Pressure Distribution on the MK-13 Series Torpedoes with Shroud Ring Tails

This report is a supplement to a previous report of this laboratory entitled "Pressure distribution. Measurements on the MK 13-1, 13-2. and 13-2A Torpedoes", file marked Section No 6.1-sr207-1643, and dated June 23, 1944. It is a part of the program of investigation requested and authorized by Dr. E. H. Colpitts, Chief of Section 6.1 of the National Defense Research Committee, in a letter dated October 8 1943. The preceding report, referred to hereafter as Report 1643, included measurements of the pressure distribution about the bare hull and about the hull with fins but without shroud ring tail. The tests reported herein cover pressure distribution measurements on the torpedo with fins and shroud ring tail. The main objective of these investigations was to determine whether or not the depth control mechanism is actuated by true hydrostatic pressure.This is of interest because the immersion mechanism can keep the torpedo at set depth only if it is actuated by true hydrostatic pressure of the water at the running depth, and if this pressure is unaffected by variations in speed and in yaw or pitch angles.