Tambor class Submarine

The Tambor-class submarine was the last prewar US Navy submersible class design. Also called the “T class” based on their names (except the sub-class Gar), they were essentially the first USN truly successful fleet submarine, capable of 21 knots (39 km/h) in reliable conditions, 11,000 nautical miles giving them Japanese home waters and six bow torpedo tubes, plus an improved combat operations by all main operators under the the conning tower. Six were close or in Pearl Harbor (Tautog) on 7 December 1941 and saw the brunt of WW2 Pacific operations, with seven our of twelve lost in action and they were so worn out in early 1945 as to be retired and versed to training for the new Gato/Tench/Balao class crews, their immediate successors. These losses were the highest percentage of any US submarine class ever. But this was repaid by one of the most imprssive hunting board ever, with presidential units citations and battle stars ever in US sub service. USS Tautog alone was credited with sinking 26 ships, a record that still stands today.

Development

The Tambor-class submarine needed to arrive to create afterwards the wartime Gato class, a war-winning instrument in the Pacific. This new United States Navy submarine design proceeded always from the same idea, first expressed in 1915, to have a wokrable fleet submarine, capable of of the same speed as the new “standard” US battleships, 21 knots. This was practically never attained albeit each interwar class was used as a testbed for new engineering solution, each step closing on this ultimate goal. The preceding Sargo class was of course already a good starting point, on the point of view of settling the question of welding, fuel tank location, and the way their diesel-electric powerplant was managed with state and private ventures trying to reach reliability in the plant, an always fleeting objective.
This class addressed the only real complaint against the Salmon/Sargo-class, namely, that eight torpedo tubes were still considered too few. Therefore, Tambor and her sisters added two more tubes forward for a total of ten. They were the last boats to be completed before Pearl Harbor and, as such, they bore the brunt of fighting in the first year of the war. Seven were lost in the war, One of the survivors, Tautog, had the distinction of sinking more enemy ships than any other American boat.

USS Tresher (SS-200)

A small, but vocal, faction in the Navy (led by Admiral Hart) still thought American boats had gotten too big and fancy with their air conditioning and TDCs and pressured the General Board into ordering (wo submarines barcly half the size of Tambor. Mackerel and Marlin were fine boats, bigger than the German Type VII, smaller than the Type EX, but extremely unpopular with the Submarine Force, because they had less of everything they liked in the big ‘fleet’ boats.

For the submarines of the FY39 programme two TT were added forward, at a cost of about 15 tons. The 6-tube salvo had been debated for some years, and the Submarine Conference rejected it in 1935 largely in the belief that it would require an advance in displacement to 1750 tons. In 1937 it became obvious that SO great a sacrifice would not be needed, and the major units afloat voted unanimously for 6 forward tubes, in an improved Sargo design. Torpedo capacity remained unchanged, and diesel-electric propulsion was reintroduced. In these boats all torpedoes were carried internally, 16 forward and 8 aft. Each torpedo reload rack could hold two mines, for a total capacity of 40 mines plus 4 torpedoes. Diving depth was 250ft, but this equated to a collapse depth of 500ft; range was as for the Salmons. The Gar class (FY40) was also designed to operate at 250ft, but two boats were to be tested at 300ft, and the next class was designed for operation at 300ft.

Tambor class profile as completed in 1940 (the blueprints)

A long way towards the perfect fleet subs.

Early WWI U.S. submarine designs were either designed for coastal deterrence, better alternative to torpedo boats, or escort shipping bu they found little use otherwise. The experience of WWI showed that U-boats could be a powerful tool to wage a trade war and that even no sea power could do without submarines, Navy planners in 1918 thus completely rethought about the role of submarines in the US doctrine, and the first step was to determine the best caracteristics for a new type, which went through German captured designs.

This revealed the potential for long offensive submarine operations, imposing a new powerplant and larger fuel reserve. As said above the concept of a “fleet Submarine” in operations with the fleet imposed 21 knots requirement in speed, regardless of range for a start. An high endurance was desired for these sustained patrols second, and already in 1920, planned to be in Japanese home waters. Already used as “picket boats” they would provide intel on enemy operations and sink warships. Commerce raiding was not even mentioned. This was not due to an oversight but due to restrictions of the Washington Naval Treaty. On the tech standpoint, looking for a “new all-purpose fleet submarine” remained the apparent drive in all subsequent interwar classes.

The first attempt, the AA-1 class, launched 1918-19 had indeed the required high speed with four engines clutched together in tandem pairs but this expedient caused such excessive vibration and engine damage that this was considered a failure. The next Barracuda and first three V-boats (launched 1924–25) combined large direct drive main diesels with small diesel-electric diesels but these BuEng designs based on German MAN designs were completely unreliable. These Barracuda class also had poor seakeeping qualities and saw limited service. Also tested the concept of long-range cruiser submarine with a more moderate speed (Argonaut, Narwhal, and Nautilus) influenced by the “U-cruisers” made in service doubt planners as their huge size was a disadvantage in most tactical situations. They still found use as “transport spec ops sub” in WW2.

Navy designers eventually created a practical fleet submarine with the Porpoise (“P”) and then Salmon/Sargo (“S”-class) submarines of the 1930s, smaller, more maneuverable but still lacking speed and with unreliable diesel-electric propulsion. The latter “S” class managed to have a successful “composite” power plant between a direct drive and diesel-electric but still lacking in reliability (sepcially the ones with the new ooven-Owens-Rentschler double-acting diesels) and also firepower.

Development start: 1937 Lockwood proposal

By the fall of 1937 a team of sub officers worked on their own initiative on an improved fleet submarine, presented to the admirakty by Commander Charles A. Lockwood, later Admiral and Commander of the Submarine Force in the Pacific. He was seconded by Lieutnant Commander Andrew McKee, as planning officer at Portsmouth Navy Yard, and Lt. Armand M. Morgan of the submarine design section. Their design was larger at 1,500 tons, had the latest diesel engines and ten instead of six torpedo tubes, as well as a larger 5-inch (127 mm) deck gun plus an updated Torpedo Data Computer. The crew was not forgotten with the installation of fresh water distillation units and air conditioning.

Still, they faced strong opposition from Admiral Thomas Hart which was Chairman of the General Board, definding the vision of small and coastal defense boats for short sorties and thus no particular “comfort” additions. By dropping the air conditioning he entended to eliminate potential electrical shorts and fires. However with skilled political maneuvering, Lockwood’s team eventually prevailed over Hart, which was eventually conceded the new boats havin a 3-inch (76 mm) deck gun. This was on purpose, to prevent submarine commanders from attempting to engage surfaced heavily armed escorts, a design finally adopted by the Navy’s General Board in the Conference for the 1939 program, so two full years after the proposal was made.

Design of the class

The first Submarine Central Operation

It was also suggested, partly to avoid parasite sounds jamming the sonars, and easier teamworkk to have the operator and his diplay relocated into an enlarged conning tower, as well as a ballsitoc computer and its operator. This early “central operation” enabled quickr and easier communication with the captain and XO. Also a new periscope with a small head to avoid detection when surfaced was provided. These boatd also renewed the now long discarded practice of a “negative tank” or “down express” tank installed on the original 1918 S-boats. This was a “flash-flood” tank enabling quicker crash dives. It provided fast provide negative buoyancy and the hull in general had improved streamlining to reach a higher cruising speed.

A new Torpedo Data Computer

The TCD or Torpedo Data Computer was a electromechanical analog computer solely devoted for fire control, given the riding complexity of ballistic calculation at sea over larger distances, greater speeds of both the target and launcher, and their respective motions. It was designed to reduce human error, and it was found handy to ease and quicken firing solutions in tight opportunity windows, with raw recruits as WW2 flared out, as standard manual trigonometric calculations with a slide rule-type device needed some training.

The USN created arguably the most advanced TCD of the time. It was a heavy and bulky addition to the conning tower and was operated alone by two cremen. At a time of streight-course torpedoes, the TCD needed many inputs already, semi-automatically fed: The submarine course and speed (from the gyrocompass and pitometer log), the estimated target course, speed, and range information passed on from the periscope, as well as the Target Bearing Transmitter (TBT), radar, and sonar, plus the manually input torpedo type and speed. There was a set of extra corrections added over the years such as water temperature, even saltiness. Here is the original Mark 3 mods 5-12 manual. The Tambor class received the 2nd generation Mark II, from Ford Instrument Co. The Mark I from 1938 was indeed too complicated and the Mark II was transitional. It seems the excellent Mark III was installed on submarines launched in 1940 onwards, which was the case for most Tambor/Gar class.

Fairbanks-Morse Engines

Going with performances, the Tambor class were given the best full diesel-electric propulsion plant so far. This was the results of testsmade on some of the Sargo class, with many improvements eliminating arcing issues plaguing these. The Sargo were given for comparative tests General Motors-Winton engines or Hooven-Owens-Rentschler (HOR) engines, and the latter proved quicky fairly unreliable in service, they were replaced by early 1943. But this was not yet apparent when the Tambor were designed, and given shortages of HOR engines, those not completed with the GM Winton units had instead the Fairbanks-Morse 38 8-1/8 engines. This was a lucky pick as they proved the mpst reliable submarine diesels so far. In fact they were so good that they were soon ramped up in production for the next Gato class (the first serie of Gato-class boats were given HORs, to speed up production, despite their now clearly apparent issues). The Fairbank Morse proved so useful they were still used as backup power on the nex generation of USN nuclear submarines and soldiered on for decades.

