Accession Number : ADA104152

Title :   Brash Ice Behavior.

Descriptive Note : Final rept.,

Corporate Author : COAST GUARD RESEARCH AND DEVELOPMENT CENTER GROTON CT

Personal Author(s) : Greisman,Paul

PDF Url : ADA104152

Report Date : May 1981

Pagination or Media Count : 35

Abstract : The behavior of brash ice, its formation and recommended vessel operating procedures are presented. Brash ice behaves as a Mohr-Coulomb solid below a critical strain rate or ship speed. Above this speed, fluidization of the medium occurs and the resistance appears to be that of a viscous, laminar fluid. The optimum operating speed for a vessel in brash is at the viscous threshold, found here to be 0.12 sg.rt of gL) where g (32.2 fS-2) is the acceleration of gravity and L is the length of the vessel. Repeated passages through brash-filled channels to keep them unconsolidated are generally unadvisable due to the attendant enhancement of the accretion rates. The laboratory and field experiments employed in this study are presented. Laboratory tests in brash ice appear to yield very useful results that are good predictors of full-scale resistance. (Author)

Descriptors :   *Ice, Fragments, Channels(Waterways), Mechanical properties, Ship hulls, Interactions, Resistance, Laboratory tests, Field tests

Subject Categories : Snow, Ice and Permafrost
      Civil Engineering
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE