Did I set the tension right on my rigging?

[Stu Jackson]

Originally Posted by Stumble

YOU DO NOT TIGHTEN LOOSE LEEWARD SHROUDS. IF YOUR LEEWARD SHROUDS LOOSEN WHILE SAILING IT MEANS YOUR WINDWARD SHROUDS ARE TO LOOSE. .............................
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LOOSE LEEWARD SHROUDS ARE A SIGN THE WINDWARDS ARE TOO LOOSE, NOT THATTHE LEEWARDS NEED TIGHTENING.

Greg, thanks, I agree. I provided the link with the hope that you wouldn't have to type all that, but it is in line (pi!) with my link!

Originally Posted by jefndeb

I very much appreciate all the input so far, thanks again, please keep the comments coming...

If you have a masthead rig with double lowers, this is really nothing more to add.

Good luck.

[mowerandy]

For those who doubt it, the loose-rig fatigue risk is real - something I learned to my detriment a couple of years back when my forestay snapped in a storm, thankfully while safely tied up at the marina. The circumstances were quite specific - I had been under the misapprehension that taking tension off the rig while not sailing was a good thing, so had developed the habit of releasing the running backstay on my Adams 31 when leaving the boat. This left the forestay slightly slack to look at. This slack allowed the forestay to move slightly in the wind with the boat in storage. One day in a decent storm the (9/32nds SS) forestay just sheared off right below the furler drum, which then proceeded to punch out every window down the port side of the cabin as it swung wildly from the mathead. The sail was trashed, as was the furler. To cap it all off, I dropped the lot when I finally got the forestay clevis out at the the masthead, and it went straight down through a rather expensive glass hatch - ho hum. Mostly fixed now, but I don't have a furler anymore darn-it.
So rigging wire that aint meant to flex definitely shouldn't be allowed to I would say....

[knockabout]

i do the opposite / if there is not a ever so slight looseness on the downwind shroud adjust the windward side till there is / best to back off both sides half a turn then test to keep the pressure on the hull even / this hull is over 100 years old it was probably rigged with sisal rope shrouds originally / fitted with Z spar and 6mm stainless rigging tightened and aligned and then sailed to work out a comfortable looseness / then venomously resist suggestions to tighten every time a shroud has some working load caused slackness otherwise continuous adjustment may find a weakness / firm enough to hold on to without them wobbling is a good starting point / many fibreglass boats have keel problem due to rig over tension not groundings / light rig tension less likely to harm your boat and with experience can be a when to reef gauge

[Tessellate]

Very helpful post by Stumble, thanks. Any suggestion on how to make this process easier on a double spreader masthead rig? Where it's discontinuous at the lower spreader, with a turnbuckle for the D2s?

I can't adjust the D2's under sail (well I could, but I'd rather not), and if I tighten the V1's at deck, that's fighting / also tensioning the D2's - when really I may want to only tension the cap shrouds, when I see the masthead falling off a bit to leeward.

Would you just leave the D2's a bit loose in the at dock tune, tune cap shrouds under sail in 5-15 kts, and then tighten the D2's at dock while climbing the mast?

Originally Posted by Stumble

In very light air 5-10kn at most you go sailing. Start off heading upwind on startboard tack. The pretend and rake shouldn't change, but the mast is probably falling off to port, so tack to port, take up two turns on the starboard shrouds then tack back. Rinse and repeat, tightening just the startboard shrouds until the mast stays in column. Then do the same to the port side.

When you get the mast verticle on both tacks, head back to the harbor. Is the mast verticle and in column while at rest? Great, you found your light air settings.

[Suijin]

Originally Posted by spadresailor

I hope this does not sound too stupid but I also need to tune the rig on my new (to me) boat and would rather not buy a tension gauge. If it makes sense maybe you could do the same.
Can you sail 40 degrees or so into the wind and tighten the lee shrouds until they are not slack, turn to the opposite tack and do the same? Adjust the forestay and back stay by eye looking at the mast?

You don't need a gauge. Get your mast straight first and then tighten cap and lowers to "piano wire tight". Assuming that you have an adjustable backstay, make sure the mast is straight (from the side) when the tension is off or has a bit of prebend, and is not "S" shaped (aft lowers too tight). Then go sailing and check your leeward shrouds, if loose tighten them down a bit until not loose but not over tightened, tack and repeat.

BUT, you'd be best advised to hire an experienced cruising rigger for an hour to go over the rig and tune it with you following behind. You'll learn a lot that will help you make intelligent decisions about keeping the rig in tune and what changes will do what.

A lot of people just "go out and sail" without understanding that very simple and modest changes to their tune can have rather dramatic impacts on their boat's performance, including speed, performance to weather, weather helm, etc. The difference can be rather shocking.

