The first Gato class submarine built was the Drum, which was commissioned on November 1, 1941, the only Gato class submarine to be in service before the attack on Pearl Harbor. She was the first of 73 Gato class subamrines ordered in 1940 in response to the realization that the US would probably become involved in the current war. The Gatos were enlarged versions of the Tambor submarine class. They were 350 tons heavier and four feet longer, most of the additional weight being taken up by improved diesels and batteries giving improved performance and endurance. The remainder of the changes had to do with habitability (increased fresh water storage). The Gatos carried the burden of the submarine war from late 1942 until victory. Of the 73 boats ordered, one (Dorado) was lost in the Atlantic. Of the remaining Gatos, 18 were lost to enemy action in the Pacific. Mahogany Wood. Scale: 1/160. Length 24 inches.