I also am posting an account of the attack on the USS WASP by the I-19.
Certain demonstraits that the I boats were very capable of inflicting damage and this is probably one of the better examples for the IJN. Most notorious would have been the sinking of the Cruiser Indianapolis. Of note the use of Type-95 Torps - the fabled "Long Lance" was a Destroyer and Cruiser weapon only - NO IJN Submarines carried 61cm (24 inch) tubes. They carried only 53 CM (21 inch) tubes.
Table Courtesy of
http://www.combinedfleet.com/torps.htm