But most important, if the powerplant provided the same top speed as before, 21 knots, and same underwater speed at 8.75 kts, range was slightly improved. However this was all rosy as the Tambor in order to gain space did not separated the four engines. In case of a leak, all four could be flooded, dooming the submarine. This was corrected on the next Gato class, as well as their test depth increased from 250 ft (76 m) to 300 ft (91 m) after depth charges were tested against USS Tambor… So the Tambors were the best interwar submarine design, and prepared a recipe that was just increased to produced a war-winning, mass-produced design.

Six bow TTs and better storage

The T (Tambor) class improvements over the Sargo class were many, starting, as recommended by Lockwood’s team six instead of four bow torpedo tubes forward to maximize chances of a hit in one go. This wa slong overdue and in fact had been constantly pushed back based on a faulty estimation of required tonnage to accomodate these extra tubes. The four stern tubes of the Sargo class were retained however, all reloadable from the pressure hull. The size was increase in order to accomodate Larger torpedo rooms. This eliminated exotic deck stowage, which was impractical for any reload at sea.

Provision for a larger gun

Another contentious debate was about the installation of a 3-inch (76 mm)/50 caliber deck gun. The Officer’s team gained sufficient leverage to gain eventually the last work despite objections of Admiral Hart for a strenghtened deck in order to support a 5-inch (127 mm)/51 caliber gun (instead a shorter barrel was installed). In the meantime, the concession was to accept a standard 3-in or 76 mm gun. In 1942–43, SS-198, SS-199, SS-200, SS-203, and SS-206, SS-209, were all rearmed with the 5-inch/25 guns, taken from the now obsolete, discarded Barracuda class or spares. The guns were unique as having a “wet mount”. The others soldiered on with the 3″/50 until swapped for the 4-inch (102 mm)/50 caliber guns from old S-boats withdrawn from service.

Construction

The Tambor class were produced in the usual rival yards, the private EB and state-owned Portsmouth NyD, but also Mare Island on the west coast for political reasons.
Electric Boat: SS198-200 Tambor, Tautog, Tresher, SS-206 Subclass: Gar, Grampus, Grayback
Portsmouth NyD: SS201-202 Thresher. Triton. SS209-210 Grayling, Grenadier
Mare Island Naval Yard: SS 203, 211 Tuna, Gudgeon.
Both Portsmouth and Mare Island shared the exact same plans and powerplant centered around the GM Winton diesels.
Electric Boat replaced as seen above its disastrous HOR engines by Fairbank-Morse units. The GM Winton were much immproved over the years and were now almost as good as the Fairbank-Morse.

Hull and general design

The Tambor class were not just improved repeats of the Sargo class. They displaced more at 1476t standard versus 1450t on the Sargo, but they were slightly shorter at 307 ft 2 in overall (93.63 m) versus 310 ft 6 in (94.64 m). They were however wider at 27 ft 3 in (8.31 m) versus 26 ft 10 in (8.18 m) but a lighter draught at 15 ft (4.57 m) versus 16ft 8in (5.08m). Overall these made them somewhat more stable.

Powerplant

The Sargo’s full diesel-electric propulsion plant was repeated. Improvements over the Porpoise class managed to solve the arcing issue that plagued previous boats. The Sargo class inaugurated General Motors-Winton engines or Hooven-Owens-Rentschler (HOR) engines. The latter appeared very unreliable, and were replaced in 1943. Those without GM engines were granted the Fairbanks-Morse 38 8-1/8 engine, an excellent model still used as backup power on nuclear submarines to this day and heralded as the very best marine diesel ever made in the US. The Tambors skipped the horrid HORs due to purely procurement reasons whereas the next twelve Gato class were fitted with them. The problem was their location, all four insode the single single space. In case of fire or flooding, this meant loss of all power. That’s the first aspect the Gato class corrected, but this forced to increase their hull from 250 ft (76 m) to 300 ft (91 m) after depth charges tests made on the Tambor class.

Armament

Mines:
The Tambor class had another novelty compared to previous designs which made operations more interesting. It could substitute mines in place of torpedoes, using the newly developed Mk 10 and Mk 12 type mines (see later) with two mines per tube in capacity, plus reloads, making for a grand total of 48 mines, reduced however to 40 to keep four torpedoes for safety. However in practice it was rather a mix of at least 8 torpedoes, and max 32 mines.

Extra Torpedo Tubes:
Going from four to six torpedo tubes forward was of course a game changer. The previous “new S-class” had a symmetrical, internal arrangement of foure tubes forward four aft, all reloadable through the pressure hull, an approach not taken by the RN which preferred mixing non-reloadable external tubes for shorter missions (The T class British method), but this was not popular with the crews. Before the Sargo, the standard on the Porpoise and Cachalot class was four tubes in the bow, two in the stern, 16 total but the design solutions found for the Salmon class for 24 torpedoes, with four stored close to the conning tower in vertical tubes proved unfeasable in reality. It was a hard, dangerous work and required perfect conditions.

Mark 14 issues:
The Tambor class were of course given the promising new Mark 14 as standard when completed in 1940. They had an abysmal record and ushered in a storm of captain’s protestations in upper echelons, which coupled with the stubborness of the Ordnance delayed the issue to late 1942, mid-43, when their numerous issues were fixed. There were still stocks of the older, straight course contact fuse Mark 10 aplenty, which were “pillaged” every time they were available on forward deployment zones. The problem was that Mark 14s had been provisioned to the frontline, notably from Guam and Midway, so fustrated captains had to make due with these. Nevertheless, the Tambor rolled an impressive hunting board, still. But in 1942 their kills should have been far greater, and albeit detonations were often heard, it did not meant the warheads exploded in a useful way, in fact they did so prematurely quite often or too low under the keel to do any damage. Many alleged “kills” were debunked postwar.

Swap to a larger deck gun:
The third point was of course, the use of a bigger deck gun. Even for the prewar Tambor class, US submarine doctrine, often wrote by senior officers not always acquired to the submarine, basically prevented the installation of a large deck gun as a way to prevent young and brash sub commanders to engage targets when surfaced and risk their boat to counter battery fire. Simple fact is that in terms of raw firepower, most escorts were an overmatch for their single deck gun. The same doctinal limitations applied also to US destroyer commanders that were given side torpedo tubes banks to prevent them firing all their torpedoes at once in an engagement. Of course in 1942, reports piled up in the issues encountered by the Mark 14 and inadequacies of the puny 3-in/50 in engagements against smaller vessels, too shallow and “cheap” for a torpedo.
At least it was obtained to reinforce the base support of the deck gun to mount later a heavier caliber. Most saw the installation of a 3-in/50 as a provisional peacetime measure but in 1942, many received the 5-in gun upgrade. The heavier gun was presented as a safety measure by captains, arguing that the less time they spent surfaced dealing with a small target the better. They were plenty of examples of surface engagements that went awry though and not all Tambors were given the upgrade.

3-inch/50-caliber gun Mk 17/18

This proven ordnance went right back to the O class and its 3 inch (76 mm)/23 caliber gun, non-retractable in later batches. The new 50 caliber model became pretty standard, with a design going back to 1898 when designed, Mark 6 for the Electric Boat models. The 3″/50-caliber Marks 17 and 18 were installed on the Cachalot class, first used on R-class submarines launched in 1918–1919 and all subsequent models inclusing the Sargo and Tambor class as completed. The Tambor class were the last US submarine fitted with such gun. The Mark 17 guns had a Mark 11 mounting and the Mark 18 guns had the Mark 18 mounting. Image: 3-in/50 Mark 18 specs and sheet, src HNSA via navweaps.

⚙ specifications 3-in/50 Mark 18
Weight	6,500 Ibs
Barrel length	120 inches
Elevation/Traverse	-15/+40 degrees
Loading system	Manual, vertical sliding wedge type breech
Muzzle velocity	2,700 fps (823 mps)
Range	14,000 yards (12,802 m) at 33°
Guidance	Optical
Crew	6
Round	24 lbs. (10.9 kg) AP, HC, AA, Illum.
Rate of Fire	15 – 20 rounds per minute

4-inch/50-caliber gun Mk9

Standard intermediate light gun which design dated back 1898. The Mark 9 was installed as an alternative to the 5-in/25 in short supply. It had heavier rounds and higher muzzle velocity but was slower to fire and only had a marginally better range.

⚙ specifications 4-in/50 Mark 9
Weight	5,900 lb (2,700 kg) (with breech)
Barrel length	204.5 in (5,190 mm)oa, barrel 200 in (5,080 mm)
Elevation/Traverse	-15/+20 degrees
Loading system	Manual, vertical sliding wedge type breech
Muzzle velocity	2,900 ft/s (880 m/s)
Range	15,920 yd (14,560 m) at 20°
Guidance	Optical
Crew	6
Round	Fixed 33 lb (15 kg), 62.4–64.75 lb (28.30–29.37 kg) complete round
Rate of Fire	8 – 9 rounds per minute

5-inch/25-caliber gun Mk17

Installed on the Tambor class when available, this ordnance started its career in the 1920s as a new 5″/25 AA gun before being declined in furth variants, Mark 17 being the last of these, developed for submarines. It weighted 2 metric tons, used the Mark 40 submarine gun mount for semi-fixed ammunition (case and projectile handled separately), but existing WW II photographs and drawings of ammunition storage show fixed ammunition. Range was just of 14,500 yards (13,300 m) the same or inferior to the 3-in/4-in/50 guns due to the short barrel, at 40 degrees elevation which was manual as well as training. From august 1944 some Gato class received even two of these (additional one forward) assisted by the Mark 6 “Baby Ford” fire control computer with a Mark 6 stable element. Not on the Tambor. They kept their single aft gun all along.

