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Offshore Mast Crane

Boy, that thing doesn't even seem to list.
Must be a ... boat load ....:leaving: of balast down in the hold on that bad boy!


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Think Snow Eh!
Ox
 
I have heard....(only as a comment someone said in passing)

That some ships have computer controlled ballast, as the crane swings,
ballast is being pumped around in various tanks to compensate.

And when that system fails.....
 
I have heard....(only as a comment someone said in passing)

That some ships have computer controlled ballast, as the crane swings,
ballast is being pumped around in various tanks to compensate.

And when that system fails.....

Seems likely based on how slowly they are slewing the crane boom.

I like how it say is giant letters "no welding" right above where they are clearly welding it :D

If I'm reading it right, the crane is rated for 3000 metric tons at 30 meter radius. Wow.
 
Bokalift are a big semi submersable ship company, they move things in the multi thousand tons as the norm. Yes the ship is actively ballasted, its why they can only swing so much before letting the pumps catch up. most of them can put there decks several meters bellow water level so loads just get floated on.

No welding is about no welding fixings to that part of the structure to secure the load. Normally on these you weld the load down to the deck.

I know this as one of my excavator designs got mounted on one of these, to dig out under a specific part of a port job and as that was there for something else (port crane delivery) it was cheaper than bringing in something far smaller. Had a couple of spare days in its plans, Had also been planned years in advance too and my modified excavator design let them dig out around a outfall structure in a way nothing else was do to the sticky clay it was in. Though admittedly the 40 ton excavator did not need the active ballasting, but just lowering the deck to the water line, litrally waves washing over the deck! but only a 1" or so deep, except the swell when a ship passed! but it sure is a cool ship. Our job was done in like 10 hours and let the outfall structure settle about 5 meters lower hence clearing the final obsteical on that side of the berth before it was brought into container traffic.
 
How far into the ocean does something like that move? It surely has a righteous metacentric height and plenty of bouyancy, but at least naively it looks like it would be no fun at all in any kind of storm.

And a crane question - there's a "main hook" (presumably the one rated for 3Kt), and a second hook, which I take it is for help handling long objects, flipping things over, and so forth.

But why would there be 3?
 
storm.

And a crane question - there's a "main hook" (presumably the one rated for 3Kt), and a second hook, which I take it is for help handling long objects, flipping things over, and so forth.

But why would there be 3?
Some drilling rigs (probably most) have a small "Straw line" my neighbor called it. IIRC on his 22-w it was 3/8" cable

Picking up tongs, bringing in a piece of casing, etc.

In the case of this big crane, also for handling the large slings.
 
Some drilling rigs (probably most) have a small "Straw line" my neighbor called it. IIRC on his 22-w it was 3/8" cable

Picking up tongs, bringing in a piece of casing, etc.

In the case of this big crane, also for handling the large slings.


Also the main hoist is reeved with many parts of line and is painfully slow for less than capacity lifts, a whip line and a 4 part would be the best choice for lifts up to 50T or so.
 
Watching again I see the very end of the boom (the red/white striped part) is labelled "Personnel Lift 100mT" or words to that effect - and looks like a single line - this jives with other posts - a cage with workers in it will likely be well under that, and you don't want the work crew to die of old age waiting to be hoisted up to the work site.
 








 
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