Archive for January, 2019

USS Tunny

While our museum houses some impressive and large artifacts, some of our exhibits are physically a part of the building itself. When you walk through the halls, you may notice some murals depicting different moments in the submarine force. These images are just as fascinating as the physical items stored around them. Over the next few months, we will look at these murals and the stories they tell.

In the main walkway, is a black and white image of the USS Tunny (SSG-282.) The image shows the submarine launching a Regulus cruise missile, which was the precursor to the first generation of the Polaris missiles.  USS Tunny was a Gato-class submarine and one of the first nuclear deterrent submarines that served in World War II and Vietnam.  During her service, she received nine battle stars and two Presidential Unit Citations.

A Presidential Unit Citation for a Failed Attack—USS Tunny‘s Second War Patrol, 9 April 1943

H-Gram 018, Attachment 3
Samuel J. Cox, Director NHHC
April 2018 


USS Tunny (SS-282) was awarded the first of two Presidential Unit Citations for her second war patrol—from 24 March to 23 April 1943. Up until that point in the war, the U.S. submarine force had largely under-performed. Two primary reasons were the difficulty of finding targets in the vast expanse of the Pacific Ocean and malfunctioning torpedoes; although, in some cases, lack of experience and aggressiveness in some submarine skippers was determined to be a factor. However, in Lieutenant Commander John A. Scott, Tunny had a truly aggressive and capable skipper. Tunny also had another advantage in that by early 1943, U.S. Navy codebreakers at Fleet Radio Unit Pacific (FRUPAC) had broken—and were copying with great regularity—the Japanese “Maru” code. Although not as sophisticated as the Japanese JN-25 series navy general operating codes, the Maru code nevertheless contained extremely valuable intelligence about Japanese ship movements. Lieutenant Commander Jasper Holmes had the lead for FRUPAC for sanitizing and passing communications intelligence-derived data to Commander, Submarine Force Pacific (COMSUBPAC) in a way that would not compromise the sensitive source. The ad-hoc process actually worked very well. As U.S. submarines were increasingly provided with the sanitized intelligence, their opportunities to sink Japanese ships also increased. The faulty torpedoes, however, were still a problem. (In H-Gram 008/H-008-3 “Torpedo Versus Torpedo,” I discussed these problems in detail.)

Tunny departed Pearl Harbor on 18 March 1943 for her second war patrol. After a brief stop at Midway Island she commenced transit on March 24 toward Japanese-held Wake Island. While conducting reconnaissance around Wake Island, Tunny sank the Japanese cargo ship Suwa Maru, firing two torpedoes for one hit. Tunny then survived being depth-charged and bombed twice. She moved on from Wake, and based on intelligence, located and sank the cargo ship Toyo Maru on April 2—firing three torpedoes for one hit. Lieutenant Commander Scott had a good shot at the cargo ship, but not the escorting destroyer 1,000 yards behind. He boldly sank the Toyo Maru anyway. Tunny then survived two sustained depth charge attacks. On 4 April, Tunny sank the cargo ship Kosei Maru—two for two on torpedoes. She then endured yet another sustained depth charge attack from escorting destroyers.

Lieutenant Commander Scott was among those submarine skippers who had come to believe, based on hard experience, that war-shot torpedoes ran deeper than the depth for which they were actually set. Since U.S. torpedoes were intended to pass under a ship and explode via magnetic influence, this was a serious problem. Although the Bureau of Ordnance continued to place the blame for poor results on the skippers rather than the torpedoes, some skippers like Scott were compensating by setting their torpedoes to run shallow. For the first part of this war patrol, Scott was having decent success with this technique, having sunk three ships in three attempts. What Scott didn’t know for sure—although he and other skippers suspected—was that the magnetic exploders were also unreliable. After that problem was discovered and fixed—by de-activating the magnetic exploder—it was learned that the contact exploders were unreliable too.

