I'm looking for rigging tension spec's for a Hunter 33.5. Does anyone know of a site that lists them? Has there been anyone who has had their rigging tuned (recently) and would be kind enough to share the tension data with the group or update the spec page? A friend of mine recently had his Catalina professional tuned. He then measured all of his stays and collected the data to share for his group. If I can't find someone who has them for a 33.5 I'll do the same. -R Thanks in advance, -R
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And you probably wont.
However, there are specs for the shrouds on your boat. All steel cable has a rated breaking load. It is almost impossible to tune your rig correctly without some sort of tension gauge. When tuning your rig, the shrouds are tensioned to a percent of that breaking load. An example, typical 7/32 1 x 19 cable has a minimum breaking load of 5300lbs. When properly tuned that cable should be tensioned between 20 and 25% or 1060 to 1325lbs. The higher the tension percent the lower the amount of headstay sag and leeward mast bend. As for "recently" tuned, all rigs should be tuned at least once a year but I doubt that most do it. If you can post the sizes of your boats shrouds and the luff curve of your main sail I can help with setting up a tunning guide for you.
However, there are specs for the shrouds on your boat. All steel cable has a rated breaking load. It is almost impossible to tune your rig correctly without some sort of tension gauge. When tuning your rig, the shrouds are tensioned to a percent of that breaking load. An example, typical 7/32 1 x 19 cable has a minimum breaking load of 5300lbs. When properly tuned that cable should be tensioned between 20 and 25% or 1060 to 1325lbs. The higher the tension percent the lower the amount of headstay sag and leeward mast bend. As for "recently" tuned, all rigs should be tuned at least once a year but I doubt that most do it. If you can post the sizes of your boats shrouds and the luff curve of your main sail I can help with setting up a tunning guide for you.
My understanding of proper tension is....
that the STATIC tension in any wire should not exceed 20% of it's breaking strength. According to the Loos website (they make tension gages) the initial tension is recommended to be about 11%. See the attached link. My Z-Spar rig is currently adjusted to about 7.7% to 11.4% for the various shrouds. I am not sure these are correct tensions, but I don't observe any slack stays under load. However, I am learning about these adjustments and I may decide to make some minor changes. I would contact Hunter, but they may tell you (like they told me) to call the manufacturer of the rig and ask them for the proper tension. I called and emailed US Spars (formerly Z-Spar) but have not yet received a response. I suspect that nobody is likely to tell you what it should be because of the potential liability. At least that will be the excuse...
that the STATIC tension in any wire should not exceed 20% of it's breaking strength. According to the Loos website (they make tension gages) the initial tension is recommended to be about 11%. See the attached link. My Z-Spar rig is currently adjusted to about 7.7% to 11.4% for the various shrouds. I am not sure these are correct tensions, but I don't observe any slack stays under load. However, I am learning about these adjustments and I may decide to make some minor changes. I would contact Hunter, but they may tell you (like they told me) to call the manufacturer of the rig and ask them for the proper tension. I called and emailed US Spars (formerly Z-Spar) but have not yet received a response. I suspect that nobody is likely to tell you what it should be because of the potential liability. At least that will be the excuse...
Rich
I have done an enormous amount of trial and error research into tunning my rig because I could never get a definitive answer from anyone. I have to tell you that if you are using those numbers on a 40.5, your mast is doing a great deal of pumping in any kind of waves and your upwind performance is seriously lacking compared to what it could be. This country is so 'legal' oriented and companies are afraid that they may get sued that it has become counter productive to everyone. All of that has no bearing on how to properly tune your rig except that they're all afraid to give a reasonable answer.
I have done an enormous amount of trial and error research into tunning my rig because I could never get a definitive answer from anyone. I have to tell you that if you are using those numbers on a 40.5, your mast is doing a great deal of pumping in any kind of waves and your upwind performance is seriously lacking compared to what it could be. This country is so 'legal' oriented and companies are afraid that they may get sued that it has become counter productive to everyone. All of that has no bearing on how to properly tune your rig except that they're all afraid to give a reasonable answer.
