I have a Catalina 36 with a split back stay. The lower stays are 1/4" diameter. I recently had to remove them at their lower ends. I am readjusting them. I am using a Loos gauge to get the tension. The gauge shows a table ranging from 250-1800 for 1/4" cable. As I pull on the gauge, what should it read on the top part. I figured it should be around 50, but when I get the turnbuckle tightened almost all the way to the end of the threads, the gauge still only reads about 40-43 or so. Is this okay?
back stay tension
- Thread starter John
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Loos gauge
Hi John; I do not have my Loos guage with me, so I don't know what those readings correspond to in pounds. Generally you want about 10% of the wire's breaking strength, and enough tension on the back stay so there is very little sag to your headstay/furler. In a split back stay, it is a little tricky, but I have found that if I have 500 lbs on each part of the "Y" when I measure the single stay above the "Y" it will read close to 1000lbs. Figure out what diameter wire the backstay is, find its rated breaking strength, (Look in West Marine catalog under rigging.)and adjust it to 10% of that value. That is a good starting point to tune your rig. Of course check that the mast is true and that you have the disired rake, (very little on a C36) You can check the upper part of your backstay by walking out on your boom holding on to a spare halyard for balance and use your Loos guage about the "Y" fitting. Another clue is to look closly at your turnbuckles and adjust them close to where they were before. (the threads will be a slightly different shade) good luck Dave
Hi John; I do not have my Loos guage with me, so I don't know what those readings correspond to in pounds. Generally you want about 10% of the wire's breaking strength, and enough tension on the back stay so there is very little sag to your headstay/furler. In a split back stay, it is a little tricky, but I have found that if I have 500 lbs on each part of the "Y" when I measure the single stay above the "Y" it will read close to 1000lbs. Figure out what diameter wire the backstay is, find its rated breaking strength, (Look in West Marine catalog under rigging.)and adjust it to 10% of that value. That is a good starting point to tune your rig. Of course check that the mast is true and that you have the disired rake, (very little on a C36) You can check the upper part of your backstay by walking out on your boom holding on to a spare halyard for balance and use your Loos guage about the "Y" fitting. Another clue is to look closly at your turnbuckles and adjust them close to where they were before. (the threads will be a slightly different shade) good luck Dave
John, My Loos gauge model B has a chart that
stops at 43 for 1/4 wire at a rating of 1,800 lbs. Normal 1/4 1-19 strand wire has a breaking strength of 7,000 to 8,000 lbs. At 10% of breaking strength you are looking at about 750 lbs which according to the chart in the gauge should be attained with a reading of around 37. I'm afraid you may have overtightened the stay. The split backstay divides the load in half between the two turnbuckles so the reading must be made above the "Y" on the single stay. Check the gauge of the wire for that single stay as it could be larger than the two lower ones which only carry half the load. Good luck.
stops at 43 for 1/4 wire at a rating of 1,800 lbs. Normal 1/4 1-19 strand wire has a breaking strength of 7,000 to 8,000 lbs. At 10% of breaking strength you are looking at about 750 lbs which according to the chart in the gauge should be attained with a reading of around 37. I'm afraid you may have overtightened the stay. The split backstay divides the load in half between the two turnbuckles so the reading must be made above the "Y" on the single stay. Check the gauge of the wire for that single stay as it could be larger than the two lower ones which only carry half the load. Good luck.
Backstay tension ......
is dependent on how you sail On most marconi rigs the 'initial' backstay tension is probably in the range of 12-15%. The following discussion is rigorous/advanced so I apologize if this seems beyond a 'newbie' discussion: Headsail 'shape' is dependent on backstay tension and if you sail your boat 'hard' you will need increased backstay tension to compensate. When a head sail is made the sailmaker will assume that the headstay/backstay is at that 12-15% tension and then cuts a smooth curve from the luff front edge of the sail (called 'luff hollow') to **compensate for the headstay to 'sag' off to leeward when the sail is fully windloaded** on a 'beat', etc. If the tension in the headstay (reacts directlly with the backstay) is too loose the 'curve' at the front of the headsail will be too much, the draft in the headsail will move 'aft' in the sail and the angle of attack will lessen as the leading edge / luff physically MOVES to leeward. This will result in a boat that heels over easily or too much, the boat begins to skid off to leewards (instead of 'pointing'), and wont be moving very fast .... and the helmsman will erroneously blame 'weather helm' when he/she feels the 'skid' as adverse helm pressure. When beating in your 'maximum customary conditions' (unreefed) you need to match the 'luff hollow' curve that the sailmaker cut into the sail with the curve or *sag* that the headstay is taking ..... by adjusting the backstay tension. That *sag* should *match* the luff hollow. You do this by changing backstay tension (or running backstays if you have them). How much *sag* , how to determine? ASK your sailmaker what is the maximum value of 'luff hollow' and 'eyeball' that curve by adjusting the backstay tension so that 'luff hollow' shape is close when on a hard beat. If you never met the sailmaker.... take the sail and lay it on flat clean ground (emphasis on clean). The object is to make the luff section ....2-3 ft. back from the leading edge FLAT on the ground: make an 'accordian fold' at and parallel to the luff. This accordian fold will allow the LUFF section of the sail to be FLAT on the ground. remove all the 'wrinkles near the luff and pull the head and tack to get the sail to be FLAT at the luff. Then take a string from the head to the tack and pull tight ..... youll notice that the luff is 'very curved' in comparison to the taught string .... this is the "luff hollow". Just REMEMBER what that shape is (or measure the max. dimension that is 'missing' ... as thats what the shape should look like when sailing, especially beating ....... you adjust the backstay tension up or down so that 'the luff hollow' is close to what you saw when the sail was laying FLAT on the ground. If you have the (bad) habit of overloading the jib sheet with a LOT of winch tension .... you'll also need to increase backstay tension to compensate to restore the proper 'luff hollow shape' in the sail. For a 'static' tune .... 