The Application of the Stern Jet Thruster to Super Oil Tankers

Abstract

In this stern jet thruster system, the turbines for the cargo oil pumps are used as the power source for thruster pumps, and sea water taken from the intakes on the port and starboard sides is driven by the thruster pumps to the jet nozzles designed to produce a thrust athwartships. The system was first introduced to the M.S. YOSHINOGAWA MARU, a 70,000 dwt oil tanker completed in August, 1964. The following results were obtained through various tests and these results prove that the stern jet thruster is of great service to the maneuverability of a super oil tanker at mooring, unmooring and heading with a low speed. The results of the tests 1. Thrust 7 tons by 2×1,200 HP pumps 2. Turning ability a. At standing still in fully loaded and free condition Angular velocity 0.10 deg./sec. Time taken to turn 90° 20 min. b. At heading at a low speed in fully loaded condition Ship speed 4 knots Angular velocity 0.11 deg./sec. (Max. 0.16 deg./sec.) Time taken to turn 90° 15 min. c. At standing still in ballasted and anchored condition Angular velocity 0.10 deg./sec. Time taken to turn 45° 10 min. 3. Speed for shifting the ship sideways The jet thruster shifted the ship in light loaded condition 100m sideways within 5 minutes with only one tugboat supporting at the bow.