Dynamic Characteristics of Pelprene Protective Device for Ship Collision

Abstract

Owing to increase of marine traffic and bridge piers in navigable waters, ship collision accidents with bridges have been increasing. In these years, many bridges which span waterways are constructed. For example, the Honshu-Shikoku Connecting Bridges was opened and the Tokyo Bay Crossing Bridge-Tunnel is being constructed. After 1980, serious accidents do not happen but accidents do not decrease yet. The record indicates an average of ten collision accidents per year at least. To keep off these circumstances various kinds of protection system are planned. The protection system should be designed not only to protect the bridge structure but also to protect the vessel against serious damage. Pelprene protective device reported here is one of these protection systems contacted with bridge and absorbed colliding energy by elastic deformation of the protective device. Pelprene is a new material that is a kind of thermoplastic elastomer and has intermediate characteristics between rubber and plastic. In this paper authors studied the effect iveness of this protective system by model experiment. Dynamic penetration test of the ship model to the pelprene protective device was executed. Static penetration test was also executed in order to compare with dynamic test. From these experiments, the characteristics of this protective device and effectiveness for actual ship collision were considered.