CABLE RACKS FOR REDUCED STRESS AND INCREASED LOAD CAPACITY

Methods and devices for reducing stress and for increasing the load-bearing capacity of cable racks supporting electrical power and communication conduits and cables having increased versatility for conduit and cable sizes and quantities. Underground devices including rack arms for these applications are desirably made from plastic or composite materials. Rack arms desirably include openings for tying down the conduits and cables atop the arms. While non-metallic materials are designed to withstand environmental stresses, they typically have strength and rigidity properties less than the metallic structures previously used in such applications. Non-metallic rack arms with such openings may be reinforced locally with a stress attenuator or with ribs to increase their load-bearing and buckling capacity and to reduce their stress, strain and deflection under load. A stress attenuator may be made by increasing the in-molded thickness of the web in areas adjacent to or surrounding the tie-down openings.