Alan, at the risk of hijacking this thread .....
from the original poster, RDavis, I would like to have your opinion on how to best determine and perform a rig tune. I have ordered a video that was recommended by another Hunter owner and it is called "Tuning your Rig" by Brion Toss. I've also asked a friend who is a racer and much more knowledgeable than I for his opinions. Still waiting on both to arrive. I have a Loos PT-3 gauge and that is how I measured my present tensions. My rig was last tuned in 2000 and I'm pretty sure the yard did it by "feel" and did not use a gauge. However, I have never observed or felt any pumping or slack shrouds and I have sailed in winds to 40kts. If I had a loose rig, I think I would have detected it sometime over the last 6 years. Hunter customer service told me to call US Spars and ask them for the proper tension setup. I guess I need to call them again; it's been since June 7th.
from the original poster, RDavis, I would like to have your opinion on how to best determine and perform a rig tune. I have ordered a video that was recommended by another Hunter owner and it is called "Tuning your Rig" by Brion Toss. I've also asked a friend who is a racer and much more knowledgeable than I for his opinions. Still waiting on both to arrive. I have a Loos PT-3 gauge and that is how I measured my present tensions. My rig was last tuned in 2000 and I'm pretty sure the yard did it by "feel" and did not use a gauge. However, I have never observed or felt any pumping or slack shrouds and I have sailed in winds to 40kts. If I had a loose rig, I think I would have detected it sometime over the last 6 years. Hunter customer service told me to call US Spars and ask them for the proper tension setup. I guess I need to call them again; it's been since June 7th.
Rich
I don't think you could characterize this as 'hijacking'. It's a legit discussion about rigging. I agree with your assessment of "..yard did it by "feel" and did not use a gauge". I suspect that this is true in almost all cases. Tunning a rig takes time and diligence. Installing a mast and rigging at the start of the sailing season is just that, installing. Getting the rig properly tuned is a whole other thing. As for the numbers, 7.7% is hardly a significant force to load any shroud with on a 60+ ft tall mast. This would put your shroud loads at about 400 to 500 lbs. That is hardly enough to keep that monster from pumping. Your headstay tension would translate to about 200 lbs. The headstay sag at that point would run close to a foot. Far too much for any kind of upwind work. While I admit I am looking to get maximum tension and performance out of my rig I feel that you are doing yours a disservice by grossly under tensioning and unwittingly damaging the whole rig. I am sure when you see Brion Toss's rig tunning you will realize the error. By bringing you rig back into proper tune your boat will thank you with a safer and more efficient sail.
I don't think you could characterize this as 'hijacking'. It's a legit discussion about rigging. I agree with your assessment of "..yard did it by "feel" and did not use a gauge". I suspect that this is true in almost all cases. Tunning a rig takes time and diligence. Installing a mast and rigging at the start of the sailing season is just that, installing. Getting the rig properly tuned is a whole other thing. As for the numbers, 7.7% is hardly a significant force to load any shroud with on a 60+ ft tall mast. This would put your shroud loads at about 400 to 500 lbs. That is hardly enough to keep that monster from pumping. Your headstay tension would translate to about 200 lbs. The headstay sag at that point would run close to a foot. Far too much for any kind of upwind work. While I admit I am looking to get maximum tension and performance out of my rig I feel that you are doing yours a disservice by grossly under tensioning and unwittingly damaging the whole rig. I am sure when you see Brion Toss's rig tunning you will realize the error. By bringing you rig back into proper tune your boat will thank you with a safer and more efficient sail.
Let me give you some numbers....
