Accession Number:

ADA232115

Title:

Ice Formation in Frequently Transited Navigation Channels

Descriptive Note:

Special rept.

Corporate Author:

IOWA INST OF HYDRAULIC RESEARCH IOWA CITY

Personal Author(s):

Report Date:

1990-12-01

Pagination or Media Count:

119.0

Abstract:

Results are reported of a study aimed at determining and documenting the effects of frequent vessel transit on ice cover formation over navigation channels. A practical objective of this study was to evaluate the merits of scheduling vessel transits as a means of mitigating problems caused by transiting of ice-covered channels. Vessels transiting through ice covers lead to increased ice growth and transform ice to brash ice, which collects in thick accumulations that may halt traffic. The study entailed extensive laboratory experiments conducted with an ice tank and model hulls that simulated river tows and ships. It also included the formulation and use of mathematical models of ice formation. Another brief study examined the mechanics of ice accumulation beneath flat-bottomed tows. The results from the ice-tank experiments and the numerical model indicate that, except for convoys of vessels, the problems incurred by frequent transiting are not readily mitigated by a sophisticated transiting schedule. Convoying does hold promise of reducing the severity of problem because it reduces the number of icebreaking transits. Of greater promise, however, is an approach involving mechanical methods for controlling brash ice accumulations at perennially difficult channel locations.

Subject Categories:

  • Hydrology, Limnology and Potamology
  • Snow, Ice and Permafrost

Distribution Statement:

APPROVED FOR PUBLIC RELEASE