⚙ specifications 5-in/25 Mark 17
Weight	2 metric tons
Barrel length	11 ft 10 in (3.6 m) oa, Barrel 10 ft 5 in (3,175 mm)
Elevation/Traverse	-15/+40 degrees
Loading system	Manual, vertical sliding wedge type breech
Muzzle velocity	2,100 ft/s (640 m/s) average
Range	14,500 yards (13,300 m) at 40° (effective)
Guidance	Optical
Crew	6
Round	Fixed, 127 × 626 mm R 54.5 lb (24.7 kg)
Rate of Fire	5 rounds per minute

Mark 10 Torpedoes

These boats were capable of firing the 21-inches Mark 10 21″ (53.3 cm) Mark 10, a 1917 design entering service in 1918. From 1927 these were the Mod 3, last designed by Bliss and manufactured by the Naval Torpedo Station at Newport. They equipped the WWI R and S boats, most V Boats, The Cachalot, Porpoise and Sargo, but were not intended for the Tambor class. They soldiered on in World War II still, as a trusted straight course in replacement for the infamous Mark 14. Before the latter had its defaults ironed out in 1942-43, the Mark 10 was in high demand and stocks starting to dwindle down rapidly. Thus, production was maintained until 1943.

⚙ specifications Mark 10 Mod 3
Weight: 2,215 lbs. (1,005 kg)
Dimensions: 183 in (4.953 m)
Propulsion: Wet-heater
Range/speed setting: 3,500 yards (3,200 m) / 36 knots
Warhead: 497 lbs. (225 kg) TNT or 485 lbs. (220 kg) Torpex
Guidance: Mark 13 Mod 1 gyro

Mark 14 Torpedoes

In 1941 she carried the Mark 14, entering service in 1930. Designed replacement for the Mark 10, this was the new standard. Unfortunately the model was infamous for its legendary unreliability, explaining the poor results obtained in 1942 and until mid to late 1943; Long story short, the Mark 14 was a revolutionary new model that was tailored to use a gryroscope combined with a magnetic pistol. The principle was not to detonate on impact, but use magnetoc proximity of the enemy hull to explode ideally under the hull of the target. This way, it was easier to break its hull instead of just making contact below the waterline. These torpedoes were designed at the Naval Torpedo Station Newport, Rhode Island from 1930 and considered state of the art, benefiting from a $143,000 budget for its development.

Production was pushed forward after testings, and at 20 ft 6 in (6.25 m), it was incompatible with older submarines’ 15 ft 3 in (4.65 m) torpedo tubes, like the R and O classes. It was also the best performer, capable of 4,500 yards (4.1 km) at 46 knots (85 km/h). Lots of promises, but the war proved that testings had not been thorough and the rate of misses compared to the Mark 10 became obvious in reports in 1942, this infuriated many captains that disabled the magnetic pistol, but did not solve the problem as it was proved later that their too fragile impact fuse was also faulty.
Responsibility lied with the Bureau of Ordnance, which specified an unrealistically rigid magnetic exploder sensitivity setting while not providing enough funding to a feeble testing program. BuOrd had a hard time later accepting it and enable a new serie of tests, which were mostly from private initiatives.
Only by late 1943 and early 1944 most problems had been allegedly fixed, so that the 1944 Mark 14 at least allowed captains to claim far more kills. The “mark 14 affair” sparkled a lot of controversy postwar and it’s not over.

⚙ specifications Mark 14 TORPEDO
Weight: Mod 0: 3,000 lbs. (1,361 kg), Mod 3: 3,061 lbs. (1,388 kg)
Dimensions: 20 ft 6 in (6.248 m)
Propulsion: Wet-heater steam turbine
Range/speed setting: 4,500 yards (4,100 m)/46 knots, 9,000 yards (8,200 m)/31 knots or 30.5 knots
Warhead Mod 0: 507 lbs. (230 kg) TNT, Mod 3: 668 lbs. (303 kg) TPX
Guidance: Mark 12 Mod 3 gyro

Mark 10 Mines Mod 1

In December 1941 the USN had in stock some 1,200 Mark 10 as Moored Hertz Horn for 21-inch torpedo tube and only 600 Mark 12.
Production was rapidly ramped up. The Mark 10 project was started in 1921, halted and resumed.
Base specs were:
Mod 1 contact fired: 1,760 lbs. (798 kg) total, charge 300 lbs. (136 kg).
Mod 2 was cancelled
Mod 3: Magnetic: Weighed 1,800 lbs. (816 kg) with a charge of 420 lbs. (190 kg) TNT.
Mod 11: Moored contact mine for USS Argonaut (SS-166) only.

Mark 12 Mines Mod 3

Submarine launched mine designed to be launched from a standard 21 inches or 53.3 cm torpedo tube. They were cylindrical, with an aluminum case. The model was derived from war prize German models in the 1920s, the S-type mines. The Mod 1 was an (airborne) parachute mine, M3 was the submarine type. Some were delivered to Manila just before the Japanese invasion and were dumped into deep water to prevent capture. In total, when carrying just a few spare torpedoes in minelaying missions, the S-class could carry a total of 32 Mark 12 mines.

⚙ specifications Mark 12 mod 3 Mines
Dimensions: 94.25 inches long, 20.8 inches wide. (2,394 m x 0.53 m).
Weight: 1,445 lbs. (655 kg), 1,100 lbs. (499 kg) TNT charge or 1,595 lbs. (723 kg) with a 1,250 lbs. (567 kg) Torpex charge.
Pissibly replaced in 1944 by the Mark 24 submarine launched ground mine. src

Sensors

QCC sonar: The QC/JK gear was located in the Conning Tower, companion units with the QC gear as active/passive sonar and JK gear (passive only). Raides and lowered by a hydraulic system, training by electric motor controlled by handle in the operating station. QCC: No data.
JK sonar: The JK/QC combination projector is mounted portside. The JK face is just like QB. The QC face contains small nickel tubes, which change size when a sound wave strikes this face. (The NM projector, mounted on the hull centerline in the forward trim tank, is used only for echo sounding.)
Se the full reference here

Modernizations

In 1942-1943, all Tambor class which survived so far had their conning tower rebuilt to the new “light” standard fitted with two AA platforms and depending of the boat some kept their 3-in/50 deck guns while others swapped to the 5-in/51, and their initial two Browing M2HB 0.5 in HMGs were removed and replaced by at least one 20 mm Oerlikon AA gun. Some exchanged their 3-in/50 deck gun for a 4-in/50 Mk 9 or an older 5-in/25 Mk 17. The final AA complement was either twio 20 mm AA or a single 40/56 Mk 1.2, and a 20mm/70 Mk 4. The new CT was also fitted to install the SD and SJ radars.
In 1945, many had been revamped and received either the new 4-in/50 Mk 12 or the 5-in/25 Mk 40, Bofors Mk 3, and 20mm/70 Mk 10 and in addition t the aforementioned radars, the QCG sonar.

Appearance

USS Tambor SS198, 1940 Measure 9

USS Tautog SS199 ms 32/3SS-B
The Tambor class were all painted in Measure 9 at least until 1943.
MS 9: Vertical Surfaces above the waterline black, formula 82 for all that was visible for the air with the capstan and running light boards and bridge rails, radio insulators. Underbody with darker tones of bottom antifouling paints.
Horizontal Surfaces except wood decks in Dark Gray 5-D even for sloping surfaces.
As for 1945 the only boat that wore an alternative camouflage is USS Tautog (depicted here) with MS 32/3SS-B.
MS 32/3SS-B: Haze Ocean Gray 5.O blending into a dull black stern, dekcs in gloss black, but Measure 9 still shown in other parts, saddled tanks in matt black.

⚙ Tambor class specifications
Displacement	1,475 lt standard surfaced, 2,370 lt (2,410 t) submerged
Dimensions	307 ft 2 in x 27 ft 3 in x 14 ft 7+1⁄2 in (93.62 x 8.31 x 4.458 m)
Propulsion	4 diesels 6,400 hp surfaced, 4 EM RG 2,740 hp submerged, 2x 126 cell batteries
Speed	20.4 knots (38 km/h) surfaced, 8.75 knots (16 km/h) submerged
Range	11,000 nm (20,000 km) at 10 knots
Endurance	48 hours at 2 knots (3.7 km/h) submerged
Max service depth	250–300 ft (76–91 m) Crush Depth Possible 500 ft (150 m)
Armament	10x 21-in TTs (6 fwd, 4 aft, 24 torpedoes), 1×3-in/50 deck gun, 4x 0.5-in HMG AA
Sensors	QCC-JK suite, SD-SJ radars 1942-43
Test Depth	250 ft (76 m)
Crew	6 officers and 54 ratings

General Evaluation

When the war broke out for the US on December 7, six Tambors were already in Hawaiian waters or underway training in the Central Pacific. USS Tautog was the only one actually at Pearl Harbor during the attack. The remainder were still freshly commissioned and in trials or early training on the East and West coasts of the United States. No Tambor was forward deployed to the Philippines in October 1941. The Tambor soldiered on hard for the duration of the war, with seven out ofthe twelve boats sunk after more than a dozen patrols on average.

The survivors in 1944 were eventually withdrawn from front-line service due to wear and tear and escaping depht-charging attacks that shook them, plus having worned out diesels. They were retired for training and experimental duties by early 1945 after a last overhaul often. They remained records holders as a class for the most battle stars and most losses. Tautog with 26 confirmed ships, had the record for US subs in World War II. USS Tuna was spent as target to test atomic blast effects while surfaced in Operation Crossroads in the Bikini Atoll but showed she was strong to avoid crippling damage but was still irradiated and ended as target in 1948. One of the other legacies of the Tambor class, leading directly to the bespoke wartime Gato, Tench and Balao.

