DESIGN LIMITS ON CRITICAL FLOAT EMERGENCE IN A TETHERED FLOAT BREAKWATER

An investigation was undertaken to determine if a limiting relationship exists between the float diameter and the length of the ballast section in the beam direction. In a random sea, the ballast/float assembly attempts to follow the sea surface variations and to move towards an equilibrium between buoyant and inertial forces. Assuming a large number of floats per rigid ballast section, a fixed ballast length (B), and a constant volume of floats independent of float diameter (D), the attitude of the ballast can be considered to be nearly independent of float diameter. It was concluded under conditions of limited fetch and short wave lengths, selection of small float diameters and reasonable ballast lengths could result in a critical condition. Under ocean wave conditions, with the float diameters presently anticipated, the ballast section lengths required to yield a critical condition would far exceed the limits imposed by bending strength, handling and logistics. Therefore, it can be concluded that D/B ratio does not present a realistic design restraint on the tethered float breakwater except for smaller scale applications.

• Supplemental Notes:
  • Prepared in cooperation with California State Dept. of Navigation and Ocean Development, Sacramento.(PC A02/MF A01)
• Corporate Authors:

  University of California, San Diego

  Institute of Marine Resources
  La Jolla, CA  United States  92037

  California State Dept of Navigation & Ocean Devel

  Sacramento, CA  United States  95814

  National Oceanic and Atmospheric Administration

  Sea Grant Program Office, 6010 Executive Boulevard
  Rockville, MD  United States  20852
• Authors:
  • Hanes, D M
  • Seymour, R J
• Publication Date: 1976-1

Media Info

• Pagination: 13 p.

Subject/Index Terms

• TRT Terms: Ballast (Railroads); Breakwaters; Design; Floating breakwaters; Floating structures; Ocean waves; Offshore structures; Shore protection; Structural design
• Uncontrolled Terms: Ballast; Floating bodies
• Old TRIS Terms: Breakwater design; Floats
• Subject Areas: Bridges and other structures; Design; Marine Transportation; Railroads; Terminals and Facilities;

Filing Info

• Accession Number: 00146629
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: IMR-76-2, NOAA-76100401
• Contract Numbers: NOAA-04-5-158-20
• Files: TRIS
• Created Date: Feb 16 1977 12:00AM