The Important Difference In An Underhung Or Top Running Bridge Crane

byAlma Abell

There are two different types of overhead cranes that are used in most industrial, manufacturing, fabrication and processing types of applications. These include the underhung and the top running bridge crane options.

While both are highly effective and often can be used for the same type of lift and movement of the load, there are some important differences between the two that are well worth considering. The major difference between the two is the position of the end trucks, or the part of the hoist system that connects with the crane runway.

With the top running crane, the end trucks are on the top of the runway so the bridge, the part that the trolley moves across, sits on top of the runway beam. With the underhung crane the end truck sits on the bottom flange of the runway beam. This allows for more flexibility in these systems, while the top running cranes are able to lift larger loads based on their design.

YouTube Preview Image

Support Options

The top running bridge crane will require support columns along the length of the system. The underhung styles will not, rather they can mount directly to the beams of the ceiling or they can be suspended from the beams. There are also free standing runways for the underhung cranes and these will have the necessary support columns, but they are ideal in areas where the building will not support other options or for use outdoors or in other specialized applications.

Multiple Systems

Underhung bridge crane designs will allow multiple cranes on the same runway and also the option to have multiple runways across a bay. These systems can also interconnect with other underhung cranes to allow for bay to bay transport or to even move from the bridge crane to a monorail system without the need to handle the load between the two.

The top running bridge crane is ideal for a straight run with heavy loads. This type of crane system can be designed for up to 20 ton or more, while the underhung systems are typically rated for 15 ton or less.

Speed of Movement

Comparing motorized underhung and top running cranes against each other will result in the top running system running faster even with a heavier load. These systems can travel at up to 200 feet per minute while the underhung system will be significantly slower.

If production is based on the need to move the load quickly and down a straight run, the top running crane is often the best answer. For flexibility and configuration options, the overhung crane is the system to choose.

October 20, 2018 in Stainless Steel Fabrication