Overhead crane overview

An overhead crane also known as bridge crane, overhead travelling crane machine, or industrial crane is a material handling machine which lifts, lowers, and transport a load horizontally. Typically, an overhead crane involves a hook-and-line mechanism that moves along a horizontal beam which moves on a runway beam, the supporting structure. Overhead canes are heavy duty material handling equipment with high lifting capacities for transporting load. Overhead crane travel is directed by an operator, either manually or with a wired pendant station or wireless controls. Typically, overhead crane is used for the multi-directional movement of materials to help manufacturing, storing, loading or unloading works inside a facility or outside in a yard, or at a railway, or shipping port, and other application environments.

Overhead crane components

Generally, the overhead crane is consisted of three main parts, the crane bridge, the hoist or trolley, and the runway. The crane bridge is the part which traverses across the runway. The hoist or trolley is the lifting mechanism which traverses across the crane bridge and lifts vertically. The runway is tied to the building structure. Besides, there are other parts are involved, showing in the following diagram for your reference.

Double Girder Overhead Crane componets drawing

Basic crane terminology

Crane capacity: The maximum weight the overhead crane is required to handle. Crane span: The horizontal distance between the rails of runway on which the crane travels. Lift or hook height:The distance from the floor to the crane hook, which determines the height of the runway from the floor and is subjected to the clear inside height of the building. Bridge, trolley and lift speeds: The rate at which the bridge or trolley runs or at which the hoist lifts. Dual speeds are available. Crane bridge: The main travelling structure of overhead crane which is consisted of two end trucks and one or two bridged girders varying with the type of the crane. End trucks: The end trucks is located on both sides of the span. The end trucks house the wheels on which the crane runs. Bridge girder(s)：Bridge girder is the principal horizontal beam of the crane bridge which is supported by the end trucks. The bridge girder of the crane is meat to support the trolley. Trolley hoist: The trolley hoist is consisted of hoist and the trolley frame. According to the lifting requirements, one or more hoist can be installed, which can be supplied on the same trolley or on separate trolleys. Trolley: The trolley takes the hoist across the bay along bridge girder(s) traversing the span. Hoist: Hoist is mounted to the trolley and is the main lifting equipment together with the crane hook or other lifting attachment.

Overhead crane configuration

Overhead crane mainly have two configurations: Top running overhead cranes and under running overhead cranes.

Top running overhead cranes

The top running overhead crane or