Members' Online Book: Sail Handling and Rigging Made Easy, Chapter 32 of 35

Rig Tuning, Part 1—Preparation

Getting ready to tune the rig.

Although just about every facet of sailing has been written about in great depth by many writers, rig tuning seems to be an exception. (There are some articles around on the internet, but most are way too simplistic, and many contain fundamental errors.)

So I’m going to give it a go…

Why DIY?

But first, why learn to tune our own rigs?

Simple, most boatyard crews who step masts have little or no idea how to properly tune a rig. I know that’s harsh but trust me, I have watched masts being stepped in a bunch of different boatyards, including some high-end expensive ones, and it’s sadly true.

Also, a well-tuned rig is not just for racing boats, as many cruisers seem to think (judging from what I see out there). Why? Because poor rig tuning has a surprisingly negative affect on speed and can even, in a variety of ways, actually cause a dismasting and/or stress-cracks in the mast.

Caution

And that brings me to a caution: If we are going to take on tuning our own rigs, we need to pay attention and take our time, as this is no place to screw up.

Also, we could really hurt ourselves in the tuning process if we daydream and, for example, unscrew a turnbuckle too far, thereby bringing the whole thing down on our heads. If that sounded like a disclaimer…it was.

And, finally, learning to tune a rig properly and safely, while within the capabilities of most reasonably handy sailors, is not simple. That’s why this series looks like it’s going to be four chapters and over 6000 words.

Even so, since there are so many variables in rigs and boats, you will have to apply these instructions to your own boat with a large helping of thought—I can’t possibly cover every detail for every boat.

You Can Opt Out

By the way, no shame if you decide rig tuning is not for you.

But Still Worth Reading

But even if you decide to let a pro tune your boat—look to a rigger or sailmaker, not a boatyard—reading this series is worth your time, because doing so will give you the knowledge to at least determine whether the person that you are paying hard-earned cash to actually knows what they are doing.

I Do It My Way

Oh yeah, one more thing before we move on to the good stuff: It’s important to realize that there are ways to tune that are different from mine…used by the misguided. 

Seriously, the key point is that tuning is a methodical process that builds on a full understanding of the forces on, and geometry of, the whole rig viewed holistically. (Wow, who wrote that convoluted sentence? Sounded like something out of a privacy policy.)

What follows is the way that I have evolved over some 40 years. But I’m sure there are other systems that work and some might even be better than mine…naw, couldn’t be.

Whatever, the key point is that we each need to find the system that works for us and then stick with it from start to finish, not mix and match from one or more systems, at least without really thinking about it.

What We Will Cover

I’m going to assume a standard two-spreader keel-stepped mast, first off, because that’s the most common offshore voyaging boat rig and second, because that’s what I know best. 

If you have three spreaders this should work fine, although it will take you longer than two spreaders…a lot longer. John’s first law of rig tuning: Complexity of tuning goes up by the square of the number of spreaders.

If you have a single-spreader rig, just ignore all the stuff about intermediate shrouds.

And if you have a deck-stepped mast, ignore the stuff about mast chocking at the partners.

I will also cover tuning a cutter rig, and that will help anyone with an internal head stay, cutter or not.

What We Won’t Cover

But if your boat relies on radically swept-back spreaders to stay standing, or is a really funky B&R rig, sorry, although this series will give you some pointers that will help, you are on your own simply because I have never tuned one of those types. In fact, back in the day when I was a sailmaker and rigger, these rigs did not even exist! Or at least were not in common use on cruising boats.

Also, in the interests of brevity, although I do know how to tune them, I’m not going to cover fractional rigs.

Wow, that was a lot of ifs, ands, buts, and maybes…on with the show.

Stand Up Straight

The first thing we need to do is get the mast stood up so it’s not leaning off to one side. Don’t laugh, I know that sounds obvious, but most people don’t even try, and of those who do, most do it wrong.

Why wrong? Because they start from the assumption that the boat is perfectly symmetrical and, in so doing, start down the long and winding road to tuning failure and frustration. 

Here’s the reality. In all likelihood:

  • The mast step is not perfectly centred in the boat,
  • and, even if it is, the partners (hole through the deck) is almost certainly not.
  • Anyone who believes that the shroud chainplates are perfectly symmetrically installed in relation to each other and the mast step is probably still writing to the North Pole just before Christmas.
This is why the common advice you see, to use the main halyard or a tape measure to measure down to each cap shroud chain plate (or the toe rail) to centre the mast, is wrong.

Well, then, what should we do?

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Meet the Author

John

John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 12 years, as co-editor/publisher of AAC.

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