Longnitudinal stiffening

 

Home Forums General Olson 30 Discussions Longnitudinal stiffening

This topic contains 18 replies, has 9 voices, and was last updated by  Jason Adamson 6 years, 1 month ago.

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  • #1907

    Old School
    Participant

    Looking at the forestay thread, and examining some boats, it is becoming apparent that our boats are indeed softening over the years. Of course, this can be expected in thirty year old boats, but I for one would like to lengthen the racing lifespan as long as possible!

    In our current constitution, it is not permissible to have any non-stock longnitudinal stiffners installed, except for the exemption of allowing boards between the main bulkhead and the forward bulkhead. It is also suggested that jock-straps and the mast-deck strap also help in this regard.

    But I think more could be done. I am not an engineer, but there could very well be some more simple solutions have not been looked at.

    What does the association membership think about using some of the funds in the class’ account to hire a NA to go over the boat and make some suggestions? If there are some new ideas, we could vote on them at the next AGM.

    Scot

    #2958
    Bruce Hubble
    Bruce Hubble
    Participant

    In my opinion..jock straps without a BOD could actually make the problem WORSE. Think about a bow and arrow.

    The best fix would be a SS Rod from deck to keel (or to a SS mast base plate). Most modern boats have this. If the deck can’t rise..the sides can’t come in. Our toe rails are strong.

    I know on my boat that I cannot install my ladder pins when it is on my trailer sitting on the keel. Once in the water, pins go in easily. To me, that means the bottom of the boat has a tiny bit of flex. That means your mast compression can push the keel down further. A rod would prevent some of that.

    #2959

    Old School
    Participant

    I am sure a rod would help, but I still think having a NA’s opinion would be valuable.

    #2960

    Lilya Vorobey
    Participant

    I picked up a SS plate from Buzz. He recommends not using the BOD but something with a turnbuckle that goes from the keel to the deck. His SS plate has 4 tangs on it. 2 for the jockstraps and 2 front and aft of the mast. I haven’t done this yet but will measure what ever I can when I do.

    #2963
    Bruce Hubble
    Bruce Hubble
    Participant

    Lilya…I agree. Jockstraps though? I think it could be worse!

    Would the class have issue with a SS rod from the deck to a keel bolt? I don’t race class, so I may go there. Currently I have a turnbuckle from the deck to the front of the mast. I keep it pretty tight. I will be adding some extra tension for a regatta in a week.

    #2964

    Ray
    Participant

    I’d definitely be interested in something to stiffen fore/aft as well. I have trouble attaching my backstay until I drop the boat in the water. Once that’s done- stern and bow flex upward, and voila- connection. For some reason, though, I figured it would be a very long carbon fiber pole running from stern bulkhead to stem bulkhead and lashed to the mast, no?

    #2965

    Curt Rodgers
    Participant

    We all put a lot of tension on the backstay with our 48:1’s. Has anyone had their forstay pull off the bow? I put a 1/8″ G10 backing plate under the forstay attachment just because it looked like an accident waiting to happen.

    Also, does anyone have pictures they would share of boards between the main bulkhead and the forward bulkhead? I would be interested in doing that if folks think it actually helps.

    #2966

    Ray
    Participant

    “does anyone have pictures they would share of boards between the main bulkhead and the forward bulkhead?”

    Is that where most of the flex occurs? Exactly which bulkheads are the forward and main bulkheads?

    #2967

    Old School
    Participant

    I don’t have any pics, but it is legal to have boards between the chainplate bulkhead and the v-berth bulkhead. Here is the verbiage from the constitution:

    Fore and aft stiffeners or stringers are allowed only in the area between the cabinets and the aft end of the V-berth on both sides of the hull, extending upward from the hull, no higher than the height of the v-berth. The material should be of plywood, similar thickness and strength, and fastened in keeping with the existing construction method. The bulkhead shall not have cut outs other than a half (1/2) inch weep hole at the aft end to allow for water drainage.

    #2968

    Derek Lay
    Participant

    Has anyone installed these stiffeners? Any noticeable change? Any pictures?

