Marine Trader Crane question

[RyanK]

Hello Group, WE have a 44 MT yachtfish, She has a single tube curved, Heavy crane over the aft sundeck, it does go thru the hardtop to the floor of the sundeck.
I am curious if anyone knows the weight capacity of this, Our dinghy all in weighs 200. with fuel and anchor etc. weve used it to lift it but it does bend a few inchs under the weight.

 

[Turtle Blues]

Well I see no one ventured into this so I will provide a worthless anecdotal comparison. Have pretty much the same description some unknown alloy curved tube, unknown wall thickness. probably lift over 300lb regularly but would not comfortably exceed that. Have measured tip to deck on occasion to verify that it is not permanently deforming but it does flex slightly under load. Seems pretty generic to other Taiwanese trawlers I have been on.

 

[jungpeter]

Hello Group, WE have a 44 MT yachtfish, She has a single tube curved, Heavy crane over the aft sundeck, it does go thru the hardtop to the floor of the sundeck.
I am curious if anyone knows the weight capacity of this, Our dinghy all in weighs 200. with fuel and anchor etc. weve used it to lift it but it does bend a few inchs under the weight.

Hi RyanK,

Speculation can literally be the death of you in this situation. I strongly suggest you engage the services of a professional structural or mechanical engineer to provide you with a reasonable answer. He/she will likely look into all aspects of your crane (crane geometry, tube size, wall thickness, material, mounting arrangement, hoist specification, cable size and material, cable terminations, cable wraps, yada yada yada).

You're asking a simple question (...weight capacity of...). Unfortunately, there is no simple answer, even if the OEM provided that information upon launch. Even then, I'd be doubtful of its veracity, given the unknowns of age and condition since launch.

Regards,

Pete

 

[koliver]

Hi RyanK,

Speculation can literally be the death of you in this situation. I strongly suggest you engage the services of a professional structural or mechanical engineer to provide you with a reasonable answer. He/she will likely look into all aspects of your crane (crane geometry, tube size, wall thickness, material, mounting arrangement, hoist specification, cable size and material, cable terminations, cable wraps, yada yada yada).

You're asking a simple question (...weight capacity of...). Unfortunately, there is no simple answer, even if the OEM provided that information upon launch. Even then, I'd be doubtful of its veracity, given the unknowns of age and condition since launch.

Regards,

Pete

Adding to pete's post:

Anecdotally, I watched as a GB42 sedan (Europa?) with an upper deck mounted crane picked a dinghy of unknown weight out of the water and the crane toppled over. Seems the failure there was in the crane to deck attachment. That looked professionally done, but failed anyway.
You don't know how well any part of it is done when it is not done by you, or at least under your supervision.