12-15% is probably ideal. For 'hard sailing' in high winds, etc. 30% is probably the max. you want to be (for structural/strength concerns). Start out at 15%, leave the gage on the backstay, take the boat out in your 'max. unreefed conditions', adjust the backstay tension until you get close to that leading edge shape .... then go sailing and watch the gage on the backstay so that you dont see the gage going over 30%, 'often' when beating. If you need high tension to get good 'performance', be sure to 'detune the backstay when back at the dock down to 15% .... dont leave a backstay at high tension when youre not using the boat. Summary: So, to answer your question of how much 'backstay tension' ..... what ever tension it takes to keep the luff of the headsail and headstay sag 'close' to the 'luff hollow' shape that the sailmaker put into the sail when it was made. Match the headstay sag to the 'luff hollow' shape ..... and you will have a FAST boat, a boat that will 'point' extremely well, a boat that wont excessively heel over, and a boat that will 'tack' easily. If you have a 'split backstay' and you are measuring with the gagte ON the split, all the values are 'half'.
is dependent on how you sail On most marconi rigs the 'initial' backstay tension is probably in the range of 12-15%. The following discussion is rigorous/advanced so I apologize if this seems beyond a 'newbie' discussion: Headsail 'shape' is dependent on backstay tension and if you sail your boat 'hard' you will need increased backstay tension to compensate. When a head sail is made the sailmaker will assume that the headstay/backstay is at that 12-15% tension and then cuts a smooth curve from the luff front edge of the sail (called 'luff hollow') to **compensate for the headstay to 'sag' off to leeward when the sail is fully windloaded** on a 'beat', etc. If the tension in the headstay (reacts directlly with the backstay) is too loose the 'curve' at the front of the headsail will be too much, the draft in the headsail will move 'aft' in the sail and the angle of attack will lessen as the leading edge / luff physically MOVES to leeward. This will result in a boat that heels over easily or too much, the boat begins to skid off to leewards (instead of 'pointing'), and wont be moving very fast .... and the helmsman will erroneously blame 'weather helm' when he/she feels the 'skid' as adverse helm pressure. When beating in your 'maximum customary conditions' (unreefed) you need to match the 'luff hollow' curve that the sailmaker cut into the sail with the curve or *sag* that the headstay is taking ..... by adjusting the backstay tension. That *sag* should *match* the luff hollow. You do this by changing backstay tension (or running backstays if you have them). How much *sag* , how to determine? ASK your sailmaker what is the maximum value of 'luff hollow' and 'eyeball' that curve by adjusting the backstay tension so that 'luff hollow' shape is close when on a hard beat. If you never met the sailmaker.... take the sail and lay it on flat clean ground (emphasis on clean). The object is to make the luff section ....2-3 ft. back from the leading edge FLAT on the ground: make an 'accordian fold' at and parallel to the luff. This accordian fold will allow the LUFF section of the sail to be FLAT on the ground. remove all the 'wrinkles near the luff and pull the head and tack to get the sail to be FLAT at the luff. Then take a string from the head to the tack and pull tight ..... youll notice that the luff is 'very curved' in comparison to the taught string .... this is the "luff hollow". Just REMEMBER what that shape is (or measure the max. dimension that is 'missing' ... as thats what the shape should look like when sailing, especially beating ....... you adjust the backstay tension up or down so that 'the luff hollow' is close to what you saw when the sail was laying FLAT on the ground. If you have the (bad) habit of overloading the jib sheet with a LOT of winch tension .... you'll also need to increase backstay tension to compensate to restore the proper 'luff hollow shape' in the sail. For a 'static' tune .... 12-15% is probably ideal. For 'hard sailing' in high winds, etc. 30% is probably the max. you want to be (for structural/strength concerns). Start out at 15%, leave the gage on the backstay, take the boat out in your 'max. unreefed conditions', adjust the backstay tension until you get close to that leading edge shape .... then go sailing and watch the gage on the backstay so that you dont see the gage going over 30%, 'often' when beating. If you need high tension to get good 'performance', be sure to 'detune the backstay when back at the dock down to 15% .... dont leave a backstay at high tension when youre not using the boat. Summary: So, to answer your question of how much 'backstay tension' ..... what ever tension it takes to keep the luff of the headsail and headstay sag 'close' to the 'luff hollow' shape that the sailmaker put into the sail when it was made. Match the headstay sag to the 'luff hollow' shape ..... and you will have a FAST boat, a boat that will 'point' extremely well, a boat that wont excessively heel over, and a boat that will 'tack' easily. If you have a 'split backstay' and you are measuring with the gagte ON the split, all the values are 'half'.
