Is it normal for the boom to lift under sail. When sailing the topping lift wire is flapping around. Thanks
Boom lift
- Thread starter Tom23400
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Correct
Sails being triangular and 'supported' only on the luff and foot, pressure on the leech will cause the boom to lift. In moderate to heavy weather **a vang** (alternately by adjustment of the mainsheet vs. traveller) will keep the boom in proper position ...... with respect to amount of proper 'twist' aloft. In very light wind, you may consider to use/apply the topping lift to help 'equalize' the weight of the boom. By all means get a copy of Don Guilettes "Sail Trim Users Guide", etc. ... found in the chandlery / online store section of *this* website. This 'booklet' will give you a better basic understanding of sail shaping and trimming. hope this helps
Sails being triangular and 'supported' only on the luff and foot, pressure on the leech will cause the boom to lift. In moderate to heavy weather **a vang** (alternately by adjustment of the mainsheet vs. traveller) will keep the boom in proper position ...... with respect to amount of proper 'twist' aloft. In very light wind, you may consider to use/apply the topping lift to help 'equalize' the weight of the boom. By all means get a copy of Don Guilettes "Sail Trim Users Guide", etc. ... found in the chandlery / online store section of *this* website. This 'booklet' will give you a better basic understanding of sail shaping and trimming. hope this helps
A vang is
normally used to pull the boom down when needed. Usually the boom will start to lift during a broad reach and contine through a run. This is because as the boom swings outboard the main sheet gets extended it exerts less and less downward pull on the boom allowing it to lift. This is compared to being close hauled or on a close reach where the boom is much nearer the center line of the boat and the main sheet is pulling the boom nearly directly downward. I'm not sure what you mean about "the topping lift wire is flapping around". What model boat are we talking about?
normally used to pull the boom down when needed. Usually the boom will start to lift during a broad reach and contine through a run. This is because as the boom swings outboard the main sheet gets extended it exerts less and less downward pull on the boom allowing it to lift. This is compared to being close hauled or on a close reach where the boom is much nearer the center line of the boat and the main sheet is pulling the boom nearly directly downward. I'm not sure what you mean about "the topping lift wire is flapping around". What model boat are we talking about?
Tom , the short answer is yes
Thats why as Jerry said, you need a boom vang to hold it down, and the topping lift should always be loose unless as RichH said you are adjusting it to give some shape to the main in extreme light air. The topping lift normally just supports the weight of the boom when the main halyard is slack as in reefing, setting, or dousing except for that one light air situation. Have fun Joe S
Thats why as Jerry said, you need a boom vang to hold it down, and the topping lift should always be loose unless as RichH said you are adjusting it to give some shape to the main in extreme light air. The topping lift normally just supports the weight of the boom when the main halyard is slack as in reefing, setting, or dousing except for that one light air situation. Have fun Joe S
bouncing boom
Listen to Joseph Shirley he knows what hes talking about. Its normal for a boom to rock up and down on a reach or run. Dont unhook the topping lift unless your looking for extra work. Leave it connected but make sure there is enough slack in it so its not to snug going to weather. If the topping lift flops around on a reach dont worry about it. Its not going anywhere. A boom vang is used to change sail shape. Mostly for racing. Some people use a vang as a preventer to stop a gybe and hold the boom steady when running down wind. I dont think its a good Idea. Unless of course you dont mind breaking the boom when the vang trys to stop a flying gybe. After 50 years sailing Ive figured a few things out
Listen to Joseph Shirley he knows what hes talking about. Its normal for a boom to rock up and down on a reach or run. Dont unhook the topping lift unless your looking for extra work. Leave it connected but make sure there is enough slack in it so its not to snug going to weather. If the topping lift flops around on a reach dont worry about it. Its not going anywhere. A boom vang is used to change sail shape. Mostly for racing. Some people use a vang as a preventer to stop a gybe and hold the boom steady when running down wind. I dont think its a good Idea. Unless of course you dont mind breaking the boom when the vang trys to stop a flying gybe. After 50 years sailing Ive figured a few things out
Messing with the topping lift
I just snug up the topping lift so it does not flap around a lot. When you drop the sail be sure you have the boom to mast angle less than the sail design angle (boom end above the gooseneck) or you release the outhaul or you could stress out your luft attachment lugs. A mainsail with less than 90 degrees foot to luft angle will stress the luft at an area that is perpendicular to the mast and at the level of the clew. I had lots of hoist and drop issues till I discovered this little documented geometric fact. Seems the length of the foot is longer than the distance between the clew and the mast perpendicular to the mast. So as that part tries to descend below the perpendicular it has to be stretched or it just will not come down. If you have rope attaching the lugs to the mast at the lower luft up to the clew perpendicular level (the name escapes me right now)you don't have to worry about it as it allows the luft to move back and keeps it from stressing out.
