Giant cantilever cranes, or hammerheads, were developed in 19th century Germany and were among the first mechanical systems to benefit from steam engine technology spreading through Europe at the start of the Industrial Revolution.

Hammerhead cranes have become vital tools in the British, Japanese and American shipbuilding industry because they were capable of lifting items that were heavier than traditionally powered cranes.

This modern day gigantic hammerhead from Kone is incredibly strong. It can lift a 747. [GE Reports - Wiki - Kone]