Various special underwater / salvage magnets have been developed for Smit/Boskalis in Rotterdam. These magnets are relatively small in diameter (approx. 1500 mm) and have a lifting force of approx. 60,000 kg.
The breakout force underwater for loosening the steel parts to be lifted is approx. 80,000 kg. This is achieved by a special magnet operating system that is fitted on the deck of the salvage ship.
The illustrations show the salvage of steel coils from a sunken seagoing ship. The magnet sometimes takes 2 coils per lift up out of the water.
The illustrations also show underwater magnets that are used at depths of 150 metres. In order to work at this depth the magnet is designed with lighting and cameras. This magnet was supplied to Friendship Offshore.