My measured tensions are: Shroud (size) Port %B-S Starboard %B-S Upper (3/8") 1350# 7.7% 1450# 8.3% Intermediate (5/16") 1050# 8.4% 950# 7.6% Lower (3/8") 2000# 11.4% 1900# 10.9% I cannot measure my forestay due to the installation of roller furling. My backstay is an inverted "Y" configuration and I don't believe that the tension measurement of it is meaningful. I have to admit that I don't know how much the forestay is sagging. RDavis- I hope that you will somehow get some useful insight from this discussion, even tho' it is not specifically for your h33.5.
My measured tensions are: Shroud (size) Port %B-S Starboard %B-S Upper (3/8") 1350# 7.7% 1450# 8.3% Intermediate (5/16") 1050# 8.4% 950# 7.6% Lower (3/8") 2000# 11.4% 1900# 10.9% I cannot measure my forestay due to the installation of roller furling. My backstay is an inverted "Y" configuration and I don't believe that the tension measurement of it is meaningful. I have to admit that I don't know how much the forestay is sagging. RDavis- I hope that you will somehow get some useful insight from this discussion, even tho' it is not specifically for your h33.5.
Tuning rigging
I found the Loos website most useful. I also ran around my marina and compaired other boats with the same sized riggin with the Loos standards. I feel confident that I'm in the ball park without being to tight. Once I take it out thats the time to do the fine tuning. Again, Loos.com does a great job of taking the mystery out of this..
I found the Loos website most useful. I also ran around my marina and compaired other boats with the same sized riggin with the Loos standards. I feel confident that I'm in the ball park without being to tight. Once I take it out thats the time to do the fine tuning. Again, Loos.com does a great job of taking the mystery out of this..
Anton
Tensioning the cap shrouds pulls the mast head back creating that curve. Tensioning the intermediates and lowers pulls the curve(prebend) out by pulling the center of the mast back. These two sets of shrouds together produce opposite bending forces on the mast but both produce the tension needed to reduce headstay sag. Headstay sag is the great killer of upwind performance and needs to be kept to a minimum. When the shrouds are tensioned properly to maximize headstay tension and allow for a 1% prebend(with no backstay) and 1 to 4% mast rake you will find that the shrouds will be tensioned 20 to 25% of breaking tension range. This will be the optimal rig tensions based on my exhaustive trial and error tunning of my rig. Increasing backstay tension will bend the mast approx 12 to 14" flattening the main and minimally increasing headstay tension. These are the numbers that my rig is tuned to and it produces the best combination of speed and pointing with a minimum of weather helm. As has already been said, this assumes a good main that is capable of being properly flattened.
Tensioning the cap shrouds pulls the mast head back creating that curve. Tensioning the intermediates and lowers pulls the curve(prebend) out by pulling the center of the mast back. These two sets of shrouds together produce opposite bending forces on the mast but both produce the tension needed to reduce headstay sag. Headstay sag is the great killer of upwind performance and needs to be kept to a minimum. When the shrouds are tensioned properly to maximize headstay tension and allow for a 1% prebend(with no backstay) and 1 to 4% mast rake you will find that the shrouds will be tensioned 20 to 25% of breaking tension range. This will be the optimal rig tensions based on my exhaustive trial and error tunning of my rig. Increasing backstay tension will bend the mast approx 12 to 14" flattening the main and minimally increasing headstay tension. These are the numbers that my rig is tuned to and it produces the best combination of speed and pointing with a minimum of weather helm. As has already been said, this assumes a good main that is capable of being properly flattened.
No Backstay...
Just a curious note from when I tensioned the rig on my 23...my backstay turnbuckles are just about useless. With cranked all the way down, it just barley tensines everything..the running backstay takes it from there. Would you consider this correct? (I know that many other hunters of my size don't even HAVE backstays) I have about 2 degrees rake to aft, and slight (1" maybe) pre-bend. The general method I used was that: the shrouds that go ouboard the spreaders are the shrouds that do the bending. The swept-back means they push the mast forward at the spreaders, and pull back at the top. The lowers and the forestay set your rake...So for me, I triangulate the mast into palce with these 3 (lowers and forestay), the other 3 slack. then I added the uppers for some bend, which I could probably use more. This is because the lowers are below the forestay, remove a little pre-bend, and I didnt account for this. (my mast is quite un-bendy anyway..it's a big heavy kenyon MORC section). Finally the running backstay actually gives me some bend when I want it at the top of the mast. I'm sure my method could use some tweaking as well!