Appearance

The Tambor class differed little in general design compared to the Sargo class, nor to the Gato class. The general shape or dimensions were about the same, albeit the Tambors were a few feet shorter, but they shared the seam beam. The Gato were a bit draftier though. As completed they had the same typical, tall, bathrub like conning tower, with portholes in the forward enclosed steering bridge, and open bridge with squared face and wave breaker, the CT central tub for the plated-in sheared periscopes (unlike on the Gatos) and a cutout rear deck with two posts for 0.5 in liquid-cooled removable HMGs, albeit many former subs photos shows deck posts as well. Other photos showed an installation of a wrapped, so permanent HMG under a waterproof tarp on the railing at the base of the persiscope shears.
Colors: Prewar Gloss black, Measure 9. Numbers in white on the CT and name at the nose. Dark blue gray for the deck, which was cut open on the froward section, over 1/4 of the ship’s lenght. The hull was entirely black, including below the waterline, without any separation.

Wartime:
Covered conn protecting the helmsman from base weather removed (redundent due to the secondary helm inside the CT), plus watch and officers which needed to be out. The new CT needed to be compact and open at the same time, with platforms for AA on both ends.
After the demoval of the plating around the periscope shears (which trapped air and slowed down diving), this leaft a “sekeleton” strcutre to hold and protect both periscopes, making it more difficult to detect at a distance unlike the previous plating which created a sizeable wave.
The same structure was used to support radar masts or lookouts in ring holders and a projector.
Measure 32/3SS-B or “light gray job” applied to the upper surfaces, and former base dull black below.
Measure 32/9SS (“Dark Gray job”) was applied later in 1944, still dull black below, but the upper outer hull received Haze Gray 5-H forward and Ocean Gray 5-O aft, starting roughly immediately aft of the CT. The CT and shears were in Navy or medium gray.
The cigarette deck was in Measure 32/3SS-B.
In 1945 the same scheme remained applied but all vertical surfaces were in Haze Gray 5-H except at the stern, horizontal surfaced in gloss black, numbers only kept in white. None of the class was camouflaged.

Admiral Hart’s Oddball

The immediate “succession” of the Tambor was the Gato class but in reality a competitor project was ordered for the Navy by the most vical opponents of the stretching of US subs, as they wanted a return to the coastal S-Boats for home defence only. These were the Mackerel class. These two small submarines were built largely at the instance of Admiral T.C.Hart, the General Board’s submarine expert, fearing these new ‘fleet boats’, were becoming too large, and who looked forward to replacements for the many ‘S’ class boats about to become over-age.

They were justified as ‘patrol’ or coast; defence units, but met very great resistance on the part of the submariners, who felt that a 1500-ton ‘fleet boat’ could do quite as much, but could also function in the all-important Western Pacific. Ultimately two boats were built under the FY39 programme, one (SS204) to an Electric Boat Company design, and the other to a Navy in-house design; after the war Electric Boat built six modified Mackerels for Peru, with ‘guppy’ sails and a deck gun. Mackerel had direct drive, Marlin diesel-electric through motor-generators. Designed depth was 250ft, and there were 6 TT and 12 torpedoes. Although the Board of Inspection and Survey was very favourably impressed with these small submarines, neither saw effective war service and both were discarded. The need which Hart forsaw for large numbers of boats to protect the Hawaiian Islands, the US coast and the Canal Zone never really materialised. Aftr Pearl Harbor the need for new large submarines to bring war to Japanese home waters overruled all previous considerations.

Gallery

Books

Friedman, Norman (1995). U.S. Submarines Through 1945: An Illustrated Design History. Annapolis NIP
Bauer, K. Jack; Roberts, Stephen S. (1991). Register of Ships of the U.S. Navy, 1775–1990 Greenwood Press.
Alden, John D., Commander, USN (retired). The Fleet Submarine in the U.S. Navy Annapolis NIP 1979
Johnston, “No More Heads or Tails”, pp. 53–54
Blair, Clay, Jr. Silent Victory. New York: Bantam, 1976
Lenton, H. T. American Submarines (Navies of the Second World War) Doubleday, 1973
Silverstone, Paul H. U.S. Warships of World War II Ian Allan, 1965
Schlesman, Bruce and Roberts, Stephen S., “Register of Ships of the U.S. Navy, 1775–1990: Major Combatants” Greenwood Press, 1991
Campbell, John Naval Weapons of World War Two. Naval Institute Press, 1985
The Fleet Submarine in the U.S. Navy: Design and Construction History Hardcover 1979 by John D. Alden.
Gardiner, Robert, Conway’s All the World’s Fighting Ships 1922–1946, Conway Maritime Press, 1980.
Alden, John D., Commander (USN, Ret). The Fleet Submarine in the U.S. Navy: A Design and Construction History. NIP
Blair, Clay, Jr. Silent Victory: The U.S. Submarine War Against Japan. New York: Bantam, 1976. ISBN 0-553-01050-6.
Campbell, John Naval Weapons of World War Two (Naval Institute Press, 1985)
Friedman, Norman (1995). U.S. Submarines Through 1945: An Illustrated Design History. NIP
Lenton, H. T. American Submarines (Navies of the Second World War) (Doubleday, 1973)
Roscoe, Theodore. United States Submarine Operations in World War II. NIP

Links

on navypedia.org/
on oneternalpatrol.com
on theleansubmariner.com/
on pigboats.com/
web.mit.edu/ Newell analog computers
On navweaps.com 4 in/50 mk9
on navweaps.com 5-in/51 mk7
on pwencycl.kgbudge.com
on navsource.org
on uboat.net/
on navsource.org
on uboat.net
on uboat.net
on en.wikipedia.org
on commons.wikimedia.org/
on subsim.com/
on lewin of greenwich naval history
on 2db.com
on shipcamouflage.com tambor_class.htm
shipcamouflage.com/tambor_class.htm

Model Kit

https://sdmodelmakers.com/tambor-class-submarine-model-12-inch.html
on scalemates.com

Video

The Tambor class in Action

USS Tambor was laid down at Electric Boat on 16 January 1939, launched on 20 December 1939 and completed on 3 June 1940 with Lt.Cdr. J. W. Murphy Jr. as first CO.She was fitted out at New London after which she departed on 6 August 1940 for her shakedown cruise to NyC and Washington, D.C. as well as Morehead City, Houston, Colón (Panama)and back for fixes at New London for post-shakedown overhaul in Portsmouth. She was voluntarily tested against depth charges, which was rich in lessons for future constructions. She started active service in May 1941 in the Pacific Flee under RADM Thomas Withers, COMSUBPAC. She departed for her first peacetime patrol by late November 1941 and at the time of the Pearl Harbor attack was she at Wake Island, returning to Pearl after loosing one diesel, and sent underway back directly to Mare Island Navy Yard, returning to Pearl Harbor in March 1942.
Her first war patrol started on 15 March to 12 May. She sailed to Wake, Truk, New Ireland, New Britain, Rabaul, made nine attacks like on 16 April, sanking the tanker Kitami Maru (not verified postwar). Just as the skippers of the Sargo class, the Mark 14 were severely criticized.
After a small refit she was assigned to Task Group 7.1. a “wolfpack” of six submarines sent to Midway on 21 May 1942, patorlling over 150 miles (240 km) waiting for the IJN invasion fleet. At 07:15 on 4 June Admiral Robert H. English informed the subs to wait for 11:00 to close, surfaced. Tambor was strafed by IJN aicraft while underway.
At 02:15 on 5 June, Tambor signalled “four large ships” 90 nmi north of Midway from 3 nmi which complicated identification, as possible “friendlies” in that area.
Tambor sighted these again at 0238 and confirmed these were Japanese ships, changing heading to the northwest. At 0258, Murphy’s own fleet turned due west to caught them with blackened silhouettes, regained but lost sight twice. Later at periscope depth, Tambor idendified IJN Mogami, her bow damaged. Later Mogami collided with Mikuma. Tambor reported an oil slick, that dive bombers found to sink Mikuma, which was Tambor’s contribution to the battle of Midway.
On 7 June after making a short range radar contact she dived top have both periscopes damaged, an all battery blower motors blasted after a misidentification by a B-17 which also concerned USS Grayling. She was back on 16 June.
Lt.Cdr. Murphy was relieved of command, for “timidity in the face of the enemy” as he failed to close with and attack or properly identify the cruiser force. Spruance deplored this lack of intel allowed Suzuya, Kumano and Mogami to escape unscaved. Her was replaced by Lt.Cdr. Steven H. Armbruster.
Her 3rd patrol started on 24 July 1942 at Pearl Harbor and ended on 19 September at Fremantle in Australia. She ws sent to the Marshall Islands and on 7 August near Wotje she sank the net tender Shofaka. On 19 August she was ordered south of Truk and later the Caroline Islands, notably Ponape on the 21st, hitting the freighter Shinsei Maru No.6. On 1 September she hot and damaged a tanker off Truk.
She sailed for the Hainan Strait on 12 October, to lay mines, and on 3 November, fired, but missed a freighter but retook contact 30 minutes later and sank Chikugo Maru by the stern. On 6 November she fired on a French flagged cargo-passenger ship but missed. On 10 November she sank by gunfire an unarmed sampan. Back in Australia she had a refit, obtaining among others a 5-inch (127 mm)/25 deck gun.
Her 5th patrol was From 18 December 1942 to 28 January 1943: Sunda Strait (Krakatau-Thartway Island): Sighted a destroyer on 1 January 1943, four torpedoes missed, took 18 depth charges. On 29 December 1942 Fukken Maru was claimed by one of her mines.
For her 6th patrol from Fremantle on 18 February 1943 she was sent for spec ops in the Philippines, carrying reinforcements and supplies to “MacArthur’s Guerrillas” and landed a small party (Lt.Cdr. Charles Parsons) with 50,000 rounds of .30 (7.62 mm) ammunition, 20,000 rounds of .45 ACP (11.4 mm) ammunition, and $10,000. On the 22th of March she attacked a tanker SW of Apo Island, Bugen Maru, damaged, and later an unconfirmed freighter, believed sank. She was back on 14 April for refit, receiving an aft CT platform 20-mm AA gun.
Her 7th patrol under Lt.Cdr. Russell Kefauver saw her in the Malay Barrier from 7 May to 27 June 1943. On 26 May she missed a tanker and 3 days later a cargo ship. She later claimed Eiski Maru sunk. On 2 June and on 6 June she attacked two cargoes, one appeared to break in half, only Eika Maru was confirmed on 2 June and on 16 June, she attacked but missed a tanker off Cam Ranh Bay.
She departed from the last time from Fremantle on 20 July 1943 for Lombok Strait and on the 27th she claimed the Teiken Maru (by a mine). On 3 August she spotted a five cargo convoy in the Palawan Passage, had two hits, but no sinking reported postwar. On 21 August, she sighted a convoy of three tankers, five freighters, scored no hits. Next day, the same in opposite direction, launched 5 at a large freighter, 3 hits, failed to explode. Back at Midway on 7 September with a furious Skipper she was sent to Pearl Harbor and San Francisco on 20 November for her major overhaul.

