Called a mine for security reasons, the Mk 24 was developed as an outgrowth of work on an underwater listening device sponsored by the Naval Defense Research Committee during World War II. This torpedo, with a small warhead, was a crippling weapon designed for "mission kill" vice "platform kill." Approximately 4000 of these aircraft-launched, passive acoustic, antisubmarine torpedoes were produced and in service during World War II and subsequent years until replaced by Torpedo Mk 34. Mine Mk 24 was developed by a group of activities including Western Electric Co., Kearney, N.J.; Bell Telephone Laboratories, Murray Hill, N.J.; Harvard University Underwater Sound Laboratory, Cambridge, Mass.; and General Electric Col Schenectady, N.Y. The Western Electric Co., Kearney, N.J., and General Electric Co. in Erie and Philadelphia, Pa. were the producers.
http://www.maritime.org/doc/jolie/part2.htm#page118