An interactive program for microcomputers, TOWCALC, was developed to implement the results of recent theoretical work in nonlinear towing dynamics. This thesis makes possible a statistical description of extreme tensions in towlines based on the seakeeping motions of the tug and the tow, where the extreme tension is defined as the sum of static tension and peak dynamic tensions which has a probability of 0.001 of occuring in a given day of towing. The resulting data base of extreme tensions (for a range of tugs, tows, towing speeds, towline lengths, sea states, and wave angles) is incorporated into TOWCALC, which automates the process of estimating mean towline tension and extreme towline tension. Mean towline tensions is estimated using methods given in the U.S. Navy Towing manual for resistance of the tow, and an analytic method is developed for the towline resistance. TOWCALC gives tow planners the ability to quickly evaluate the feasibility of a given tow, as well as to evaluate the level of risk; tug operators at sea will be able to anticipate dangerous peak tensions and take steps to reduce the risk of towline failure. As a result, using TOWCALC will lead to safer and more efficient ocean towing. (KR)
Computer-Aided Decision Making for Ocean Towing
1989
347 pages
Report
Keine Angabe
Englisch
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