USS Helena was a light cruiser built for the United States Navy in the late 1930s, the ninth and final member of the class. The Brooklyns were the first modern light cruisers built by the US Navy under the limitations of the London Naval Treaty, and they were intended to counter the Japanese ; as such, they carried a battery of fifteen guns, the same gun armament carried by the Mogamis. Helena and her sister were built to a slightly modified design with a unit system of machinery and an improved anti-aircraft battery. Completed in 1939, Helena spent the first two years of her career in peacetime training that accelerated as tensions between the United States and Japan increased through 1941. She was torpedoed at the attack on Pearl Harbor in December 1941 and was repaired and modernized in early 1942.
After returning to service, Helena was assigned to the forces participating in the Guadalcanal campaign in the south Pacific. There, she took part in two major night battles with Japanese vessels in October and November 1942. The first, the Battle of Cape Esperance on the night of 11–12 October, resulted in a Japanese defeat, with Helenas rapid-fire 6-inch battery helping to sink a heavy cruiser and a destroyer. The second, the first night of the Naval Battle of Guadalcanal in the early hours of 13 November, saw a similar defeat imposed on the Japanese; again, Helenas fast shooting helped to overwhelm a Japanese task force that included two fast battleships, one of which was disabled by heavy American fire and sank the next day. Helena sank a destroyer and damaged several others in the action while emerging relatively unscathed. During her tour in the south Pacific, she also escorted convoys carrying supplies and reinforcements to the Marines fighting on Guadalcanal and bombarded Japanese positions on the island and elsewhere in the Solomons.
Following the American victory on Guadalcanal in early 1943, Allied forces began preparations to advance along the Solomon chain, first targeting New Georgia. Helena took part in a series of preparatory attacks on the island through mid-1943, culminating in an amphibious assault in the Kula Gulf on 5 July. The next night, while attempting to intercept a Japanese reinforcement squadron, Helena was torpedoed and sunk in the Battle of Kula Gulf. Most of her crew were picked up by a pair of destroyers and one group landed on New Georgia where they were evacuated the next day, but more than a hundred remained at sea for two days, ultimately making land on Japanese-occupied Vella Lavella. There, they were hidden from Japanese patrols by Solomon Islanders and a coastwatcher detachment before being evacuated on the night of 15–16 July. Helenas wreck was located in 2018 by Paul Allen.
Design
As the major naval powers negotiated the London Naval Treaty in 1930, which contained a provision limiting the construction of heavy cruisers armed with guns, United States naval designers came to the conclusion that with a displacement limited to , a better protected vessel could be built with an armament of guns. The designers also theorized that the much higher rate of fire of the smaller guns would allow a ship armed with twelve of the guns to overpower one armed with eight 8-inch guns. During the design process of the , which began immediately after the treaty was signed, the US Navy became aware that the next class of Japanese cruisers, the , would be armed with a main battery of fifteen 6-inch guns, prompting them to adopt the same number of guns for the Brooklyns. After building seven ships to the original design, additional changes were incorporated, particularly to the propulsion machinery and the secondary battery, resulting in the St. Louis sub-class, of which Helena was the second member.
Helena was long overall and had a beam of and a draft of . Her standard displacement amounted to and increased to at full load. The ship was powered by four Parsons steam turbines, each driving one propeller shaft, using steam provided by eight oil-fired Babcock & Wilcox boilers. Unlike the Brooklyns, the two St. Louis-class cruisers arranged their machinery in the unit system, alternating boiler and engine rooms. Rated at , the turbines were intended to give a top speed of . The ship had a cruising range of at a speed of . She carried four Curtiss SOC Seagull floatplanes for aerial reconnaissance, which were launched by a pair of aircraft catapults on her fantail. Her crew numbered 52 officers and 836 enlisted men.
The ship was armed with a main battery of fifteen 6 in /47 caliber Mark 16 guns in five 3-gun turrets on the centerline. Three were placed forward, two of which were placed in a superfiring pair facing forward, with the third being directly pointed aft; the other two turrets were placed aft of the superstructure in another superfiring pair. The secondary battery consisted of eight /38 caliber dual purpose guns mounted in twin turrets, with one turret on either side of the conning tower and the other pair on either side of the aft superstructure. As designed, the ship was equipped with an anti-aircraft (AA) battery of eight guns, but her anti-aircraft battery was revised during her career. The ship's belt armor consisted of 5 inches on a layer of of special treatment steel and her deck armor was thick. The main battery turrets were protected with faces and they were supported by barbettes 6 inches thick. Helenas conning tower had 5-inch sides.
