On a Method of Launching Model Test

Abstract

To ensure safe launchig of super large vessels onto limited waters, it is a matter of great importance to estimate the launching motion of ship and the position of stop.Although there are several ways to estimate the ship motion by means of numenical method, they all lack in accuracy because of the existence of uncertain elements which can not be analyzed exactly.On the other hand, there is a certain way to estimate the motion by means of model ship test, but it has hardly been taken notice of by reason of non-accuracy because of the difficulty of realizing the launching way friction in model.The Auther has manufactured, for trial, a control unit which simulate the frictional force of launching way, by using in combination a low speed analogue computer, wire strain gauge type load cells and direct current servomotor. With the above simulator, the model test was carrid out on a 47, 000 T tanker 1/70 scaled model ship and the Auther ascertained the accuracy of the test by means of compering the model test data to the measured real ship motion, and established a method of model test of launching.