Ladder cable tray is available in widths of 6, 9, 12, 18, 24, 30, 36, 42 and 48 inches with rung spacings of 6, 9, 12 or 18 inches. In practice, cable tray dimensions are a system of interrelated measurements —width, depth, length, and material thickness—that directly affect cable fill compliance, heat dissipation, structural loading, and long-term expandability. Note that wider rung spacings and wider cable tray widths decrease the overall strength of the cable tray. Specifiers should be aware that some cable tray. Formed side rails are welded to 15⁄8 in. A fabricated structure consisting of integral or separate longitudinal rails and a bottom having openings sufficient for the passage. Materials available: Aluminum, Steel, Steel HDGAF, Stainless Steel, PVC-coated Aluminum or Steel Cable Trays.