Falling Behavior of a Pipe in the Sea

  • T. Shimogo
  • T. Kawashima
Conference paper


To set up a cold water pipe at the OTEC plant, a long pipe floating initially on the sea surface is sent to the sea bottom or vertically suspended in the sea. In this paper, dynamical behavior of a falling pipe in the sea were studied for two methods of setting up. At the first method, a pipe is initially suspended by many floats distributed along the pipe and pulled by a wire rope. One end of the rope is fastened at the shore and the other end is carried by a tugboat. By cutting off the floats in turn from the shore-side or the offshore-side, the pipe is sent to the sea bottom. The maximum bending moment occurred at the pipe, a collision velocity of the pipe with the sea bottom, and a required time to laydown the pipe were examined for various cut off speeds of the floats and various tensions of the rope by a theoretical analysis and a numerical simulation. At the second method, a pipe, which is initially filled with air, is sunk by pouring water into the pipe through an orifice provided at the end of the offshore-side and by discharging air out of the pipe through an orifice provided at the end of the shore-side. In this case, the end of the shore-side is supported by a pinjoint. An inclination of the pipe, a water level in the pipe, a reaction at the supporting end, and a bending moment occurred at the pipe were investigated with the lapse of time by a theory and an experiment. The effects of a pipe length and an orifice area on the falling behavior of the pipe were clarified.


Wire Rope Pipe Length Intake Port Uniform Cross Section Exhaust Port 


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Copyright information

© Springer-Verlag Tokyo 1985

Authors and Affiliations

  • T. Shimogo
    • 1
  • T. Kawashima
    • 1
  1. 1.Department of Mechanical Engineering, Faculty of Science and TechnologyKeio UniversityKohoku-ku, Yokohama, 223Japan

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