[Stumble]

Originally Posted by Tessellate

Very helpful post by Stumble, thanks. Any suggestion on how to make this process easier on a double spreader masthead rig? Where it's discontinuous at the lower spreader, with a turnbuckle for the D2s?

I can't adjust the D2's under sail (well I could, but I'd rather not), and if I tighten the V1's at deck, that's fighting / also tensioning the D2's - when really I may want to only tension the cap shrouds, when I see the masthead falling off a bit to leeward.

Would you just leave the D2's a bit loose in the at dock tune, tune cap shrouds under sail in 5-15 kts, and then tighten the D2's at dock while climbing the mast?

My advice is to hire a pro, make careful notes of the tensions they set, and get on with your life.

Multi-spreader linked rigging is a pain to get right, but it isn't more difficult. It just adds in a new complexity. Everything I said above is still 100% applicable, but you have a new dimension that has to be considered.

The V# shrouds are there to carry the loads down to the deck, but their primary tuning concern is to keep the shrouds at 90 degrees to vertical. Because changing the V# also changes tension on the D# shrouds above it it takes a good bit of fiddling to get it right, and the only way I know to do it is underway while cranking someone to each D# shroud and changing the turnbuckles.

Interlude- riggers are stupid and so the naming convention starts at the deck. The V1 is the shroud attached between the deck and the first spreader, the D1 between the deck and the first lower. Why is this stupid? Because you tune a rig from the top down so they are named in reverse order. It also means that every rig has to have its own name for the top most shroud, things should have been named the other way so the D1 on every boat is the top most diagonal.

So how do you do it? Just like any rig get the stick itself squared away, then start at the top, while at the dock. Cap shrouds first, center and add prebend. Once that's set, attach a loose gage to the V2 (in your case) and make a note of the tension, this should also be the tension for all the V shrouds since it's the only thing that is loaded at the moment.

As you tighten the D2 it will ease the preassure on the V2(and thus the D3), so get the D2 halfway, then tighten the V1 up until the V2 is back at it's set tension. Then check the D2 again. Once you get the load sharing between the V2 and D2 correct then you have to shift the spreader into it's horizontal position. Ease both the V2 and D2 one turn, then tighten the V1 one turn to more the spreader down a notch... then you have to recheck their individual tensions again, because the D actually needs a little more ease for the same spreader travel. How much more depends on the angle of the shroud, the size of the wire, the size of the constituent turnbuckles...

Then go sailing, tuning the rig while your out is really the only way, but it shouldn't take more than three trips up the rig a side. The upside for tied rigging is that it tends to be more stable because and you can probably getaway with just adjusting the V1 and maybe the D2 a bit.

It's a slow process, to get right. But once it's done you never have to do it again (well until you replace the rigging). On tied rigging more than any other USE A MICROMETER on the rigging studs. If you ever have to take it down, you can immediately put everything back exactly where it was by measuring the throw remaining on each turnbuckle.

Once these measurements are taken, get an aluminum plate, and bring it to a jewelry store, then have them inscribe the numbers on the plate. Screw the plate to the underside of the chart table. Because loosing that scrap of paper you had the numbers written on I should just too easy.

[TomLewis]

Originally Posted by Lokiyawl

Hello, More than 40 years of tuning masts of all types. Perhaps the best bit of advice is to avoid excessive tension and tune to keep the mast straight under all conditions. Setting the mast up straight in the boat at the dock is a good start but since the geometry of every mast is different you also need to check for straightness with the rig under load. You can ease a stay or tension as required with the same result in tuning. Wire doesn't stretch much but it stretches enough to induce a bend if the tuning is not correct. Think of the wire as behaving a little like a spring initially as the slack is removed under tension. This means that the longer the wire, the higher the tension so that the various stays stretch the correct amount to leave the spar still in column. Some people go crazy with the tension loading the wire to 1/3 or more of the ultimate breaking strength which puts more static load on the boat than it will ever see out sailing..do the numbers the loads are crazy. Most materials including fibreglass will creep under load. Excessively loose rigging can cause things to come un pinned, wire to just out of a spreader slot etc. but the fear of fatigue seems to mostly a myth. Best of luck. James

Great thread all the way through. Great info from all. You did strike a chord with me with your post Loki. Thank you..

[TKDSailor]

Originally Posted by Stumble

YOU DO NOT TIGHTEN LOOSE LEEWARD SHROUDS. IF YOUR LEEWARD SHROUDS LOOSEN WHILE SAILING IT MEANS YOUR WINDWARD SHROUDS ARE TO LOOSE.

The goal is to keep your mast at a certain amount of pre-bend and rake, and verticle in column. Not to reach some specific tension, or percent of the wires MBL.

