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I am Stuck on Standing Rigging

Discussion in 'Catalina 30' started by reprieve, Dec 26, 2017. Add this thread to a FAQ

  1. reprieve

    reprieve

    Joined Dec 3, 2003
    14 posts, 0 likes
    Catalina 30
    6205 US mobile
    Hey Folks, it's been a long ole time since I was last here. Glad to see my login works.

    I am completing a total refit of Reprieve, my 93 C30sr and I have a question: Is it advisable to beef up my rigging for off-shore work by "going up" a size in my standing rigging. I have the 1/4" head stay and such, but would it be better to increase that to a 5/16" or even 3/8" diameter? Of course I'd adhere to the same increase per shroud. Thoughts, comments, suggestions? Please

    Thanks, Kevin
     


  2. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    2,582 posts, 1,065 likes
    O'Day 19
    US Littleton, NH
    Kevin,
    What kind of off-shore work? Are you crossing or just sailing to Bimini? Are you sailing over-night or long days within radio contact of local traffic?
    Have you ever been in 30+ knot winds and thought you might lose your rigging?
    If it would make you feel more comfortible, change it out. If you NEED to know where the limits of your 1/4" stays are, I'm sorry, I'll help with a little research but you're probably fine if you pay attention, reef correctly and haul it all in when you need to. Wear and tuning are most important. But, sh!t happens too.
    - Will (Dragonfly)
     


  3. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    2,582 posts, 1,065 likes
    O'Day 19
    US Littleton, NH
    Kevin, this is what I have found that may be the answer to your question. The prices on PBO rigging have come way down in recent year. You can stay within your original specs and greatly improve the strength of your standing rigging.
    https://www.westmarine.com/buy/west-marine--1-4-powerlite-pbo-cable--8025116
    I hope this is helpful. Please thoroughly research this because I am only pointing you in a direction. I have no experience with PBO rigging. I couldn't even find out what PBO stands for.
    Happy New Year
    - Will (Dragonfly)
     


    reprieve likes this.
  4. kappykaplan

    kappykaplan

    Joined May 1, 2011
    768 posts, 116 likes
    Pearson 37
    US Lusby MD
    @Will Gilmore, PBO = polybenzoxazole - took some serious searching to find.
     


    Will Gilmore likes this.
  5. Ron20324

    Ron20324

    Joined Jan 22, 2008
    6,100 posts, 538 likes
    Beneteau 323
    US Annapolis MD
    There was once a thread where a reply was if you go to a larger size, you should tune it tighter, which could put more stress on all the other parts connected.
     


    reprieve likes this.
  6. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    2,582 posts, 1,065 likes
    O'Day 19
    US Littleton, NH
    Was there a rationale for tuning it tighter? I would think the added stiffness of heavier cable would mean you wouldn't have to do that. The increased rigidity would resist play more. Just speculation on my part.
    - Will (Dragonfly)
     


  7. pateco

    pateco

    Joined Aug 12, 2014
    1,997 posts, 517 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    PBO fiber (polybenzoxazole) is the next generation super fiber, offering the highest strength and modulus of any synthetic fiber now available, almost double that of kevlar (p-Aramid fiber).
     


  8. LeeandRick

    LeeandRick

    Joined Apr 26, 2015
    375 posts, 116 likes
    S2 26 Mid
    US Lake Havasu
    As you know the stays are just part of system, which includes the mast and it's parts, chainplates, and the various load paths built into the boat to tie all of this together. Going up a size may give you a small amount of protection if the stays start to corrode but that's about it. It would be more prudent to replace things a little more often, especially in good old humid Mobile.
    If you want to shove the mast through the bottom of the boat, warp the side decks, or pull the chainplates out, go ahead and over tighten the stays. Your boat was engineered for a certain size and this could be to allow for a certain amount of stretch during certain dynamic load situations to keep from tearing anything else loose. I'm not a naval architect just a mechanical engineer.
     


    reprieve, Rick D and Will Gilmore like this.
  9. mortyd

    mortyd

    Joined Dec 11, 2004
    937 posts, 12 likes
    Catalina 30
    US easy living
     


  10. mortyd

    mortyd

    Joined Dec 11, 2004
    937 posts, 12 likes
    Catalina 30
    US easy living
    and i'm an aeronautical engineer and agree with leeandrick.
     


