Rig tuning

[Gulfislander]

Hi All,
I am going to attempt to tune the rigging on my Niagara 31. I have never done this before but have read a number of threads on this issue and have also read Ivar Dedekam's book (Sail & Rig Tuning). What I'm not sure about is if I start by loosening off and lubing all the rigging before starting to tune. This seems like the thing to do, but I have not seen this stated anywhere so I thought it best to ask. I am very open to any tid bits of wisdom anyone is willing to share. Thanks.

[AnchorageGuy]

First I have to ask why you are tuning the rig? Does it show signs of needing it or is this just something you want to do? I usually don't loosen anything for tuning but make adjustment as needed according to what the problem is. I have a hard and fast rule on our boat. If it ain't broke don't fix it!

[Gulfislander]

When I bought the boat the previous owner told me the lower shrouds were loose and needed tightening. When out for a sail I noticed that the leeward shrouds were very loose. So I started do some reading. I was under the impression that if you are going to tune the rig you should do it all and in a sequence. If I can get away with just tightening the lower shrouds I would be very happy. But as stated I'm a newby at this and I don't want to screw anything up on my baby.

[Joli]

Bar tight on the caps then work up from the D's. Easy as pie.

[Sandero]

I believe the there is an excellent Selden manual referred to in the Online Shop Manuals which gives you a step by step instruction on how to tune a rig. My rig is a Selden so I have a hard copy and have done this a few times. The principles involved are universal and will work for any rig.

If you have a keel stepped mast you can slack, even remove and clean all the rigging and the set it up. If you are deck stepped more care should be taken so the rig can't topple!

[Gulfislander]

This may be a dumb question, but what do you mean by "work up to the D's"??

[ssullivan]

The rest of the sailing community here might think I'm an idiot, but I'll share with you my way of tuning a rig. I learned this on my first boat, a 23' trailer sailer. Since it was a trailer sailer, you had to take the mast down each time and re-tune with every launch. Boy, did that get old.... Take it for what it's worth:


First, doing as you said is fine... grease stuff, look it over for rust, check for "fish hooks", or places where the cable on your shrouds me be failing. Look for rust coming out of the joints, etc... Check attachments points, etc... just do a nice, slow look-over for anything that doesn't seem right.

Next, get the mast into position (I think it already is on your boat).

Now, look at all of the shrouds. See where they attach to the mast and just make a mental note. Think thoughts like, "If I tighten my backstay, it will compress the mast, pull the mast aft by the top of the mast and give it a slight bow to aft." Just look at all the shrouds and understand what tightening and loosening them will do. This is more of a holistic approach than reading fancy rigging books.

Next, my big secret: Lay down on the deck forward of your mast with your feet pointing toward the bow and your head touching the mast. Look up the mast and sight it like you would a piece of lumber at the lumber yard. You'll easily see any incorrect twists and bends in the mast that are a result of incorrect tuning.

Now, keep working your way around, using the knowledge you have of which shroud does what as you tighten it to get all the twists and bends out. Just keep at it, never over-tightening, sometimes loosening, but achieving a nice, straight stick.

If you desire any aft rake or special tuning, you can do that fancy stuff this way too.

Tuning a rig is a lot more simple than the books and riggers want you to know. It's just a matter of pulling "here and there" on the mast by tightening the turnbuckles that associate with the direction you want the mast to bend. Laying on the deck allows you to see the bends.

Last tip: If you want to get a good view of the fore/aft rake, get off the boat and go walk at 90 degrees or 270 degrees to your boat's bow. Walk far away and take a peek... then get back on deck, lay down and look at the mast from the front again.

Take your time and take as long as the job takes. Could take 10 mins, could take an hour. You just have to be "at one" with the boat for this one.

Good luck.

[ssullivan]

Oh, and speaking to what DefJef mentioned:

You can always tie off a halyard to take the place of the forestay or backstay for stability if you have to do something where you need to disengage one of them.

[Sandero]

Your aim should be to tension the cap shrouds to 15-20%
of the breaking load (the final check on tuning should be
left until you are under sail). Then you know that the lateral
staying is optimal both for the security of the rig and for
sailing performance.
There are measuring instruments of greater or lesser
reliability for this purpose on the market. Seldén has
developed a simple method of obtaining the information
you need with material you probably already have. What
you need to know is:
• All 1 x 19 stainless wire stretches under load, but returns
to its original length when the load is removed. 1 mm
stretch per 2 m wire is equivalent to 5% of the breaking
load, irrespective of the diameter of the wire.
• A grp hull, on the other hand, changes its shape permanently
when the rig is put under load. This makes it
necessary to set up the rigging again after some time.
This applies particularly to new yachts.
• At the dockside, both cap shrouds always have the same
load. If you tension the starboard shroud, the port shroud
is affected to precisely the same extent.

[Sandero]

Here's the link: (pick your language)

It explain it all with great illustrations:

Seldén Mast AB

[Joli]

Umm,

Let me re-start.

Loosen the rigging.
Center the rig by tightening the cap shrouds (the deck to masthead shrouds)
Make sure it is centered in the boat with a halyard side to side checking.
When the caps are tight and the rig is centered then work from the lowest shroud (D) up.
If it is a single spreader you only have one D (one lower) Maybe fore and aft, no biggie.
If it is a double spreader you will have 2 (D's) a lower and an intermediate.
If it is a triple you will have,,,well you understand.

Get the rig centered, make the caps tight, then bring up the D's.

We have a triple spreader rig that we pull every fall.
In the spring when we reset the spar and we jack it to 30,000 pounds (ie we lift the mast and block it inside the boat with a hyd ram since it will gall the screws if we try to turn the screws that tight) This brings the cap shrouds bar tight. We then start tuning the D1's (the lowers fore and aft) and work our way up to the D2's then the D3's getting progressivley lighter as I go up. ~2 hours work.

So, center the rig, bring on the caps shrouds, then tighten the D's botom to top, lighter as you go. No S's in the spar while sitting inthe dock, then go sailing a take a looksie. Look up the mainsail track. The spar should be straight or slghtly fallnig off on top when sailing in a moderate breeze. If the center is falling off, tighten the D's, lowest first then the next one up.

[Gulfislander]

Thanks. This has been helpful.

[Joli]

By the way. Niagras are nice boats. Congrats

[AnchorageGuy]

Looks like you have some really good info to get you started.

[jrd22]

I start by snuggin up the upper two shrouds then raising a 100' tape to the mast head and measuring from side to side and adjusting until they are exactly the same. Then I tighten each the same number of turns; 5 port/5 stb until I've got the about the right tension on them. The intermediates and lowers I do by sighting up the mast making sure it is straight. I tend to err on the side of being too loose, then adjusting after observing the rig during a sail. I've found that none need be bow string tight.

John