A number of manufacturers have developed products so that the anchor piece can be placed almost flush with the ground. These products can be used either to retrofit
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FIGURE 7.31 Commercially available hinge plates by Transpo Industries. |
existing slip base designs or for new installations. One such manufacturer is Transpo, which markets the Breaksafe breakaway system for ground-mounted signs. These devices use breakaway couplings and brackets designed for different support types and sizes. Included are back-to-back concrete and direct buried U-channel, 3- to 4%-in (75- to 114-mm) round pipe, 3- to 5-in (75- to 127-mm) square tube, and various sizes of wide-flange and standard beam shapes. The advantage of the retrofit is that proper torquing, to prevent blowdown or walking due to environmental loads, yet permitting slip during vehicle impact, is not required with the frangible coupling retrofit.
