Am also surprised to see that Mammoet did it this way, a very expensive mistake. The pre lift risk assessment should have set off more alarm bells. Dual lifts with mobile cranes are never the easiest to plan, but dual lifts from a floating pontoon or barge was always going to be an enormous challange.
They are contracted to sort the cock-up mess.
access is an issue for jack-up barges hence the tandem lift. This is how the original deck was removed 2 yrs ago
It looks like it wasn't Mammoet doing the lift that went wrong. The removal of the old section was done quite a bit differently - didn't involve such big crane movements, but it looks as though they had first removed the counterbalance arm with a gas axe. It was not the same contractor doing the removal.