John: Loos sells gauges and they sell gauges. You can't tell whether the economy series (#90 and #91) will measure your upper backstay w/o having gauge in hand, or calling Loos customer service. But the Loos professional PT series has a gauge for each of three different wire size ranges. Dave from MI seems to have it about right. You should expect the upper wire to be under slightly less than double the sum of the the tensions of each lower leg. I would think that the correct way to go would be to correctly tension the upper wire, and accept whatever tension it takes in the lower legs to get the correct result. If your gauge can't handle the upper wire diameter and you don't want to buy the correct gauge for that wire, there is a method of coming adequately close to the correct upper wire tension w/o use of a gauge. It involves measuring the stretch of the backstay from a minimum load condition to the full working load condition. You measure the stretch of a specific length of wire (i.e. of a % of total wire length)and adjust the wire tension to achieve the desired stretch, which gives you close to the proper/desired % of the wire's breaking strength. Specifics i.e. wire lengths to be measured and acceptable results, escape me, but perhaps other forum members can help out here.
RichH gave a good overview but Dave mentioned mast rake
which is of premium importance. If your rake on a masthead rig is negative (mast leans forward), you will abnormally tension your backstay, and your Headstay will never be tight enough. Rake on any boat should be the first thing you should check . It could be as small as 1 or 2 inches or on some boats as much as 18. Without positive rake, your backstay will always have a higher load than the headstay whichis not what you want. This should be done by snugging the rig only. Once rake is set, the mast should be centered by adjusting the uppers; and then the mast should be straightened by ajusting the lowers. Then the lowers can be tightened to spec followed by the uppers. The headstay and backstay should then be adjusted together to keep the mast straight. A mast bending forward is out of column and is weaker, and it increases the draft in your main. A mast bending aft is initially weaker also, and it flattens the main. When all the rig is static and as tight as you want, it should be straight and have the required rake. Adjusting the backstay alone is a NO NO. Remember also that the sum of the horizontal loads at the "Y" in the split backstay is zero, that means that they don't have to be adjusted much to be perfectly equal as they will shift a little to port or starboard to self adjust (within reason of course). When you are sailing and you tighten the backstay adjuster you put a bend in the mast and tighten the headstay, an advantage in going to weather. The out of column of this bend is slightly compensated for by the main being attached. Then when you go off the wind you ease the backstay off to increase the draft in your sails again. Be aware that the more backstay you adjust in, the slacker your uppers become and the more your masthead bends off to leeward. If you set the rig up tight and crank hard on the backstay you can drive the mast through the bottom or break the back of the boat (I have seen both happen with Hudraulic Backstay Adjusters). Remember that tight rigging is more responsive makes the boet faster, and is harder on the boat; looser rigging is not as quick but is more comfortable sailing and is easier on the boat. If all this advice has your head swimming perhaps the easiest thing to do is follow Dave's advice and tighten the turnbuckles to where they were before. Joe
which is of premium importance. If your rake on a masthead rig is negative (mast leans forward), you will abnormally tension your backstay, and your Headstay will never be tight enough. Rake on any boat should be the first thing you should check . It could be as small as 1 or 2 inches or on some boats as much as 18. Without positive rake, your backstay will always have a higher load than the headstay whichis not what you want. This should be done by snugging the rig only. Once rake is set, the mast should be centered by adjusting the uppers; and then the mast should be straightened by ajusting the lowers. Then the lowers can be tightened to spec followed by the uppers. The headstay and backstay should then be adjusted together to keep the mast straight. A mast bending forward is out of column and is weaker, and it increases the draft in your main. A mast bending aft is initially weaker also, and it flattens the main. When all the rig is static and as tight as you want, it should be straight and have the required rake. Adjusting the backstay alone is a NO NO. Remember also that the sum of the horizontal loads at the "Y" in the split backstay is zero, that means that they don't have to be adjusted much to be perfectly equal as they will shift a little to port or starboard to self adjust (within reason of course). When you are sailing and you tighten the backstay adjuster you put a bend in the mast and tighten the headstay, an advantage in going to weather. The out of column of this bend is slightly compensated for by the main being attached. Then when you go off the wind you ease the backstay off to increase the draft in your sails again. Be aware that the more backstay you adjust in, the slacker your uppers become and the more your masthead bends off to leeward. If you set the rig up tight and crank hard on the backstay you can drive the mast through the bottom or break the back of the boat (I have seen both happen with Hudraulic Backstay Adjusters). Remember that tight rigging is more responsive makes the boet faster, and is harder on the boat; looser rigging is not as quick but is more comfortable sailing and is easier on the boat. If all this advice has your head swimming perhaps the easiest thing to do is follow Dave's advice and tighten the turnbuckles to where they were before. Joe
Will have to study all this
Thanks very much for all the advice. It's clear that there is no one correct answer - just as there is no one correct answer to "what's the best boat?" Also, what I'm gathering is that this is a fluid thing - as the very existence of adjustable back stays implies. It also leads to another question: I have noticed that my boat points very badly - that I can't get at all close to the wind without the headsail luffing. I always thought this was a function of having a in-mast furling main sail. Now, on thinking about it, it seems to me that there is no reason why a not very efficient main sail should cause the head sail to luff easily when close hauled. After all, the wind gets to the head sail first at that point of sail. What I'm wondering is whether the back stay was incorrectly tensioned all along and that's the cause of my problem. Maybe it was not tight enough? In any case, I'm thinking of getting a rigger to check it all out and give me some advice. Reading the advice on this list is great and very helpful, but maybe it would be more helpful to get somebody who really knows what they are doing to directly look at my particular boat. Thanks again.
