U.S. Naval Undersea Warfare Engineering Station - Alignment Of Torpedo Acoustical Guidance System

A U. S. Navy Undersea Warfare Engineering Station needed an improved method of checking and adjusting the alignment of acoustical torpedo guidance systems for the Mark 46, 48, 50, and ADCAP torpedoes.

The Navy used a large water filled tank for testing torpedo guidance systems. Hydrophonic microphones were suspended in the tank to simulate a target. A hydraulic arm with adjustable alignment was used to lower torpedoes into the tank. The testing procedure involved comparing the torpedo's physical aiming point to the computed target point provided by the torpedo guidance system.

The problem was to ensure that the torpedo was physically aimed directly at the noise source prior to calibration of the guidance system.


To design and build a system which would ensure that each time a torpedo was mounted in the tank, its physical centerline was pointed precisely at the underwater target noise source.


Research Technologies designed and fabricated an underwater system using a laser and a two-axis laser target that was installed in the torpedo test tank.

The laser was mounted to the hydraulic are with its beam aligned with the torpedoes physical centerline. The laser now provided a repeatable pointing reference indicating the torpedoes physical aiming point.

A position referencing laser target fed information to an LED operator display in the control area outside of the tank. The laser target was mounted in the tank directly in line with the underwater noise source. The system was calibrated so that the operator could ascertain when the torpedo was aimed directly at the center of the laser target.

The operator could now quickly and accurately align a torpedo via above water adjustments prior to calibration.

The system significantly reduced setup time and increased the precision and accuracy of torpedo guidance calibration.