She was back at Pearl Harbor on 15 December 1943 for a refresher training and started her next patrol on 5 January 1944 to the East China Sea. She sighted a Natori-class cruiser on 22 January, lost slight. Later on the 28th she spotted a convoy heading north and tracked it util her attack on the next day, sinking Shuntai Maru. But she was almost rammed by an escort, firing on her with her aft 20-mm gun while turned hard to port, missed by 20 yards (20 m) astern. She dived and lost the convoy. On 3 February she sunk Ariake Maru and Goyo Maru but was depth charged from 04:18 to 13:15. On the 13th, she spotted and attacked a convoy by night surfaced, sinking the Ronsan Maru. This was Tambor’s best patrol with 18,400 tons confirmed.

After her Pearl Harbor refit she departed on 9 April 1944 for her 10th patrol in the Mariana Islands. On the 18th she attacked a 250-ton trawler in surface, sending a boarding party klling the crew and capturing the XO. Food and papers were rocovered and the gunboat Shinku Maru No. 3 sank. On 10 May she spotted an 8-ship convoy escorted by five destroyers plus two destroyer escorts. The sent 4 submerged, heard 2 hits and escaped. This was Keiyo Maru. On 26 May she sank Chigo Maru and ended in Midway on 2 June.
Under command of William J. Germershausen she sailed for her 11th patorl to southern Hokkaidō and the Kuril Islands (6 July to 23 August 1944). On 28 July, she fired 4, heard 3 explosion, possibly the escort Kunashiri. On 13 August she photographed and sank Toei Maru (2,300 tons). Via Midway she returned to Pearl Harbor for refit.
She departed for her 12th patrol from Midway on 6 October 1944 and the Tokyo Bay area. On the 15th she fired at radar ship, one hit. On the 18th she attacked an escort but no sinking verified. She was back in Saipan on 8-10 November and resumed her patrol entering the wolfpack “Burt’s Brooms”, SubDiv 101.
After midnight on 15 November she missed a patrol boat, and 45 minutes later another so at 06:10, her decided to surface to deal with the escorts with deck guns; but had several crewmen severely wounded. She managed so sink the escort Takashiro Maru 30 min. later, took two prisoners, transferred later to USS Grayson (DD-435) on 18 November for interrogation. She was at Pearl Harbor on 30 November 1944 but given the fact she was pretty worn out, escaped at least four depht charge attacks, it was decided to retire her from the frontline.
After a main overhaul at San Francisco from 10 December 1944, she was sent to Puget Sound on 9 March 1945 for training USN patrol aircraft pilots under Fleet Air Wing 6 and was in this role when the war ended. On 17 September she sailed via Panama to Portsmouth Naval Shipyard, decommissioned on 10 December 1945, in reserve until April 1947. Reassigned to the 9th Naval District to train Reserve personnel she ws sent to Detroit station on 8 December 1947 until 1959. She made an historical first as being drydocked at Toledo, Ohio, Great Lakes, on 2 October 1953 for 5 weeks. In 1959 a Board of Inspection and Survey proposed she was stricken, on 1 September 1959, sold for BU.

USS Tautog (SS-199) was laid down on 1 March 1939, launched on 27 January 1940 and completed on 3 July 1940. Not only the most successful in class, but also of the Pacific war and perhaps the allies with 26 confirmed victories, allegedly 50+ probable kills and badly damaged ships, earning 14 battle stars. Retrospectively it’s a shame she was not preserved.
Following a short training at Long Island Sound, she made a shakedown cruise in the Caribbean from 6 September 1940 to 11 November 1940 and back to New Londofor a few fixes and stayed in base untl early February 1941 before departing to the Virgin Islands in the context of the Battle of the Atlantic. By late April, she was back to New London to load supplies and depart in group with their tender for Hawaii on 1 May via Coco Solo and San Diego, arriving on 6 June 1941. Tautog operated there until mid-Octobe and on the 21st with USS Thresher at sea under sealed orders for a 45-day simulated war patrol around Midway. For 38 days she stayed submerged for 16-18 hours daily and was back to Pearl Harbor on 5 December 1941 Two days later at dawn her crew rushed to battle stations as fire and havoc rained on Ford Island. She co-claimed with her Browning AA with Narwhal and a destroyer a Japanese torpedo bomber over Merry Point.
She escaped any damaged and was repared for war, for a first war patrol which started on 26 December and brought her to the Marshall Islands for reconnaissance over 26 days, notably to Kwajalein, Rongelop, Bat, Wotho, Bikini. On 13 January 1942 she attacked but missed a small minelayer, and was depth charged in return. Due to her fogging periscope she was back on 4 February and repaired at Mare Island.
For her 2nd patrol she departed on 9 April 1942, toward Hawaii and left Pearl Harbor 15 days later for the Marshall Islands. Around 10:00 on 26 April she sighted the periscope of an enemy submarine trying to gain a firing position but Tautog made a sharp turn, fired her stern torpedo which exploded above being officially credited the sinking Ro-30 (1,047 tons), the first US sub on sub kill, but it remained unconfirmed postwar.
She ordered to Truk to intercept the fleet back from the Battle of the Coral Sea, especially Zuikauku and Shōkaku but as ther understimated their speed, they missed them. Still, she topedoed, hit once Goyo Maru and had a second torpedo (Mark 14 of course) entering a circular run. Upon realizing this, the skipper ordered a crash dive deeper. Goyo Maru was damaged but beached herself. Later she received from ULTRA new of four Japanese submarines in hea area and was caught by surprise by the first, failed to attack in tme but detected and fired two at the second, but was not officially credited with the sinking. Later he spotted “I-28” which managed to fire at Tautog. She launched two and dived to 150 feet. One torpedo hit home and she was credited her. This was the third sunk sub-on-sub kill of the Pacific war.
On 22 May she crossed path with a convoy and made a submerged sound attack, believed to have sunk but only damaged the 5,461-ton cargo ship Sanko Maru. Later she made a periscope attack and sank Shoka Maru. She ended her successful patrol (6 claimed kills) at Fremantle on 11 June.

Her third patrol started on 17 July and ended on 10 September 1942 off Indochina to lay mines (due to torpedo shortages) notably at Cahn Ram Bay which only claimed Ohio Maru (5,900 tons) on 6 August. After being refitted by the tender USS Holland (AS-3) at Albany and loaded with mines she set sail on 8 October 1942. On 20 October for her 4th patrol when her lookouts spotted a ship in a rain squall believed to be a Japanese 75-ton fishing schooner and surfaced, closed range and fired to stop her at the bow. The Japanese crew escaped but four Filipinos swam on board and later enlisted in the USN.
On 27 October, Tshe attacked a passenger-cargo ship, believed to be the Hokuango Maru formerly Chinese Pei An and later attacked another merchantman, but missed (duds). In the night of 2 November she laid mines off Haiphong. On 11 November she missed a cargo but suffered a severe depth charge attack. She was back at Fremantle ten days later for repair/refit.
Her fifth patrol, from 15 December 1942 to 30 January 1943, was in the Java Sea and Ambon, Timor, Celebes, spotting a freighter in Ombai Strait on 24 December, fired three stern tubes, sank Banshu Maru N°2. Whilke underway to Alors Strait she spotted a freighter coming west with an escort but was detected, septh charged and escaped. On 5 January 1943 she inspected a sailing ship. On 9 January at 08:38 she was informed of the presence of the IJN Natori (Nagara-class) off Ambon Island, fired at 3,000 yards (2,700 m). She was hit but still underway at reduced speed, so two more were launched. In returned she fired at her periscope and managed to eescape to Ambon for repairs.
While in the Salajar Strait, she spotted but missed a second cruiser in heavy seas. She spotted a freighter on 22 January in the Banda Sea and sank Hasshu Maru, former Dutch passenger-cargo ship turned troopship. Upon arrival in Fremantle her skipper was commended for his “extreme aggressiveness.”

