Design and construction of 6-component balance dynamometer for measurement of the forces, moments andmotions of ship models in the towing tank

During design spiral of a merchant ship or a naval vessel, it is important to perform towing tank tests in order to measure its performance either in calm water maneuvers or in waves for seakeeping performance. Also, to optimize a hydrodynamic design, towing tank tests are advantageous.This article presents the results of an applied research project. The objective of this project is to design and manufacture a six-componentbalance dynamometer to measure drag force, lateral force, yaw moment, roll moment, andheave and pitch motions. Various stages of this work are presented in the text. The main steps of this activity are to design, prototype,and install strain gauges, and eventuallycalibratethem. Using this procedure, implementing the relevant criteria, the appropriate measures of the strain were selectedmore on the basis of recommendations of professional bodies.Material selection of suitable metal machining and construction work is done. Next, the strain meters were installed onthe balance. After equipment calibration, dynamometer is ready for the ultimate test in towing tank