Standing rigging.....
- Thread starter NYSail
- Start date
But, it will if you get the angles the same. This means make sure your mast is plumb. That is number one.
-Will (Dragonfly)
Last edited:
That is my priority when setting the tension with my Loos gauge. I check for side to side equidistance with the main halyard.
But, it will if you get the angles the same. This means make sure your mast is plum. That is number one.
-Will (Dragonfly)
What exactly did the rigger think? That you had to tension both sides of your stays to get the mast centered?
Just relax the turnbuckles all around. Hang a weight on your halyard just above the gooseneck and get the mast plumb with a few inches of rake by measuring the distance from the mast at the gooseneck to the weight. I don't know how your sails are cut, but usually, an inch for every 6' to 7' of height is not bad for rake. (Some boats don't do rake). Then tighten both sides equally to keep your mast centered until they feel nice and tight when you try to deflect the shrouds by hand. Then use the gauge to make sure you haven't over tightened them. Your tuning guide that came with the boat may have a phase that says something like, "use the least amount of tension necessary. Tension to no more than 15% of breaking strength."
For me, that means sailing on a broad reach in 15 to 20 knots of wind and having my leeward shroud just barely loose. If they are dancing, then tighten both sides equally until they are not dancing. If the lee shroud still feels tight when plucked, it's too tight.
All this should be done on the water not a trailer to keep everything level.
-Will (Dragonfly)
Thanks Will...... On my old boats I always did my own tuning. The rig on my Beneteau 423 is different so I just wanted someone to get it set the first time as the top of the mast had an S at the second spreader. It has what I think is called non continuous shrouds?? There are terminals at the first spreader as well as clamps on the second set of spreaders. My adjustments need to be at the top of the mast so I need to release the top spreader from the cap shroud first the relax turnbuckles to let mast go naturally back. This fall I am going to drop the mast as I want to rewire plus add new vhf wiring and antenna. When down I figure I will set it up and release everything and at least get it column. Then go from there in the spring. In regards to a rake, its an in-mast furling that US Spar says needs no rake as it is already built into the design of the mast.
Again thanks for the advise!!
Greg
Will, this has been the lore on shroud tension for man years, but authoritative texts on the topic contradict this.
(I will supply references when I can get to my sailing library).
Here's what Loos has to say on the matter:
"Contrary to popular thought, a slack rig is more punishing on a hull than a properly adjusted, tight rig. Insufficient tension will not reduce the loads transmitted in the hull. Slack rigging will punish the spar and rigging needlessly by allowing excessive movement, chafe and shock loading."
"...for properly tuned rig the leeward \ shrouds will not go slack under normal sailing conditions.
The lateral stiffness of the mast and the fore and aft stiffness of the spreaders is reduced by a factor of 2 when the leeward shrouds go slack. This Important structural characteristic is not generally recognized."
"...for properly tuned rig the leeward \ shrouds will not go slack under normal sailing conditions.
The lateral stiffness of the mast and the fore and aft stiffness of the spreaders is reduced by a factor of 2 when the leeward shrouds go slack. This Important structural characteristic is not generally recognized."
My primary concern with a rig where the leeward shrouds go slack - even a little bit - is that if the rig fetches up, you can get a shock load that can break things.
Quotes above from here:
https://loosnaples.com/how-tos/tension-gauges
Last edited:
Jviss,
I appreciate that and agree. I'm not advocating letting the rig go slack, just loose enough that tension is minimal. Allowing the mast play is a bad idea. However, I was not taught to tighten a rig to a measured tension and with the changes today in stay materials, it seems using the 15% of breaking strength rule might lead to over-stressing other elements of your rig, like chainplates, spreaders and mast. The literature I've seen, including a manual someone posted here on SBO, advocate the minimum tension necessary.
For a modern in-mast furler, that approach may be completely out of place. The engineering on modern rigs may require more exact tensions.
I once read an article about a guy who wanted to upgrade his stays to a modern composite cable and his rigger told him that would mean higher tension on his rig because of the 15% rule. That is simply not so. The tension required to keep a mast steady under sail is static for a particular design. Changing the stays for stronger material doesn't mean they should have more tension on them. In fact, stronger composite materials are harder to stretch so they are less likely to relax under the same sailing conditions. Thus no need for more tension.
I look forward to seeing your references, but I do believe you. I'll have to consider whether 20 knots on a beam reach should still see tight lee stays. That's the way my family has done it for 50 plus years.
-Will (Dragonfly)
I appreciate that and agree. I'm not advocating letting the rig go slack, just loose enough that tension is minimal. Allowing the mast play is a bad idea. However, I was not taught to tighten a rig to a measured tension and with the changes today in stay materials, it seems using the 15% of breaking strength rule might lead to over-stressing other elements of your rig, like chainplates, spreaders and mast. The literature I've seen, including a manual someone posted here on SBO, advocate the minimum tension necessary.
For a modern in-mast furler, that approach may be completely out of place. The engineering on modern rigs may require more exact tensions.
I once read an article about a guy who wanted to upgrade his stays to a modern composite cable and his rigger told him that would mean higher tension on his rig because of the 15% rule. That is simply not so. The tension required to keep a mast steady under sail is static for a particular design. Changing the stays for stronger material doesn't mean they should have more tension on them. In fact, stronger composite materials are harder to stretch so they are less likely to relax under the same sailing conditions. Thus no need for more tension.
I look forward to seeing your references, but I do believe you. I'll have to consider whether 20 knots on a beam reach should still see tight lee stays. That's the way my family has done it for 50 plus years.
-Will (Dragonfly)
My favorite book on this topic is "Illustrated Sail and Rig Tuning," by Ivar Dedekam.
https://www.amazon.com/Illustrated-Sail-Tuning-Nautical-Manuals/dp/1898660670
He has a detailed and complex procedure. The book is beautifully illustrated. He has cap shrouds at 20% breaking strength.
The instruction book for the Loos gauge has recommended initial tension that's approximately 10% breaking strength for shrouds, 15% for forestay.
https://www.amazon.com/Illustrated-Sail-Tuning-Nautical-Manuals/dp/1898660670
He has a detailed and complex procedure. The book is beautifully illustrated. He has cap shrouds at 20% breaking strength.
The instruction book for the Loos gauge has recommended initial tension that's approximately 10% breaking strength for shrouds, 15% for forestay.