On April 8, the Intelligence analysts and code-breakers at FRUPAC decrypted a Maru code message that indicated a convoy including three aircraft carriers was due to arrive at the Japanese stronghold of Truk Island on early morning of April 10. Tunny was vectored to intercept. Scott planned to make a night surface attack, with his decks awash, making use of Tunny’s new “SJ” radar, which the Japanese had no means to detect. As described in the introduction, Scott’s initial set-up was textbook perfect, and although it was disrupted by the untimely appearance of three motor torpedo boats which forced him to attack submerged, it was still a great tactical set up. All four of the stern torpedoes fired at the lead smaller carrier were heard to explode, and three of the six fired at the larger carrier were heard to explode. Yet another sustained Japanese counter-attack by depth charges kept Tunny from getting visual or other confirmation of the hits.

Commander, Submarine Force Pacific would describe Scott’s attack as “an illustrious example of professional competence and military aggressiveness.” And it was—except for the torpedoes. In this case, setting them to run shallow backfired. The carriers were larger than the previous targets Scott had attacked, and the combination of shallow depth and larger magnetic signature caused the magnetic exploders to detonate prematurely—approximately 50 yards from their targets. These malfunctions were confirmed by subsequent intercept and decryption of Japanese communications that identified the small escort carrier Taiyo as having suffered minor damage as a result of the premature detonation of torpedoes. Analysis of this failure was a major factor in Admiral Nimitz’ decision to order the deactivation of the magnetic exploders in June 1943.

Tunny’s attack on the three carriers off Truk is also a great case study in how the “fog of war” becomes the “fog of history.” The identity of the three carriers is still in doubt, with the exception of the Taiyo. Accounts that identify the carriers by name state they were JunyoHiyo, and Taiyo. This, however, would not match Scott’s description of one large and two small carriers. Junyo and Hiyo were sisters, and although not full-size fleet carriers, were much larger than Taiyo. The small escort carrier Taiyo—and her sisters Chuyo and Unyo—proved to be a bad design, and the Japanese used them as aircraft-transport ferries rather than operational aircraft carriers. The three generally made runs between Japan and Truk ferrying aircraft. Japanese records show that Taiyo departed Yokosuka, Japan on April 4, in company with her sister Chuyo and escorts en route to Truk via Saipan. A U.S. submarine reported sighting the Junyo and Hiyo at Saipan at the same time Japanese records show Taiyo and Chuyo there. This misidentification made its way into official reports, and later histories. Japanese records also confirm that Taiyo and Unyo were present during Tunny’s attack, and would account for Scott’s sighting of two small carriers. The Junyo and Hiyo, as well as the Fleet Carrier Zuikaku and the smaller Zuiho, were at or near Truk at the time of the attack after having flown off their air groups to Rabaul and the Bougainville area of the northern Solomon to participate in Operation I-GO (see H-018-2). However, Japanese records do not indicate which, if any, of those other carriers were present during Tunny’s attack. On the other hand, the records of Zuikaku, Zuiho, Hiyo, Taiyo, and Unyo all eventually wound up on the bottom of the ocean. Only Junyo survived the war—sort of—as a badly damaged derelict in port, having been hit by three torpedoes from a “wolf pack” of three U.S. submarines. Unyo would be sunk by USS Sailfish (SS-192) on 4 December 1943, also near Truk. The true identity of the “large” carrier may never be known.

Tunny’s adventure was not yet over. On April 11, Tunny sighted the Japanese submarine I-9 on the surface near Truk. Tunny fired her three remaining forward torpedoes at the I-9; however, the Japanese submarine maneuvered to avoid them and counter-fired. Two torpedoes narrowly missed Tunny. She was then unsuccessful in trying to maneuver to sink a Japanese destroyer with her last torpedoes. The Japanese destroyer attacked first, and Tunnywas pounded yet again by depth charges, sustaining minor damage. She then concluded her patrol at Midway, and would receive a Presidential Unit Citation for her second war patrol. Lieutenant Commander Scott was awarded a Navy Cross.