    #2979

    Ray
    Participant

    I just read a fairly lengthy thread over on SA about this topic, and I think if I do anything I’ll only tab in some stringers between the two forward bulkheads as described above. I think my boat was just meant to get to the windward mark whenever it does, then go fast back down. I’m hearing/reading this more and more. Here’s the thread- http://forums.sailinganarchy.com/index.php?showtopic=95578

    #2980

    Jonathan Pollak
    Participant

    I am not sure if it would work but last year I thought up an idea to use cables to complete the circuit from the headstay to the aft chainplates in a similar manner as the BOD/Jock Straps essentially form a 2nd/3rd spreader and continue the shrouds to the mast step. In this you would tap in some sort of tunnel along the whole base of the boat [maybe pvc pipe or something]. This cable would have a turn buckle in the middle for adjustment. So in effect you would have a complete truss structure in both planes [fore aft/port starboard] from mast bast to masthead. Moreover this truss would be tied into the hull in a very important way. If you just ran a cable from the headstay to the mast step the high aspect dimensions of that part of the truss would require excessive tension to impart a downward force on the headstay. most of the force would be pulling back. With the tabbed in tunnel tied into the base of the hull this would not be the case.

    Just an idea. Not sure if it would work. It would certainly be light.

    -Jon

    #2981

    Jason Adamson
    Participant

    I have to say I feel pretty lucky to not be experiencing much of any type of flex in the hull. Sure I have a couple soft spots in the deck, but that is understandable from the age of the boat. I think we need to take a look at what we are expecting from a 30+ year old boat, built of fiberglass and wood. Both these materials bend and flex, and over time they fatigue. If you really want to solve the problem why not just do a total makeover and use carbon/kevlar to re-enforce the hull and deck. I enjoy the boat and appreciate it for what it is. If you want a stiff hull, buy a new boat. I don’t have jock straps or a BOD, nor do I have a dbl spreader rig, but I do fine in our fleet and really can’t see spending money on a NA only to be told that “hey it’s 30 yrs old what do you want from it?”
    Bigger issues then minute amount of flex are going to slow you down, like slow tacks, old sails, a rig that isn’t in tune, too little weight, too much weight, poor bottoms…and on and on. Before we go spending the class’s money, which isn’t a lot, maybe we should just focus on fine tuning our own skills. Enjoy the boat go win races but don’t expect miracles when pushed against newer updated designs.

    #2982

    Old School
    Participant

    Respectfully, I think you miss the point Jason. Historically, the Olson 30 OD has been a bit fluid. When weaknesses are found, solutions are sought. This is how we came to endorse elliptical rudders, multiple rigs, BOD’s and straps. I draw your attention to a few spots in our constitution:

    ARTICLE II – OBJECT

    The object of the Olson 30 class Association shall be to promote the development of the Olson 30 as a high performance sloop and to promote Olson 30 class racing. Inherent in this Association is the belief that the value of this class lies in its desire to keep the Olson 30 keenly competitive in all types of racing.

    ARTICLE III – POLICY

    It shall be the policy of this Association to:

    B) To recognize that yacht racing is dynamic, not static, and that, within the limits of this Constitution, owners shall be encouraged to develop and modify the Olson 30 as new equipment becomes available.

    C) To develop an attitude of cooperation and exchange of ideas so that the Olson 30 can remain at the head of any fleet of racing yachts.

    D) To keep the cost of being competitive in both handicap and class racing at a level which will enhance the enjoyment and value of all Olson 30 sloops.

    E) To protect the investment of all owners of the Olson 30 sloop by a vigorous development of a strong Class Association.

    I am also lucky to have a pretty stiff platform, but several boats do appear to have some flex issues. Of course, this can be expected in old fiberglass boats. But, it is an identified weakness in our boats, that can potentially be remedied to an extent, and quite possibly without excessive costs. Nobody is asking for a boat that is as stiff as a new carbon boat, but we have an opportunity here to slow the inevitable degradation of our boats, and to maintain whatever value we still enjoy.

    I understand that the association account is not rich, but there is money sitting in there essentially doing nothing. I believe that hiring someone to make recommendations is a very worthwhile investment, one that our prior members would probably endorse, and that current and future members will reap the benefit of.