    reprieve likes this.
  11. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    2,582 posts, 1,065 likes
    O'Day 19
    US Littleton, NH
    Let me add my voice to that sentiment also. But, I still can't imagine why having heavier cabling would require tighter tensions. The increase in material weight would do that at the masthead anyhow, but not by a worrisome amount. The force required to hold a mast in position doesn't change just because your medium for doing the job is different. As LeeandRick point out, the lower stretch in larger cable would actually require less tension, not more.
    rerieve, let us know more specifically, what kind of sailing you have done with your boat. Open ocean sailing is more stressful than coastal sailing in that consequences for failure are more dire and the chance of getting caught in heavy weather is greater, but it generally doesn't represent any more extremes than those potentially faced within 4 miles of land. There are big waves and high winds and collision dangers in both areas. Your 93 C30sr was probably up to it when her rigging was new.
    The next question is, are you?
    - Will (Dragonfly)
     


  12. Ron20324

    Ron20324

    Joined Jan 22, 2008
    6,100 posts, 538 likes
    Beneteau 323
    US Annapolis MD
    Will, maybe think of it as each diameter wire has it's optimum tightness, each engineered for it's load needs by a naval designer. Somewhat, but not exactly like, a musical instrument. Each string is tightened to a different amount. Each size of string has an optimum note/stretch they can be tuned to. Several notes, actually. Either too tight or too loose and it does not sound right- an E string tuned to an A, for example. my 2 cents.
     


  13. Siamese

    Siamese

    Joined Aug 2, 2009
    397 posts, 78 likes
    Catalina 28MKII
    US Muskegon
    My knowledge is sketchy on this subject, but I'll add this:

    When using a Loos gauge to get into the ballpark of tensioning rigging, the shrouds are tensioned to about 15% of their breaking strength. And, final adjustment can be performed under sail.

    15% of breaking strength for a 1/4" shroud will be x amount of pounds of tension. 15% of breaking strength for a 3/8" shroud is considerably more pounds, and may exceed what your boat was intended to handle. At the point where you've taken the slack out of your leeward shroud (somewhere north of 15%), with a larger diameter, you may have exceeded what your chainplates were engineered for.

    Even with the correct diameter shrouds, you may notice interior doors fitting differently as you tension the shrouds and they re-shape your boat. Heavier rigging with it's greater tension will exert more loads on your entire hull and deck structure.

    In short, it's my understanding that the boat and it's rigging were designed to work as a package, and simply going up a size isn't feasible.

    Bottom line, it ain't simple.

    Guitar strings have already been mentioned. If you change string gauges on your guitar, you can expect heavier strings, when tuned to the same pitch as your previous lighter strings, to exert more pull on the neck. You can easily measure the increased bow in you neck. Adjusting the the truss rod, the steel rod in the neck that counters the string force, will remove the bow from the neck.
     


    Last edited: Dec 27, 2017
  14. Will Gilmore

    Will Gilmore

    Joined Oct 19, 2017
    2,582 posts, 1,065 likes
    O'Day 19
    US Littleton, NH
    Ron, I appreciate the response. Is this something you have come to know or are you just suggesting a possible explanation? It is not exactly consistent with what little I know about materials science. However, as an amateur non-musician, I see perfectly what you are saying.
    "Non-musician" = I play the harmonica and play WITH a few stringed instruments, but no one can say I actually "play" them.
    - Will ("no virtuoso", Dragonfly)
     


  15. Rick D

    Rick D

    Joined Jun 14, 2008
    6,530 posts, 157 likes
    Hunter Legend 40.5
    US Long Beach, Shoreline Marina, CA
    About 30 years ago, there was a French guy near me who purchased a Catalina 30. He decided to "improve" it with tankage, some longitudinal stringers, different stove, modified refrig, etc. He also decided he wanted outboard shrouds, big gauge standing rigging and an inner forestay. He put a ton of work on it. Off Mexico (sailing to Europe) he found the deck lifting off. Just a work of caution. Someone has calculated loads carefully when that boat was designed.
     