Thanks very much for all the advice. It's clear that there is no one correct answer - just as there is no one correct answer to "what's the best boat?" Also, what I'm gathering is that this is a fluid thing - as the very existence of adjustable back stays implies. It also leads to another question: I have noticed that my boat points very badly - that I can't get at all close to the wind without the headsail luffing. I always thought this was a function of having a in-mast furling main sail. Now, on thinking about it, it seems to me that there is no reason why a not very efficient main sail should cause the head sail to luff easily when close hauled. After all, the wind gets to the head sail first at that point of sail. What I'm wondering is whether the back stay was incorrectly tensioned all along and that's the cause of my problem. Maybe it was not tight enough? In any case, I'm thinking of getting a rigger to check it all out and give me some advice. Reading the advice on this list is great and very helpful, but maybe it would be more helpful to get somebody who really knows what they are doing to directly look at my particular boat. Thanks again.
Mast rake is probably the LAST thing you need to do.......
in setting up a rig. The reason for most 'weather helm' problems is simply that most folks dont know how to raise their mainsails !!!!!!!!!!!!! Most mainsails are constructed with 'bolt-ropes' - a 3 strand dacron rope in a sleeve at the luff. The bolt-rope is used so that the sail doesnt unduly stretch along the luff when its fully windloaded (ie. 15 kts. of true wind). A sailmaker will take such boltropes and 'preload' the rope by shortening it (by about 1 " for every 10-11 ft. of luff length) before attaching it at the head/foot of the sail. Unless one stretches-out this pre-load when raising the sail, the sail will take on an 'ungodly' shape .... the draft will be aft, the draft will be too full, the battens will be slightly hooked to weather, etc. - a slow 'powered-up' sail that (unless the preload is taken up by the halyard) will cause 'weather helm'. Its easy to see a sail that isnt correctly raised on another sailboat .... the head of the sail wont be 'full-up' and the aft end of the boom will be horizontally lower than the gooseneck. Probably 99% of cruisers sail this way. So, when raising a boltroped sail, after the sail is 'up', add additional halyard tension and stretch out that boltrope (1" for every 10 - 11 ft. of luff length) as this 'tension' will get you to the shape that sailmaker intended/designed ... THEN see if you have 'weather helm'. When 'setting' such a sail, get it up, stretch out the boltrope pre-load then note if you have 'weather helm'; if so, keep adding stretch to the halyard until the boat's helm goes 'NEUTRAL' then 'back off' the halyard tension until the boat has a few small degrees of 'weather helm'. If this cant be done, THEN, consider to re-rake the mast. If the mainsail has no 'boltrope' or is a 'taped' luff - just raise it. Typically a mast should have a small forward bow (called prebend) forward near the middle of the mast. This 'pre-bend' will vastly add 'stiffness' and will prevent the mast from 'pumping' (severe vibrations) in the higher windranges. The typical 'prebend' is 3/4" forward bow for a single spreader rig or 1-1.5" for a double spreader rig .... check with the sparmaker for the exact recommendations. Sailmakers usually add this 'prebend' in their design calculations .... so if your mast doesnt have the 'prebend', then the sail will be have a 'deeper' and more 'full draft' when set with a 'straight' mast. Check with your sparmaker.
