Industrial buildings, as well as some other building types, require large clear spans and heavy loadings. It is generally conceded that a tapered web-rigid frame is one of the most economical types of framing for the loads and spans normally encountered in crane buildings. When conditions beyond the normal are encountered, a truss frame may be more appropriate.
The building manufacturer should be given the opportunity of recommending the building type and support system to be used for the cranes.
Top-running Cranes
Runway beams for top-running cranes located within the building may be supported by brackets attached to the building frame columns, by separate columns located inside and in line with the building frame columns, or by stepped. When crane aisles extend outside the building, A-frames are commonly used to support the runway beams.
Brackets on the building columns are commonly used to support the runway beams for cranes up to 10-ton capacity. However, cranes with up to 20-ton capacity may be supported in this manner depending on the type, span, and service classification of the crane.
For cranes of more than 20-ton capacity, it may be more economical to support the runway beams with separate support columns. However, the columns for buildings having high eave heights and/or large wind and snow loads may support heavier cranes without substantial weight penalty.
Runway beams for cranes with capacity of 20 tons or less, but with bridge spans greater than 50 feet, may also be more economically supported by separate columns.
Underhung Bridge Cranes
Runway beams are supported by hangers or brackets attached to the rafter of the building frame. The location of the support hanger can materially affect the design, shape and economy of the building frame.
It is usually more economical to purchase a crane with a bridge span approaching the building width. This places the crane end trucks near the building columns. The savings in the building support framing will normally exceed the extra bridge cost. This savings can be substantial in long buildings with a large number of frames.
Underhung Monorail Cranes
Runway beams for underhung monorail cranes are supported similar to runway beams for an underhung bridge crane.
Crane loads and other crane data varies between crane manufacturers. These variations can affect the design and economy of a crane building. Significant economics may be achieved if the crane manufacturer is selected prior to the design of the building. This provides the building manufacturer with specific crane data for design of the crane building. For crane loading information, please consult us.