Top Running Overhead Crane Runway Systems
Runway beams and columns for top-running bridge crane applications may be provided by the building supplier or the crane supplier. The design of these beams takes into account the vertical impact of the crane, the lateral force resulting from the effect of moving crane trolleys and longitudinal force from moving cranes. Typical sections include mill shapes and welded built-up plate sections. Support Columns-The columns can be part of the building columns, Independent tie back columns, or an independent column. For new construction the runway system is designed as part of the building. For use in an existing building you have two options.
1) Independent tie back columns that use the building structure to take the horizontal load of the runway system.
2) Independent columns that are freestanding on the foundation or floor, that take the horizontal and vertical loads.
Runway Rail should be installed in such a manner so that wear to the crane, runway beam supports and the rail itself will be minimized. Rails should be arranged so that joints on opposite runway beams for the crane will be staggered with respect to each other and with respect to the wheel base of the crane. Rail joints should not coincide with runway beam splices. Runway rails should be ordered in standard lengths with one short piece on each side to complete a run. The short piece should not be less than 10′ long. Rail ends will normally be furnished saw cut only, unless otherwise specified by the buyer. Rail ends will normally be furnished with standard drilling for commercial rails splices, unless otherwise specified by the buyer.
Common methods of fastening rails to runway beams are hook bolts, bolted clamps, welded stud clamps and welded clamps with a pad. Crane rails should not be painted as this may cause the wheels to slip, resulting in skewing of the bridge and columns.