lifting points - marking at hull...

Discussion in 'Boat Design' started by User_U, Jan 4, 2006.

  1. User_U
    Joined: Jan 2002
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    Location: Hamburg, Berlin, Germany

    User_U Junior Member

    Hi guys,

    does anybody know some rules which advise the boatbuilder to fix some lifting markings at the hull to indicate where the crane with belts should lift a boat?

    I have not found anything in German Lloyd and all ISO-Standards for recreational crafts...:confused:

    No need to discuss that they should be there - concerning weight and strength of hull structure ist could be very usefull :D to know where to lift - but what I am really looking fore are any rules and information about it....

    Thanks in advance, greets from Germany...
  2. safewalrus
    Joined: Feb 2005
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    Location: Cornwall, England

    safewalrus Ancient Marriner

    No rules as far as I am aware! Normally left up to the rigger / crane driver / supervisor (whatever you want to call them) at each lift.:rolleyes: Occasionally an Architect MAY put some information in his drawings! :rolleyes: But it's a thing most people don't recognise as boats don't normally spend their lives swinging around in the air.

    Occasionally, if the boat is required to be lifted regularly (ships boats etc) chains and lugs will be fitted but this is very much an experience & individual thing!:cool:

    No doubt some 'expert' will come up with some far fetched idea but I've never seen it - that is not to say there isn't such a thing!:eek:
  3. stevel
    Joined: Aug 2004
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    Location: Ventura, CA

    stevel Lost at sea

    I marked my boat after the first time that I had it hoisted. I am the only person who knows what my marks mean, and I'm actually planning to change the marks when I repaint this year. The original mark was a paint dot on the top edge of the rubrail. When I repaint, I will put a small tick in the bootstripe. If you come across any rules, please share, as I would probably follow the standard, rather than make my own.
  4. User_U
    Joined: Jan 2002
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    Location: Hamburg, Berlin, Germany

    User_U Junior Member

    yes guys, I absolutly agree with the need of them and how to use. Of course after a first try and error (hopefully not :D ) by raising the boat a bit you can find the right position or better the manufacturer indicates them at the boat.

    The problem is that there happend an accident with a boat being craned and which fall down - now the quarrel is about the responsibility. So I am still looking for a rule that says that there have to be some markings...not where, how to fix, which size, how to calculate:D - no, only if....
  5. stevel
    Joined: Aug 2004
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    Location: Ventura, CA

    stevel Lost at sea

    I guess you now know one location that is not a hoisting location:( That raises an interesting point, however. My boatyard asked ME where to lift, probably to avoid liability for just such a problem. That is what gave me the idea to mark the boat. I am definitely interested if anyone finds an answer.
  6. Eric Sponberg
    Joined: Dec 2001
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    Eric Sponberg Senior Member

    There are no rules for lifting points, because each boat is different, and it is hard to make generalizations as to where to pick it up. Therefore, you don't have any standards to back you up in the dispute you describe. A number of racing sailboat designs have a single-point lift right over the keel. These are obvioius to the owners and users. Usually, you like the straps, as in a Travellift, to fall on bulkheads, but it is not always obvious on the outside of the hull where the bulkheads are. You also want to avoid lifting on the propeller shaft and/or strut. This is why SteveL wisely marked the hull himself so that he would avoid any problems in the future. You will likely have a battle of the experts to fight out where the lifting points should have been.

  7. marshmat
    Joined: Apr 2005
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    Location: Ontario

    marshmat Senior Member

    Some builders around here use an oval-shaped stainless steel plate- four of them, about 6-12" long, are fixed to the hullsides near the gunwales at the sling points. It's a pricey, but fancy-looking and effective solution. Marking the bootstripe or just above it, in much the same manner as bulbous bows and thrusters are marked on ships, is also common. Where the marks go is decided by the designer based on how he's analyzed the boat's structure and balance, there are no regulations or standards regarding where the lift points go.
  8. Danger Mouse
    Joined: Oct 2004
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    Location: UK

    Danger Mouse Junior Member

    The marina where I used to work did it much as described by using experience and beginning the lift & repositioning slings if necessary. The also had small stickers available to mark the sling positions for the next year.

