Study of the Interceptors Effect on Ship Manoeuvrability Using the Open Free Running Test Method

Abstract

Interceptors are plates that are attached to the stern of the ship to produce lift that controls the trim angle of the ship. This paper describes the use of interceptors on the fast boat to enhance its ability to perform the turning manoeuvre. The ship model of High-speed crafts (HSCs) with a scale of 1: 26.9 is tested in an open pool with the open free running test method, namely the movement of the model is controlled from the edge of the pool with a remote control. The ship trajectory data is obtained by using the colour object tracking method, that is, the ship trajectory captured by the camera is processed based on colour filters. The main concern is the varying dimensions of the interceptor including 0% (no interceptor), 50% (half length), and 100% (full length) of the design cord length. The initial trim conditions are examined, such as even keel, trim by bow, and trim by stern with a trim angle of 2 degree. The test results show that the interceptor contributed to improve the manoeuvrability of the boat by decreasing the tactical diameter length respectively at half and full length of the cord by 8.8% and 17.9% in even keel, 6.3% and 15% in bow trim, and 12.9% and 14.8% in stern trim.