Overhead crane, also known as bridge crane, is a type of crane where the hook-and-line mechanism runs along a horizontal beam that it runs along two widely separated rails itself. Often it is in a long factory building and runs along rails along the building's two long walls. It is similar to a gantry crane. Overhead crane is mainly composed of bridge, running gear of crane, trolley and electric device, etc. 

Overhead cranes typically consist of either a single beam or a double beam construction. These can be built using typical steel beams or a more complex box girder type. Double Girder Bridge is more typical when needing heavier capacity systems from 10 tons and above.

Overhead cranes are widely used in hoisting operation, for instance, factory, mines, transport materials in the fix span scope, mechanical processing workshop, metallurgical factory and subsidiary workshop, warehouse, material yard and power plant.

Looking forward to receive your enquiry with the below details information: 
1. lifting capacity. 
2. span length. (cantilever length)
3. lifting height. (hook center to ground)
4. Power supply: Voltage. 
5. Do you need rails? How long is the crane traveling distance? 
6. Working condition: which material to lift? temprature? 
7. Would be better if you have drawings of your plant.