Occasionally, some confusion arises as to the number of Gato-class submarines built, with some sources listing the total as 73, due to the transitional nature of the first four ships (SS-361 through SS-364) constructed under the second contract by the Manitowoc Shipbuilding Company of Manitowoc, Wisconsin. These were originally intended to be Balao-class subs and were assigned hull numbers that fall in the middle of the range of numbers for the Balao class (SS-285 to SS-416, SS-425, and SS-426).Fleet Submarine index page at Navsource.org Manitowoc was a designated follow-on yard to Electric Boat; they used construction blueprints and plans supplied by Electric Boat and used many of the same suppliers. The government-owned shipyards (Portsmouth Naval Shipyard and Mare Island Naval Shipyard) began to make the transition to the new Balao design in the summer of 1942. Electric Boat, due to the huge backlog of Gato-class construction, was not ready to make the transition to the new design until January 1943. Manitowoc had already completed their allotted production run of Gatos and could not switch over to the Balao design until Electric Boat supplied them with the plans. Faced with a work stoppage while they waited for Electric Boat to catch up, managers at Manitowoc got permission to complete four additional boats (SS-361 through SS-364) to Electric Boat's Gato-class plans. Manitowoc's first Balao-class ship was .
occasionally some confusion arises as to the number of gato-class submarines built with some sources listing the total as 73 due to the transitional nature of the first four ships (ss-361 through ss-364) constructed under the second contract by the manitowoc shipbuilding company of manitowoc wisconsin these were originally intended to be balao-class subs and were assigned hull numbers that fall in the middle of the range of numbers for the balao class (ss-285 to ss-416 ss-425 and ss-426)fleet submarine index page at navsourceorg manitowoc was a designated follow-on yard to electric boat; they used construction blueprints and plans supplied by electric boat and used many of the same suppliers the government-owned shipyards (portsmouth naval shipyard and mare island naval shipyard) began to make the transition to the new balao design in the summer of 1942 electric boat due to the huge backlog of gato-class construction was not ready to make the transition to the new design until january 1943 manitowoc had already completed their allotted production run of gatos and could not switch over to the balao design until electric boat supplied them with the plans faced with a work stoppage while they waited for electric boat to catch up managers at manitowoc got permission to complete four additional boats (ss-361 through ss-364) to electric boat's gato-class plans manitowoc's first balao-class ship was 