I just snug up the topping lift so it does not flap around a lot. When you drop the sail be sure you have the boom to mast angle less than the sail design angle (boom end above the gooseneck) or you release the outhaul or you could stress out your luft attachment lugs. A mainsail with less than 90 degrees foot to luft angle will stress the luft at an area that is perpendicular to the mast and at the level of the clew. I had lots of hoist and drop issues till I discovered this little documented geometric fact. Seems the length of the foot is longer than the distance between the clew and the mast perpendicular to the mast. So as that part tries to descend below the perpendicular it has to be stretched or it just will not come down. If you have rope attaching the lugs to the mast at the lower luft up to the clew perpendicular level (the name escapes me right now)you don't have to worry about it as it allows the luft to move back and keeps it from stressing out.
I remember once...
I was sailing along and did not loosen my topping lift. I had a little Catalina 22 pass me and I was embarrassed. I looked up and was trying to figure out why when I noticed the topping lift was very taut. Once I loosened it, the sail filled correctly and I got a burst of speed. Passed that C22. Like everyone said, yes, the topping lift should be slack unless you are using it to help form the sail. Enjoy!
I was sailing along and did not loosen my topping lift. I had a little Catalina 22 pass me and I was embarrassed. I looked up and was trying to figure out why when I noticed the topping lift was very taut. Once I loosened it, the sail filled correctly and I got a burst of speed. Passed that C22.
Like everyone said, yes, the topping lift should be slack unless you are using it to help form the sail. Enjoy!
Normal setting/tensioning of the topping lift.
On a windless day, raise the mainsail including the proper amount of extra 'preload' to the boltrope (about 1" of additional halyard strain for every 11 ft. of sail luff length - this additional pre-load will shape the sail for approx 15kts of wind, less preload for lighter winds). Proper pre-load to the luff boltrope will raise the boom end. Then, put the traveller on the centerline and put in the MAXIMUM amount of strain that you normaly apply to the mainsheet (includes the extra strain necessary to 'hook up the battens to weather' when power-pinching, etc.). **Now, set/cleat the topping lift with this amount of 'stretch' in the sail. Make a mark (wrap of tape) on the topping lift at its cleat/restraint/clutch so you can easily and exactly return to this 'basic' dimension .... or better yet dont ever release this dimension as you can shorten the Topping lift by simply cleating 'over' this basic setting. A too tight topping lift will 'oppose' the mainsheet tension, leaving the mainsail overly 'twisted', etc. If the topping lift is 'too sloppy' for your tastes, leave the above alone / cleated; but, slightly shorten the length of the topping lift until its 'quiet enough' for you, cleating 'over' or 'on top of' the above setting. When done sailing, etc. or you need to 'power-pinch' just release the extra bit that was cleated 'over' on top of the 'basic' setting. Much much better is to use a spring loaded 'rigid' vang ... does the work of the vang AND topping lift, all at the same time .... .
On a windless day, raise the mainsail including the proper amount of extra 'preload' to the boltrope (about 1" of additional halyard strain for every 11 ft. of sail luff length - this additional pre-load will shape the sail for approx 15kts of wind, less preload for lighter winds). Proper pre-load to the luff boltrope will raise the boom end. Then, put the traveller on the centerline and put in the MAXIMUM amount of strain that you normaly apply to the mainsheet (includes the extra strain necessary to 'hook up the battens to weather' when power-pinching, etc.). **Now, set/cleat the topping lift with this amount of 'stretch' in the sail. Make a mark (wrap of tape) on the topping lift at its cleat/restraint/clutch so you can easily and exactly return to this 'basic' dimension .... or better yet dont ever release this dimension as you can shorten the Topping lift by simply cleating 'over' this basic setting. A too tight topping lift will 'oppose' the mainsheet tension, leaving the mainsail overly 'twisted', etc. If the topping lift is 'too sloppy' for your tastes, leave the above alone / cleated; but, slightly shorten the length of the topping lift until its 'quiet enough' for you, cleating 'over' or 'on top of' the above setting. When done sailing, etc. or you need to 'power-pinch' just release the extra bit that was cleated 'over' on top of the 'basic' setting. Much much better is to use a spring loaded 'rigid' vang ... does the work of the vang AND topping lift, all at the same time .... .
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