A hydraulic crane is a type of heavy-duty equipment used for lifting and hoisting. Unlike smaller cranes, which rely on electric or diesel-powered motors, hydraulic cranes include an internal hydraulic system that allows the crane to lift heavier loads. This fluid-filled hydraulic system enables the crane to transport objects such as heavy shipping containers and tractor trailers, which are well beyond the size and scope of any other lifting device.
Each hydraulic crane consists of an enclosed operator's cab set atop a steel base. Some of these cranes may be set on wheels or rollers, while others are stationary. From the cab, the operator controls a large arm known as a boom. Many hydraulic cranes feature a telescoping boom, which allows the operator to reach objects from a greater distance. Cables and hooks attached to the boom can be fastened to different objects for hoisting or lifting.
The crane's engine powers a hydraulic pump, which applies pressure to an oil or fluid within the hydraulic system. Because oil can't be compressed, the oil transfers this applied force to other parts of the crane. By redirecting this force where its needed to lift an object, hydraulic systems help increase power and performance.
Hydraulic cranes are rated based on their total lifting capacity, which is a factor of both their construction and the strength of the hydraulic system. A 10-ton crane for example, can lift up to 10 tons (9,070 kg). Each hydraulic crane must be chosen carefully based on the demands of a specific project, and lifting a load that's too heavy will cause the crane to fail.
Different hydraulic crane designs allow users to more easily perform specific tasks. Those on tracks or wheels may be best suited to construction sites, while many shipyards and warehouses rely on stationary cranes. Smaller hydraulic cranes can even be found on board ships or even tow trucks.
Because of the large size and power of a hydraulic crane, all operators should undergo vigorous safety training to reduce the risk of accidents. A crane that suffers operational failures could put operators or those nearby at risk from fire or falling objects. Poorly trained operators may direct the boom into nearby buildings or even people. Cranes that have not been set up properly can even tip over, leading to large-scale damage. While not all areas require safety training, individuals or organizations often pursue training to minimize liability and maximize safety.