Her 6th patrol (24 February 1943 to 19 April) was started in Makassar Strait and Balikpapan to lay mines. On 17 March, she finished off a grounded tanker after an air attack. She later attacked but missed a freighter. On 9 April in the Celebes Sea she spotted a convoy of five, sank the 5,214-ton Penang Maru and the destroyer IJN Isonami (Fubuki class) and rescued crew from the Penang Maru. She also tested her newly installed (salvaged from an S-Boat) 5-in/25 deck gun in four battle surfaces with a schooner, sailboat and motor sampan.
Her 7th patrol started from Fremantle on 11 May 1943, heading for the Flores Sea, the Gulf of Boni, Molucca Sea, Celebes Sea, Moru Gulf. On 20 May, she gunned down a sampan. On 6 June she sank Shinei Maru in Basalin Strait and later the the 4,474-ton Meiten Maru on 20 June before sailing back aft 53-day. She was re-routed to the US for a major overhaul at Hunter’s Point followed by a refresher training underway to Hawaii.
Her 8th patrol started on 7 October 1943 from Pearl Harbor to the Palau Islands and on 22 October, she surfaced near Fais Island and bombarded a phosphate plant. She sank the Submarine Chaser Number 30 on 4 November, damaged a tanker and three cargo and after speinf all her torpedoes expended she tracked and reported a convoy for two days before heading to Midway on 18 November.

Her 9th war patrol started on 12 December 1943 this time in Japanese home waters, southeast of Shikoku and southern coast of Honshū. On 27 December she fired at a freighter, never confirmed as she stayed under for four hours to endure 99 depth charges. On 3 January 1944 she went to the mouth of the Kumano Kawa River, very close from the seawall, fired three at a cargoi, then turned for deep water. She claimed Saishu Maru but ws flew over by an aircraft and had to flee.
On 4 January, radar contact brought her in a good firing position, launched all six bow torpedoes for four hits, sinking Usa Maru. On 11 January she crossed two freighters, launched three, heard explosion while she fled Escorts. She was only credited damage on Kogyo Maru. Back in Pearl Harbor she was refitted by USS Bushnell (AS-15) on 30 January.
Her 10th patrol sent her to the northern Pacific, Kuril Islands, Paramushiro and Hokkaidō, refuelling underway at Midway and started patrol on 5 March 1944. While surfaced she lost Motor Machinist’s Mate R. A. Laramee, washed overboard by a giant wave. On 13 March she torpedoed a freighter from 1,500 yards, two hit but Ryua Maru stayed afloat and she had to sent four more to this “damn rubber ship”. As she was still afloat, albeit dread in the water she surfaced to finish her off by gunfire when another ship was spotted over the horizon to rescue survivors. She dived and approached submerged, firing three at Shojen Maru. On 16 March she crossed a convoy of seven ships off Hokkaidō, maneuvered, launched, observed one hit, but escaped deep the escort. She passed to attack again on the starboard flank, firing three but was attacked by a Japanese destroyer, being later officially credited Shirakumo (1,750 tons) and Nichiren Maru after reaching Midway on 23 March.
For her 11th patrol from 17 April to 21 May 1944 she returned to the Kuril Islands. On 2 May she spotted a cargo in a small harbor close to Matsuwa To, launched four from 2,000 yards, then two more and sinking the 5,973-ton Army cargo ship Ryoyo Maru. She however remained in shallow water, still recuperabe. By heavy fog, she surfaced andlaunched four more, two hit. Later she spotted her prey, Fushimi Maru (5,000 tons) sinking for good. On 8 May she spotted a convoy off Esan Saki, fored at the largest ship, slowed by a hit, then two more on Miyazaki Maru (4,000 tons) but she had to pay a salty addition of seven hours chase. On 9 May she missed a freighter and on the 13th fired her last three torpedoes at Banei Maru Number 2 (1,100 tons), sank too.

On 23 June 1944 she started her 12th patrol from Pearl Harbor, again to Japanese waters, Honshū and Hokkaidō. On 8 July she torpedoed a small freighter identified as Matsu Maru. While off Simusu Shima she spotted and closed on a coastal steamer engaged surfaced, lobbing on her 21 rounds putting her afire causing later an explosion, she rescued six survivors confirming she was Hokoriu Maru. On 2 August she spotted a convoy off Miki Saki, launched three from 800 yards (730 m), claiming Konei Maru. She evadded escorts and headed back to Midway, arriving on 10 August. Later she sailed for the US and a major, last overhaul.

Her 13th patrol started at Pearl Harbor on 17 December 1944, via Midway and Saipan with USS Silversides in the East China Sea. On 17 January 1945 she sank the IJA troopship “Transport Number 15”. Later she claimed the torpedo boat tender Shuri Maru (1,800 tons) underway to Sasebo. A day later she damaged a tanker and had to flee escorts. Underway back to Midway, she gunned down a wooden trawler. She arrived in port on 1 February 1945, to be assigned to training duty from 2 March at Pearl Harbor, to better train aircraft in ASW. Next she was in San Diego on 9 April to start safety search tests with the University of California’s Department of War Research. On 7 September she was sent to San Francisco, Pacific Reserve Fleet but was redeployed on 31 October for the East Coast, Portsmouth, on 18 November.
Not selected for the Bikini Atoll tests in 1946 she entered the 9th Naval District on 9 May 1947, reserve training ship, then at Milwaukee, 26 December for the Great Lakes Naval Reserve Training Center until sold for scrap 15 November 1959 at Bultema Dock and Dredge Company of Manistee, Michigan.

USS Thresher SS-200 was laid down at Electric Boat on 27 April 1939 like her sisters above, launched on 27 March 1940 and completed on 27 August 1940 under command of Lieutenant Commander William Lovett Anderson. She was a very successful submarine, which name was resurrected by the 1960 Thresher SSN class. In fact she was the most decorated United States Navy submarine of World War II, with 15 battle stars and a Navy Unit Commendation. After sea trials she left New London on 25 October for engineering trials in Gravesend Bay and shakedown off the Dry Tortugas. She was ordered to leave the East Coast on 1 May 1941 for the Caribbean Sea and transited Panama on 9 May to San Diego and was at Pearl Harbor on 21 May, assigned to the Pacific Fleet. With USS Tautog (SS-199) she departed on 31 October for a realistic, simulated war patrol north of Midway with live torpedoes. Tautog was back before her, she was still underway on 7 December 1941, and was escorted by USS Litchfield (DD-336) to avoid being mistaken for a hostile submarine. She entered the devastated posrt at 08:10 as bombs were still running, gunners on her deck on high alert.
Thresher was to be prepared for her 1st war patrol, and she was to be escorted by the same destroyer, with a RDV taken. When she surfaced at the pre-appointed time and point she spotted a similarly looking destroyer… which fired on her immediately, forcing her to crash-dive, showing that an escort in this high intensity post-battle time was necessary. As she tried to returned to the harbor on 8 December she was depth-charged by a patrol plane until USS Thornton (AVD-11) arrived to escort here safely at least.
Her 2nd patrol (technically her simulated patrol became real on December 7) started on 30 December 1941, to the Marshall and Mariana Islands, Majuro, Arno, and Mili 9-13 January 1942, then Guam on 4 February, spotting a small freighter 7 miles (11 km) north of Agana Harbor, she closed in, launched three and opened her long hunting board (not confirmed postwar though). On 24 February as she approached Pearl Harbor again she was attacked by a Navy plane. Two days later she was in.
Her third patrols started after refit, sailing out on 23 March 1942 for the Japanese home islands to take intel off Honshū of IJN ships coming and going for Admiral Halsey’s relaliation TF (Enterprise (CV-6), Hornet (CV-8) for the Doolittle raid planned for 18 April).
ULTRA informed her of four Japanese submarines off Tokyo Bay and she eventually spotted and attacked one but missed. On the morning of 10 April she spotted, toproedoed and missed a freighter as mist prevented an other attack. Later that day she had more luck with Sado Maru (3,000 tons) off Yokohama but she was depht-charged in payback by 4 patrol vessels. This was precise and so bad she lost depth control, making it down to 400 feet (120 m) (below test depth), managing to regain control. She was recalled but remained to continue assisting Halsey indaily intel checks. On 13 April while surfaced to recharge batteries, a wave crashed over her CT and cascated trhough the hatches, causing shorts. Between quick thinking and damage control the worst was averted, she was repaired. The next dy she gathered weather data and made day periscope patrols in advance screen for Halsey until detached on 16 April back to Pearl Harbor on 29 April.

On 26 June 1942 she departed for her 4th war patrol between the Palau and Marshalls. On 6 July she torpedoed a tanker off Enijun Pass (which survived) but could not finished her off due to surface escorts and aircraft in a three-hour hunt. On 9 July she was off midway between Kwajalein and Wotje when spotting and torpedoing a 4,836 ton torpedo boat tender, but later was depth charged and even caught by a large grapnel in an attempt to capture her. After repairs, she went to Truk for recce, missing a freighter on 20 July. The next day in a squall her sonar picked up screws and a patrol craft rushed to ram her, but she turned hard right to a parallel course just 50 yards (46 m) and fired as Thresher crashed dived.While off Ambon, Neth. East Indies she attacked what was a Q-ship, her two torpedoes were duds, and she was depth charged. Next she was reassigned to the Southwest Pacific Submarine Force, and ordered to Fremantle, which she reached on 15 August.

