Kako

The Japanese Heavy Cruiser Kako: A Resilient Pillar of the Pacific War

Introduction: Kako, Japan’s Stalwart Cruiser

The Furutaka-class heavy cruiser Kako which entered service in 1926 holds a unique place in Pacific Theater history during World War II. The ship received its name from the Kako River in Hyogo Prefecture and represented Japan’s interwar fleet expansion with its modern capabilities to oppose Western maritime forces. Despite not reaching the legendary status of battleships such as Yamato or carriers like Shōkaku, Kako achieved vital participation in key wartime battles including Guam and Wake Island invasions and the clashes at Coral Sea and Savo Island marking her last victory before her abrupt demise. Kako gained distinction from her innovative early Japanese heavy cruiser design features and operational adaptability through periodic refits which enabled her to make significant contributions during Japan’s initial wartime victories. The article explores her technical specifications as well as her wartime activities demonstrating why she remained an essential component of the Imperial Navy's Pacific operations until her premature loss during August 1942.

Design and Characteristics: A Foundational Heavy Cruiser

Japan developed the Furutaka-class heavy cruisers which included Furutaka and Kako to modernize its navy while adhering to the Washington Naval Treaty of 1922 limitations. The construction of Kako began at Kawasaki’s Kobe shipyard on December 17, 1922 and she set sail as a commissioned vessel of the imperial fleet on July 20, 1926 after her launch on April 10, 1925. Kako was built as a sister ship to Furutaka while adopting a revolutionary design that served as the standard model for Japan's heavy cruiser fleet.

The Kako measured 185.17 meters (607 feet) in length with a beam measuring 16.55 meters (54 feet) and had a standard displacement of 7,950 tons that increased to 9,150 tons after refits. The original weapon system on Kako included six 20 cm (7.9-inch) /50 caliber guns arranged in individual turrets with three guns positioned at the front and three at the rear creating an innovative yet unconventional design for heavy cruisers of that era. From 1936 to 1939 Sasebo Naval Arsenal executed a major refit which substituted her original armament with three twin 20.3 cm (8-inch) turrets (two forward and one aft) to improve her firepower and meet the contemporary standards of heavy cruisers. After refitting she had four 12 cm anti-aircraft guns which received upgrades along with eight 61 cm torpedo tubes that launched Type 93 "Long Lance" torpedoes. The Type 93 "Long Lance" torpedoes equipped her with powerful long-range capabilities and destructive warheads which established her as a significant threat during surface battles.

Her propulsion setup incorporated four-shaft Parsons geared turbines paired with twelve Kampon boilers which generated 102,000 shaft horsepower to achieve a maximum speed of 34.5 knots but later refits decreased this performance because of extra weight. The vessel's ability to travel 6,000 nautical miles at 14 knots allowed Japan to conduct widespread operations across the Pacific. The ship possessed armor of 76 mm thickness for the belt, 35 mm for the deck and 51 mm for the turrets which provided adequate protection for a cruiser but left it exposed against more powerful weapons. The deeply submerged magazines were a standout feature because they reduced explosion risks and proved vital during combat situations.

Kako distinguished herself by serving as the foundation upon which subsequent designs were built. The vessel served alongside Furutaka as Japan's initial heavy cruiser and experimented with high-speed reconnaissance and extended-range artillery techniques which shaped future ship classes like Aoba, Myōkō, and Takao. By 1941 her modification program solved primary design problems related to stability and outdated weaponry turning her into an advanced naval vessel. The diminished size and armor of Kako compared to her successors did not overshadow her importance as a pioneer ship that enabled the progression of Japan’s cruiser fleet.

