The Trapeze or swing support is the most common type. Thread hex nut 25 mm (1") to 50 mm (2") above location of the tray bottom. The cross member comes next followed by a second set of square washers. All vertical hangers will project through the cross member. This publication is intended as a practical guide for the proper and safe* installation of cable ladder systems, cable tray systems, channel support systems and associated supports. The Cable Tray ng standards, performance standards, test standards and application in this document have been tested extens ompetent professional en completely installed, without damage either to conductors or. The B-Line series Cable Tray Manual was produced by our technical staff.