    That being said, it would not take a NA long to indicate if there is no hope. But, it would not hurt to ask. There are a couple of good guys up here on Ontario that we could get involved, and of course there are lots in California.

    #2983

    Derek Lay
    Participant

    Scot,
    If we are going to have anyone look at the boat with an eye to keeping it “competitive in both handicap and class racing,” it would be worth investigating ways to meet the latest offshore stability requirements without sacrificing the basic OD hull shape and weight. Looking at the additions that Bruce Hubble had to make to his keel for the ChiMac, I can’t help to think that lightening the rig would have been a more favourable approach while making the boat more nimble, not heavier. Our boats are supposed to be ULDBs; why not improve the ballast/displacement ratio and prove that they can still be competitive?

    Has anyone tried a carbon rig to see what advantages could come of the swap? Would we be able to lessen the forces on the hull by tailoring the strength and flexibility of a fully-engineered spar? Acknowledging that the cost is a factor and would keep most of us with our current rigs, knowing what the potential benefits would be would at least provide the fuel for an educated discussion on the best way forward for the class.

    Derek

    #2984
    Bruce Hubble
    Bruce Hubble
    Participant

    carbon in lake michigan phrf is a three second penalty. Keep in mind, the new carbon spars are STIFFER! Ask a J/111 owner.

    Fix your mast step first..double it up. It will spread the compression across the boat more AND maybe lesser shroud settings because the step is not flexing.

    By measurement, ORR, the outboard is already more stable than the IB. In hindsight, I should have taken a chunk of lead from the middle section of the keel and moved it to the bottom. No displacement change and gain 3″ of draft. No PHRF penalty so far for my keel mod. ORR might have given me some, but no more than an outboard rating, so it was ok.

    #2985

    Jason Adamson
    Participant

    Respectfully Scot,
    I do understand that the class tries to keep up with weaknesses and address them in a way that is fair to all competitors. I just don’t see this a known weakness, there are many many factors at play here outside of a flexible hull.
    First, if we are basing our opinions off of one person who is having issues with rig tension then we need to look at that specific boat to see what the problem is. It sounds to me like there may be an issue here with the mast step more than a flexible hull.
    Second, if you are concerned with this problem and you believe it is a major issue (which I personally do not) then I would suggest you invest in a NA personally. If results from his evaluation prove there is an inherent flaw in the design then we as a class can investigate further to eliminate it.
    Lastly, as everyone knows when we go about updating/changing rules to improve the boat we will always encounter the “if’s” of life. “If we really want to improve the boat we should allow carbon rigs”. “If we want to gain better control we should allow carbon rudder blades”…The “if’s” Again I believe the idea of the Olson was to have a fast, fun and affordable boat that every man could enjoy. I would hate to see this turn into an arms race with people spending exorbitant amounts of money just to gain the advantage. I mean we can’t even get the class to vote on the idea of allowing the stern rail to be opened for easy access to the motor…imagine trying to decide on what materials are allowed for hull stiffening.

    I would much rather see the class money spent on promoting and expanding class events. I want to see “prizes” awarded for those who earn them in regatta’s. I want to see participation in Nationals and NA Championship regatta’s go up. That is what the funds, and I use that term loosely, are there for. Let’s get people out and racing.
    I appreciate the open discussion that has been created and if people want to see changes made to the Class By-Laws then I would suggest they do as we did this year and form a list to be sent to the next general meeting. Along with that list I would encourage everyone to attend or send their Proxy vote in so we can vote on these changes.

    Jason Adamson
    2013 Class President

    #2986

    Jim Saylor
    Participant

    Thank you Jason!
    We have all these boats yet we get seven to the nationals??? How many boats were sitting around unused within 100 miles? I would have paid to use one, and it would come back better for it. I’m just sayin…

    #2987

    Jason Adamson
    Participant

    Jim,
    I am sorry we couldn’t wrangle up a boat for you this year. The conditions were perfect and the class had a great time. I does irritate me that no one was willing to share their boat and actually make some money in the process. We are again doing the Nationals at LBRW next year and I sure hope this time we can get you a boat. And hopefully the class will be able to supply actual prizes to those who trophy.

    Jason Adamson

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