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OCR for page 76
76 Figure 65. Misaligned or missing bearing plates (photo: courtesy of South Dakota DOT). pact head to deform the w-beam rail during a head-on impact Figure 68 shows a failed attachment between lag screws and the with the end terminal. The deformation of the w-beam absorbs end post. A high-priority repair has been assigned to this dam- the kinetic energy of the impacting vehicle to bring it to a safe age due to the potential for vehicle spearing, especially in the and controlled stop. As such, the alignment of the impact head case where the end of the rail is outside the impact head. is crucial to the functioning of this terminal in a head-on con- figuration. This can result from missing or failed lag screws at 14.2 Recommendation the end post or a w-beam that is not properly seated in or is outside of the impact head. An example is shown in Figure 67. The criteria for repair of generic end terminals are sum- marized in Table 28. These guidelines have been based on an Ohio Department of Transportation Energy Absorbing End Terminal Maintenance Checklist (Focke, 2007). Figure 66. Incorrect stub height (photo: courtesy of Figure 67. Misaligned impact head because of South Dakota DOT). missing lag bolts (photo: courtesy of Ohio DOT).

OCR for page 76
77 Figure 68. Failed attachment of lag bolts to end post. Table 28. Summary of generic end terminal repair guidance. Damage Repair Threshold Relative Priority Damaged end post Not functional (sheared, rotted, High severely cracked) Anchor cable Missing High Loose--more than 1 inch of Medium movement when pushed down by hand Cable Anchor Bracket Loose or not firmly seated in Medium rail Stub height of steel tube or Height which exceeds 4 inches Medium hinged post Lag bolts on impact head Missing or failed lag bolts High (Energy Absorbing Terminals Only) Bearing Plate Loose or Misaligned Medium Missing High