Rig Tension with 5/32" Rigging

Sep 23, 2021
9
Catalina 22 Davis Island Yacht Club
I've got a 1979 swing keel that is rigged with 5/32" standing rigging.

I've been reading the C22NSA Tech Manual, the North Sails Tuning Guide, and the Loose Tension Gauge instructions to understand rigging strategies. I note that these references are based on 1/8" inch rigging.

Question 1:
What's the proper tension for the 5/32" rigging on a C22?
The Loose Tension Gauge Instructions referenced a desired shroud tension of 10%-12% of breaking strength and forestay tension of 15% of breaking strength. For 1/8* rigging this equates to 230 lbs of tension on the shrouds and 315 lbs on the forestay. For 5/32 rigging that's 360 lbs for the shrouds and 495 lbs for the forestay due to the roughly 50% increase in breaking strength .

The Tuning guide articles in the 2006 Tech Manual list between 100 lbs and 240 lbs for the lower shrouds and 400 lbs. for the uppers.

Do I tension my 5/32 rigging for the same lbs of tension as the 1/8* rigging or should I increase by roughly 50% due to the increased breaking strength of the larger rigging? Can the rest of the boat (deck, chain plates, compression post, etc.) tolerate the added tension?

Question 2:
Also, what's the current consensus regarding mast rake vs. pre-bend? I see articles suggesting 6-7" of rake and/or 2-3" of pre-bend.
 
Sep 23, 2021
9
Catalina 22 Davis Island Yacht Club
I've used (and misplaced) A Loos 91 Model A. Planning on replacing with a Loos PT-1.
 
Jan 1, 2006
6,185
Slickcraft 26 Greenport, NY
... Do I tension my 5/32 rigging for the same lbs of tension as the 1/8* rigging or should I increase by roughly 50% due to the increased breaking strength of the larger rigging? Can the rest of the boat (deck, chain plates, compression post, etc.) tolerate the added tension? ...
I would split the difference. Since the boat is spec-ed for the 1/8 that is what it is engineered for. However you may like the extra tension you can put on with the 5/32. It may show up as less forestay sag or maybe a more consistent mast shape as the wind pipes up. But there's no need to crank it up all the way and, in my opinion, it is much easier to bend a boat that we think. One the boat starts to bend tightening the rig doesn't translate to more tension - just more bend. You can see this for yourself using the loos gauge. The tension hits a point where it doesn't go up in proportion to the tightening. You can also see bending by running a caulk type line from bow pulpit to push pit. Tighten it. Then crank on some backstay. It won't be too long before you see the caulk line sag. the mast is a tremendous lever.
 
Sep 23, 2021
9
Catalina 22 Davis Island Yacht Club
That's sound logic. I'm also not too comfortable loading the boat up.

I probably should have stated that the main interest in tuning the rig is to maximize performance for local club racing. Nothing too intense. Just want to learn to sail the boat to its capabilities.

Any thoughts on the mast rake vs pre-bend?

Should I move this topic to the racing forum?
 
Jan 1, 2006
6,185
Slickcraft 26 Greenport, NY
Nah, I think you are in the right forum.
I just can't speak to rake and pre-bend as I've never sailed that boat.
In general I can say rake relates to weather helm. If you are fighting the helm move the mast tip forward. The standard rule is 3 -5 degrees of tiller in moderate wind. It's important because the tiller is a brake. Too much and you are slowing the boat down significantly.
As far as pre-bend, the curve of the mast should match the curve of the luff of the mainsail. Someone on this forum once suggested laying out your main on the ground and moderately tension the luff (Like with stakes). Then measure the depth of the curve of the luff by measuring from a line from the tack to the head. Whatever that number is - probably 3 to 6 inches - is how much pre-bend you should have in the mast.
 
Sep 15, 2016
621
Catalina 22 Minnesota
Be careful with advice on rig tuning from boats larger than the 22. They are a completely different beast as I can attest to both from experience and ownership. If your cruising, make sure the mast is center, have 6-8 inches of rake, and stays just over hand tight will do you just fine. If your racing well them...