After a refit she changed command for William J. “Moke” Millican. She loaded mines due to torpedo shortages in Australia and and departed Fremantle on 15 September 1942 to lay a small minefield in the Gulf of Siam like her sisters. She fired but apparently missed two freighters north of Lombok Strait (19 September) and again on 25 September in the Sulu Sea. While surfaced the next night north to Pearl Bank she was the first of her sisters to lay mines, also first in the Pacific War. They barred the shipping lanes to the Southwest Pacific filled the gap between patrol zones off Malaya, Siam, and Indochina in preparation for the Solomon Islands campaign.
While in intel at Balikpapan, Borneo and Celebes coast she spotted and attacked a tanker aground on a reef off Kapoposang Island (Java Sea) and decided to burn her out in a deck gun attack. She was back in Fremantle on 12 November for refit and departed again on 16 December 1942 for Soerabaya to intercept a convoy of freighters. She sent 5 “fishes” to the leading three ships, heard two explosions, observed a sure kill at periscope depth, the other dead in the water, smoking. She escaped and later spotted an enemy aircraft carrier while surfaced by night, until detected by her escorts. The night of 29 December she spotted a 3,000-ton freighter, missed, but waited for the moonrise and surfaced for gunning her. She was forved to outmaneuvering the cargo’s ramming attemps. She landed many hits from her then 5 inches gun, noted her “probably sank”. This was a first.
Back to Fremantle on 10 January 1943, she was prepared to sail 15 days later for her 7th patrol, with four torpedoes less and at 11:00 on 14 February she spotted an unidentified I-65 class submarine east of Thwartway Island, launched two, one a dud, the other exploding too deep. She surfaced for reaching the deck gun but the IJN submarine disappeared over the horizon. In the Flores Sea she spotted a three-ship convoy on 21 February she torpedoed the stern of a transport, evaded depth charges and one hour later being back at periscope depth observing her prey dead in the water, barges transferring troops. With the escorts away, she closed and torpedoed the second transport and dived. On 2 Mrch she spotted and attacked a tanker and freighter, sank the 5,232-ton tanker but the freighter evaded. She was kept away by an and arrived in Austrlia on 10 March.
Like for her sisters, her skipper was furious as the loosy performances of his Mark 14 torpedoes, which was denied by Admiral Ralph W. Christie, which relieved him.
She started her 8th war patrol under CO Harry Hull from 4 April to 23 May 1943. In the 9nth she scored another kill. Off Balikpapan she spotted a 3-ship convoy, escorted by IJN Hokaze on 30 June 1943. She launched three, missed, escaped DC attacks, came back later, leaving a tanker ablaze and badly damaging a 5,274-ton passenger freighter in the Makassar Strait. On 5 July she was in Tambu Bay behind a tanker along the Celebes coast, wating for the escort to leave before closing, furing three, one hit at the bow, then surfaced to gun deck, but the Navy tank was well armed and keep her at bay. On the 8th she was at Catmou Point, Negros Island for a spec ops mission, delivering 500 pounds (230 kg) of stores, 40,000 rounds of ammunition to Filipino guerrillas and receiving intel in return. Her patrol ended on 9 July and she she sailed on orders to the West Coast of her major overhaul via Midway Island and Pearl Harbor at Mare Island.
She departed for Pearl on 8 October 1943 and started her 10th war patrol on 1 November in the Caroline Islands, starting north of Truk, tracking a five-ship convoy from 12 November, fired three on a 4,862-ton transport but was DC attacked and had to leave. Unconfirmed results.

For her very successful 11th war patrol under Duncan C. MacMillan as CO, she was sent to the South China Sea, south of Formosa (Taiwan). While surfaced on 10 January 1944 she spotted a pair of masts on the horizon and later closed on a 150-ton trawler shat she gunned down while surfaced with 45 main gun rounds, 20 mm and .50 cal rounds for good measure. Next she proceeded to the Luzon Strait and at At 11:43 on 15 January she spotted a Japanese aircraft carrier with strong escort, submerged as she had been spotted and approached by two enemy destroyers. She went deep and silent, waiting two hours while DCs fell. She was unscathed.
At 17:00 she spotted a 4-ship convoy at 12,000 yards escorted by a sub-chaser as escort, surfaced at 19:11 for a chase, tracking these by radar, maneuvered to the west until having four launched from her stern tubes at 22:07 from 1,800 yards (1,600 m). Two hits sent to the bottom a 6,960 ton freighter and next she fired three bow tubes at a 4,092 ton freighter which exploded. She then engaged the third when fired upon by with deck guns and passing down her port side at 800 yards, so she dove as the sub-hunter arrived to drop 20 DCs. Next she sailed for the Singapore-Japan trade route and on 26 January, made radar contact with a small convoy, attacked at 00:11 (three bow torps whuch sank a 1,266-ton freighter). Later a second which claimed a 2,205-ton freighter but she missed the 3rd, faster and firing. She managed to stay behind for four hours fiuring her last torpedoes at 04:46, which caused a massive explosion. As she was close, the concussion was alone to stop Thresher dead in the water the main engine overspeed trips actuated. Repairs took timle and the convoy was gone. On 28-29 January she patrolled the Formosa-Palau lane (Luzon Strait) and sailed back via Midway to Pearl Harbor on 18 February. For his brillant campaign, CO MacMillan was awarded the Navy Cross.

She started her 12th pator on 18 March 1944 for the central Caroline Islands but remained as plane guard during air strikes on Truk. She surfaced and shelled Oroluk Atoll on 11 April, photographed islands but sighted only two enemy ships and was too far to attack. She was back to Pearl Harbor on 8 May. Her 13th patrol started on 14 June 1944 and on the 25th she joined a wolfpack with USS Apogon (SS-308), Guardfish (SS-217), and Piranha (SS-389), soon dubbed the “Mickey Finns” since it was under Captain William V. “Mickey” O’Regan, USS Guardfish. On 27 June they were in SAR mission. On 11 July Thresher made radar contact with six ships steaming between Formosa and Luzon and signalling to Guardfish and Apogon. She manoeuvered 15,000 yards (14,000 m) astern of the convoy to pick up stragglers while Guardfish took the port flank, Apogon to starboard. A Japanese escort then spotted and shadowed Thresher but Piranha sank a 6,504-ton passenger/cargo ship whereas Apogon was rammed, forced to return for repairs. On 16 July; 16:00 Thresher sighted smoke on the horizon, surfaced reported to Pirhana and Guardfish conformed mater six ships. At 23:29, she close to 2,000 yards (1,800 m), launched three to the lead escort, three to the first freighter and turned to fire all four stern tubes at a second freighter with four explosions sighted then, six. The crew then started to reload her tubes at midnight and was bacl to attack what was left, a freighter, oiler and escort at 01:18, fired two bow tubes at the escort, three at the leading freighter, pivoted and fired her stern tubes at the oiler. Six explosions head but she dived as the escort depth charged her. Back to periscope depth she saw the ships still afloat and the crew began reloading her tubes again whith what was left at 01.22, the fired two bow tubes at the freighter again, two at the oiler, the remaining one at the escor, swapped and fired her stern tube, two torpedoes heard at 02:46, cargo down, and oiler down in a majestic ball of fire. It seemed the escort went down or at least was badly damaged as well. Post-war assessment confirmed Sainei Maru (4,916 tons) and Shozan Maru (2,838 tons) and when back, MacMillan received a Navy Unit Commendation and second Navy Cross.

Her 14th patrol was under orders of John R. Middleton Jr. from Midway on 23 August 1944, to the Yellow Sea and East China Sea. She was brutalized when surfaced by heavy seas. At the southern tip of Kyūshū she only small craft but was chased off by two subchasers on 10 September. On 13 September she missed a large oiler passed (out of reach) and a freighter which stayed afloat after four torpedo hits. The aircraft escorting her kept her head down.
At 15:31 on 18 September she spotted a silhouette on the horizon, locked the cargo with radar at 19:23 and then an escort vessel, making into position at 21:00 to the frighter’s port bow and the better part of her zig zag. She launched four torpedoes, missed, and still undetected, fired four stern torps from 1,200 yards, sinking the 6,854-ton freighter Gyōkū Maru. After reload she launched more, but barely missed. She then sailed to the waters off Manchuria, sighted only fishing craft until 26 August then a large cargo at 09:44, surfaced at 13:15 but a sub floatplane on patrol spotted her and she dived. At 16:00 she surfaced, retook contact at 18:15 and while she was heading for Daisei Gunto in intercept course she fired her two bow tubes and sank her. On 26 September she fired her stern tubes at an oiler from 4,000 yards (3,700 m), claimed sank. She headed for Midway tracking underway on 3 October a small trawler and guned her down after sunset but after 27 rounds return fire forced her to back off.
She refueled at Midway on 8 October, arrived at Pearl Harbor on 12 October 1944 for a second and last major overhaul departinf for a patrol on 31 January 1945 in the Marianas with USS Tilefish (SS-307), Shad (SS-235), and Peto (SS-265) via Saipan (12–13 February) and north of Luzon. Attacks were inconclusive and she shifted to SAR duties and a shore bombardment of Basco Harbor (Batan Island) on 28 March with Piranha and Puffer (SS-268).
Her patrol ended alongside USS Fulton (AS-11) before sailing to Oahu on 4 April 1945, arriving 20 days later and written off her active combat service. After a refit she trained airmen out of Pearl Harbor and Eniwetok until 15 August. She left on 15 September for Pearl Harbor then San Francisco on 4 October, transited the Panama Canal on 10 November for Portsmouth, decommissioned on 13 December. Recommissioned on 6 February 1946 she was to be spent at the Bikini Atoll test but given her general state this was deemed unfeasible, so she was decom. on 12 July 1946, stricken fon 23 December 1947, sold on 18 March 1948 for BU.

