The New Mark 14 Submarine Torpedo

The United States Navy Bureau of Ordnance, BuOrd, introduced a new weapon to the Fleet in 1941, the Mark 14 steam driven torpedo with its Mark 6 magnetic influence exploder, both of which were developed at the U.S. Naval Torpedo Station, Newport, Rhode Island (established in 1869 as the world’s first naval station dedicated to the development of the torpedo). This new weapon was designed to detonate under the keel of the target vessel and break its back (through the action of the expanding and collapsing sphere of gas), thus quickly sinking the ship. As an additional advantage, a detonation under the keel would overcome the ever greater side wall armor protection then being installed on the newer capital warships of that era. To achieve warhead detonation, the magnetic influence exploder sensed the variations in the intensity and direction of the earth's magnetic field adjacent to the target’s hull.

It was hoped that this would minimize the number of torpedoes expended by getting at an enemy warship’s vulnerable underbelly. BuOrd was very proud of the new Magnetic Exploder Mark 6, and subjected it to very tight security. Few operational commanders knew of its existence. There was no Fleet training using the Mark 6, and the training manuals were even locked away. Security was so tight that any defects were sure to be hidden from the very people who imposed the tight security and from those capable of providing a remedy. However, to many of the world’s navies, the inherent problems associated with magnetic influence detonation were already known and in most cases these kinds of exploders were consider unreliable and rejected from use.

An experimental version of the influence exploder was only tested once, on 8 May 1926, and then under ideal conditions (not in a simulated wartime environment). An obsolete submarine hulk (the ex-L8) was towed to sea and sunk by a warshot torpedo, but the torpedo was not fired from a submarine. The exploder activated at the proper instant and the target sunk. It was a great success, so great that any further at sea testing of the new exploder was deemed unnecessary. However, the exploder was subjected to further testing at Newport, with at least one report back to BuOrd that the exploder exhibited a tendency to prematurely activate. But BuOrd took no significant action and the exploder was repackaged into a version that would fit into the Mark 14 Torpedo and designated the Magnetic Exploder Mark 6. The only testing of the Mark 14 Torpedo itself was on a tracking range to determine that the torpedo ran straight and true with very little deflection for the specified distance at the specified speed. Depth measurements were not made, and wartime conditions were not simulated. The thought of destroying a new Mark 14 in a warshot test was deemed too wasteful by BuOrd, since each Mark 14 cost $10,000 in those days. Testing had to emphasize the safe return of the torpedo. No warshot tests of the Mark 14 were conducted in the 1930s; and when World War II began there was no one in the Navy who had ever seen, or heard, a torpedo detonate.

Conditions Ripe For A Disaster

Looking back on that period of time it is possible to list a number of contributing factors, all interacting with each other, which set the stage for the ensuing torpedo disaster.

Production Problems

Prior to World War II, BuOrd had concentrated all torpedo production at Newport, partly in response to the Washington Naval Conference of 1922 at which an agreement had been reached to reduce the overall number of warships capable of firing torpedoes. In fact Newport enjoyed a virtual monopoly on torpedo production from 1869 to 1940. In 1937 torpedoes were produced at a rate of about 2.5 per day which resulted in not enough torpedoes being available to meet training and testing needs (this was later increased to 23 torpedoes per day during the war).

It is important to realize that the torpedoes being built at the time were not designed with mass production as an objective. The tolerances were much tighter than those practiced by commercial companies and many torpedo components were considered tool room jobs rather than assembly line tasks. How do you, with production line automation, duplicate what had traditionally been made through hand-worked precision? In essence, they were designed to be built at the Naval Torpedo Station at Newport. Politics came into play when BuOrd tried to open another torpedo production facility before the war broke out. The local state politicians cried foul as they feared that such a move would threaten jobs in Rhode Island.

Hence, no plans were made for mass production. Early in the war the building of torpedo firing craft actually outstripped the capacity to build the torpedoes for them.

Naval War Fighting Doctrine

There is another reason why torpedoes were not produced in mass quantity before the war. The U.S. Navy was not going to practice "unrestricted submarine warfare" against the international commerce of any nation, as was practiced by the German U-Boats in World War I. Our submarines were to support the battle fleet and act as scouts in accordance with War Plan Orange. U.S. Navy submarines saw no combat in World War I. In fact, in the entire 41 years of existence of the submarine service in the U.S. Navy no ship had ever been sunk by a U.S. Navy submarine before 1941. But, the next war was sure to be different. It would mark the first use by the U.S. Navy of this new combination - the submarine firing the anti-ship torpedo.

With no rush to build up a stockpile of Mark 10 or Mark 14 torpedoes as war came closer to America, an early shortage of torpedoes resulted (only to be made worse by the loss of Manila Bay, along with nearly half of the remaining torpedoes, to the advancing Japanese early in World War II). During the Japanese air raid against the Cavite Naval Station on 10 December over 200 Mark 14 torpedoes were destroyed. To compensate for this shortage, submarine commanders were told to use their few torpedoes very sparingly and were sometimes sent out on patrol with less than a full load of torpedoes.

More Mark 14 Torpedo

The Silent Service WWII USN Mark 14 Submarine Torpedo. Part 1 [# 120]
The Silent Service WWII USN Mark 14 Submarine Torpedo. Part 2 [# 121]
The Silent Service WWII USN Mark 14 Submarine Torpedo. Part 3 [# 122]
The Silent Service WWII USN Mark 14 Submarine Torpedo. Part 4 [# 123]
The Silent Service WWII USN Mark 14 Submarine Torpedo. Part 5 [# 124]