The answer will depend. I race a Wing keel so its different than the swing. I start with the mast centered (checked with halyard side to side) and then have a rake of 6-9 inches depending on weather. If using composite sails you'll want to get the sail makers numbers. The current best Sails are made by Joe Waters in South Carolina at Waters Sails. Give him a call and he will set you up with more tuning info than most can handle. To start no more than about 20-25 on the uppers and about 10 on the forward lowers with the aft lowers being loose to barely hand tight (numbers all based on a Loose A). With the back stay loose you should have about 6 to 8 inches of play at nose height on the forestay. It is crazy loose but the sag is what will power up the big 150. As weather helm increased add backstay tension to take the sag out. The C22 is a mast head rig so the back stay directly affects the forestay. If your still relatively loose and struggling with weather helm add a 3/4 inch (or so) spacer to the upper rudder gudgeon to decrease drag and increase speed. This will give you a good start. Form there you'll have to experiment with crew and find out what works best for your boat. Wing keels are slow out of a tack but better in heavy air. Sing keels are faster and lower hull numbers are the fastest but you'll figure out what works. Racing can be a lot of fun and the C22 can be competitive against similar sized boats is tuned properly. Just make sure you don't get mast pumping when going up wind or you may just find your rig coming down. All of this is of course assuming your rigging is in good shape, bow tang is properly reinforced, and spreader brackets are the proper SS not cast ones that originally came with the older boats. For more racing tips try the Facebook group (that's where a few racers hang out) and contact a local C22 fleet if you have one. If not then pack up the boat and head to Nationals. Race in Silver fleet and you'll learn more in a week than you will in 10 years of club racing. Its a great group of guys. Trust me on this one its well worth your time.

Picture for motivational purposes of course!
IMG_2019.JPGIMG_2023.JPEGIMG_2193.JPG
 
Oct 19, 2017
7,028
O'Day 19 Littleton, NH
This is exactly why I don't like the standards for tuning based on breaking strength. It takes a specific minimum tension to hold your mast in place under sail load. It does not matter what the breaking strength of your stays are, that minimum doesn't change.

New tech in wire, upgrading size for weather, ocean sailing, whatever reason the breaking strength of your stays my change, it is not a good idea to over tension. Pulling down harder on the mast pulls up harder on the chainplates and pushes the step into the cabin top and through the compression post down harder against the bottom of the boat. Boats bend. Just look at how they move on the hard or on a trailer that's been poorly adjusted.

Forget the guage and learn to tune your rig by sight. Your mast will tell you when the tension is correct.

Set your rake angle, then tension the backstay(s) until you see the mast just beginning to bend. Back it off to barely straight. Whatever that tension is, that's the right tension and it always will be. Add a little more if you like a pre-bend.

It is similar for the lowers. Adjust the lowers to be in column. Tension them to feel like a bass string on a guitar when you pluck them, enough to firmly hold the mast in place. Then work the uppers. Tension the port upper, for example, just until you see it start to flex the top of the mast, then back it off until straight when sighting up it. Now tighten the starboard upper in exactly the same way. Keep the mast in column.

Last, take her sailing and if the turnbuckles start to lay over on a reach in a good wind, tighten booth sides equally until they don't. Watch the mast, keep it straight and in column. That's the right tension and it doesn't matter what the breaking strength is, unless the wire is undersized. That's another issue and breaking strength will matter then.

-Will
 
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Sep 23, 2021
9
Catalina 22 Davis Island Yacht Club
Be careful with advice on rig tuning from boats larger than the 22. They are a completely different beast as I can attest to both from experience and ownership. If your cruising, make sure the mast is center, have 6-8 inches of rake, and stays just over hand tight will do you just fine. If your racing well them...

To start no more than about 20-25 on the uppers and about 10 on the forward lowers ..........
Thanks for all of the great input. It sure helps me to wrap my head around this.

I presume the object is to keep the mast in optimal position given light, moderate, and heavy winds. I anticipate that the difference in loading characteristics (i.e., stretch) of the 5/32" rigging vs. the 1/8" rigging are negligible. Given tendency of the hull to flex, it seems best to tension the rig using the 1/8" rigging recommendations to avoid overloading the hull.

Just curious, will the 5/32" rigging be allowed at a C22 event?.
 
Sep 15, 2016
621
Catalina 22 Minnesota
Thanks for all of the great input. It sure helps me to wrap my head around this.

I presume the object is to keep the mast in optimal position given light, moderate, and heavy winds. I anticipate that the difference in loading characteristics (i.e., stretch) of the 5/32" rigging vs. the 1/8" rigging are negligible. Given tendency of the hull to flex, it seems best to tension the rig using the 1/8" rigging recommendations to avoid overloading the hull.

Just curious, will the 5/32" rigging be allowed at a C22 event?.
@Any Sea You actually want the mast to remain centered or in column when racing but be able to bend forward downwind and back when going up wind. This will reduce weather helm and increase speed.

As to the Class rules questions most any local club will be fine with you racing that way. Nationals will be fine in Silver fleet since the rules are a bit more lax and competition is not for the big trophy. As for Gold fleet I cant find anything saying heavier rigging is not allowed. The only thing I found is that standing rigging must remain original and no synthetic rigging is allowed. This ruling I believe cam about as people would disconnect the aft lowers to increase performance at times but don't quote me on that one. If you truly want an answer contact the Chief measurer at the C22 association. He has seen just about everything done to these boats over the years and would be able to answer easily.

Are you considering racing at the National event in Fort Walton next year?

Class Rules: https://catalina22.org/index.php/bylawsandrules/39-class-rules