People often ask us “what is a double girder crane?” If you want double girder cranes explained, this is the webpage for you.
Double girder overhead cranes are used for picking and placing within factories and work places. They are of a twin beam design, offering greater stability over single beams. As you can see on the photographs below, the hoist sits astride the cranes 2 parallel main beams. The hoist spans the 2 beams, hence is often called a “crab unit or hoist crab”.
Double girder cranes explained
Traditionally double girder cranes are used in heavier lifting applications and on wide span factories. The twin beams are usually of a box beam design.
Double girder cranes are usually used when larger safe working loads are required, and are much more common upwards of 10 tonnes or 15 tonnes SWL’s, or in much wider overhead cranes.
It is commonly thought is that double girder cranes obtain better lifting heights, or hook height. This is because the hook can be lifted high up between the twin beams slightly. However as the hoist sits on the top, the crane has to be lower to avoid the roof, so the hook to floor height often results in being the same.
How To Gain More Crane Hook Height.
In addition when an industrial unit has a pitched roof, the hoist when sitting on top of the cranes beam’s can clash on the factory’s eaves. This can cause the hoist to have very limited left and right travel depending on the pitch of the factory roof. Moreover, end stops are used to limit the hoists left and right travel.
One way to overcome the lack of hoist left and right travel is to under notch the cranes twin beams below the level of the gantry rails. Click here for more details on under notched cranes beams.
Likewise, if roof height, hook coverage, or price is an issue, you can always consider a single girder crane.
Single girder crane with hoist.
Learn more about overhead cranes in general.
Lastly, visit our YouTube channel for many more double girder crane examples.