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Comment by antidamage | Hacker News Reader

Helicopters are a thing.

And yeah, even completely empty with no fuel or ballast you will never see the bow out of the water like that. However it is more than capable of surviving being dragged along sand. It's just that they have nothing strong enough to drag it with.

Eventually someone will stake some anchors into the ground and use an industrial winch, but that's where hull design starts to suck - there's no good anchor points by which to pull it, so there'll need to be a large number of straps cradling the hull that are being pulled.

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This was my though, winchers/dozers etc pulling back the angle it went in on a high tide. Of all the solutions suggested this seems the simplest and easiest materials.

For anchor points they could easily weld additional steel plates/rings at numerous points on the hull for a many lines spread out.

Maybe place some cables under the front section attached to airbags. It would not lift it off the sand but may help with downward pressure on the pull back + the excavator work.

Also cant you vibrate/aerate sand to make it have a liquid effect? Might help pressure but no idea how that could be done at scale required... winches and cable seems easy to access fast.

Just an order of magnitude viz-a-viz a winch:

-- the Ever Given has a mass of ~220,000 tons (2.2e8 kg)

-- let us very conservatively assume that it is a homogeneous block, 1/3rd of which is on sand, 2/3rds of which is on water

-- the Coulomb coefficient of friction for steel on sand is a very complex function of sand composition and size, but roughly it's about µ=0.5 and F=µR [1]

-- For the 2/3rds of the ship that are in the water assume that it moves frictionlessly in an inviscid liquid (not true at all else ships wouldn't have huge engines!)

-- You therefore need to apply a net tension of ≥0.3 x 0.5 x 2.2e8 ≈ 33 MN to a wire to have a remote chance in hell of accelerating the ship backwards

-- This is about twice the thrust of a Space Shuttle solid rocket booster at liftoff.

[1] https://www.jstage.jst.go.jp/article/sandf1972/26/4/26_4_139...

The weight on sand equals the weight of the portion of the ship that has been raised above sea level by the collision. The bow appears to have been raised, but not the stern. The lift is by about 10% of the ships height (or less), so 5% on the average of the ships length. That cuts the above estimate by a factor of 6. The remaining required force could be provided by a number of winches of a pull of 1000 tons each operating from the opposite bank of the canal and pulling in the direction opposite to the ship. Tugs would then have to turn the ship straight as soon as it starts getting afloat.

How long do you think it would take to unload 20,000 40-foot containers via helicopter?

I'll start with my guess: A long time

You would probably need to be the US military. Once you have a setup onsite; helicopters, pilots, fuel, maintenance, crew to rig containers, you could rapidly unload the containers. Check out this video: https://www.youtube.com/watch?v=08K_aEajzNA

US Military is probably the only entity that could pull this off in a timely manner. At great cost of course...

Except the US Military has exactly zero helicopters capable of lifting anything that heavy.

Russian Military has: https://en.wikipedia.org/wiki/Mil_Mi-26

That's the one they've used to rescue downed US helicopters :)

Looks like your right. The US has: https://en.wikipedia.org/wiki/Sikorsky_CH-53E_Super_Stallion... as its near equivalent with a external payload of 36,000 lb. The Russian helicopter carries 8000lbs more at 44,000lb, though Wikipedia doesn't say if this is an external or internal payload.

Looks like a 40ft shipping container weights around 8000lbs empty, couldn't find a stat on full. It seems such an operation would be outside the capacity of these helicopters. Sure they could comfortably lift empty containers, but probably not full ones.

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