I thought my time on the Forum was up but the good folks at Sailboatownners.com decided to hold me over for a month due to the great sail trim dialog we had last month. Lets talk about BOOM VANGS. Boom vangs have been around for many years. The first ones were just a line attached to the end of the sail with the other end attached to the windward rail. Gaff rigged mainsails used them to prevent the mainsail from sagging to leeward. These days, boom vangs are used to control TWIST in the mainsail but sadly only about 50% of the cruisers and racers worldwide actually use this devise. If you are a middle of the pack to the back of the pack racer you should use this sail trim control as the guys ahead of you are certainly using it to beat you. If you are a cruiser, you should understand how this devise works as it will make your voyages a lot easier. Cruisers that attend my seminars sometimes preface their questions with the statement "I'm just a cruiser but --------". I always answer their question with the statement "there is no difference between cruising trim and racing trim. There is only a right way and a wrong way to trim your sails". Most sailors, be they racers or cruisers want to get as much speed from they boats that they are capable of giving. Dennis Conners once asked " How many times have you heard a sailor brag that last year it took him 4 hours to get to Catalina but this year he is happily and proudly doing it in 6 hours!". I will add that a well shaped mainsail can get you to your destination a lot quicker, will relieve pressure on your autopilot, give you a more balanced ride and prevent wear and tear to your mainsail. Now don't those benefits interest you? Hopefully, you have read my recent article on TWIST. You'll recall that as you move up the mast from deck level, the wind forces increase. In fact, the wind blows 60% harder at the top of a 45' mast than at deck level so some twist is necessary and sail makers automatically build it into the sail. To control twist in the mainsail, most sailors use only the mainsheet. That works but only to a certain extent. Sometimes they pull the traveler all the way up in an effort to control twist but they completely neglect that all important twist control, which is the BOOM VANG. Here is why the boom vang is so important. When the boat heads off on a reach or a run and the boom extends over the side of the boat, the mainsheet becomes almost useless as it can no longer exert a downward force on the boom and consequently the boom lifts up as the mainsheet is eased and MORE twist is blown into the top of the sail. Experiment with this the next time your on the water and see what happens. Sailors try to correct the situation by trimming the mainsheet in an effort to correct the twist problem at the top of the sail and completely neglecting the device (boom vang) that was designed to easily correct the situation as it exerts a downward pull directly to the boom. The result of only using the mainsheet is that the lower portion of the mainsail, which is obviously the largest part of the sail, become a trimming mess, which results in a excessively heeled over boat with a lot of weather helm. If any of this sounds like a situation you encounter on your boat, try this simple solution. Grab the boom vang line and CRANK ON IT. Experiment with it and like the old song says "take it to the limit". Pull the boom vang completely tight and then ease it all the way and watch what happens to your mainsail as you do so. Once you see how it works you'll use it all the time. Any questions or comments?
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dave
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Peter Brennan
Bigger boat vang
The vang discussion has mentioned rope vangs with purchases as low as 3:1. Our O'Day 37 came with a rope vang with an 8:1 purchase. This just was not enough in any sort of breeze and the thing worked better as a preventer than a vang. We have no traveller but the old fashioned end of boom sheet to two blocks on either side of the aft coach roof. This arrangement is very poor for leech control. Our sailmaker suggested a Garhauer solid vang instead of a traveller, which would have been an ugly, expensive and difficult solution. So we bought the Garhauer, which gives a 20:1 purchase. What a difference! Absolute and total control of the leech in all conditions. The old rope vang can still be clapped on as a preventer and can also be used with the Lifesling.
The vang discussion has mentioned rope vangs with purchases as low as 3:1. Our O'Day 37 came with a rope vang with an 8:1 purchase. This just was not enough in any sort of breeze and the thing worked better as a preventer than a vang. We have no traveller but the old fashioned end of boom sheet to two blocks on either side of the aft coach roof. This arrangement is very poor for leech control. Our sailmaker suggested a Garhauer solid vang instead of a traveller, which would have been an ugly, expensive and difficult solution. So we bought the Garhauer, which gives a 20:1 purchase. What a difference! Absolute and total control of the leech in all conditions. The old rope vang can still be clapped on as a preventer and can also be used with the Lifesling.
