ICE LOADS AND SHIP RESPONSE TO ICE: USCG POLAR CLASS 1982/83 DEPLOYMENT

This paper presents work toward development of local ice load criteria for icebreaking ships. A bow panel of approximately 100 sq.ft. was instrumented, being divided into 60 sub-panel areas over which uniform pressures were calculated during each impact with ice. Finite element models of the hull structure were used to develop a data reduction matrix relating the measured strains to uniform pressures. Approximately 1400 events over a preset threshold strain were recorded. Extreme pressure-area curves were developed for each event, and extreme envelopes for each of five geographical areas. Trends in peak force and peak pressure are examined in terms of ship impact speed and ice conditions. Frequency-of-occurrence tables for highest average pressure are developed as a function of impact area for each geograhpical area. A statistical analysis of the extremes of the north Chukchi Sea data indicated that the peak pressure data followed a Gumbel extreme value distribution. Finally, a non- dimensional analysis was performed on selected data, and an empirically based approach is presented for developing extreme pressure-area curves as a function of ice conditions, ship impact speeds, and the return period.

• Supplemental Notes:
  • Report; Vol.1-Report; Vol.2-Appendices; For related reports, see AN 1789, Record 2098; AN 1791, Record 2099
• Corporate Authors:

  Arctec Canada Limited

  311 Legett Drive, Kanata
  Ottawa, Ontario  Canada  K2K I28

  Arctec, Incorporated

  9104 Red Branch Road
  Columbia, MD  United States  21045

  Maritime Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  Transport Canada

  Transportation Development Centre, 800 Rene-Levesque Boulevard West, Suite 600
  Montreal, Quebec  Canada  H3B 2X1
• Authors:
  • St John, J W
  • Daley, C
  • Blount, H
• Publication Date: 1984-12

Media Info

• Features: References;

Subject/Index Terms

• TRT Terms: Design; Ice; Icebreakers; Icebreaking; Loads
• Uncontrolled Terms: Design criteria
• Geographic Terms: Beaufort Sea; Bering Sea
• Old TRIS Terms: Chukchi sea; Ice forces; Ice loads
• Subject Areas: Design; Marine Transportation;

Filing Info

• Accession Number: 00650067
• Record Type: Publication
• Source Agency: Maritime Technical Information Facility
• Report/Paper Numbers: AI-757C, ACL-FR991C, TC-TP-6039E
• Files: TRIS, USDOT
• Created Date: Jul 21 1994 12:00AM