USS Triton (SS-201) was laid down at Portsmouth Navy Yard in Kittery, Maine on 5 July 1939, launched on 25 March 1940 and completed on 15 August 1940.
She performed 5 patrols, the last by late 1942 to the Truk–Rabaul–New Guinea shipping lanes. In her sixth patrol, she was lost to an attack by three destroyers on 20 March 1943. How it happened: Under strict tactical control of Admiral James Fife, Jr., under CO George K. MacKenzie she departed on 16 February for an area between the Shortland Basin and Rabaul. On 6 March, the submarine attacked a convoy of five destroyer-escorted ships and sank the Kiriha Maru, damaging another freighter, but had a torpedo making a circular run, running deep. On 8 March she claimed 5 hits out of 8 fired, could not observed results due to the escorts which forced her down. On 11 March she chased two convoys, informed Trigger (SS-237) and on 13 March, Triton was warned of three enemy destroyers led by IJN Akikaze in ASW patrol in her area. On 15 March she reported attacking and being depth charged. No further messages were received and post-war cross-examination of Japanese records revealed she was most likely spotted and depht charged until sunk by the three Japanese destroyers signalled earlier. They noted a clear oil slick, debris, and US items after being picked up, no survivors. On 10 April 1943 she was presumed lost and later stricken.

USS Trout (SS-202) was laid down at Portmouth on 8 August 1939, launched on 21 May 1940 and commissioned on 15 November. She received 11 battle stars for her service and a Presidential Unit Citation in three war patrols (11 total). She notably delivered ammunition to the besieged forces on Corregidor and brought out 20 tons of gold bars as well as Philippines silver pesos to Pearl Harbor. In 1941 she acted as target for DC tests. For her patrols, she claimed near 20 ships but was credited only 12 postwar (37,144 tons). In her first ten war patrols she made no less than 32 torpedo attacks, spent 85 torpedoes for 34 hits but also a total of 5 confirmed premature detonations, 5 confirmed duds, 25 suspected duds which further fuelled the bonfire of discontent on the Mark XIV torpodo. She also made six battle surface actions and escaped eight depht charge attacks. Reported overdue under Lt. Harry Eades Woodworth, on 17 April 1944 from her 11th patrol to sink troopships from Mandchuria to Guam, she was presumed lost with all hands by IJN Asashimo on 29 February, after she had claimed a passenger-cargo ship (badly damaged) and sank the 7,126-ton transport Sakito Maru (carrying the 18th Infantry Regiment). One postwar hypothesis is that as she used the still problematic Mk. XVIII electric torpedoes, one circled around and hit her back. The case happened for her sister USS Tang indeed.

USS Tuna (SS-203) was laid down at Mare Island Navy Yard in Vallejo, California on 19 July 1939, launched on 2 October 1940 and completed on 2 January 1941.
She earned a total of seven battle stars for her service, for 13 war patrols across all hot points of the Pacific. On her 12th patrol she operated from Majuro Atoll on 15 July 1944 with “Roach’s Raiders” (Haddock and Halibut), for Operation “King Two”, the invasion of the Philippines. On her 13th From 28 January to 30 January 1945 she was in special mission to reconnoiter the northeast coast of Borneo and later landing personnel and 4,400 pounds (2,000 kg) of stores near Labuk Bay. After the war, she participated in the Bikini Atoll atomic testing in 1946. She survived and was later sunk under 1160 fathoms on the west coast, struck on 21 October 1948.

Gar sub-class

USS Gar (SS-206) was built at Electric Boat in Groton, Connecticut on 27 December 1939. She was launched on 27 November 1940 and completed on 14 April 1941. In total she made 15 war patrols, the last two for spec ops in the Philippines, carrying stores and personal. After overhaul at Pearl Harbor she departed to serve until V-Day on 2 April 1945 as target trainer for ASW vessels at Saipan and Guam. She was decommissioned on 11 December 1945. Reserve training ship postwar; sold for scrap 18 November 1959 to Acme Scrap Iron and Metal Company.

USS Grampus (SS-207) was laid down at Electric Boat on 14 February 1940, launched on 23 December 1940 and completed on 23 May 1941. She completed five war patrols in 14 months, sinking over 45,000 tons, including a few warships. She was declared lost with all hands in March 1943, to probable enemy action on the 5th. She was awarded three battle stars for her service. The circumstances of her loss are still debated. In company with Grayback she left Brisbane on 11 February for her 6th war patrol. Japanese seaplanes reported sinking of a submarine on 18 February in her patrol area. However Grayback reported seeing USS Grampus on 4 March. She torpedoed and damaged the Keiyo Maru (6,442 GRT) on 19 February and minesweeper W.22 on 27 February 1943 but on 5 March 1943, IJN Minegumo and Murasame reportred a submarine attacked and probably sank near Kolombangara island after spotting a heavy oil slick the following day. She was avenged if it’s the case, as her tormentors were both sunk in the Battle of Blackett Strait soon afterwards. She was struck from the Register on 21 June 1943.

USS Grayback (SS-208) was laid down at Electric Boat 3 April 1940, launched on 31 January 1941 and completed on 30 June 1941. She was lost as well on 27 February 1944. Before this, she was quite a successful submarine. She ranked 20th with a total tonnage sunk of 63,835 tons and 24th in number of ships sunk, 14 for 10 war patrols, for which her skipper and crew received two Navy Unit Commendations for their 7th, 7th, 10th, and 9th war patrols and eight battle stars.
In her last patrol from 28 January 1944 she headed for the East China Sea, reported two cargo ships sunk on 19 Feb. two more damaged (Taikei Maru and Toshin Maru sunk) and sent her last report on the 25th with Nanho Maru sunk and Asama Maru badly damaged. On 30 March ComSubPac listed her as missing, presumed lost with all hands. Postwar reports as most probable cause dunk by aircraft operating from the Japanese aircraft carrier Zuikaku south of Okinawa, 27 February 1944.
CO John Anderson Moore was awarded his third Navy Cross posthumously. Rediscovery of the wreck in 2019 conformed the narratrive.

USS Grayling (SS-209) was laid down at Portsmouth Navy Yard in Kittery, Maine on 15 December 1939, launched on 29 November 1940 and completed on 1st March 1941.
She completed 7 war patrols in 20 months, sinking over 20,000 tons for six battle stars. She was declared lost with all hands in September 1943, probably lost between 9 and 12 September 1943 with uncertain causes. This will be perhaps one day elucidated if the wreck is rediscovered. No Japanese reports strickly confirmed her destruction, but she is presumed Lost off Manila around 9 September, not given her last report but one from the passenger-cargo vessel Hokuan Maru which reported a submarine in shallow water west of Luzon. A memorial was erected postwar in Sloan’s Lake Park at the corner of 17th Ave. and Sheridan Blvd. in Denver.

USS Grenadier (no CC photo) was laid down on 2 April 1940 at Portsmouth, launched on 29 November 1940 and completed and commissioned on 1 May 1941 with Lieutenant Commander Allen R. Joyce in command. Prewar On 20 June 1941 she took part in the search for the old USS O-9, which failed to surface after a deep test dive. She performed her first patrol from February to March 1942 to the home islands. Among others she torpedoed and sank on 8 May the transport Taiyō Maru underway to the East Indies with renown Japanese scientists, economists, and industrial experts and the hydraulic engineer Yoichi Hatta for the exploitation of the conquered territory. On 1 May 1942, she mistakenly sank the Soviet merchant ship Angarstroi in the East China Sea SSW of Nagasaki.
She performed 5 war patrols but was loss following enemy action on 22 April 1943. This happened on the night of 20 April 1943 whe she sighted two merchant ships, closed in for attack surfaced at dawn on 21 April when spotted in turn by a Japanese plane. She dived below 130 feet (40 m) but DCs ran and she was badly damaged, hitting the bottom at 270 feet (82 m), in repairs and combating a fierce fire in the maneuvering room. She spent 13 hours on the bottom and surfaced after dark. But her machinery was inoperable and her CO Fitzgerald tried to jury-rig a sail to beach her to the nearby island. On 22 April lookouts two Japanese ships heading for them, notably the netlayer Choko Maru which fired first. Fitzgerald believed it was now unsafe to dive again without power and instead gave directives to evacuate the boat, destroy documents and placed explosive charges. This was done undedr heavy fire, answered for by her deck gun, 20 mm and HMGs. An aicraft dropped a torpedo that landed 200 yards (180 m) away and exploded. All vents were opened when she was evacuated. The crew of 8 officers and 68 ratings was rescued by Choko Maru, transferred to Penang to be tortured and starved, separated and transferred to various camps in the Malay Peninsula and Japan. All but four survived their brutal two years in captivity. She received 4 battle stars for her service.

USS Gudgeon (SS-211) was laid down at Mare Island Navy Yard in Vallejo, California on 22 November 1939, launched on 25 January 1941 and completed on 21 April 1941. In all shescored 14 confirmed kills for 71,372 tons (15th on the honor roll) for 12 war patrols, a Presidential Unit Citation for her first patrol, a Silver star and Bronze star and the Asiatic-Pacific Campaign Medal with 11 battle stars. She was declared overdue, and presumed lost with all hands, on 7 June 1944.
How it happened is also a matter of debate still today.
On her 12th and last patrol she departed on 4 April 1944, refuelling at Johnston Island on 7 April, but never sent any report afterwards. On 7 June 1944, she was presuled lost but some sources argues she was paobably lost on 18 April 1944 southeast of Iwo Jima, sunk by attack near the Maug Islands. Until the wreck is found, it will remained a victory.