A bridge crane runs on an elevated runway system and provides three axes of hook motion (up/down, left/right, and forward/backward). The hoist moves the load up and down, the trolley moves the load right and left (along the girder(s)), and the end trucks move the load forward and backward (along the runway). Both single girder and double girder overhead traveling bridge crane designs allow very precise hook positioning and gentle load placement.
Bridge Crane Girder Configurations
Bridge cranes are designed with either one or two girders:
Single Girder Bridge Crane
A single girder bridge crane weighs less and is less expensive, all other things equal, and offers other advantages based on the particular application. They are more common in lighter-capacity crane systems.
Double Girder Bridge Crane
A double girder crane typically provides greater hook height, and due to the added steel, generally weighs more and is more costly than a comparable single girder crane.
Bridge Crane End Truck Designs
Top Running Bridge Crane
An ASCE rail or 2" x 2" square bar is installed on top of the runway beams. The end truck wheels ride on the rail rather than directly on the runway beam.
Underhung Bridge Crane
The end trucks of an underhung bridge crane ride on the top surface of the runway beam’s bottom flange. The underhung runway system is suspended from the roof structure of the building and is typically available only for lighter capacity crane systems, usually 10 tons or less.
Advantages of Bridge Cranes
Bridge cranes offer the greatest flexibility for hook coverage and control over the load.
Because runways can ride along haunch- or column-mounted runways, bridge cranes are the least intrusive on your factory floor.
