groove. A simple way of doing this is to step the mast and gradually apply finger tightness to all four shrouds, then add addition turns to each shroud, one turn at a time in rotation to each shroud, until the rig is not flapping, with some tension in it, then add three full turns to the lowers. If the luff grove is not straight adjust the lowers or caps on one side to straightened the mast. Experimentation will soon show you, when adjusting a particular shroud, what affect it has on the bend.
Once the mast is straight you now add tension to the rig evenly on both sides until the following settings are obtained:
Caps 30 to 32 Lowers 34 to 36
All figures are taken using the rig tension gauge Loose Model PT-1M
These settings will vary from yacht to yacht, but for those that don’t have any starting figures suggest you use the middle numbers of caps 31 and lowers 35 and work up and down a turn on each to see what works best for your yacht?
It does appear that one common figure is the difference between the caps and the lowers settings being around the 4 mark. So if the caps are 30 the lowers are 34 or if the caps are 32 the lowers are 36, this may vary on each yacht though as to what works best?
Once the appropriate rig tension settings have been obtained, ensure the mast is straight again by looking up the luff groove, if not straight, adjust the caps and lowers accordingly until straight, then re-check the tension and adjust if necessary.
As a general rule the tighter the rig tension the better the upwind performance, the more forward mast rake downwind the better the performance, but there is an issue when trying to optimise both settings, so a compromise will be needed.
When raking the mast forward it gets to a point where the mast S bends and becomes unstable, as raking forward automatically causes tightening of the rig tension and subsequently compression, ideally the resulting S bending should be avoided. The shroud anchor position on each yacht is different and therefore the rig loads will vary on each yacht when raking the mast forward. Even a yacht with a shroud position 5 mm more aft will mean the mast will S bend earlier when raking the mast forward, than a yacht with the shroud anchor point further forward. The same amount of forward rake though can be achieved, without S bending the mast, if the rig tension is reduced slightly on a yacht with the shroud position further aft.
If you feel your yacht sails well up wind, but not fast downwind as little forward rake can be achieved without S bending the mast, then you may wish to reduce the rig tension loads. This may reduce up wind performance, but enable you to increase forward rake and subsequently downwind speed? Likewise vice versa, if your downwind performance is good due to a lot of forward rake without the mast S bending, but the upwind performance is not so good, then you might want to increases your rig tension loads and reduce the amount of forward rake before the mast S bends. The upwind performance may now increase?
The amount of mast rake when sailing upwind is not so critical on a 17ft, unlike many other classes. You can measure the rake on a 17ft mast by having no sails up and the forestay and back stay set with a little tension on, just enough to hold the mast in position without is flopping backwards and forwards whilst on the water. Hoist a thin piece of cord to the top of the mast with a weight on the end by using the main halyard. With the weight hanging freely measure from the back of the mast track to the centre of the cord, the figure you are looking for is between 11 inches to 14 inches. Adjust the backstay and forestay evenly until the desired measurement figure is reached, say 12 inches to start with. Again your yacht may perform better when set at 11 inches or say 13 inches, it is trial and error to see what suits your yacht the most. You can now mark your forestay setting and the backstay on the actual backstay if you want to, so you can return to these setting after each downwind leg ready for the beat whilst racing. When sailing you can set the forestay to the mark when on a beat and then set the jib halyard appropriately and mark that as well, making setting the rig at the leeward mark much easier. These setting should be ideal for light wind, as the wind increases the backstay is applied, it might be worth putting a couple of other marks on the backstay, at say 3 inch intervals, one for medium and the other for heavier winds. This will give you mean points to work around in the varying conditions to determine the optimum for your yacht.
For consistency of jib setting you can mark your jib sheets in two position in relationship to the jib cars, one for light winds and the other for stronger winds, this will provide key settings, enabling you to quickly reproduced them once you have found what works best on your yacht. Putting black tape around your spreaders, measured at 2 inch intervals from the spreader end, can also help when comparing the jib batten end in relationship to the black bands. The relationship to the outer band will be appropriate for light winds and the relationship to the inner band for stronger winds, trial and error will determine what the relationship is?