I have been dissatisfied with the way my mainsheet is 'threaded' through the blocks on my traveler and boom. This does not allow me control over my sail. I cannot use the traveler to effectively flatten my sail as much as I should. The block leading back to the cockpit is on the Port end of the traveler and the secured end is at the other end of the traveler (Starboard). Even when the car is fully over to port (or starboard) I cannot get the downward pull on the sail. I also get a fair amount of twist in the line. The attached photo describes the current set up best. Does anyone have a better way of running the sheet that will allow me to flatten the sail better? I am willing to purchase new blocks.
How does your mainsheet go?
- Thread starter Steve Ord
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Flatten Main Sail
Its rather hard to see what you are talking about in the photo, but I'll try to give you some things to think about. What is your reason to want to flatten your main sail? High winds should be about the only reason you would want to flatten it out. In essence a flat main is depowered. Is that what you really want to do? Your traveler is used to adjust twist in your main. If you really want to flatten the sail then install a back stay adjuster and pull it down hard when you want to depower the main. This will bend the mast and flatten or depower the main. Hope this helps.
Its rather hard to see what you are talking about in the photo, but I'll try to give you some things to think about. What is your reason to want to flatten your main sail? High winds should be about the only reason you would want to flatten it out. In essence a flat main is depowered. Is that what you really want to do? Your traveler is used to adjust twist in your main. If you really want to flatten the sail then install a back stay adjuster and pull it down hard when you want to depower the main. This will bend the mast and flatten or depower the main. Hope this helps.
A couple things
We need to agree on the function of the sail controls and terms being discussed here. The traveler is used to adjust the angle of attack of the main (within the span of the traveler beam) once the desired twist of the main has been achieved. Moving the traveler car should NOT affect the twist (downward pull) however, yours will, given how it's reaved (more in a minute.) The main sheet is used to provide the downward pull (within the span of the traveler beam) which determines the twist of the main. Once the boom clears the end of the traveler beam a vang takes over the twist control and the mainsheet now only controls angle of attack. We also need to be sure we're all discussing the same thing when we talk about 'flattening' a sail. Hauling in on the mainsheet will indeed make it less twisted (think vertical curve) so that it is (in a sense) 'flatter.' However, most experienced mainsail trimmers refer to the flattening of the main as the reduction or relocation of the camber (think horizontal curve) of the sail. Typically when we discuss the flattening or the fattening of the sail we're referring to the thickness and/or shape of the cross section of the foil. Tightening the backstay tension on most stout masthead cruising rigs will not bend the mast enough to relocate the main draft. That usually only works effectively on bendy fractional rigs. It will flatten the headsail by tensioning the headstay however. You can flatten (reduce draft) on the main using outhaul and halyard/cunningham adjustments. The way your mainsheet is terminated and reaved to port and starboard will probably hamper the traveler's ability to move the boom athwartships when the mainsheet is tensioned. In other words, your mainsheet will always be partially tensioning your boom to the center regardless of the position of the traveler car. My solution would be to terminate the mainsheet on a becket on either the top or bottom mainsheet block then exiting the block sets forward to the base of the mast, out a deck organizer/turning block then back under your dodger. This will put your mainsheet tension entirely within the vertical plane of the boom and allow the traveler to do what it's designed to do. I'd suggest reading everything you can get your hands on regarding sail trim and maybe a visit to the Garhauer website. Hope this helps.
We need to agree on the function of the sail controls and terms being discussed here. The traveler is used to adjust the angle of attack of the main (within the span of the traveler beam) once the desired twist of the main has been achieved. Moving the traveler car should NOT affect the twist (downward pull) however, yours will, given how it's reaved (more in a minute.) The main sheet is used to provide the downward pull (within the span of the traveler beam) which determines the twist of the main. Once the boom clears the end of the traveler beam a vang takes over the twist control and the mainsheet now only controls angle of attack. We also need to be sure we're all discussing the same thing when we talk about 'flattening' a sail. Hauling in on the mainsheet will indeed make it less twisted (think vertical curve) so that it is (in a sense) 'flatter.' However, most experienced mainsail trimmers refer to the flattening of the main as the reduction or relocation of the camber (think horizontal curve) of the sail. Typically when we discuss the flattening or the fattening of the sail we're referring to the thickness and/or shape of the cross section of the foil. Tightening the backstay tension on most stout masthead cruising rigs will not bend the mast enough to relocate the main draft. That usually only works effectively on bendy fractional rigs. It will flatten the headsail by tensioning the headstay however. You can flatten (reduce draft) on the main using outhaul and halyard/cunningham adjustments. The way your mainsheet is terminated and reaved to port and starboard will probably hamper the traveler's ability to move the boom athwartships when the mainsheet is tensioned. In other words, your mainsheet will always be partially tensioning your boom to the center regardless of the position of the traveler car. My solution would be to terminate the mainsheet on a becket on either the top or bottom mainsheet block then exiting the block sets forward to the base of the mast, out a deck organizer/turning block then back under your dodger. This will put your mainsheet tension entirely within the vertical plane of the boom and allow the traveler to do what it's designed to do. I'd suggest reading everything you can get your hands on regarding sail trim and maybe a visit to the Garhauer website. Hope this helps.
Standard setup
The main sheet should be run to a block at the base of the mast in order to get the proper angle of force. Both the boom at the gooseeck and the block at the base of the mast are on the same plane. The force is equal than thur the 180 degree range of the boom. Hope that helps.
The main sheet should be run to a block at the base of the mast in order to get the proper angle of force. Both the boom at the gooseeck and the block at the base of the mast are on the same plane. The force is equal than thur the 180 degree range of the boom. Hope that helps.
twist in the line?
Steve... You mention "fair amount of twist in the line" and I presume you're talking about twist in the main sheet. If so, it may be resulting from your coiling the sheet from the end back towards the blocks. As you coil, you're putting in a twist and pushing it to the blocks. If this is the cause, you can avoid it by coiling from the blocks out to the end of the sheet or using a sheet bag. Paul s/v The Lord Nelson
Steve... You mention "fair amount of twist in the line" and I presume you're talking about twist in the main sheet. If so, it may be resulting from your coiling the sheet from the end back towards the blocks. As you coil, you're putting in a twist and pushing it to the blocks. If this is the cause, you can avoid it by coiling from the blocks out to the end of the sheet or using a sheet bag. Paul s/v The Lord Nelson
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