Homw much weight can go on the Fornt of a 96 550 DB

rnanaples

New Member
Dec 20, 2015
11
Florida
Boat Info
1996 550 DB
Engines
3408 Cats 800
I have a 1996 550 DB and am thinking of installing a front deck crane. Sea Ray will not comment as to the max recommended weight as they say the did not design one into the plan so they never spec'd it out.
 
I've seen pictures of cranes on larger Sea Rays but if they said they didn't design one into the plan then I would take that to mean it's not structurally able to handle a crane and heavy accessories without additional reinforcement.
 
manaples, I have my doubts about how successful it would be. First of all, directly below the front deck is the master stateroom. The support pole for a crane would have to go down through the deck, through the master stateroom area and be secured to the hull beneath the stateroom floor. So now you have a stooped pole right smack at the aft end of the berth.

The weight of the crane and dinghy would have to be supported by the hull. The floors are not strong enough, nor is the deck itself. I think you'd be better off putting a davit on the swim platform. But that's just my opinion and we all know what they are worth.

BTW, we LOVE our 550. We're headed out this afternoon for our first trip of the spring. It'll be just a short cruise but it's still "boat time".
 
I have seen one done on a 380AC and another on a 52DB. Both installations consumed the master stateroom closet as the davit's vertical support was about 6" in diameter. It passed thru the deck, the closet, the closet floor then was epoxied into a foot made by building a box under the pole to hold the fiberglass/epoxy where it was bonded to the inside of the hull. It can be done, if the closet location is where it makes sense, it isn't cheap, and the forward deck capacity still must be considered for whatever you plan to put there while underway.
 
Love mine as well. I have actually seen them mounted off to the side. Frank above is correct they pole goes through the closet. I got lucky with my 550 that I just purchased it is one of (so I am told) 3 that got out of the factory with the 3408 800 HP cats. Heading to Key West tomorrow for the second time this month. The guy at Sea Ray said they just did not spec it out as it was not an option they offered. So they were comment less on the subject.
 
The issue is not so much weight as it the bending loads created when the crane is in lift/lower mode. You may have already spotted this from the comments about other cranes actually being installed to the hull of the boat. As someone who has been involved in large maritime crane designs in the past, I can attest that the crane is only as good as the foundation it is attached to.

I would suggest you get a naval architect involved as you have a number of issues; first where and how can you secure the crane based to the specifics of your crane and dinghy, and the potential effect of the deadweight of the dinghy on the bow deck structure, and the overall impact of crane and dinghy on the center of gravity /center of buoyancy on vessel handling. You can contact the Society of Naval Architects and Marine Engineers (SNAME.org) for a list of their members. You will then have to sift through the list to find someone in your area that specializes in yacht design. The membership of the Society covers a number of disciplines not just vessel design.

Henry
 
Not technical, just my honest opinion. I can't stand the look of this on the bow of a boat, I just think it ruins the whole look of the boat. Put the dinghy on the stern
 

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