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Bill O'Donovan
Easy solution
One way to get more oomph is to set up a second parallel set of blocks next to the existing boom vang. By doubling the purchase, you can pull down farther. Don is right about cranking it in. The difference is palpable. All this improvement with just a second set of blocks is an inexpensive investment.
One way to get more oomph is to set up a second parallel set of blocks next to the existing boom vang. By doubling the purchase, you can pull down farther. Don is right about cranking it in. The difference is palpable. All this improvement with just a second set of blocks is an inexpensive investment.
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Hayden Watson
easier solution
There is an easier and much cheaper way to double or triple your vang purchase. You can install a cascade to the vang. To double the power you run a line from the bottom of the mast through a single block on the boom where the vang attached. The existing vang is attached to the end of this line. To triple the power you run a line from the bottom of the mast through a single block with becket on the boom where the vang attached then through a single block on the vang and back to the becket. I have made my 3:1 vang into a 9:1. I have also changed my 3:1 inboom outhaul to a 6:1 by adding a wire block on the clew of the main sail. Hayden Watson S/V Papillon 1988 C30 tr/bs Spokane, WA
There is an easier and much cheaper way to double or triple your vang purchase. You can install a cascade to the vang. To double the power you run a line from the bottom of the mast through a single block on the boom where the vang attached. The existing vang is attached to the end of this line. To triple the power you run a line from the bottom of the mast through a single block with becket on the boom where the vang attached then through a single block on the vang and back to the becket. I have made my 3:1 vang into a 9:1. I have also changed my 3:1 inboom outhaul to a 6:1 by adding a wire block on the clew of the main sail. Hayden Watson S/V Papillon 1988 C30 tr/bs Spokane, WA
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Stuart
Rigid vang?
Would moving to a rigid boom vang be a good option for us on a Hunter 340? Would it provide a meaningful performance or ease of use advantage? Have looked into a Garhaurer.
Would moving to a rigid boom vang be a good option for us on a Hunter 340? Would it provide a meaningful performance or ease of use advantage? Have looked into a Garhaurer.
Stuart, I think that it really helps!
Stuart: I think that it really helped the sail shape. The Garhauer has 20:1 purchase so you can adjust it without even using the winch. Good investment.
Stuart: I think that it really helped the sail shape. The Garhauer has 20:1 purchase so you can adjust it without even using the winch. Good investment.
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Peter Brennan
Stuart: Absolutely!
The Garhauer solid vang with 20:1 purchase is probably the most cost effective thing you can do to improve performance. An added bonus, some say, is that it supports the boom so you don't need a topping lift. However, the topping lift is also a sail control and you may want it in very light air to put a lot more belly in the sail. We need it to clear the bimini too on our O'Day 37.
The Garhauer solid vang with 20:1 purchase is probably the most cost effective thing you can do to improve performance. An added bonus, some say, is that it supports the boom so you don't need a topping lift. However, the topping lift is also a sail control and you may want it in very light air to put a lot more belly in the sail. We need it to clear the bimini too on our O'Day 37.
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Bob England
Hayden: Excellent suggestion!
Sometimes it takes a bit of genius to state the obvious when it's not obvious! Thanks. I'll try doubling the ratio of my almost useless 4:1 vang ASAP. Bob.
Sometimes it takes a bit of genius to state the obvious when it's not obvious! Thanks. I'll try doubling the ratio of my almost useless 4:1 vang ASAP. Bob.
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Steve
Main Sail Trim Sequence
Being a new owner, and learning the trim to add speed, I was wondering what sequence you would recommend to adhere to when trimming the main? IE: Sheet, Outhaul, Vang, etc. I know there is a lot of interaction, but I am assuming that there should be sequence of triming to minimize the readjustment.
Being a new owner, and learning the trim to add speed, I was wondering what sequence you would recommend to adhere to when trimming the main? IE: Sheet, Outhaul, Vang, etc. I know there is a lot of interaction, but I am assuming that there should be sequence of triming to minimize the readjustment.
