What it does:
The biggest of the three cranes onboard is obviously used to lift equipment on and off the ship whilst in port. It is capable of lifting 30 tonnes, but because of moments (these are turning forces around a pivot which you study in year 9) can only transfer 14 tonnes to and from the quayside. That’s still quite a lot though roughly 3 African elephants or 2 killer whales...
All lifting machines are safety rated so that you do not try to lift too much with them. At sea, the crane is safety rated at 1.25:1. This means that it has been safely tested lifting something that is 1.25 times heavier than the heaviest object you are allowed to lift with it.