From what I have read about the Type 93 (Long Lance), it was very long range, but had the disadvantage of going off during an attack. This would sink or seriously damage a war ship. In some cases they were jettisoned to prevent this. Seems like a less voliate back-up torp would have been a good idea. In case they had to get rid of the Type 93 torps in a battle. It would be of shorter range, but would still have worked. Was there any torp used this way by the IJN? The 93 worked when they could send it before they were attacked. But, as US air power grew. This happened less and less. It was a night when the 93 worked so well.
For additional information on Japanese torpedoes, go here, to the USN Technical Mission to Japan: http://www.fischer-tropsch.org/primary_documents/gvt_reports/USNAVY/USNTMJ%20Reports/USNTMJ_toc.htm Scroll down to Series O: Ordnance Target For specific info in the Type 93 aboard surface warships pluck off report # JM-200D-0-01-1 (54+Mb/448 pages) and report # JM-200-D-0-01-3 (2+Mb/20 pages). Of the two, 01-1 is far more detailed and informative. A word, some of the early pagination in JM-200D-0-01-1 is, charitably, a little odd, but the info can be followed if patience endures. Additional models and variations are described. As my eyes glazed over from looking at equations, it occurred to me that there is more here than I want to know, your results may vary. Scroll down further and find JM-200-F-0-32 - Torpedo fire control (2.9+Mb/39 pages) and, lastly, JM-200-F-039-3 Torpedo Models - don’t get excited, this one is about models, as in scale models, used for testing, not models as in types (2.3+MB/24 pages) Not to say there were not other examples of ships jettisoning their torpedoes (not a subject I have particularly investigated) so there probably were, but the only instance that pops into my head is the Mogami on the morning of 5 June after the collision with Mikuma. Rich
