Updated:
Original:

Tiny Tunes

Joseph Serio of Brooklyn, New York, asks: "What is the best way to check that the shrouds and stays are properly adjusted on my Irwin 40 Mk 11?" Win Fowler replies: Let's talk about a single-spreader rig. For more spreaders the principles are the same, but the process is a bit trickier. Before you start, make sure the spreader-tip heights bisect
Author:

Joseph Serio of Brooklyn, New York, asks:

"What is the best way to check that the shrouds and stays are properly adjusted on my Irwin 40 Mk 11?"

Win Fowler replies:

Let's talk about a single-spreader rig. For more spreaders the principles are the same, but the process is a bit trickier. Before you start, make sure the spreader-tip heights bisect the angle of the shroud above and below it. Never let a spreader tip form an obtuse angle with the shroud, either above or below, because it's dangerous. Check the spreader angles from astern.

There are two parts to tuning: static and dynamic. A static tune is done at the dock or mooring and consists of centering the mast athwartships. First, take a centerline halyard and measure the distance to the same spot on each rail, then adjust the upper shrouds until the masthead is entered and the distances are equal. When that is done, use the lower shrouds to align the mast between masthead and deck. Once the mast is centered, tighten both sides evenly. Count the turns until you cannot tighten the shrouds any further by hand. Then take an additional full turn, using the appropriate tools, on both the uppers and lowers.

For a dynamic tune you need to go sailing. Sail upwind in enough wind to fully load your rig, i.e., enough wind to heel the boat about 20 degrees. Sight up the mast and note if it is bending to leeward or to weather. Also note the tension of the leeward shrouds; they should be just snug enough so that they do not move around, but not any tighter. If the mast is bending to leeward, the lower shroud is too tight relative to the upper. If it is bending to windward, the opposite is true. The tightness of the leeward shrouds will tell you whether the looser shroud needs tightening or the tighter shroud needs loosening. Tack and adjust the new leeward upper and lower shrouds in a similar fashion. Then sight along the mast again. Tack again and adjust the new leeward shrouds accordingly.

As you are making these adjustments, always take the same number of turns on each upper and lower shroud. This will ensure the mast remains centered athwartships. Continue tacking back and forth until the mast is straight up and down on each tack and the leeward shrouds are just snug. It may take a number of tacks to get things right.

The headstay and backstay tension should be tight enough so the headstay doesn't sag more than about 1 percent of its length, or about 6in in your case. That may or may not be possible without using so much stay tension that you bend the hull of your boat. Finally, be sure that if your mast has any fore and aft bend it is bending aft at the head, not forward. I think your boat also has a babystay - a short centerline inner forestay - that you can use to control fore and aft bend.

It may take a few hours to get the rig tuned properly, and you may have to give the rig a tweak or two during the sailing season. But taking the time to get things right will pay off in safety, boat performance and the satisfaction of a job well done.

Related

Hurrican-PHOTO

A Storm by Any Other Name

According to the National Oceanic and Atmospheric Administration (NOAA) hurricanes (the term most U.S. sailors are familiar with) and typhoons are just two different names for the same weather phenomenon: tropical cyclones, i.e., “a rotating, organized system of clouds and ...read more

01-LEAD-IMG_1002

Cyclone Season in Polynesia

Thinking of spending cyclone season in the South Pacific? Plenty of sailors take the chance every year, with the recent travel restrictions imposed by the pandemic making this an especially popular option in 2020. Cyclone season in this part of the world runs from November to ...read more

01b-LEAD-INSET-Kirby-IMG_0077

Eight Bells: Bruce Kirby, Creator of the Laser

With 2021 drawing to a close, Laser sailors find themselves reflecting on both their class’s 50th anniversary and the passing of the man who made it all possible: Canadian designer, sailor and sailing journalist, Bruce Kirby. Kirby, who died this past July at the age of 92, ...read more

2021ROLEXIC_DF_0061

Southern Yacht Club Wins Rolex NYYC Invitational Cup

Newport, R.I. -- The 7th Rolex New York Yacht Club Invitational Cup wrapped up on Saturday after five days of highly competitive racing in an international fleet that saw the Southern Yacht Club (SYC) of New Orleans best a fleet of 19 teams from Europe, Canada, Bermuda and ...read more

DUFOUR-530_NAVIGATION_009

Boat Review: Dufour 530

Dufour Yachts seems to have shifted its strategy with the introduction of the new 530. Previously, the French builder maintained two lines: Performance and Grand Large, with the latter targeted at the cruising crowd. With the Dufour 530, however, Dufour decided to combine the ...read more

210913-11HRT-SKIPPER-PORTRAITS-VC-122

11th Hour Christens Two IMOCAs, Hits a Snag

This week has been a big one for the American-founded, sustainability-centric ocean racing team 11th Hour Racing. In addition to christening their two new boats, the team also took them out for a quick test ride—against some of the most intense IMOCA 60 skippers in the world. ...read more

01-LEAD-DSCF3091

Clewless in the Pacific

Squalls are well known to sailors who cruise the middle Latitudes. Eventually, you become complacent to their bluster. But squalls vary in magnitude, and while crossing from Tahiti to Oahu, our 47ft Custom Stevens sloop paid the price for carrying too much canvass as we were ...read more

Nigel

SAIL’s Nigel Calder Talks Electrical Systems at Trawlerfest Baltimore

At the upcoming Trawlerfest Baltimore, set for Sept. 29-Oct. 3, SAIL magazine regular contributor Nigel Calder will give the low down on electrical systems as part of the show’s seminar series.  The talk will be Saturday, October 2 at 9am. Electrical systems are now the number ...read more