Dinghy Weight on Aft Roof

[wndsr]

I am planning on putting a hard bottom dinghy on the aft deck roof of our 53MY. The total weight is approx 750 lbs. I have the original stainless steel fixed davit. Is the davit and roof supports sufficient to handle this?

 

[ThirdHatt]

You won't have a problem. I carry a ~780lb 13'4" rigid inflatable with a 50hp four stroke and have had no issues with weight from the hardtop but you must confirm the davit rating before making a lift.

 

[Pascal]

shoudlnt' be a problem but check the davit capacity just to play it safe.

there were different type of support, mine has a 2" alum pole at each corner (actually, they're about 30" forward of the transom). I've seen 53s without these and with 3 1" SS tubes along the transom. Either should be fine, these boats were designed for a 13 whaler afaik.

 

[MikeP]

THe other day I was talking to folks here about replacing our hard-bottomed inflateable with an oem whaler. Several folks said that doing so would cause a problem with the roof and that the reason there are so many inflatebles up there now is because there was a problem with the oem boat weight.

I have no idea from a personal point of view but it's worth being very careful researching this.

 

[SKYCHENEY]

The 11' Whaler was a fixture on the 53MY for years. There were never any problems until core rot set in. This was caused by improperly mounted cradles and tie downs.

If the integrity of your upper deck has not been compromised, you will not have a problem with weight. One way to think about it is would you let 6 big guys stand up there? I would.

Here is a link to the Nautical Structures original aluminum tube davit. They were manufactured in 600 and 800lb capacities.

http://www.nautical-structures.com/tubularyacht.htm

 

[Brian Degulis]

I don't think the weight on the roof will be a problem. You could engineer a cradle to better distribute the load. I would be more concerned about the davit and the effort required to rotate it.

Brian

 

[bobk]

I would be more concerned about the davit and the effort required to rotate it.

Brian

Good point. I have a 12' AB RIB with 25 HP 2 stroke Merc and it is a bear to manage the lift and rotation. I need at least two people. Any tips on how to do this single handed? I have a hi-lo lift mounted on the aft port side.

Bob

 

[SKYCHENEY]

I have the same problem. The only solution I see is the power rotating davit. I'll bet those are pricey.

 

[Brian Degulis]

I don't know why they don't put some bearings in them? I they had bearings they would work just fine and you could put an adjustable friction brake to keep it from swinging wildely when deploying. On your existing unit you might try some grease fittings and maybe some sort of super slippery teflon grease?

Brian

 

[fissioneng]

In this thread, Pete describes the problem pretty well.

http://www.samsmarine.com/forums/showthread.php?t=9312

His solution is to sell his old hoist and put in a power rotation unit for (gulp )$20K.

 

[StratPlan61]

I have the same difficulty but have significantly reduced my frustrations by this procedure. I realize every davit is different so 'bear' with me. My davit is a Marquipt TenderLift 1000. It is 110v and has about a 10' control cord/controller. I am hoisting a 13' Whaler w/40hp outboard - not sure of the specific weight. I secure a fender to each side of the Whaler prior to hoisting.

I stand between the Whaler and my flybridge weather board and lift it about 1 foot above the chocks. Then I use a long boat hook pushing on the far-side of the Whaler (on the lifting cables) to swing the beast out over the transom or starboard side. This distance from the davit-cable center liftpoint gives me a little better leverage for swinging. Then I lower the beast down about 4 feet adjacent to the aft deck. I carefully lower the cord/controller onto my aft deck, run downstairs to the aft deck and complete the lowering. Using the boathook on the gunwale cables gives plenty of control as I lift/lower the Whaler. It makes the rotation much easier. I agree with adding a bearing to that standpipe, it mush just have a bronze bushing now?

I realize some do not have aftdeck access. I replaced the standard black rubrail on my Whaler with white 'dockguard' P' shaped linear rubber cushion material and don't get anymore Whaler black streaks on the hullsides. I also have the same rubber strip cushion material around the perimter of my swim platform. I think it came in rolled 25' strips from WM.

 

[Pascal]

it takes me 2 or 3 minutes to launch or retrieve my 13' heavy hard tender... it takes a little muscle to pull it back from the side of the boat onto the boat deck since it's uphill due to the list the boat takes with all that weigth hanging off the side. i let a line hang off the bow so that when it's up, i can grab the line with a boat hook and rotate the crane/dink.

power woudl be nice, but $20 000 nice.

 

[bobk]

I'll have to try the boat hook idea.

We are in Cambridge, MD this week for the MTOA rendezvous, and will probably start south tomorrow afternoon, first stop probably Solomons. I'll see how the ideas here work.

Bob