The twelve submarines of the Tambor and Gar classes were the high water mark of pre-war submarine construction in the USN. Although authorized in two different fiscal years (FY-39 & 40), the six boats each of the Tambor and Gar classes were actually identical in design with no significant differences between the two groups. They will be treated as one class here on PigBoats. The design of these boats rolled into one all of the lessons that had been learned during the 20 years of peacetime trial and error development, and their origin dates back to the beginning of the V-class in 1921. The only criticisms of these boats was that they had been optimized for peacetime cruising and thus needed modifications to be able to fight the war they faced, and they were officially rated with only a 250 foot test depth, an overly conservative value that would change with the follow-on Gato class.
Maintaining the construction trend that had started with the Porpoise class, the Tambor/Gars were divided up for construction between the Portsmouth Navy Yard (four boats), Electric Boat (six boats), and the Mare Island Navy Yard (two boats). Based on repeated calls by the Submarine Officers Conference for a heavier armament, these boats were equipped with six bow and four stern 21" torpedo tubes, carrying a total of 24 torpedoes. For gun armament, they carried a 3"/50 caliber Mk 17 gun and one or two M2 .50 caliber water cooled machine guns. Starting in the summer of 1942, six of these boats (Tambor, Thresher, Tuna, Gar, Grayback, and Grayling) were refitted to carry a much larger and more powerful 5"/51 caliber Mk 9 gun, located on an expanded sponson on the aft deck. Three of the guns had been originally installed on the earlier Barracuda-class fleet boats, the other three were production spares.
These boats were in the thick of the fight against the Japanese from the first day of the war. Seven of them (marked by a *) and their brave crews were lost in action and are considered to be "on eternal patrol".
As with all of the pre-war built fleet submarines, once the war started their external appearance was heavily modified as experience was gained. These changes came fast and often, and it is easy to be confused by it all. The authors highly recommend that you read the Visual Guide article posted here.
Special Note... PigBoats.COM normally adheres to a 1940 date for a boat to be included on these pages. We are making a small exception here. We will include all twelve of the Tambor/Gar class boats for continuity purposes even though Grayback and Gudgeon technically fall outside of that date window.
Tambor (SS-198)
National Archives photo.
Tambor underway on builder's trials off Provincetown, MA., April 8, 1940. This is a very typical appearance for the pre-war boats. The Tambor/Gar class boats, along with a few of the early Gatos, were the last boats built with a periscope station in the control room. This is indicated by the stepped appearance of the periscope shears. Both of the periscopes are 40-foot long models, but the eyepiece of #1 scope is in the control room giving it the external appearance of being shorter.
