Capt. Bill Vose, 2004. Also by Bill Vose on this web site: How Lengo Channel was Swept for Mines.
I had the unique experience to have been brought up by a Naval Officer who was a Post Graduate Ordnance Engineer (Torpedoes) (M.I.T. 1926). He always encouraged me to look at my surroundings in a mildly analytical fashion; to be inquisitive as to how things worked, and particularly, how man-made items were manufactured or constructed. As a result I was always keenly interested in all aspects of manufacturing and technological advances.
It was not until my teens, however, that I became very familiar with the MK 14 & 15 steam torpedoes, then the most modern in the US Navy. My father (then a lieutenant commander) had been ordered to the Naval Torpedo Station at Newport, RI as Production Officer. We ultimately moved into quarters on the station which at that time was on Goat Island in Newport Harbor. Access to and from the station was by ferry. Our quarters were not in the group on the south end of the island, but were situated in the industrial area with our view from the front porch being Public Works headquarters and to the rear the paint shop. Behind the paint shop was my treasure trove, the clean scrap dump, from which I could collect cast-off torpedo parts to assemble or, best of all for a teenager, collect ¼-inch steel ball bearings, discarded during an engine overhaul. They made the best slingshot ammunition a youngster could ask for!
When Father was Station Duty Officer, he would often tour the manufacturing operation after dinner (the station was working at least two full shifts at the time). I would accompany him on almost all of these tours and as a result saw every mechanical manufacturing process including assembly and initial shop tests. After school I was more or less free to roam at will into the testing laboratory, pattern shop, foundry and boat shop, learning as much as I could about the skill of the various trades. I did not ever attempt to go into the main manufacturing areas such as heavy turning where air flasks were produced.
The one place I did not enter was adjacent to the Public Works Headquarters across the street from our quarters. It had all its windows painted to prevent seeing in. When I inquired as to what was happening inside I was told to ask my father, who told me it was a special operation which I was not privileged to know about. It was the assembly shop for the infamous magnetic exploder, which I soon discovered when warm weather set in and the shop windows were opened for ventilation. I also saw the exploders being removed from the torpedoes after they (torpedoes and exploders) had been proofed on the firing range to the north. Any questions I had were again answered by “Ask your Dad.”
Toward the end of my senior year in high school, Dad was ordered to the USS Enterprise and we moved to Hampton, Virginia. I attended Severn Prep School, then entered the Naval Academy in 1938. After graduation I was assigned to USS Gamble (DM 15) based at Pearl Harbor. During the ensuing 18 months I began to hear rumors of the problems with our torpedoes. They were mostly the submarine Mk 14 version, since they were the most fired. The reports were that the magnetic exploder would not work, the torpedoes ran deep, and if they impacted the target, they often would not detonate. I did not get the actual reasons for the problems until just before the end of World War II when they were related to me by my Father who had returned to the Torpedo Station where a test program to find the solutions had been in progress. The Submarine Station at Pearl Harbor also found solutions to the problems independently of the Bureau of Ordnance testing at Newport.
In today’s technology climate, live full scale testing of a weapon before acceptance is a routine matter, and it is difficult to understand why such testing was not performed on our WWII torpedoes unless one looks back in time to the late 1930s when these weapons were developed and produced. The nation had just emerged from the “great depression,” during which my father’s salary was cut 15%, and when he was promoted to leutenant commander in the early 1930s, he received no pay increase until full pay was restored after Franklin Roosevelt became President. I believe each Mk 14 or Mk 15 torpedo cost about $10,000 to $15,000, which at that time was an enormous amount of money for a single weapon! The proofing process for these torpedoes consisted of firing them from a test barge on the Navy range in Narragansett Bay using an exercise head with the same shape and dimensions of the warhead and filled with water ballast, which was expelled at the end of the run so that the torpedo became buoyant and could he recovered by surface craft. The magnetic exploder was also checked for proper actuation as it passed a simulated steel ship’s hull. The depth of the torpedo was recorded by a very accurate “Depth and Roll Recorder” which was inserted into the exercise head. These devices were manufactured by a well known English concern and, as I remember, each instrument had its own individually calibrated scale by which the ink (pencil?) record could he read. The record was generated by a clockwork tape drive pulling a paper tape under two markers: one marker was displaced from its zero point by the water pressure (depth) on the exposed end of the recorder; the other marker recorded the position of a pendulum within the recorder oriented to detect roll of the weapon from vertical throughout the run. The recorders were tested before and after a run for accuracy.
There is no question concerning the accuracy of these recorders. The problem lay in their location, which was immediately aft of the ogive forming the nose of the exercise head. Why the engineers at the time did not recognize that the recorder was located in a hydrodynamic low pressure area akin to the low pressure area above an airfoil is moot, but it obviously was not so recognized. Thus, calibration of the depth mechanism of the torpedo was based on presumed depths which were shallower than actual by an amount that was also dependent on torpedo speed. Had the run depth been verified by firing through nets, this problem would have surfaced long before our entry into World War II. Hindsight is so acute after the fact!
The second major problem was the almost total failure of the magnetic exploder, partly caused by the deep run problem, but which was a major design failure in that the exploders were designed and tested in north magnetic latitudes and had never been tested in south magnetic or equatorial magnetic latitudes. Once the deep run problem was recognized and the depth settings reduced so that impacts were obtained, the final major problem arose. The torpedo could be seen to impact a target and break up, rupturing the air flask but failing to explode! The impact exploder mechanism was an ingenious device utilizing a steel ball sandwiched between two steel concave plates which were lightly spring loaded so that the ball remained in the center of the plates. Any impetus to this assembly from any direction would displace the ball, spreading the plates and through other linkage releasing a firing pin. This device most likely never failed to release the firing pin upon impact. Again location was the key. On impact with a target the nose of the warhead was driven back and the cast TNT charge deformed the exploder cavity, jamming the firing pin before it could impact the primer. The mercury electrical impact switch developed by SubPac cured this problem.
As mentioned earlier, hindsight is so very acute after the fact. If live full scale tests had been conducted when I was in high school, these problems would most likely have been uncovered. But the thought of expending several or many weapons at $10K to $15K each would probably have caused massive heart failures in Washington, DC.
