Top running overhead cranes have a rail that runs on the top of each runway beam. This allows the end trucks of the overhead shop crane to carry the bridge across the top of the runway, as opposed to running underneath on the bottom flange (Underhung Cranes). A top overhead running crane allows the weight of the girder crane and live load to be put onto the floor instead of applying that weight to the roof trusses. This is done with either a freestanding system of columns and runways, or in some cases, haunches can be added to existing building columns and runways are placed on those haunches for the overhead crane.
At TC/American, we manufacture two types of top running cranes, Wide Flange and Box Girder Crane. Both of these styles can be designed as a single or double girder overhead crane.
For both the Wide Flange and Box Girder top running crane, the hoist and trolley travels on the bottom flange for a single girder, while they travel on top.
Wide Flange Top Running Crane Construction
Wide flange top-riding cranes are designed with an “I-Beam” style structural girder. This girder is composed of plate steel fabricated to include a top flange, bottom flange, and web plate. This overhead crane design is ideal for freestanding, short span, or low capacity cranes.
A wide flange overhead crane can be stretched out to longer spans or higher capacity if needed, but as the span and capacity increase, the size of the girder gets deeper and heavier. This can cause unneeded stress to the shop floor or building columns and can often surpass what the floor or columns are rated for.
When the overhead shop crane weight starts to become an issue, this is when you would start to look at a box girder crane design.
Box Girder crane Construction
A box girder crane is similar to a Wide Flange overhead shop crane in functionality, but much different in design.
This style of overhead crane for shop functionality is manufactured with plate steel as well, but fabricated into a box with internal baffles and stiffeners, creating a stronger construction than a wide flange overhead crane, but providing a lower weight per foot.
TC/American is currently manufacturing Box Girder Overhead Cranes up to 140’ span, and up to 150 Ton Capacity. These are our standard capabilities. Larger cranes are possible but will require further engineering to assess plausibility.
We also offer several different options when it comes to completing the overhead shop crane. We can:
Fabricate and assemble the entire overhead crane utilizing TC/American box girders, and Jaso Industrial Crane components.
Fabricate and assemble the overhead crane utilizing TC/American box girders, but you provide the crane kit and components of your choosing.
Fabricate just the box girders themselves and send you “naked boxes” for you to paint and assemble in your shop.
