I imagine they attach super strong pulleys to the high side attached to tugs which pull away in coordination but that is really just a guess.

Counter weights anchored to a pully system and actuated by a bunch of tugboats.

So I was right!

Very carefully, the load shift that may have caused the capsizing means there are loose cars on the decks.

The Costa Concordia was righted and refloated by using a combination of giant flotation bags and a system of pulleys. It wasn’t done all at once, but degree by degree a little bit at a time. I imagine a similar system was used here.

Also, ships are designed to rest upright and not tip over, and what gets them to do capsize usually involves internal flooding, so if you can seal the hull and pump out most of the flood water, it would undo most of the cause of the capsize.

Assuming that it’s a similar problem, this is how they uprighted the Costa Concordia about 5 years ago.

I watched such an operation about 45–50 years ago. First they brought in barges with cranes and off-loaded as much stuff as they could. Then they brought in six tugs, three per side and attached cross-deck hawsers, (2 or 3 per tug) and as three pulled her upright from starboard, the three portsiders countered with slightly lesser pull to enable the righting, but avoiding an opposite side capsize. It was a long time ago, but I imagine that the same principles would apply.

Unlike the Costa Concordia, at least they are not having to deal with the extra problems of decomposed remains and all the polluting sludge that was present in the cruise ship.

The Concordia was also on a ledge. They had to build an underwater platform to keep it from sliding into deeper water