If your crane is a MarQuipt I have a complete unit with standpipe and base in my storeroom. It’s an electric unit that we removed for a hydraulic one off of a Viking Sportfisher.
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Thread: Catastrophic davit crane failure
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05-26-2020 09:36 AM #11Senior Member
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Re: Catastrophic davit crane failure
Michael & Beth
Hull Number CV312
63’ Cockpit Motor Yacht
1986 model launched in August 1987
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05-26-2020 09:57 AM #12Senior Member
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Re: Catastrophic davit crane failure
Somebody may correct me, but don't these MarQuipt units achieve rotation by pipe-in-a-pipe action? There was a discussion here a few years back about how hard it is to rotate under load (mine has that issue).
If true, when at full extension the maximum lateral pressure is at the lowest point of the inner pipe, and a deck flexure at the upper flange would cause Ron's scenario; the lower flange breakage is collateral damage.
Ron, if you examine the inside of the upper mid-pipe break you may see the inner pipe for confirmation.
A future solution is to replace the obviously broken outer sleeve but certainly reinforce/stiffen the upper flybridge flange area for some distance away from the flange base.
My $0.02
DAN
ps Sorry for this problem--probably ruined a day of boating for you.Last edited by drburke; 05-26-2020 at 09:58 AM. Reason: I am great
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05-26-2020 10:41 AM #13Senior Member
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Re: Catastrophic davit crane failure
A98B4870-776E-469B-840B-42F4571F20C8.jpg8F85B2CE-E68C-4802-BD1B-5A88BEC59762.jpg4E557A3F-0120-4B59-A79B-2D3F6DE536A5.jpgAttachment 40528
Marquipt does not use a sleeve type system for rotation. There is a greased phenolic ring that sits on top of the standpipe that allows for rotation. The standpipe should be a one piece non-welded extruded pipe with very thick walls. If you want I can send you the exact dimensions of the standpipe used on a 1987 63' CPMY.Michael & Beth
Hull Number CV312
63’ Cockpit Motor Yacht
1986 model launched in August 1987
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05-26-2020 11:07 AM #14
Re: Catastrophic davit crane failure
What will you replace it with? Will it have the same pole support system?
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1984 61MY #353 with 9' cockpit extension.
Sydney, Australia.
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Re: Catastrophic davit crane failure
Sorry to see that Ron. I have the same Davit. Keep us posted on the failure analysis. Do you think it is corrosion related?
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Re: Catastrophic davit crane failure
The boatyard hoisted the yacht today. There was no obvious corrosion . The hole where the shaft came through the roof has very little coring. The yard really doesn’t have an answer for why it happened. I’m getting quotes for a new stand pipe and crane motor repair. The crane motor started spoiling out before the standpipe cracked. I can only guess that the fast descent could of put undue pressure on the standpipe but it’s only a guess. I’m also getting quotes for a remanufactured fully hydraulic davit. Low end for repairs looks like $7000 with a new pipe, glass work and motor service. High end$30,000 plus. They are working on the full quote nowI’ve attached pics on the plate where the pipe stood. It didn’t budge. The poorly cored roof didn’t do so well. On a good note the coring is dry as an old dog bone
Looking for a 80 plus foot yacht
Hatteras of Cheoy Lee
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Re: Catastrophic davit crane failure
I don’t see any thru bolts holding the flange thru the ceiling. Mine has two flanges, one on each side of the roof, thru bolted together.
I hope you didn’t haul out just for that ...Pascal
Miami, FL
1970 53 MY #325 Cummins 6CTAs
2014 26' gaff rigged sloop
2007 Sandbarhopper 13
12' Westphal Cat boat
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Re: Catastrophic davit crane failure
I meant to type they hoisted the crane out. I went into the straps but they figured out they could do it in the waterI have two flanges too. The one underneath had the screws ripped out when it snapped. One of the earlier pics show it midway on the standpipe. The flange on top had half of the screws ripped out and was bent.
Looking for a 80 plus foot yacht
Hatteras of Cheoy Lee
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05-26-2020 06:59 PM #19Registered Member
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- Sep 2016
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Re: Catastrophic davit crane failure
Is it possible your tender has water in the hull, making it heavier?
Joshua1985 60C #379SCYLLAGalveston, Tx
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Re: Catastrophic davit crane failure
The two flanges should not be screwed in the fiberglass skin but thru bolted together. Screws in fiberglass is a last resort. That was probably was started the failure.
Pascal
Miami, FL
1970 53 MY #325 Cummins 6CTAs
2014 26' gaff rigged sloop
2007 Sandbarhopper 13
12' Westphal Cat boat