THE FISH HAS WINGS AND SOME UNPLEASANT TRUTHS, 1925-1930
Up to 1925 the Navy’s aerial torpedo had been variants of the 18” Mk 7 destroyer torpedo. Testing had shown that it worked reasonably well as long as you did not exceed the specified deployment parameters of dropping it at 95 knots or less and from altitudes of less than 35 feet. As aircraft performance increased, and as the anti-aircraft capabilities of ships got better, it was realized that these parameters were dangerously low. In order to ensure a reasonable chance of survival for the aircraft crews these launching parameters had to get better. Also, the small size of the weapon meant it carried a small warhead and thus a bigger boom was desired.
Accordingly, in 1925 Newport initiated Project G 6 for the development of a new aerial torpedo. Initial specs called for a 21” weapon capable of being launched at 140 mph from an altitude of at least 40 feet with a warhead charge of 350 lbs. of TNT. At first excited by the project, the Council and the FLO were soon frustrated by Congress and their usual penny-pinching ways. In addition, the Bureau of Aeronautics (BuAer) vacillated on the whole concept. There was talk in some aviation circles about doing away with the concept of aerial torpedoes altogether. Low level development work continued at Newport while the Council worked these issues, once again turning to their patron FDR for help. FDR assisted in clearing the obstacles in Congress and the Council was successful in clearing the fog from BuAer on concept issues.
The engineers at Newport studied several different concepts for this new torpedo, including trying to make it all fit into a weapon that did not exceed 1,000 lbs. This was found to be nearly impossible with the existing state of the art and by 1930 they had settled on a weapon that was short and squat, designating it the Mk 13. It was only 13.5 feet long, but they compensated for that by making it 22.5 inches in diameter. It had a warhead of 404 lbs. and could do 33 knots for 5700 yards.
Work on the ultra-secret magnetic influence exploder proceeded apace. CDR Ralph Waldo Christie, an experienced submariner and a graduate of MIT took charge of the project in early 1926. Work had proceeded to the point that an operational test was needed and the new exploder was fitted to a Mk 8. An obsolete submarine, the L-8 (SS-48) had been provided and it was moored in Narragansett Bay off Goat Island. On the 8th of May the Mk 8 with the new exploder was loaded aboard a test barge and fired at the L-8. The weapon passed under the old sub and failed to detonate. Recovered, it was checked out and reset for another test. Once again it failed to detonate and a frustrated Christie took the exploder back into the shop for thorough bench test. Not finding a problem, he was determined to try again. In the intervening days, changing weather and tidal conditions in the bay forced the NTS to move the L-8 to a new spot and re-moor her. On the 26th the range was ready and this time the L-8 disappeared in a huge blast as the weapon detonated dead center under the old boat.
A jubilant Christie pressed the Council for another more extensive test series and they quickly granted it, having obtained an old destroyer, the Ericsson (DD-56) as a target. Wanting to obtain as much data as possible, Christie substituted the warhead for one of the new calcium chloride filled exercise heads. Over the course of the summer 30 test firings from a barge were conducted against the Ericsson, but a dejected Christie found that the exploder tripped only eight times, with three of those proving to be premature, a timing device showing that the exploder activated before the weapon passed under the ship. In one other instance the exploder activated after a run of only 75 yards. The Council was not impressed and Christie, mystified at the inconsistent performance of the exploder, took Project G 53 back to the lab in an attempt to find the cause.
Further testing during this period also revealed some other unpleasant truths. Even though the earlier testing on the S-3 and Reuben James had rung out the depth keeping problems on the Mk 8, 9, and 10 weapons, those tests had been conducted under controlled conditions and in calm sheltered waters. More rigorous and realistic testing in Maine, Hawaii, and in other locations showed disturbing problems in torpedo performance. Cold runs (i.e. failure of the motor to start), erratic course keeping and depth control, and failure of the contact exploder resulted in an end to end success rate of only 61%. With many of these weapons having been built by Bliss, some very pointed questions were asked of the Bliss representatives on the Council. Embarrassed, the company undertook a top down review of quality control at its’ plant in New York, finding numerous but minor issues that had led to a larger problem. The company managers quickly stamped out these issues and quality rapidly improved. NTS Alexandria closely mirrored the production techniques and practices of Bliss and they too found and corrected quality control issues.
Fleet Problem IX, an exercise conducted in the Pacific near the Panama Canal in January 1929, included live ordnance testing and it showed that the issues with torpedoes had been largely corrected. The old cruisers Pueblo (CA-7) and Charleston (CA-19) served as destroyer and submarine targets with Pueblo going down after taking five Mk 8 hits and Charleston succumbing to three Mk 10’s from USS R-7 (SS-84). The old battleship South Carolina (BB-26) proved quite resilient, absorbing two aerial Mk 7’s and two Mk 8’s before going down under a hail of bombs by dive bombers from the Lexington (CV-2). The use of Mk 7’s in this exercise and their lack of power against the armored South Carolina underscored the need for a new aerial torpedo and gave the G 6/Mk 13 project greater emphasis.
Despite having largely corrected quality control problems, the Navy’s existing torpedoes were beginning to show their age by 1930 and with new and much more capable ships being designed and built, Navy was desirous of a new torpedo to match. The new decade marked the beginning of an idea that would prove to have momentous consequences in the years to come.
Author’s note: ITTL the initial work on the Mk 13 proceeded pretty much along the lines of the OTL. The big POD’s here are the further testing of the G 53/Mk 6 exploder, and the correction of the deficiencies noted in the field tests of the other torpedoes. None of that actually took place and it greatly contributed to the breadth and depth of the scandal. Fleet Problem IX was real, but I added the live testing.