in setting up a rig. The reason for most 'weather helm' problems is simply that most folks dont know how to raise their mainsails !!!!!!!!!!!!! Most mainsails are constructed with 'bolt-ropes' - a 3 strand dacron rope in a sleeve at the luff. The bolt-rope is used so that the sail doesnt unduly stretch along the luff when its fully windloaded (ie. 15 kts. of true wind). A sailmaker will take such boltropes and 'preload' the rope by shortening it (by about 1 " for every 10-11 ft. of luff length) before attaching it at the head/foot of the sail. Unless one stretches-out this pre-load when raising the sail, the sail will take on an 'ungodly' shape .... the draft will be aft, the draft will be too full, the battens will be slightly hooked to weather, etc. - a slow 'powered-up' sail that (unless the preload is taken up by the halyard) will cause 'weather helm'. Its easy to see a sail that isnt correctly raised on another sailboat .... the head of the sail wont be 'full-up' and the aft end of the boom will be horizontally lower than the gooseneck. Probably 99% of cruisers sail this way. So, when raising a boltroped sail, after the sail is 'up', add additional halyard tension and stretch out that boltrope (1" for every 10 - 11 ft. of luff length) as this 'tension' will get you to the shape that sailmaker intended/designed ... THEN see if you have 'weather helm'. When 'setting' such a sail, get it up, stretch out the boltrope pre-load then note if you have 'weather helm'; if so, keep adding stretch to the halyard until the boat's helm goes 'NEUTRAL' then 'back off' the halyard tension until the boat has a few small degrees of 'weather helm'. If this cant be done, THEN, consider to re-rake the mast. If the mainsail has no 'boltrope' or is a 'taped' luff - just raise it. Typically a mast should have a small forward bow (called prebend) forward near the middle of the mast. This 'pre-bend' will vastly add 'stiffness' and will prevent the mast from 'pumping' (severe vibrations) in the higher windranges. The typical 'prebend' is 3/4" forward bow for a single spreader rig or 1-1.5" for a double spreader rig .... check with the sparmaker for the exact recommendations. Sailmakers usually add this 'prebend' in their design calculations .... so if your mast doesnt have the 'prebend', then the sail will be have a 'deeper' and more 'full draft' when set with a 'straight' mast. Check with your sparmaker.
John ..... get a 'combo' analysis
get a rigger with sailmaking experience or a sailmaker with rigging experience. You cant divorce the two into separate quantities ... as a headsail on a foil or forestay is a SYSTEM. If all the curves of the headstay takes when nloaded by the sail dont match the curves that the sailmaker put into the sail ..... you will get 'adverse' results. ;-)
get a rigger with sailmaking experience or a sailmaker with rigging experience. You cant divorce the two into separate quantities ... as a headsail on a foil or forestay is a SYSTEM. If all the curves of the headstay takes when nloaded by the sail dont match the curves that the sailmaker put into the sail ..... you will get 'adverse' results. ;-)
Rich, come sail with me...
When ever you need a break from MD, head on down. I could learn a lot from a long day sailing. As far as that goes, I learn something new anytime I get out on the water. Thanks for your informative post. I will have to look up my mast better the next time I am out. Ross
When ever you need a break from MD, head on down. I could learn a lot from a long day sailing. As far as that goes, I learn something new anytime I get out on the water. Thanks for your informative post. I will have to look up my mast better the next time I am out. Ross
Well, for that matter,
if any of you with loads of experience would like to spend a day out on the bay with me here in California, let me know. Beer would be on me in exchange for the opportunity to pick your brain.
if any of you with loads of experience would like to spend a day out on the bay with me here in California, let me know. Beer would be on me in exchange for the opportunity to pick your brain.
John --- easier than that.
just go hang around the docks where the racing fleets congregate. Especially on Wednesday nites, etc. they are always looking for 'extra crew' or 'rail beef'. Tell them that you're a 'newbie' looking to 'learn'. Just be careful not to pick a boat with a "Captain Bligh" as the master.
just go hang around the docks where the racing fleets congregate. Especially on Wednesday nites, etc. they are always looking for 'extra crew' or 'rail beef'. Tell them that you're a 'newbie' looking to 'learn'. Just be careful not to pick a boat with a "Captain Bligh" as the master.
Oh Boy! Do I disagree with Rich
The reason To check mast rake first is as I stated, to make sure that it is positive, so that the backstay can tighten the headstay to control sail shape. A prebend is often used by more dedicated racing sailors because they crank the backstay early to tighten the headstay, and that often straightens the mast. Rich talked about weather helm and mainsail shape which was not all incorrect, and weather helm can be affected by both rake and mainsail shape; but the correct rake is a function of the boat design, and the mast placement. Normally you can determine what is correct from serious racers of similar boats, as it does affect speed and balance. Weather helm is not just a function of mainsail shape as Rich would have you believe. All boats properly tuned are designed statically with a lee helm. As the boat sails it heels, and the driving force in the sails goes off center, producing what is known as a weather couple to turn the boat upwind (weather helm). Excessive mainsail draft and excessive mast rake can both contribute to weather helm as Rich said, but most often, it is caused by excessive heeling. Therefore when it happens regardless of your mainsail shape, you can reduce weather helm by spilling some main, twisting it off, running your jib sheets aft to twist off its head, or any combination to reduce your heel. When you do that, you will note a lot less corrective force on your helm and your boat will sail easier and faster. All that said, Rich had a valid point about mainsail shape, and in my discussion I assumed correct shape was a given. So with the correct sail shape and the normal angle of heel (say 15 to 18 degrees), and whether you use prebend or not: there is also a correct amount of mast rake; and it should never be negative. I also agree that the services of a good rigger are very beneficial , but I think he puts too much emphasis on a riggers sail making knowledge. If you are a serious racer using custom molded sails cut for prebend , thats one thing;--- but if you are a typical club or cruising sailor who gets sails from a sail maker who quotes and manufacturers them from a standards book; then use a straight mast and a good rigger regardless of how much sail making knowledge he has.
