Bow high, stern squatting

Discussion in 'Stability' started by Jolly Mon, Oct 19, 2019.

  1. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Jolly Mon, Gonzo's and Fallguy's suggestions make a lot of sense.
    The only possible 'problem' then is one of aesthetics re how she looks - does she really look like she is trimming excessively by the stern?
    If you have a digital photo available showing a broadside view, please do post it - as the saying goes, a picture is worth a thousand words.
     
  2. Jolly Mon
    Joined: Jun 2019
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    Location: East Coast, USA

    Jolly Mon Junior Member

    Gonzo, that’s a great idea. However there are two other issues..the way it looks as evidenced by a dock master calling me concerned about the boat taking on water, and two, the lee helm under light air when sailing which also indicates that weight needs to be moved forward or added back in the front.

    Also, yesterday, I added seven - 60 lb bags of the dry concrete mix. I have fore and after pictures. The best I could get at the dock. C6EA1AEE-D645-41CF-A0CF-91DDDF776607.jpeg 4BEE0E7C-18D4-4EB5-987F-168DE64481E5.jpeg
     
    Will Gilmore and bajansailor like this.
  3. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    She certainly does 'look' better in the second photo after you added the 420 lbs of dry concrete ballast up forward.
    Trouble is, that ballast is only serving one purpose - it will never have a use on the boat for anything else.
    I would be more inclined to add ballast which can multi-task, such as one or two gallon water containers (always useful to have an emergency water supply in case anything happens to your tanks or water maker).
    Or an extra 400 lbs of anchor chain and another anchor - I know you have enough chain for now, but in a hurricane you can never have too much chain available, and an extra anchor (even if you have 2 already) is always useful.
    Congratulations on doing an excellent job on that very long re-fit - she is looking very nice indeed.
     
  4. fallguy
    Joined: Dec 2016
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    Location: usa

    fallguy Senior Member

    You really need to do the levers worksheet.

    The obvious problem of removing 400 pounds of water from the front is not the whole story. There are other add ons that you ought to counter.

    An example would be the solar setup. You consider that as not a raw boat and estimate the weight and distance to center.

    Say 75 pounds at 10 feet. That is a 750 pound moment.

    Then your bags at say 15 feet would offset with one more bag of 50 pounds. 50x15=750.

    And, of course, as well pointed out, concrete is horrible onboard.

    First of all, it is not neutral buoyant even. Water is less the tank.

    Anyhow, I would make a list of all the non-raw boat items aft of center and there moments and see what you get. I am guessing you are still short by a bit.

    Great looking rig. Get rid of the concrete.

    After you calc the moments aft, there are hundreds of polyethylene tanks and tank designs online. Find one that fits under the berth and even if not plumbed; it would be better in my opinion.

    What did the level say?
     
    Last edited: Oct 22, 2019
  5. Jolly Mon
    Joined: Jun 2019
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    Location: East Coast, USA

    Jolly Mon Junior Member

    After getting out and riding around the boat in the dingy I see that the concrete made a tremendous improvement. The issue isn’t resolved however.

    Good ideas you all have! Thank you. Fallguy I really like that idea of going back and looking at the add-ons. I’ll be working on that in the days ahead.

    However, at least for now, the concrete stays. . It was a quick and cheap fix to confirm the problem. I agree it’s not the final answer.

    Rob
     
    Smj1 likes this.
  6. Will Gilmore
    Joined: Aug 2017
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    Location: Littleton, nh

    Will Gilmore Senior Member

    It seems to me, the real concern here should be the why. Why is your trim off like that? 50 gallon water tank? Nope. There is more going on.

    You can correct her trim with added weight, might as well make it a pair of 125# storm anchors and more chain, but you still don't know what is going on.

    Does she have a new engine, is her transmission bigger, a lead rudder?

    The lever arm calculation needs to go hand in hand with cross-sectional buoyancy offsets. The stern probably gains buoyancy faster than the bow as it trims down.

    Do two adult men moving forward and aft affect her from that much? Maybe she's lost some ballast from her keel. She looks light in the water, over all. How stiff does she sail?

    -Will (Dragonfly)
     
  7. Jolly Mon
    Joined: Jun 2019
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    Location: East Coast, USA

    Jolly Mon Junior Member

    Hi Will,
    Thank you for your post and interest.
    There was a water tank under the vberth I expect 65 gallons or approx 550 lbs. I’ve replaced this weight with Dry bagged concrete and the boat sits perfect now.
    Long term I’m thinking added additional diesel tankage.
    Thanks again, Rob
     

  8. fallguy
    Joined: Dec 2016
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    fallguy Senior Member

    Please pay attention to thread dates. These resolved threads from 6 months ago do not deserve comments. And the rest of us get do not deserved to get notified about nothing. Regards.
     
    Ad Hoc likes this.
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