A collapsing steel ring bridge rail system has been developed which is designed to provide reduced impact severity for vehicles in the weight range of 2,000 to 4,000 lbs at 60 mi/h and up to 25 degrees; provide redirection of vehicles up to 25,000 lbs at 60 m/h and 20 degrees; and provide an approach rail to bridge rail transition capable of redirecting a 4,000 lb vehicle at 60 mi/h and 25 degrees. Crash test results show that the energy absorbing collapsing steel ring design combined with a high performance outer rail meets all the above goals. Computer analysis and subsequent crash-testing show that even greater impact forces can be handled by the outer rail. Successful crash tests were conducted with 40,000 lb vehicles at 54 mi/h and 9 degrees. The collapsing steel rings which are fabricated from A36 steel can absorb 10,000 ft-lbs of a vehicles lateral kinetic energy. The 5-foot high outer-rail has contained 40,000 lb crash-test vehicles at 54 mi/h and 9 degrees. Vehicle roll is reduced by the top rail which is above the center of gravity of many commercial vehicles. The cantilever support offered by the rings combined with a rub rail virtually eliminates the possibility of wheelpost snagging. This demonstration project which has been initiated to encourage construction of pilot installations of the collapsing system to evaluate various procedures, costs and maintenance problems, will be made available to requesting agencies.

Media Info

  • Pagination: 2 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00128664
  • Record Type: Publication
  • Files: TRIS, USDOT
  • Created Date: Apr 21 1976 12:00AM