Want to lift a load of 86 ton in sea with a barge mounted crane. what is the in water load to be considered how to determine the capacity of the crane?
density of steel is 8 tonne/m^3
so then buoyancy accounts for 12% of the load, so the crane lifts (near enough) 80 tonnes (plus whatever safety factors).
then too I guess you have to account for "added mass" as you drag the thing through the water, maybe 12% (swings and roundabouts)?
another day in paradise, or is paradise one day closer ?
Expect you've already got this covered - but stating the obvious for safety's sake.
Capacity of a land-based crane depends on reach.
Capacity of a floating crane depends on both reach, and on the height of the sheave on the end of the jib. Forgetting the height bit is a common cause of capsize.
The below mentioned inputs I can give you:-
The load is 86 Ton in the air ( calculated load).
It will always be in the water.
In - water load means load of the object inside the water.
The distance to be moved is around 20.00 Mtrs.
The Item has buoyancy.
Remember we can't see what you're seeing so have to make it up from what you tell us.
Distance in water - vertical? horizontal? crane reach changes?
Do you mean extra buyancy? If so how much?
What is the volume of this mysterious item (any pictures, drawings you can share?
What is the sea condition? flat calm no current or ??
What exactly are you trying to do? Move something already totally submerged or?
The dead left load will be less than 86 tonnes, but might be a lot more than 86 tons once you allow for heave, barge movement, wind, currents, speed you're trying to move it at?
To be honest, this isn't something for an internet forum to work out and really needs an experienced crane operator to show you how it's done. A simple search shows you the many ways it can go seriously wrong.
Are you the crane operator or where do you fit into this?
We can help to point you in the right direction here, but only when we have a decent amount of information.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
If it's submerged in water, then the hoisting load is completely dependent on HOW FAST you want to pull it up. If it's REALLY SLOW, then the load is close to the dead weight minus the buoyancy, while completely submerged. Otherwise, you have to include the weight of the water the object is pushing aside as it rises.
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!