    Last edited: Dec 27, 2017
  16. Ron20324

    Ron20324

    Joined Jan 22, 2008
    6,100 posts, 538 likes
    Beneteau 323
    US Annapolis MD
    Someone will recall the race boat that actually folded in half due to too much rig stress. Pictures anyone?
     


  17. shemandr

    shemandr

    Joined Jan 1, 2006
    3,422 posts, 528 likes
    Marblehead Skiff 14'
    US Greenport, NY
    One Australia. I'm not sure rigging tension was the reason. I've joked with people that the last command before it sank was "Release the backstay." In reality it was surely more complicated. But if you look at the video the backstay(s) were clearly flopping around as the boat started to come apart. I don't think the rig ever fell. But when a lead mine fills with water it goes fast. You wouldn't need to tell me when to jump off!
     


  18. CloudDiver

    CloudDiver

    Joined Sep 8, 2014
    2,525 posts, 405 likes
    Catalina 22 Swing Keel
    US San Diego
    I would go with Heat Annealed Dyneema in 6mm (same size as your current 1/4"). The breaking strength of 1x19 SS wire rope (according to Hayn) is 6900 lbs. Breaking strength for 6mm NE Ropes STS HSR is 12,385 lbs. So you nearly double the strength of wire rope without going up in size, plus you will save a significant amount of weight aloft. I can tell you where you can buy a 600 ft spool for $1,220. At $2 a foot that is significantly cheaper than PBO. If you don't need 600 ft you can either sell the rest on eBay or make yourself 2 complete sets of stays.
    I haven't seen any data that says PBO is stronger than Dyneema (post if you have a reference, I don't); but I will tell you PBO is not nearly as UV resistant as Dyneema and significantly more expensive.
    You are saving money of swage fittings... $10 to $15 on labor per swage plus the cost of the fitting x 16. The closed thimbles you need are pricey (about $8 each) but honestly you can use standard 316 open thimbles, I've seen many riggers do it. You keep your turnbuckles as they are and use as normal, unless they are due for replacement anyway.
    Keep in mid, if you have headsail furling with a foil luff you might want to stick with wire just on the forestay. It's possible to have a dyneema headstay inside a foil luff, but I would guess a dyneema chafe sleeve would be in order and I would have to ensure that the foil rides on some type of bearing system that keeps it isolated from the fiber... I'm not really familiar with the 'insides' of the various furling luff foil extrusions.
     


  19. FastOlson

    FastOlson

    Joined Apr 8, 2010
    945 posts, 89 likes
    Ericson Yachts Olson 34
    US Portland OR
    It's interesting to gather info off the 'net from strangers. Better to become more knowledgeable yourself. Buy a copy of the Riggers Apprentice by Brion Toss. Really.
    One bit of wisdom is that you should never blindly go "up a size". Figure out the loads for yourself, and it's likely that, as others here have hinted at, the original spec's are fine for your boat.

    A far greater concern is that your present rigging 'gang' is old and simply needs to be replaced. Chainplates, maybe the same advice.

    Fair winds for the new year!
    :)
     


  20. jssailem

    jssailem

    Joined Oct 22, 2014
    5,541 posts, 1,836 likes
    CAL 35 Cruiser
    US Salem, Moored Port Everett WA
    :plus: With @FastOlson on the rigging size and the info Brian Toss shares. Your boat is not one known to have rigging that is undersized.

    Kevin, the type of sailing you plan to do may help lend clues as to rigging changes.
    1. Racing may cause you to take the weight reduction path with high tech (High Modulus Polyethylene) fiber lines. It will also mean continuous monitoring of line condition, chafe and UV damage replacement. @CloudDiver offer of a 600ft spool likely will save you money in the long run. You will need to up the study of seamanship knots as the Dyneema type lines do require a level of skill to safely terminate the ends.
    2. Cruising coastal waters, as designed for your boat. Trust the designer replace with same rigging design.
    3. Cruising Ocean, a grey area that might stress the rigging under certain conditions. This type of adventure means you are likely beyond the average sailing knowledge base of most and professional rigging skill would be helpful is design and replacing the rigging of your boat.
    The constant here is it is your boat and your plan. You get to experiment or choose a path.
    “Choose wisely”
     


    dziedzicmj likes this.

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