A harbor crane is a material handling machine and one of the biggest units of heavy equipment. It's a fixed or floating crane used in harbours for loading and unloading ships (especially with containers) and in shipyards for repairing and building ships. Harbour and shipyard cranes have similar construction to each other.
The history of harbor cranes dates back into the Middle Ages. The dockside crane of these times was a slewing machine equipped with two treadwheels and a wheel and axle. Old harbor cranes remained in some European harbours till today. The oldest one is situated in Gdansk (Poland) on the Motlawa River. It originates from the 14th century and used to perform both as a crane and as a fortified city gate. The crane consists of two brick towers with crane mechanism between. It was used for loading wares on ships and lifting their masts. Its lifting capacity was 4 tons, lifting height – 11 m. Well preserved historic cranes are present eg. in Treves (Germany), Utrecht (Netherlands) and Bruges (Belgium).
Crane as it is today
Contemporary harbor cranes are classified as: • gantry cranes – fixed cranes with one or two beams and a hoist travelling on rails along them; • jib cranes – cranes with a moveable hoist travelling along a horizontal jib which is fixed on a fixed pillar; • deck cranes – cranes fixed on ships or boats; • bulk-handling cranes – cranes with a grab for bulk cargoes (mineral ore, coal etc.); • level-luffing cranes – cranes with a movable jib which enables the hook to stay at the same level.
Important harbor crane and other heavy machinery manufacturers are Demag, Liebherr, Gottwald, Konecranes, Carl Stahl and GH Intertech.