Standing Rigging tension

[Guest]

Lost my mast in a gust due to loose rigging...replaced shrouds and stay, but can't figure out how tight the new ones should be. How much "play" should there be? Is there an instrument that measures tension, and what is the reading I want?

Tom Beames (tbeames65-at-cs.com)

[Guest]

I found this tunning guide on the Doyle Sails site! If you use a tension gauge, a Loos model A should read about 50 pounds.


Norm Cressy has been involved with the Daysailor Class for many years. Again this year Doyle sails have been the benchmark for Daysailor speed. Our intense focus on the Daysailor Class has enabled us to refine our designs and research the latest cloth options resulting in the finest Daysailor sails available

SETTING UP YOUR DAYSAILOR FOR DOYLE/CRESSY SAILS

BEFORE STEPPING THE MAST:
1. Make sure turnbuckles are clean and turn easily.
2. Make sure spreader adjusters are clean and turn easily.
3. Tape or tie a string to the tang or the upper end of each shroud. Strings should be slightly longer than the shrouds. Taping, rather than tying the strings, will allow them to be pulled off later without removing the mast.

AFTER STEPPING THE MAST:
1. Put the boat in the water and adjust the headstay, shrouds and mast foot so that the mast rakes slightly aft from vertical.
2.. If the mast can move more than 1/8 inch fore and aft in the mast partner (deck opening), wedge the front of the mast to remove the play.
3. Center of plumb the mast by adjusting the shrouds with the empty boat in the water. Check by dropping a plumb bob from the main halyard or by taping a level to the side of the mast and reading it from the dock.
4 Tension shrouds and headstay so there is NO slack. If you use a tension gauge, a Loos model A should read about 50 pounds. Sight up the mast to make sure there is no fore, aft, or sideways curvature.
5. Take the strings attached to the top of the shrouds. Bring each one down leading it aft of thespreader and tie it to the outer end of the clevis pin in the chainplate. Each string will now be a straight line from the top of the shroud to the bottom.
6. Adjust each spreader so that its aft edge is 1" forward of the straight line described by the string. The outer end of the spreader should be 1 1/2" to 2" outside of the string line.

SETTING THE MAST RAKE AND BALANCE:
1. Sail the boat upwind in 4-6 knots of wind. Sails should be trimmed normally for upwind legs. Skipper and crew should be in their normal positions and should keep the boat FLAT. The cunningham should be off and the centerboard should be all the way down.
2. Release the tiller so the boat steers itself. It should turn slowly into the wind.
3. If the boat goes straight or turns downwind, lengthen the headstay, tighten the shrouds, and move the mast butt forward to increase mast rake. Again sight up the mast to make sure there is no curvature.
4. Repeat steps 2 and 3 until the boat turns slowly but steadily into the wind each time it is allowed to steer itself.
5. Recheck that mast is plumb and straight and shrouds and headstay are properly tensioned.
6. If the boat turns sharply into the wind the tiller is released and carries a heavy weather helm, reduce the mast rake by tightening the headstay and moving the butt back. This condition is unlikely.

SETTING THE MAST BEND:
1. This may take several tries in different wind conditions.
2. Sail the boat upwind with the traveler set to bring the boom to the center and the top batten parallel to the boom. Make sure the cunningham and vang are off. Look for diagonal wrinkles running from the center of the mast to the boom. These should begin to appear in about 8 knots of wind and become more prominent as the wind increases.
3. If the wrinkles appear in winds below 8 knots, the mast is bending too much. To correct this, sight up the mast while the boat is sailing. If most of the bend is in the upper part of the mast tighten thspreader adjusters slightly to push the ends of the spreaders forward. If most of the bend is in the lower part of the mast, move the butt forward. Don’t change the length of the headstay as this will change the mast rake and the balance of the boat.
4. If the wrinkles do not appear at 8 to 10 knots, loosen the spreader adjustments and/or move the foot of the mast aft until the wrinkles do appear. Again do not change the headstay length.
5. Repeat steps 3 or 4 until the wrinkles appear at 8 to 10 knots.
6. When the mast bend is correct, recheck the shroud and headstay tension and the mast rake balance.

Gus Heismann (gus-at-heismann.net)