Sign Structures

Working with AMG Metals Inc. on a design build project for the Stoney Trail ring road around Calgary, Alberta, Brown & Company Engineering Ltd. developed a standardized steel tri-chord cantilever overhead sign structure. The tri-chord cantilever arm is a three dimensional space truss and connects via bolted connections at each chord to carefully detailed outriggers attached to a round HSS column. The tri-chord arm configuration is structurally more efficient and results in significant weight reduction when compared to equal long span sign structures of either monotube or planar truss type construction. An added benefit to the tri-chord cantilever is that the aero-elastic dampers usually provided with monotube or planar truss type sign structures are not required. The inherent three dimensional stiffness of the space truss prevents the initiation of a galloping excitation. Cantilever sign structures with spans as large as 21.5m were produced for the Stoney Trail project in Alberta. Highway 407 ETR has since adopted the design as their standard for long span cantilever sign structures.
AMG Metals Inc. / Highway 407 ETR Concession Company
Structural Design