Correct Shroud Tension

[swampcat]

Am a new DSII owner. Prior owner kept the boat rigged. I keep the boat
in my driveway and must put the mast up each time I launch it. Not a
problem as the mast has a tabernacle............which brings me to my post:

What is the correct tension for the shrouds? Are there any tricks to
getting it right each time? Are there any simple tools/practices to getting
it the same each time? (boat will not be raced, at leasted hard)

[Roger]

I left my shrouds attached all the time, and never changed the tension. I bungeed them to the mast for transport. When on site, I rolled the mast back on a roller crutch, and inserted it into the tabernacle, attached an extra line to the jib halyard (shackle end) and ran it through a block attached at the stemhead. I then raised the mast, took the slack out of the lifting line, and cleated it, then went forward and attached the forestay with a quick pin. You need to tension the lifting line to be able to put in the quick pin. No further adjustment necessary, and your stays all have the same tension as when you took them down. I actually did not use turnbuckles, I used shroud adjusters for all three.

[swampcat]

It's the starting point that get's me. I need to know what the shroud tension needs to be. The process of adjusting the turnbuckles is not
a problem. Knowing how tight to get them is.

[Roger]

You don't likely want to invest in a Loos guage at $90 to tension such a small rig, and you don't have to. Once the mast is up, ensure that it is STRAIGHT up. Do this by using a tape measure from the main halyard (taped to the shackle and run up to the top of the mast, then measured to each aft corner of the boat. The measurements should be the same. Adust each shroud by hand to get it equal on both sides, then tighten them by hand. The fore and aft set of the mast should also be 90 degrees from the cuddy sole. If you want mast rake don't have anything further aft than 2 degrees to start with. Tension the forestay to take out any slack using a tool for the last few turns. This will give initial tension to the rig. Now go sailing and notice if there is any slack in the leeward shroud. If there is, tighten them up a few turns (each side equally) with a tool. When you are sailing on a beam reach, the leeward shroud should be 'just' slack, not sloppy. Continue to adjust each shroud equally until you get this tension. Now to focus on the mast rake. Your boat should ideally round up into the wind and stall within a few boat turns when you let go the tiller. This is called weather helm. If you are fighting the tiller all the time, then you have too much weather helm. If your boat turns downwind, you have too much lee helm. To increase weather helm, reduce tension in the forestay and increase the tension in both shrouds so that each shroud still has equal tension. This will move your mast back and thereby the center of effort, which will increase weather helm. If your boat is perfectly balanced (bad) or turns downwind, (even badder), then slack off (equally the tension in the shrouds and increase the tension in the forestay. Only do a few turns at a time. It may take you several sails to get the boat where you can control the tiller with finger tip control, yet still have it round up into the wind if you let go the tiller. Once you have that, lock your turnbuckles with wire, mark them, or tighten down the restraining nuts so that they do not change over time. If using shroud adjusters, mark the holes. Shroud adjusters will not allow as fine tuning as turnbuckles.

Shrouds will stretch over time, and new ones will stretch in the first few seasons, so will need readjustment in the first few years.

If you do have a Loos guage, follow the directions for setting tension, but you still have to go through the above procedure to get the mast straight from side to side, and the rake perfect to get some weather helm. All that a Loos guage does is identify the amount of tension based on the size of the shroud.

[jpclowes]

If you go to the North Sails website, under one design, there should be a tuning guide. You may have to search a little for it. It isn't much different from what Roger said, but it gives actual number targets for measurements, which may, or may not be important depending on if you race or not.

[Roger]

http://www.loosnaples.com/howto/90-91gauges.htm

This site give you the number targets depending on which size shrouds you have on your boat. Originals were 3/32 but most have been upgraded to 1/8".

For 1/8 the tension is 240 and 320# respectively for the shrouds and forestay.

[swampcat]

Thank you gentlemen.........I did buy a loos gauge (on sale, $55, but looks like something from the ancient mariner days-so hope this "insurance" was worth it). Have a weekend coming up so will follow your advice & may return w/ questions