To do this correctly you set the mast up at the dock first by getting the mast base in the right position for and aft, then side to side. Then lock the partners in where you want the mast. Then you do the initial set of the rig, making sure it's in column, has appropriate pre-bend, etc. This is just a lose setting, to get you started.

In very light air 5-10kn at most you go sailing. Start off heading upwind on startboard tack. The pretend and rake shouldn't change, but the mast is probably falling off to port, so tack to port, take up two turns on the starboard shrouds then tack back. Rinse and repeat, tightening just the startboard shrouds until the mast stays in column. Then do the same to the port side.

When you get the mast verticle on both tacks, head back to the harbor. Is the mast verticle and in column while at rest? Great, you found your light air settings. Or more likely the mast will be slightly out of alignment biased to one side. This is normally, just move the mast back to verticle easing one turnbuckle then tightening the mirror half a turn at a time.

If you needed some at the dock adjustment you need to go back out and reconfirmed everything, but you should be within 1/2 a turn on either side from ideal. Once this is done for the first time you can put a loose gauge on the shrouds and make a note of the tension, this is so you can repeat the settings. I prefer using a set of micrometers to measure the stud-stud distance, but either works.

The next day you are looking for it to be blowing 15kn or so. Then do the same. The rig will fall off a bit more from the excess preassure in the sails streaticng the wire. So a bit more tightening is in order. Generally between one and two turns, but every boat is different. Then back to the dock and confirm if the mast is still in column. If not slowly move it back as above. Measure the tension, or stud-stud distance and make a note of it.

The third day you want it to be blowing above the point that you would put in the first reef. Go through the process again. Making a note of the tension/distance again.

Congrats you are done, and have created a tuning guide (basic) for your boat. If you are not going to be changing your settings regularly then I suggest leaving the rig set for reefed conditions. If you are going to change the tune regularly then this will act as a set of neutrals around which to work, and you can keep adding to the guide based on waves, wind strength, etc.

LOOSE LEEWARD SHROUDS ARE A SIGN THE WINDWARDS ARE TOO LOOSE, NOT THATTHE LEEWARDS NEED TIGHTENING.

Thanks for helping out here. I am not sure what you mean by "stud to stud clearance." Would you elaborate on what studs you are talking about? I've done many different rigs in the past, but have never heard of this. If there is a different way than via a tension gage, I would appreciate knowing this. I usually tap my shrouds and listen to the sound to make sure the same ones are close in tension, while getting them close to their final stage.

[Stumble]

Originally Posted by TKDSailor

Thanks for helping out here. I am not sure what you mean by "stud to stud clearance." Would you elaborate on what studs you are talking about? I've done many different rigs in the past, but have never heard of this. If there is a different way than via a tension gage, I would appreciate knowing this. I usually tap my shrouds and listen to the sound to make sure the same ones are close in tension, while getting them close to their final stage.

To clarify (this may sound a bit pedantic, its just hard to be clear without pictures).

If you look at a turnbuckle body coming up from the chainplate there is a screw and attached to the end of the wire is a screw. Both of these penetrate the turnbuckle. As you tighten the turnbuckle these screw ends are pulled closer together. By measuring the distance between these ends you can get a perfectly repeatable setting for the shrouds.

This won't help you get the rig in tune, but it makes it trivial to retune the rig I feel you need to disassemble it for any reason. Or I find you just want to play around with new rake or prebend but then get back to your neutral.

The downside is it is worthless when installing a new wire. For that you need a tension gauge

[zstine]

Based on the OP's measurements, his tension is fine for going out to sail. The rig will loosen as the new wire stretches and I always believe it is best to final tune by observation during sailing using the tension gauge as a backup to ensure you are not out to lunch (don't exceed 25% or under 10% breaking strength)... unless you have a specific tuning guide that says what tensions you want for a certain sail and wind condition like a race boat does... but this is a cruiser. And he seems to have done research. So, I assume(?) he has checked that the mast has proper rake is straight up and down in reference to the chainplates (not perpendicular to the water, if your boat lists the mast should lean with the boat, though I've heard a rigger argue this and set a mast vertical to water with the boat listing due to uneven stowed weight. I don't agree with that method). His initial tensions are good to go IMO. So now that initial dockside tune is complete, I would recommend that as he sails upwind, if he notices excessive looseness in leeward shrouds, that he puts a half turn in, tack and repeat on other side. always adjust both sides now to keep the mast straight... and you always adjust the leeward shroud that's slack. As far as 'feel' for tune adjustment. I basically expect my leeward shroud to have some tension up to about 12knts, which is nearly fully powered. I start thinking about reefing at 15knots, rail nearly in the water, and at that point my leeward shrouds have effectively zero tension. They're not swinging around totally slacked off, but easily moved by hand and basically loose and just hanging there under their own weight. Every boat is powered up at different winds speeds, so your results may vary. Now Go Sailing and stop worrying!