Winter 1981 Trafficability Tests of the USCGC POLAR SEA. Volume 5. Bollard and Tow-Rope Pull Tests

摘要

Prior to the Winter 1981 trafficability tests of POLAR SEA a series of bollard pull, tow-rope pull, and free-route propulsion tests were conducted in Puget Sound. The purposes of these tests were to check the accuracy of shaft instrumentation installed aboard POLAR SEA and to determine the thrust deduction factor for propeller loadings similar to those encountered during icebreaking operations. Analysis of test results indicates that the thrust deduction factor varies with propeller pitch and the advance coefficient based on ship speed varies from 0.046 at bollard conditions to approximately 0.25 at the ship self-propulsion point. Data was also analyzed to determine propulsive efficiency, wake fractions, and available tow-rope pull. Comparisons with model test data are included.