The reason To check mast rake first is as I stated, to make sure that it is positive, so that the backstay can tighten the headstay to control sail shape. A prebend is often used by more dedicated racing sailors because they crank the backstay early to tighten the headstay, and that often straightens the mast. Rich talked about weather helm and mainsail shape which was not all incorrect, and weather helm can be affected by both rake and mainsail shape; but the correct rake is a function of the boat design, and the mast placement. Normally you can determine what is correct from serious racers of similar boats, as it does affect speed and balance. Weather helm is not just a function of mainsail shape as Rich would have you believe. All boats properly tuned are designed statically with a lee helm. As the boat sails it heels, and the driving force in the sails goes off center, producing what is known as a weather couple to turn the boat upwind (weather helm). Excessive mainsail draft and excessive mast rake can both contribute to weather helm as Rich said, but most often, it is caused by excessive heeling. Therefore when it happens regardless of your mainsail shape, you can reduce weather helm by spilling some main, twisting it off, running your jib sheets aft to twist off its head, or any combination to reduce your heel. When you do that, you will note a lot less corrective force on your helm and your boat will sail easier and faster. All that said, Rich had a valid point about mainsail shape, and in my discussion I assumed correct shape was a given. So with the correct sail shape and the normal angle of heel (say 15 to 18 degrees), and whether you use prebend or not: there is also a correct amount of mast rake; and it should never be negative. I also agree that the services of a good rigger are very beneficial , but I think he puts too much emphasis on a riggers sail making knowledge. If you are a serious racer using custom molded sails cut for prebend , thats one thing;--- but if you are a typical club or cruising sailor who gets sails from a sail maker who quotes and manufacturers them from a standards book; then use a straight mast and a good rigger regardless of how much sail making knowledge he has.
tension
Thanks to all, there is a lot of good info in this thread. When I am talking to someone whose boat I am not familiar with, I am conservative on the amount of rig tension I recommend. 10% is snug, and will keep the mast upright even in a decent wind. The boat will sail acceptably for 90% of us "cruising" sailors. 10% rig tension generally will not harm any boat regardless of the condition of the turnbuckles, stay fittings, and chain plates. My boat is tuned to about 15% of breaking strength. I have tuned some boats that 10% was pushing the upper limit, and I so advised the owner. I believe the old saw that more rigs fail from to slack rigging that from overtightened. Fair winds Dave
Thanks to all, there is a lot of good info in this thread. When I am talking to someone whose boat I am not familiar with, I am conservative on the amount of rig tension I recommend. 10% is snug, and will keep the mast upright even in a decent wind. The boat will sail acceptably for 90% of us "cruising" sailors. 10% rig tension generally will not harm any boat regardless of the condition of the turnbuckles, stay fittings, and chain plates. My boat is tuned to about 15% of breaking strength. I have tuned some boats that 10% was pushing the upper limit, and I so advised the owner. I believe the old saw that more rigs fail from to slack rigging that from overtightened. Fair winds Dave
A related question
Thanks again for all the information. Also, I'd like to ask again about sailing close hauled. Up until now, I think I was unable to get any closer than 55-60 degrees, maybe even further off the wind, before the jib starts luffing. Could this be due to the stays and/or shrouds being incorrectly adjusted? If so, what sort of mis-adjustment is most likely?
Thanks again for all the information. Also, I'd like to ask again about sailing close hauled. Up until now, I think I was unable to get any closer than 55-60 degrees, maybe even further off the wind, before the jib starts luffing. Could this be due to the stays and/or shrouds being incorrectly adjusted? If so, what sort of mis-adjustment is most likely?
