Accession Number:

AD0248782

Title:

MODEL STUDY OF SURGE ACTION IN A PORT

Descriptive Note:

Corporate Author:

TEXAS A AND M UNIV COLLEGE STATION

Personal Author(s):

Report Date:

1960-12-01

Pagination or Media Count:

1.0

Abstract:

This document includes RESEARCH AND MODEL STUDIES ON RANGE ACTION TABLE BAY HARBOUR, CAPE TOWN, by Basil W. Wilson. 1959, 1v. incl. illus. Reprint from The Civil Engineer in South Africa, June and July 59. Copies not supplied by ASTIA Table Bay Harbour, Cape Town, is shown to be afflicted by two forms of surging, one of which is responsible for ranging of moored ships, the other for a pumping action of the basins and atover tendant navigational hazards. The construction and operation of a distorted model of Table Bay and harbour to reproduce the phenomena are described. The model was proof tested in various ways and found reliable. Efforts to control the surging were directed chiefly to the Duncan Basin. Internal structures and re-positioning of the basin entrance failed to reduce the disturbances to harmless proportions. Suitable external structures of outer basin type, on the other hand, proved capable of inhibiting effects in the Duncan Basin. Success of the chain-system of basins is ascribed to its throttling effect on the long wave energy in the frequency range critical for moored ships. Measurements and theoretical considerations of ship motions and statistical analysis of rope breakages and damage all confirm that the critical period range for shipping is below 2 min and more particularly in the neighborhood of 1 min. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE