Overhead cranes are a type of crane used in manufacturing and other industrial operations due to their efficiency and reliability.

Manufacturing operations require that the assembly line be moving constantly; every minute the line is down can cost the company thousands of dollars or more in lost production. Because of this, manufacturing operations requiring the movement of heavy equipment around the factory floor can greatly benefit from the efficiency and reliability of an overhead crane.

A bridge crane, which is just another name for an overhead crane, is a type of crane that is mounted along two girders with a girder spanning the distance between them. Along the spanning girder is mounted an electric hoist, which actually does the heavy lifting. In some cases, the spanning girder is able to move along the support girders to move the load around many different areas of the factory floor. Such an overhead crane is also called a runway system and the supporting girders are collectively referred to as the crane runway.

Some bridge cranes make use of a single girder along which the hoist moves; these single girder bridge cranes are capable of supporting a load of up to 15 tons  without the necessity of calculating counterweight or maximum arm distances.

Double girder bridge cranes have two girders spanning between the runway supporting girders and can support loads of up to 20 tons, again, without a counterweight requirement or calculating maximum arm distances.