Tunny would survive nine war patrols, and the fifth, also under the command of Scott, would earn her a second Presidential Unit Citation and a second Navy Cross for Scott. Among the highlights was Tunny’s duel with the Japanese submarine I-42. Although details are sketchy, it appears both submarines were aware of the other, and both maneuvered for about 90 minutes at relatively close range (under 2,000 yards) trying to gain a firing advantage over the other. Tunny won, and sank the I-42 with two torpedoes. Later in the patrol, Tunny fired six torpedoes at the Japanese super-battleship Musashi. The torpedoes passed under an escorting destroyer, which alertly signaled the Musashi, which was able to avoid all but one torpedo, which hit in her bow. The destroyer than counter-attacked down the torpedo wakes and subjected Tunny to yet another beating. The damage didn’t really faze the huge battleship, but she was out of action for a month for repairs.

Tunny continued her distinguished service after World War II. She was re-commissioned during the Korean War but did not serve there. Instead she was extensively modernized and converted to carry the Regulus land-attack surface-to-surface missile (with hangar for two missiles, and a launcher.) Tunny was re-designated as SSG-282. The drawback to the Regulus was that the submarine had to be surfaced to fire the missile. In 1966, Tunny was converted yet again into a troop-carrying submarine, with a deck shelter for small amphibious vehicles, and re-designated APSS-282. Tunny then conducted special operations and supported Marine amphibious operations along the coast of Vietnam. Tunny finally met her end as an exercise target, by a torpedo fired by the USS Volador(SS-490) in 1970.

On January 21, 2954, Nautilus was launched changing the how the submarine force would operate forever. At 10:57am, she slipped into the waters of the Thames as the sun broke through the clouds of the early morning. Complied in the archives of President Eisenhower, is a brochure complied of that fateful day. The brochure belonged to First Lady Mamie Eisenhower who served as the ship’s sponsor, breaking the bottle of champagne over its bow as it moved into the water. Within the program are paragraphs describing how historic Nautilus was.

The First Lady and Nautilus×491.jpg

Beyond the fancies of fiction
“When Jules Berne wrote Twenty Thousand Leagues Under the Sea in 1869, he imagined a true submersible which operated beneath the surface of the sea for indefinite periods, independent of the earth’s surface and atmosphere. His ship he named ‘Nautilus’ after the first practical submarine, one built by Robert Fulton in 1800. Now the sagacity and vision of the United States Navy, the Atomic Energy Commission and American industry have developed a ship which goes beyond even the fanciful creation of Jules Verne. Today’s “Nautilus’ opens the way to the world of the future.”
“…a most solemn and significant event”
“January 21, 1954 lives in history as the launching day of the world’s first atomic powered vessel, the submarine ‘Nautilus.’ Powered by the silent, invisible, airless “burning” of nuclear fuel, the ‘Nautilus’ will cruise submerged faster, farther, longer than any previous craft in history. Some 30,000 persons gathered in the shipyard of our Electric Boat Division, Groton, Connecticut, to witness this momentous occasion. That many came from great distances is a signal tribute to the scientists, engineers and craftsmen who worked to create this masterpiece of the shipbuilder’s art…..None of us who watched this unique and historic ship slide down the ways into the waters of the Thames River could doubt that we were participants in a most solemn and significant event, not only of our time but of all time.” – John Jay Hopkins, Chairman and President of General Dynamics Corporation

Chief of Naval Operations Admiral Robert B. Carney, USN addressed the crowd saying:

See the source image

Admiral Robert B Carney

“As an American I feel an intense pride in the vision, the brains, the ingenuity, the sweat, and the teamwork that went into the creating of the ‘Nautilus’.”

See the source image

Nautilus shortly after she entered the Thames River on January 21, 1954

It would take one year, seven months and seven days from the day her Keel was laid, for Nautilus to take her first ceremonial steps into the water. That September she would be commissioned and on January 17, 1955, Commander Eugene P. Wilkinson USN would signal the message, “Underway on Nuclear Power.”

Launching of the Nautilus
The brochure in the Eisenhower Archives can be viewed at the following link