Early War Operations: Guam and Wake Island (December 1941)

Rear Admiral Aritomo Goto led Cruiser Division 6 (CruDiv 6) which included Kako alongside Aoba, Furutaka, and Kinugasa during Japan's initial military actions in December 1941. Kako began her combat operations by assisting Japanese forces during the invasions of Guam and Wake Island which were crucial locations in Japan's Pacific defense strategy. During the Guam assault on December 10, 1941, the ship Kako engaged the island defenses with its 8-inch guns to support the landing troops. Kako proved dependable during the amphibious operations by completing her standard duties which led to the quick surrender of the small U.S. garrison.

The assault on Wake Island constituted a more challenging test of military capability. U.S. Marines successfully thwarted the Japanese initial landing effort on December 11 which resulted in their withdrawal to reorganize. Kako arrived back at Wake Island on December 23 bringing increased firepower to target the island's defenses with Aoba and Furutaka. The attackers used shore bombardment to destroy defensive positions and break the resistance of the defenders which allowed them to land successfully. Kako’s ability to deliver precise effective gunfire showed her endurance which supported Japan’s early territorial expansion despite these victories being eclipsed by the Pearl Harbor attack.

Battle of the Coral Sea (May 1942): Resilience in a Carrier Clash

From May 4 to May 8 in 1942 Kako entered World War II's first carrier-dominated clash during the Battle of the Coral Sea. While serving with CruDiv 6 under Rear Admiral Goto she protected the invasion force heading for Port Moresby, New Guinea together with the light carrier Shōhō. American aircraft from USS Yorktown and Lexington executed a massive attack on May 7 that led to Shōhō being sunk by bombs and torpedoes. While Kako used her anti-aircraft guns in a critical effort to protect herself from enemy attacks she escaped without damage because her magazines were submerged which likely prevented serious destruction from near-misses or stray shots.

The retreating invasion convoy received escort from Kako and Aoba after Shōhō sank while Furutaka and Kinugasa protected the damaged carrier Shōkaku on its way back to Truk. Allied forces achieved strategic success in this battle which stopped Japan's southern advance and revealed the inadequate anti-aircraft protection of Kako representative of pre-war cruisers built for surface battles. Her ability to remain operational during the conflict displayed her built-in durability while showcasing the crew’s expertise in adapting to air-dominant warfare conditions. Throughout the battle she proved herself as a reliable escort vessel while the war's underlying dynamics continued to evolve.

The Battle of Savo Island in August 1942

The Battle of Savo Island on August 9, 1942 represented Kako's greatest achievement during Japan's crucial victory in the Guadalcanal campaign. Following the Allied landings on Guadalcanal and Tulagi from August 7 to 8 Vice Admiral Gunichi Mikawa gathered a task force at Rabaul to launch a counterattack. On August 7 Kako set sail with Chōkai (flagship), CruDiv 6 (Aoba, Furutaka, Kinugasa), light cruisers Tenryū and Yūbari and destroyer Yūnagi to perform a high-speed run through "The Slot." The plan: Japanese forces executed an attack on the Allied screening fleet during nighttime using their specialized night combat skills.

On August 8 during late hours floatplanes from Chōkai and Aoba identified Allied ships off Lunga Point and discovered they were operating in separated groups. At 1: At 1:38 AM on August 9 Kako attacked south of Savo Island and used her 8-inch guns along with Long Lance torpedoes to strike HMAS Canberra. Chōkai worked together with Kako to quickly sink Canberra through her devastating gunfire which set the Australian cruiser on fire. Kako proceeded north to attack USS Quincy with torpedoes and shells scoring critical hits while Aoba and Furutaka destroyed USS Astoria and Vincennes. The Allies suffered the loss of four heavy cruisers and more than 1,000 men while the Japanese forces experienced minimal casualties. Kako experienced minor damage from several shell hits that failed to cause major problems because her submerged magazines demonstrated their value again.

The remarkable Japanese success disturbed Allied plans at Guadalcanal which allowed Japan to strengthen their position on the island. Japan maintained tactical superiority during night battles thanks to better optics and training combined with the Long Lance which became evident through Kako’s deadly performance. The battle at Savo Island represented the high point of her wartime service and established her as an essential component of a highly effective cruiser force that accomplished one of the most lopsided victories at sea during the war.