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Don Guillette
Main Sail Trim Sequence
Steve: Here is the trim sequence for the main and the jib. You always want to trim the jib first. JIB 1. Sail closehauled 2. Adjust jib halyard Light air - less tension (draft aft) Heavy air - more tension (draft forward) Imagine battens in the jib for proper twist setting. Top batten is leeward 5-10 degrees. Middle batten is parallel to center of boat and bottom is to weather about 5-10 degrees. 3. Fairlead adjustment Head into the wind to check the luff If the foot flutters, bottom luffs or the bottom telltales break first - move leads aft If the leech flutters, top luffs, or top telltales break first - move leads forward 4. Trim sheets until luff stops 5. Check telltales Light wind - Both flow straight back Medium wind - Leeward flows straight back and windward has a steady jump. If the leeward is not flowing straight back, the jib is about to stall so ease sheet. MAINSAIL 1. Trim sheet with top batten parallel to the boom 2. Adjust the Cunningham for 50% draft 3. Adjust outhaul so lower batten pointing toward windward 4. Set twist A - Position traveler so boom is near center of boat B - Trim mainsheet until top batten is parallel to boom Top batten can point slightly to weather. Top telltale should stream - if it curls, ease the sheet. C - Ease the traveler down Observe top and bottom of leech Top breaks first - trim sheet in (too much twist) Bottom breaks first - ease sheet out (not enough twist) D - Twist is now set E - Pull the traveler up slightly to obtain 3 to 5 degrees of weather helm Steve, so that's the sequence. Obviously, there are other factors to consider such as the wind speed and the conditions but basically that will get you in the ballpark. As a new sailor, you should get an understanding of how the sail trim controls work and what happens when you trim and ease them. It is easy for me to say adjust the Cunningham for 50% draft but if you don't know what the Cunningham is or what represents 50%, it causes a problem. With the above material I have just given the forum, and I might add you will not find it presented this simply anywhere else that I know of, please indulge me with a commercial. I can make sail trim very simple for anyone reading this. Please review the Sail trim Chart and the Sail Trim Users Guide, which is sold by Sailboatowners.com. Everything you will ever need to know about trimming your sails is contained in those two publications. Steve, give the above sequence a try on your boat and see if it works for you.
Steve: Here is the trim sequence for the main and the jib. You always want to trim the jib first. JIB 1. Sail closehauled 2. Adjust jib halyard Light air - less tension (draft aft) Heavy air - more tension (draft forward) Imagine battens in the jib for proper twist setting. Top batten is leeward 5-10 degrees. Middle batten is parallel to center of boat and bottom is to weather about 5-10 degrees. 3. Fairlead adjustment Head into the wind to check the luff If the foot flutters, bottom luffs or the bottom telltales break first - move leads aft If the leech flutters, top luffs, or top telltales break first - move leads forward 4. Trim sheets until luff stops 5. Check telltales Light wind - Both flow straight back Medium wind - Leeward flows straight back and windward has a steady jump. If the leeward is not flowing straight back, the jib is about to stall so ease sheet. MAINSAIL 1. Trim sheet with top batten parallel to the boom 2. Adjust the Cunningham for 50% draft 3. Adjust outhaul so lower batten pointing toward windward 4. Set twist A - Position traveler so boom is near center of boat B - Trim mainsheet until top batten is parallel to boom Top batten can point slightly to weather. Top telltale should stream - if it curls, ease the sheet. C - Ease the traveler down Observe top and bottom of leech Top breaks first - trim sheet in (too much twist) Bottom breaks first - ease sheet out (not enough twist) D - Twist is now set E - Pull the traveler up slightly to obtain 3 to 5 degrees of weather helm Steve, so that's the sequence. Obviously, there are other factors to consider such as the wind speed and the conditions but basically that will get you in the ballpark. As a new sailor, you should get an understanding of how the sail trim controls work and what happens when you trim and ease them. It is easy for me to say adjust the Cunningham for 50% draft but if you don't know what the Cunningham is or what represents 50%, it causes a problem. With the above material I have just given the forum, and I might add you will not find it presented this simply anywhere else that I know of, please indulge me with a commercial. I can make sail trim very simple for anyone reading this. Please review the Sail trim Chart and the Sail Trim Users Guide, which is sold by Sailboatowners.com. Everything you will ever need to know about trimming your sails is contained in those two publications. Steve, give the above sequence a try on your boat and see if it works for you.
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