John how are you reading the 55-60 degree's
Are you looking at the electronic Raytheon mast head wind gauge? They can be notorious for not being set dead on the wind.(You need to adjust them to be at 0 degrees when going straight ahead) Also are you reading the degrees off the "true" wind or the "apparent" wind. You have to make sure you are reading the Raytheon correctly and go back and forth. If you are reading 55-60 degree's off the True wind and you are going ~ 6kts you are not doing to bad - That might translate to 40-45% depending on the speed you are going. Sometimes the best way to tell is with the old 'analog' static windvane at the top of the mast
Are you looking at the electronic Raytheon mast head wind gauge? They can be notorious for not being set dead on the wind.(You need to adjust them to be at 0 degrees when going straight ahead) Also are you reading the degrees off the "true" wind or the "apparent" wind. You have to make sure you are reading the Raytheon correctly and go back and forth. If you are reading 55-60 degree's off the True wind and you are going ~ 6kts you are not doing to bad - That might translate to 40-45% depending on the speed you are going. Sometimes the best way to tell is with the old 'analog' static windvane at the top of the mast
John, have you given any consideration at all to
the Catalina Owners manual for your boat? The manual that came with my 387 has very explicit, simple, easy to read, understand and follow directions to adjust the stepping, setting up of the mast and the tension of the shrouds. I'll more than likely tic a lot of folks off here, but this is a complex subject, and yet it is something that can be done from a very simple easy perspective. The use of the Loos gauge only serves to correctly determine with precison accuracy the tension of the shrouds and ensure that you have uniform tension on the shrouds. I have one and use it to check the precise accuracy of my rigging after I have applied the setting up of the mast and standing rigging that is given in my owners manual. You don't mention if your boat is set up with roller furling, or in mast furling or not. If you use furling systems, then haylard tension will be critical to the tuning and will affect your set up, especially the backstay tension. When you aren't sailing, if you use a furling system, then you should slack off on the haylards, yet to tune up the rig, you need the haylards taught like they would be under sail. This could in part be a reason for your turnbuckles running out of thread and not being where they used to be before you broke the backstay loose. If you don't have furling set up, then you need to have the forestay set up properly for the correct tension and mast rake, again, this is accomplished very easily as outlined in your owners manual. What everyone here has said is with good intent and is quite accurate, yet perhaps for someone of your experience, it may be somewhat overwhelming. My advice would be to read, and perhaps copy or print all that everyone here has said, and then to get a copy of the manual that Catalina publishes for your boat. Gerry Douglas has ensured that the manual will enable us, the users, and somewhat novices to properly set up and tune the mast and the standing rigging to allow the boat to function according to the design and engineering intent for each and every different model of the product line. After you have the rig set up according to the manufactures specs and instructions, then you might try and gather and garnish bits and pieces of what is said herein about adjusting the backstay, either by increasing or decreasing the tension of the backstay according to the sailing conditions. Perhaps also, get a copy of Don Guillette's ( not sure of spelling ) book available here at the ships store, and get your sails trimmed according to his dialogue and then go back and check the rigging and shroud tension again and see if you can point higher up into the wind. If your sails aren't trimmed properly, then all the rig tuning in the world isn't going to help out. Everything together has a relationship, and the sail trim is very critical to the performance. Again, what everyone here has said is in some way or another very accurate, yet I haven't seen anyone go about explaining setting the mast and rigging up from a perspective of the mast just having been stepped. There has been no mention of dropping a weight from a haylard and having it hit just aft of the mast to check for plumbness, no mention and checking to see that the distance from one side of the mast to a common point on each side of the boat is equidistant, and other checks that are simple and easy to do and should be done from the get go on setting up the mast and the standing rig. Once you have spent a long enough time working with this part of the tuning of the boat and understand it, then you won't be asking this kind of a question. This is a good question, and these are all good answers, yet I don't think they are all or any of them completely accurate for your need, nor are or these explainations given for the perspective of a new owner of a Catalina Yacht and being given to one that is considered to be a new owner of a boat that the new owner of that vessel would be not fully familair with. Get the manual, read it and follow the step by step instructions and then try and apply some of what all have said here and experiment with the tuning under sail. A word of caution that may have been mentioned. A rig tuned with slack is really not the best thing to have. In fact it is dangerous, for with slack tuned into the rigging, you can load up the rig, and then allow that load to inadvertantly be transfered to the slack side and then all of a sudden, bam, that slack is taken up and you will get a good slap and can wind up breaking something that can be expensive to repair, plus you could get your can or someone elses tossed off the boat. When you sail in stout winds with some heel, the lee rigging should not be slack, there should always be tension and if there isn't, your rig is not tuned tight enough. It may be comfortable, yet it can be dangerous. Get the owners manual and read and apply it to your rig tuning for your model boat. Then sail it and have lots of fun. Maybe like someone else said also, get involve with crewing on a boat that races. Go check out some of those folks at Dana Point and the Balboa Yacht club, they are race-aholics and live sleep eat and breathe racing. Good luck and fair winds to you.
