The 'Indestructible Diamond' Was The Only Japanese Battleship Sunk By A Submarine During World War II

The history of the Japanese battleship Kongō is rich, with the ship being awarded renowned titles like the "Indestructible Diamond," "Indra's Spear," and "Divine Thunder." Furthermore, the vessel served as a key player in both World War I and II, ending in her demise when she fell victim to an American submarine attack.

Construction of Kongō

In January of 1911, George Thurston, a British naval engineer, started overseeing the construction of Kongō, marking a key milestone in naval history. Serving as England's inaugural and ultimate battlecruiser, the vessel was finalized in Barrow-in-Furness, Cumbria, while others of her class were being built in Japan.

Nevertheless, the construction project was marred by scandal. In January 1914, the release of a leaked telegram exposed a troubling truth: Japanese authorities had accepted bribes from both German and English arms manufacturers to secure the use of their products. Consequently, Prime Minister Yamamoto's entire administration resigned, accompanied by the resignation of senior business figures. Furthermore, Japanese Vice Admiral Matsumoto Kazu was subjected to a court-martial, resulting in a three-year prison sentence for his involvement.

Kongō was loaded with armaments

Kongō was equipped with eight 14-inch heavy-caliber main naval guns in four twin turrets, setting a pioneering standard as the first ship in the world to carry 14-inch guns. These guns could fire armor-piercing and high-explosive shells, showcasing Japan's dedication to superior firepower.

In addition to its primary weaponry, Kongō had a secondary battery of 16 six-inch .50-caliber guns housed in single casemates, eight 3-inch guns, and eight submerged 21-inch torpedo tubes.

The ship underwent further modifications in 1929 when it was transformed from a cruiser to a battleship. By October 1944, Kongō's secondary armament included eight 6-inch guns, 122 Type 96 anti-aircraft rapid-fire cannons, and eight 5-inch guns.

Service during World War I

Formally commissioned in August 1913 as a battlecruiser, Kongō swiftly entered active service. At the outbreak of the First World War , she was tasked with patrolling German lines of communication at sea and later provided support to Japanese units during the Siege of Tsingtao .

Following the British victory over Germany at the Battle of the Falkland Islands , Kongō 's role diminished. Consequently, she was either stationed at Sasebo Naval Base or patrolled near China for the remainder of the conflict.

After WWI, a collective desire among the world's powers to prevent another conflict led to the signing of the Washington Naval Treaty . This treaty imposed restrictions on the construction of new naval ships, leading to a reduction in the size of the Japanese Navy.

Interwar period and the start of World War II

In 1923, Kongō was used to transport Crown Prince (later Emperor) Hirohito to an official visit of Taiwan, and over the interwar period saw a number of upgrades. Starting in 1929, the Japanese Empire began transforming Kongō from a cruiser to a full-on battleship, completing the process six years later. The vessel was made to be significantly faster and had the armor near her ammunition magazines strengthened, among a number of other upgrades.

The newly rebuilt ship was active during the Second Sino-Japanese War , with two of her floatplanes bombing the Chinese town of Fuzhou. When the Second World War began, however, Kongō was sent off to the Pacific.

On February 22, 1942, the battleship participated in the Japanese invasion of the Dutch East Indies . The rest of year saw Kongō frequently battling and sinking ships from the British Empire across the Pacific.

The loss of Kongō in the Formosa Strait

For Kongō and Japan, the start of the Pacific campaign went very well. However, the tides turned during the Battle of Midway with the loss of four of the Combined Fleet's aircraft carriers. The ship also took part in the Guadalcanal Campaign , during which Henderson Field was bombarded with high-explosive shells in what was the most successful Japanese battleship action of the Second World War.

The next two major offensives the vessel took part in were the battles of the Philippine Sea and Leyte Gulf . Kongō played an important role in Leyte Gulf, sinking multiple American vessels, including the destroyer escort USS Samuel B. Roberts (DE-413). Despite this, the battle resulted in a victory for the Allies.

Not long after, in November 1944, Kongō was spotted by the submarine USS Sealion (SS-315) in the Formosa Strait. The vessel fired six bow torpedoes at the battleship, two of which hit and flooded Kongō 's boiler rooms. While she was able to escape the scene, the damage proved to be too much, with her sinking to the bottom of the strait after her forward 14-inch magazine exploded. Over 1,200 crewmen died.

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Kongō was the only Japanese battleship to be sunk by a submarine during WWII, while Sealion was the only Allied submarine to sink an enemy battleship.