Catastrophic davit crane failure

[RonNP]

My Marquipt davit crane failed today. The stand pipe came off of its foundation, snapped in two and ripped out from the fly bridge fiberglass. I was lowering my novurania davit in still waters. My boat had 1/4 tank of fuel so I’m guessing it was max at 700 pounds. The davit is rated for at least 1000 pounds Anybody have a used hydraulic one for sale? Mine is electric and I’m not going to repair it

 

[Boatsb]

New Davits ain't cheap but theres some nice ones out there. Marquipt quoted me about $25k for a davit then sold it direct to my customer for '$17k. I'll never bring them to a customer again.

I like the transom lift and platform lifts from freedom lift and sea lift. May not get the boat to the top deck but they seem more likely to be used in rough seas.

 

[johnjen50]

Wow sorry to hear that. Why do you think it failed? Where was your tender when it broke. Very weird place for it to break right? Maybe I’m just not seeing it with the pictures.

 

[RonNP]

The tinder was being lowered in the water , it was about halfway down when the pipe snapped

 

[SKYCHENEY]

Maybe you could just sleeve the pipe inside with another thicker walled pipe and put it all back together.

 

[rsmith]

I’d bet it was but welded there should have had a backing sleeve. That’s just the stand pipe. I’d fix it

 

[kelpy]

The standpipe should be multiple ply on a 1000 LB. davit installation.

 

[whoover]

Do you know what caused it to come off its base, is there some kind of fastener keeps it in place? It's looks like the mast failure was secondary to coming off the base. It's is definitely repairable.

Walt Hoover

 

[Glory]

"The davit is rated for at least 1000 pounds", based on what?

 

[Pascal]

Are you sure the stand pipe came off it’s base on the lower deck first ? I don’t see how that can happen with the amount of weight. Either the stand pipe broke first or the fiberglass in the roof failed because of core rot allowing the plate to shift.

Hard to see in the pictures

The best guys for hydraulic Davits is QuickLift in Miami. Their Davits and well engineered and they provide great support. Still not cheap... I ve had terrible experience with Nautical Structure customer service...

 

[Westfield 11]

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.

 

[drburke]

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.

 

[Westfield 11]

View attachment 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.

 

[scottinsydney]

What will you replace it with? Will it have the same pole support system?

 

[dottieshusband]

Sorry to see that Ron. I have the same Davit. Keep us posted on the failure analysis. Do you think it is corrosion related?

 

[RonNP]

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

 

[Pascal]

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 ...

 

[RonNP]

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.

 

[JoshuaHall]

Is it possible your tender has water in the hull, making it heavier?

 

[Pascal]

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.