Highway and railway bridges spanning navigable waterways face the real possibility of being accidentally struck by large ocean-going vessels or large barge trains. In many cases, these accidents can result in serious damage to the bridges, blockage of the waterways, economic losses to communities served by the bridges and waterways, and loss of property and life. Two basic types of systems might be used to help prevent ships from striking bridge supports. The fender system is sometimes deployed around vulnerable bridge supports, but this approach is not always practical nor cost effective. An electronic warning system is a viable alternative or complement to the fender system. The electronic system could continuously monitor the ship's position relative to a safe corridor for passage under the bridge and issue an immediate warning of any deviation from a safe-passage course. The system could also issue warnings to the bridge tender and people on the bridge when a collision is determined to be unavoidable. An advanced design concept of such a system was developed by the Georgia Institute of Technology Engineering Experiment Station (GIT/EES) during a recent study. The study uses a shore-based radar and shore-based display as the most practical concept for an electronic collision avoidance/warning system. The radar would determine the ship's position, and the displays would inform the ship's pilot of the ship's position relative to a safe-passage corridor. The system would continuously assess the potential for collision during the various stages of the ship's passage. Ship speed and trajectory would be monitored as the ship approached the bridge; this information could be displayed for use by the ship crew in navigating the channel. When the ship approached closer to the bridge and entered a critical maneuver zone, the system would continue displaying the ship position while performing trajectory calculations to determine the possibility of a collision with the bridge. Should the system determine that a collision is possible (given the ship's handling characteristics and position in the channel, tide and wind conditions, and distance from the bridge), an alarm would be sounded to alert the ship crew, the bridge tender, and those on the bridge. Safety systems such as gates could be activated to keep additional traffic off the endangered bridge span. Although the design concept was developed for the protection of highway bridges, it could be easily adapted for the protection of railway bridges.

Media Info

  • Media Type: Print
  • Features: Figures; Photos;
  • Pagination: pp 258-260
  • Monograph Title: Bridge Engineering. Volume 2
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00183803
  • Record Type: Publication
  • ISBN: 0309026970
  • Files: TRIS, TRB
  • Created Date: Dec 12 1978 12:00AM