Just a curious note from when I tensioned the rig on my 23...my backstay turnbuckles are just about useless. With cranked all the way down, it just barley tensines everything..the running backstay takes it from there. Would you consider this correct? (I know that many other hunters of my size don't even HAVE backstays) I have about 2 degrees rake to aft, and slight (1" maybe) pre-bend. The general method I used was that: the shrouds that go ouboard the spreaders are the shrouds that do the bending. The swept-back means they push the mast forward at the spreaders, and pull back at the top. The lowers and the forestay set your rake...So for me, I triangulate the mast into palce with these 3 (lowers and forestay), the other 3 slack. then I added the uppers for some bend, which I could probably use more. This is because the lowers are below the forestay, remove a little pre-bend, and I didnt account for this. (my mast is quite un-bendy anyway..it's a big heavy kenyon MORC section). Finally the running backstay actually gives me some bend when I want it at the top of the mast. I'm sure my method could use some tweaking as well!
There is no single magic set of numbers
With respect to rig tune there is no single magic set of numbers because there are so many contributing factors such as prevailing wind conditions, sea state, boat and rig design and what each skipper is looking for out of his boat in terms of performance. If you are a cruiser then you want to set up your rig, conservatively, for the typical conditions in your sailing area. If you are a racer, then you are always changing your rig tune for the different conditions on a given day and sometimes multiple times during the day. All this percentage of breaking strength stuff sounds really technical, but in reality the concept is fairly simple. You want to keep the mast centered and in column without over tensioning the rig. A rig that is too tight looses power by the functions of eliminating headstay sag and creating mast bend - both conditions that serve to depower your sails. The rule of thumb is that under the typical conditions that you would find in your area, and with your boat close hauled, you should not see any slop in the leeward shrouds - they should feel just slightly loose but with no noticeable slop. And with respect to the tensioning of the upper and lower shrouds, you should sight up the mast and tension as necessary to keep the mast straight. Cruising skippers might choose to tune to the upper end of their wind range and go a little tighter since they are usually less concerned about optimum performance and are less interested in changing the rig settings everytime they go out. On the issue of using a loos gauge to tension your rig, we have used ours on our j-24 and Carrera 290 for years and find it to be pretty inaccurate as a precise measuring tool. We use it more for comparing settings in a relative nature than for its ability to measure anything precisely. We use it to create base settings before we leave the dock and then we tweek the shroud tension prior to each race after we sail on the course and see what kind of conditions we will be sailing in. On the issue of headstay sag, if you are a cruising skipper you don't want it because it will affect the operation of the roller furling system and can actually cause damage to the sections as they can kink. As far as performance sailing is concerned, headstay sag equals power. You do not want to permanently eliminate it through your rig tune. You want the ability to remove it on the race course as necessary using the backstay on a masthead rig or running backs on a fractional rig. Removing headstay sag will give you a flatter genoa which is desireable for very light air and heavy air when the boat is overpowered. But in moderate air we use and need the power created by the deeper genoa to power through the chop, and keep the keel working. Without it we would suffer. Anton- 14" of mastbend on your 33.5 sounds way out of whack. Something is not right there. Sounds like your uppers are cranked way down and maybe your backstay too. Just curious, how loose is your headstay?
