Feasibility and Conceptual Design Study for Towed Torpedo Emulator

Abstract : A study was undertaken to determine the feasibility of towing a streamlined body at various depths up to 40!m, speeds up to 20!knots, and distances of more than 250!m behind a high speed vessel. The tow-body would house a sensor package and acoustic projectors that would emulate the signature of a torpedo. In order to reduce dynamic instabilities and acoustic noise introduced by control surfaces, a tow-body 43!cm in diameter by 1.65!m long without depressor surfaces is recommended. It is also recommended that the bottom 30!m of the towcable have rigid fairings to minimize drag and strumming. A specialized winch and over-boarding sheave are required to handle the cable fairing and sustained the required loads. The system was modeled to determine geometry and cable loads at various speeds. It was found that at a tow speed of 20!knots, a tow-body in-water weight of 227!kg, a cable tension of 16.2!kN, and a cable lay-back of 273!m, are required to achieve a depth of 40!m. One area that needs further investigation is finding a vessel with sufficient size and horsepower to deploy the tow body and tow it at the desired speed.