Final Voyage and Loss: Sunk by Submarine (August 10, 1942)

Kako’s naval career terminated suddenly within hours of her successful battle at Savo Island. Lieutenant Commander John R. Moore commanded the USS S-44 submarine which positioned itself off New Ireland as Mikawa’s task force withdrew toward Rabaul on August 10, 1942. At 8: At 8:00 AM about 70 miles northeast of Kavieng S-44 detected Japanese ships moving in a single column at 10 knots. By viewing Kako's silhouette as a Kuma-class light cruiser Moore launched four Mark 10 torpedoes from a range of 700 yards.

At 8: The Japanese ship Kako sustained hits from three torpedoes to her starboard side near her No. 1 turret at 8:08 AM. 1 turret and forward boiler rooms. The detonations triggered her fuel and ammunition supplies which resulted in massive flooding. The ship rolled to starboard and sank stern-first at coordinates 02°28’S, 152°11’E after five minutes while claiming 68 of her 616 crewmen with 34 dead and 34 missing. The destroyer Aoba together with Furutaka and Kinugasa successfully pulled 548 survivors out of the water including Captain Yuji Takahashi without suffering any damage during the attack. The quick destruction of this ship following its previous success demonstrated how submarines posed an increasing danger to naval vessels during the Pacific War.

The sinking of Kako represented an uncommon achievement for American submarines during 1942 because torpedo malfunctions frequently reduced their combat success. Her wreck has yet to be found submerged beneath the ocean's depths yet her abrupt sinking demonstrated the unpredictable nature of naval combat that allows victory and disaster to emerge one after another.

Why Kako Was Special

Kako’s distinctiveness resulted from her innovative construction process combined with her flexible operational capabilities and significant service contributions. The Furutaka-class origins of Japan’s first heavy cruisers introduced testing innovations such as single-to-twin turrets and submerged magazines that influenced later designs. The Japanese cruiser Kako underwent modernization from 1936 to 1939 to receive Long Lance torpedoes and improved gunnery which converted her into a versatile threat that showed its efficiency at Savo Island by sinking Allied cruisers using both her torpedoes and guns. Although she demonstrated superior performance during nighttime combat operations which was a Japanese strength she suffered from her original design that made her defenseless against air attacks during the Coral Sea battle and vulnerable to submarine attacks which led to her sinking. Her crews elevated her effectiveness through their expertise from initial amphibious missions to her ultimate battle success. Kako served as a historical link between Japan’s naval plans during peacetime and their actions during the war and her short yet remarkable service demonstrated both the early power and the inherent vulnerability of the Imperial Navy.

Legacy: A Short but Influential Tenure

Navy List removed Kako on September 15, 1942, which affected CruDiv 6 as they proceeded with Aoba, Furutaka and Kinugasa until their destinies emerged (Furutaka sank at Cape Esperance two months later). The design principles of the Furutaka-class cruisers shaped the future development of Japanese cruisers which took form in the Aoba-class and subsequent classes. As an embodiment of Japan's early-war naval capabilities Kako's Savo Island victory served as the peak of her achievements before submarine warfare unexpectedly ended her service. The Imperial Navy's technical ingenuity and tactical brilliance along with unexpected reversals formed the backbone of her story which defined the Pacific Theater.

Final Thoughts: Kako’s Enduring Echo

Although Kako was neither the longest-serving nor the most advanced cruiser of World War II, her contributions left an indelible mark. She played a key role in developing Japan’s heavy cruiser strategy which evolved during the war and demonstrated remarkable performance during vital battles. Her persistence and firepower defined her journey from Guam to Savo Island until a submarine’s torpedoes halted her service. Her legacy represents her innovative spirit combined with her involvement in Japan's short-lived supremacy which exemplifies the transient nature of triumph during the Pacific War.