the Catalina Owners manual for your boat? The manual that came with my 387 has very explicit, simple, easy to read, understand and follow directions to adjust the stepping, setting up of the mast and the tension of the shrouds. I'll more than likely tic a lot of folks off here, but this is a complex subject, and yet it is something that can be done from a very simple easy perspective. The use of the Loos gauge only serves to correctly determine with precison accuracy the tension of the shrouds and ensure that you have uniform tension on the shrouds. I have one and use it to check the precise accuracy of my rigging after I have applied the setting up of the mast and standing rigging that is given in my owners manual. You don't mention if your boat is set up with roller furling, or in mast furling or not. If you use furling systems, then haylard tension will be critical to the tuning and will affect your set up, especially the backstay tension. When you aren't sailing, if you use a furling system, then you should slack off on the haylards, yet to tune up the rig, you need the haylards taught like they would be under sail. This could in part be a reason for your turnbuckles running out of thread and not being where they used to be before you broke the backstay loose. If you don't have furling set up, then you need to have the forestay set up properly for the correct tension and mast rake, again, this is accomplished very easily as outlined in your owners manual. What everyone here has said is with good intent and is quite accurate, yet perhaps for someone of your experience, it may be somewhat overwhelming. My advice would be to read, and perhaps copy or print all that everyone here has said, and then to get a copy of the manual that Catalina publishes for your boat. Gerry Douglas has ensured that the manual will enable us, the users, and somewhat novices to properly set up and tune the mast and the standing rigging to allow the boat to function according to the design and engineering intent for each and every different model of the product line. After you have the rig set up according to the manufactures specs and instructions, then you might try and gather and garnish bits and pieces of what is said herein about adjusting the backstay, either by increasing or decreasing the tension of the backstay according to the sailing conditions. Perhaps also, get a copy of Don Guillette's ( not sure of spelling ) book available here at the ships store, and get your sails trimmed according to his dialogue and then go back and check the rigging and shroud tension again and see if you can point higher up into the wind. If your sails aren't trimmed properly, then all the rig tuning in the world isn't going to help out. Everything together has a relationship, and the sail trim is very critical to the performance. Again, what everyone here has said is in some way or another very accurate, yet I haven't seen anyone go about explaining setting the mast and rigging up from a perspective of the mast just having been stepped. There has been no mention of dropping a weight from a haylard and having it hit just aft of the mast to check for plumbness, no mention and checking to see that the distance from one side of the mast to a common point on each side of the boat is equidistant, and other checks that are simple and easy to do and should be done from the get go on setting up the mast and the standing rig. Once you have spent a long enough time working with this part of the tuning of the boat and understand it, then you won't be asking this kind of a question. This is a good question, and these are all good answers, yet I don't think they are all or any of them completely accurate for your need, nor are or these explainations given for the perspective of a new owner of a Catalina Yacht and being given to one that is considered to be a new owner of a boat that the new owner of that vessel would be not fully familair with. Get the manual, read it and follow the step by step instructions and then try and apply some of what all have said here and experiment with the tuning under sail. A word of caution that may have been mentioned. A rig tuned with slack is really not the best thing to have. In fact it is dangerous, for with slack tuned into the rigging, you can load up the rig, and then allow that load to inadvertantly be transfered to the slack side and then all of a sudden, bam, that slack is taken up and you will get a good slap and can wind up breaking something that can be expensive to repair, plus you could get your can or someone elses tossed off the boat. When you sail in stout winds with some heel, the lee rigging should not be slack, there should always be tension and if there isn't, your rig is not tuned tight enough. It may be comfortable, yet it can be dangerous. Get the owners manual and read and apply it to your rig tuning for your model boat. Then sail it and have lots of fun. Maybe like someone else said also, get involve with crewing on a boat that races. Go check out some of those folks at Dana Point and the Balboa Yacht club, they are race-aholics and live sleep eat and breathe racing. Good luck and fair winds to you.
How I'm reading
I give that angle to the wind by coming about and reading the difference of heading on the compass. It seems to me that from one tack to the other, it's about a 110-120 degree difference, so I figure this means half that difference is what I can get close to the wind. Also, yes, that is very helpful, the last suggestion about reading the manual. My wife is German, and we have constant conflicts over this. I tell her that she will never get American citizenship if she reads the user manuals; that's not how we do things in this country!
I give that angle to the wind by coming about and reading the difference of heading on the compass. It seems to me that from one tack to the other, it's about a 110-120 degree difference, so I figure this means half that difference is what I can get close to the wind. Also, yes, that is very helpful, the last suggestion about reading the manual. My wife is German, and we have constant conflicts over this. I tell her that she will never get American citizenship if she reads the user manuals; that's not how we do things in this country!
LOL. If you don't want to read the manual
the next best thing is to see the video Really. I strongly suggest Brion Toss's Video that he has on "tuning your rig". http://www.briontoss.com/catalog/videos.html Its done very well and very straight forward and after watching it I think you'll be tuned up better than 95% of the cruisers out there. Like they say a picture is worth a 1000 words and a video a million.
the next best thing is to see the video
Really. I strongly suggest Brion Toss's Video that he has on "tuning your rig". http://www.briontoss.com/catalog/videos.html Its done very well and very straight forward and after watching it I think you'll be tuned up better than 95% of the cruisers out there. Like they say a picture is worth a 1000 words and a video a million.- Status