With respect to rig tune there is no single magic set of numbers because there are so many contributing factors such as prevailing wind conditions, sea state, boat and rig design and what each skipper is looking for out of his boat in terms of performance. If you are a cruiser then you want to set up your rig, conservatively, for the typical conditions in your sailing area. If you are a racer, then you are always changing your rig tune for the different conditions on a given day and sometimes multiple times during the day. All this percentage of breaking strength stuff sounds really technical, but in reality the concept is fairly simple. You want to keep the mast centered and in column without over tensioning the rig. A rig that is too tight looses power by the functions of eliminating headstay sag and creating mast bend - both conditions that serve to depower your sails. The rule of thumb is that under the typical conditions that you would find in your area, and with your boat close hauled, you should not see any slop in the leeward shrouds - they should feel just slightly loose but with no noticeable slop. And with respect to the tensioning of the upper and lower shrouds, you should sight up the mast and tension as necessary to keep the mast straight. Cruising skippers might choose to tune to the upper end of their wind range and go a little tighter since they are usually less concerned about optimum performance and are less interested in changing the rig settings everytime they go out. On the issue of using a loos gauge to tension your rig, we have used ours on our j-24 and Carrera 290 for years and find it to be pretty inaccurate as a precise measuring tool. We use it more for comparing settings in a relative nature than for its ability to measure anything precisely. We use it to create base settings before we leave the dock and then we tweek the shroud tension prior to each race after we sail on the course and see what kind of conditions we will be sailing in. On the issue of headstay sag, if you are a cruising skipper you don't want it because it will affect the operation of the roller furling system and can actually cause damage to the sections as they can kink. As far as performance sailing is concerned, headstay sag equals power. You do not want to permanently eliminate it through your rig tune. You want the ability to remove it on the race course as necessary using the backstay on a masthead rig or running backs on a fractional rig. Removing headstay sag will give you a flatter genoa which is desireable for very light air and heavy air when the boat is overpowered. But in moderate air we use and need the power created by the deeper genoa to power through the chop, and keep the keel working. Without it we would suffer. Anton- 14" of mastbend on your 33.5 sounds way out of whack. Something is not right there. Sounds like your uppers are cranked way down and maybe your backstay too. Just curious, how loose is your headstay?
Many thanks
Thank you Tom, Brian and Alan. I have just replaced all the standing and running rigging, so I may consider adding jumper strut on the forward upper portion of the mast, which upon reflection does make sense. My backstay tensioner unfortunately tensions just that; the central backstay. In a perfect world I would rig running backstays, but since the boat cruises 90% of the time it does complicate things. I am going do inwardly digest all your valuable comments and set to work again this weekend. Many thanks, Anton
Thank you Tom, Brian and Alan. I have just replaced all the standing and running rigging, so I may consider adding jumper strut on the forward upper portion of the mast, which upon reflection does make sense. My backstay tensioner unfortunately tensions just that; the central backstay. In a perfect world I would rig running backstays, but since the boat cruises 90% of the time it does complicate things. I am going do inwardly digest all your valuable comments and set to work again this weekend. Many thanks, Anton
Tuning by frequency
I'm a have always tuned rigs by 'feel'-- that is by intuition regarding tension and harmonic frequency. Sometimes my brother and I (both guitar players) have done it together. An innate sense of tonal harmony and appropriate tension results in easily-adjusted rigs with no extra tools and no blind adherence to often-arbitrary numbers. It's even less an exact science than sports car tire pressure, and a little more specific than tuning two guitars together for a jam session. Also-- NO overly-loose rigs, NO over-stressing decks and hull fittings, and NO dismastings... while earning an impressive collection of racing hardware. So there must be something to it. JC 2
I'm a have always tuned rigs by 'feel'-- that is by intuition regarding tension and harmonic frequency. Sometimes my brother and I (both guitar players) have done it together. An innate sense of tonal harmony and appropriate tension results in easily-adjusted rigs with no extra tools and no blind adherence to often-arbitrary numbers. It's even less an exact science than sports car tire pressure, and a little more specific than tuning two guitars together for a jam session. Also-- NO overly-loose rigs, NO over-stressing decks and hull fittings, and NO dismastings... while earning an impressive collection of racing hardware. So there must be something to it. JC 2
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