The number of U-frames that can be used is the sum of the net weights of the U-frames plus any added loads and must not exceed the carrying capacity of the U-frame top section (60320351)
Each frame must be connected at two points to the frame above it with the enclosed connectors
A frame must be secured by the two eyelets welded to the side tubes
The drop distance should be less than 10 cm
Use sufficiently sized steel cables or chains as securing means