The hammer head crane, otherwise known as the cantilever crane, is a fixed jib crane. It consists of a steel braced tower which is connected to a revolving, horizontal double cantilever; the forward part of this cantilever or jib carries the lifting trolley, the jib is extended backwards in order to form a support for the machinery and counterbalancing weight.
The horizontal movement of the load is a marked feature of the cranes design. These cranes are generally constructed in large sizes and can weigh up to 350 tons.
The design of the hammer head crane began in Germany at the turn of the 19th century. It was later adopted and further developed for use in shipyards around Britain. The ability of the hammerhead crane to lift heavy weights was useful for installing large pieces of battleships, such as armour plates and gun barrels.
Giant cantilever cranes were also installed in naval shipyards in Japan and the United States.