Had an interesting discussion on the Wharram Builders and Friends website recently about getting the right sheeting geometry for the jib. The problem with the standard Tiki sheeting point is that it is ideal for "footing" to windward or on a close reach, but is a little far from the centerline for tight windward work when the wind is up. Many folks, including myself, have used barber haulers to pull the jib sheets inwards on a tight beat. I have also used barber haulers with great success to pull the jib sheets outboard for beam reaches. The problem with barber haulers is that they can be messy, with lines running everywhere. My own solution follows from experience sailing beach cats where the initial sheeting position is set for the tightest windward work, and any subsequent changes are all outboard as the boats angle to the wind broadens.
I have fitted multiple inboard and outboard sheeting points, and snap shackles to the jib blocks. Instead of using barber haulers, I just unshackle the block and move it too the best sheeting position inboard or outboard. This also works extremely well on reaches, as sheet tension can be applied to shape the sail. Note that I have taken another idea from beachcats which is to double the sheet back to a second block so that you are always pulling the sheet from the same place regardless of sheeting position (I also use a continuous sheet). The fixed block is an autoratchet which allows me to hand hold the sheet even with the large genoa in a strong breeze. I have been using this "system" for many miles now, and it works well (for me).
The upwind/inboard sheeting position gives me about an extra 10 degrees to windward over the standard position. However, it doesn't really work well until there is quite a bit of breeze and the sails are sheeted in quite flat, otherwise the jib will backwind the mainsail. I also use downhaul tension on the mainsail to flatten the front part of the sail (see my other post on cunningham/downhaul).
Update. I want to stress that the upwind/inboard position is only good for strong winds (minimum 15 knots apparent). In light winds the most forward standard position gives the best jib shape up to around 10 knots apparent IMHO. From 10 knots apparent the rear most standard position is probably the best. By 15 - 20 knots apparent beating to windward, the inboard position works with the full jib sheeted in tight. Over 20 knots apparent, a reef is needed in the jib.
It is important to keep in mind that trimming for strong wind is killing the power of the sail - you make it flatter and closer to the center of the boat to disrupt the airfoil shape and decrease its power (because you don't need it). In light winds, you are maximizing the air foil shape and presenting the sail to the wind in a way that maximizes its power.
I have fitted multiple inboard and outboard sheeting points, and snap shackles to the jib blocks. Instead of using barber haulers, I just unshackle the block and move it too the best sheeting position inboard or outboard. This also works extremely well on reaches, as sheet tension can be applied to shape the sail. Note that I have taken another idea from beachcats which is to double the sheet back to a second block so that you are always pulling the sheet from the same place regardless of sheeting position (I also use a continuous sheet). The fixed block is an autoratchet which allows me to hand hold the sheet even with the large genoa in a strong breeze. I have been using this "system" for many miles now, and it works well (for me).
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| Block on upwind/inboard sheet position - standard position is loop on cabin side |
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| Still a good "slot" between jib and main in upwind sheet position, as long as main is sheeted in tight |
The upwind/inboard sheeting position gives me about an extra 10 degrees to windward over the standard position. However, it doesn't really work well until there is quite a bit of breeze and the sails are sheeted in quite flat, otherwise the jib will backwind the mainsail. I also use downhaul tension on the mainsail to flatten the front part of the sail (see my other post on cunningham/downhaul).
Update. I want to stress that the upwind/inboard position is only good for strong winds (minimum 15 knots apparent). In light winds the most forward standard position gives the best jib shape up to around 10 knots apparent IMHO. From 10 knots apparent the rear most standard position is probably the best. By 15 - 20 knots apparent beating to windward, the inboard position works with the full jib sheeted in tight. Over 20 knots apparent, a reef is needed in the jib.
It is important to keep in mind that trimming for strong wind is killing the power of the sail - you make it flatter and closer to the center of the boat to disrupt the airfoil shape and decrease its power (because you don't need it). In light winds, you are maximizing the air foil shape and presenting the sail to the wind in a way that maximizes its power.
10 degrees to windward's gain is a damn good result: is the operation of closing the sheet to the centreline an easy one (given the required strenght of wind) or a bit complicated?
ReplyDeleteSergio
Hi Sergio.
DeleteThanks for your comment. Note that "10 degrees" is while trying to sail as close to windward as possible in a strong breeze with flat sails. In the standard sheet position, one is much more likely to be footing to windward, hence the big difference. I'm not sure what you mean by "easy" - do you mean setting up the block positions, or, how hard the sheeting is? Using the auto ratchet blocks, the sheeting loads are not high.