    The only time they had any direct advice was when lifting a Princess 60/65, which did have comprehensive lifting instructions in the owner's handbook :) This was a task in itself as the boat was a size that was at the limit of the travel hoist.

    Only once in my eight years of working there did they ever experience any obvious probems with damage due to lifting. I don't remember what boat it was but it had long exhaust "boxes" running down each aft quarter, whick cracked when loaded. The only way around this was fitting sections of railway sleepers, usually used for shoring, above and below the boxes to take the slings.

    Some regulations would definitely be helpful :rolleyes:
    Joined: Nov 2004
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    Location: The Netherlands

    D'ARTOIS Senior Member

    Before you haul a boat out of the water, make clear that the belts do not crush the propshaft and that they are put under the main bulheads of the boat.

    A sailing yacht shoud belifted when the belts are as close to the keel as possible. Make sure thatnthe propshaft is cleared.
  10. huntgraphic
    Joined: Feb 2013
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    Location: BUFFALO

    huntgraphic New Member

    Hull Marking Stickers

    New here and been reading this thread. I do graphics for a local marina, and they asked me to make stickers for them to mark the lift points on boats. They showed me some stickers they purchased, paying about $20.00 for 40 stickers 1/2" X 1" with the word LIFT on them. I made stickers for them, 1" X 1", with the word LIFT on them PLUS their marina logo in two color. Cost for a sheet of 90 stickers was $20.00. I'd be happy to do the same for you.
  11. Submarine Tom

    Submarine Tom Previous Member

    Most marine outlets carry something to mark lifting points.

    You only need four obviously and they should read something to the effect: SLING POINT with an arrow perhaps.

    Usually the slings are centred there.

    Depending on the hull design they can be very important as can be the use of spreaders.
  12. tunnels

    tunnels Previous Member

    The racing yachts we made had one single lifting point down through the companion way witha yoke the straddled the keel grid and had a single 1' bolt and nut thats it . the first boat was absolutly scary but after and seeing it was perfectly ballanced never gave it a second thought .
    Even when we lifted the hull out of the mould we just had a hook arrangement the went up under the Gunnel eachside and lifted off those . so easy and never a problem !!.
    See some really scary stiff with crane drivers lifting boat high in the air for no apparent reason other than it looks good !! . one slip of a strap and shes history !!.slipping straps are a worry specially with big launchs hardly never see anyone tie the straps to each other or some part of the boat .they creep when they are dry and if the forward strap is close to the forefoot of the bow its over quicker than you can blink !!:):D:p
  13. philSweet
    Joined: May 2008
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    philSweet Senior Member

    Every owner should carry a photo or schematic of the boat showing the underwater profile to show the lift operator. That would prevent most of the troubles mentioned above.
  14. CDK
    Joined: Aug 2007
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    Location: Adriatic sea

    CDK retired engineer

    Of course there must be markings on the hull, especially if you have stern drives. Many crane operators have no idea about weight distribution and assume the CoG is in the middle.

    On one occasion in Italy the crane driver used a frame that wasn't wide enough and caused long cracks on both sides of the hull. The next time they used short slings and ripped the radar dome from the arch when lowering the boat in the water.
    The only way to prevent such things is to be present before they even come near your boat.

    I don't know about liability in other countries but this large marina in Monfalcone (Italy) stated they were in no way responsible for damage to boats or equipment.

  15. cedari01
    Joined: Nov 2015
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    cedari01 New Member


    If markings are not avail you usually follow the following procedure;
    Aft sling: Place this sling as far aft as possible but ahead of where the shaft(s) come through the hull. If not sure go into the boat and find stuffing boxes. Aft sling should go just ahead of this location.
    Foreword sling: Place this sling as far forward but aft of the part of the bow that curves upward. For a powerboat this is usually just forward of the windshield base. For a sailboat this is usually just forward of the main mast. Someone should observe the underside of the boat as its being lifted to make sure sling placement is good before lifting fully out of the water.
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