Modifications The main prewar alterations to the ship revolved around her anti-aircraft battery: in 1941, the Navy decided that each member of the Brooklyn class was to be equipped with four quadruple anti-aircraft guns, but the guns were in short supply, and Helena was the only member of the class to have received any of her 1.1 in guns by November 1941. The guns Helena received were placed in the mounts for the .50-cal guns, which were transferred to wheeled carts that could be moved to different firing positions.
The ship was reconstructed in 1942 during repairs as a result of damage sustained in the Japanese attack on Pearl Harbor on 7 December 1941. SG surface search radar, SC air search radar, and FC and FD fire-control radar sets for her main and secondary batteries were installed, along with a new anti-aircraft battery of eight Oerlikon cannon and sixteen Bofors guns in quadruple mounts, along with a director for each Bofors mount. Her 1.1 in guns were removed to arm her sister ships and . The ship's armored conning tower had proved to inhibit good all-around visibility, so it was removed and an open bridge was erected in its place. In addition, the weight savings achieved by removing the tower helped to offset the increased weight from the larger anti-aircraft battery. The conning tower, along with those of several of the Brooklyn-class cruisers that were also rebuilt in 1942, were later installed on the reconstructed battleships that had been sunk at Pearl Harbor.
Service history
Construction and early career
The US Navy awarded the contract for Helena to the New York Navy Yard on 9 September 1935, and the keel for the new ship was laid down on 9 December 1936. Her completed hull was launched on 28 August 1938 and she was commissioned on 18 September 1939 with the hull number CL-50. World War II had broken out in Europe in September that year, but for the time being, the United States remained neutral. After entering service, the ship was occupied with sea trials and initial training, and she embarked on a major shakedown cruise abroad on 27 December, bound for South American waters. She stopped in Guantanamo Bay, an American-leased naval base in Cuba, on the way before arriving in Buenos Aires, Argentina, on 22 January 1940; from there, she continued on to Montevideo, Uruguay, on 29 January. While in the latter port, the crew inspected the wreck of the German heavy cruiser that had recently been scuttled after the Battle of the River Plate the previous month. Helena got underway again in mid-February to return to the United States, again passing through Guantanamo Bay on the way. After returning, she was dry-docked for repairs from 2 March to 14 July.
She took part in training exercises and sea trials over the next several months until September, when she was transferred to the Pacific Fleet. She passed through the Panama Canal toward the end of the month and arrived in San Pedro, California, on 3 October. From there, she continued on to Pearl Harbor, Hawaii to join the rest of the fleet, arriving there on 21 October. Over the course of the next year, the fleet spent its time conducting training exercises and shooting practice as tensions with Japan rose over the latter's war against China. During this period, from 14 July 1941 to 16 September, the ship was dry-docked for maintenance at the Mare Island Naval Shipyard in California; it was during this period that the ship received her 1.1-inch guns. Helena was slated to be dry-docked for another periodic maintenance in December 1941, and was moored in port with the minelayer tied alongside on 6 December, awaiting her turn in the shipyard. The ships happened to be moored in the berth normally reserved for the battleship , which was currently in the dry-dock. The ship's commander was at that time Captain Robert Henry English.
World War II Attack on Pearl Harbor
On the morning of 7 December, the Japanese launched their surprise attack on the American fleet with a first wave of forty Nakajima B5N torpedo bombers, fifty-one Aichi D3A dive bombers, and fifty B5N high-level bombers, escorted by forty-three Mitsubishi A6M Zero fighters. The Japanese expected Pennsylvania to be in her normal berth. Three minutes into the attack, which had begun at 07:55, a B5N torpedo bomber dropped its torpedo at what its pilot expected to be the battleship. The torpedo passed underneath Oglala and exploded against Helenas hull on the starboard side, nearly amidships. The blast tore a hole in the hull that flooded the starboard engine and boiler rooms and severed wiring for the main and secondary guns. The ship's crew raced to their battle stations and two minutes after the torpedo hit, the backup forward diesel generator had been turned on, restoring power to the guns. Oglala was less fortunate than Helena, as the blast effect loosened hull plates on the minelayer and caused her to capsize.
The first pilot had mistaken the superimposed silhouettes of the two ships, backlit by the sun, to be Pennsylvania. The second torpedo bomber in the wave closed to within of Helena and Oglala when the pilot realized the first pilot's mistake, breaking off his attack run and causing two more pilots to do the same. Four other pilots pressed their attacks, but all of their torpedoes missed; by this time, the ship's anti-aircraft guns were beginning to engage the Japanese attackers, forcing one of the bombers to drop their torpedo before they reached an ideal launch position. One of the torpedoes went wide and hit a transformer station, while the other three ran deep and embedded themselves in the harbor floor. During these attacks, one of the fighters strafed the ship, causing little damage.
At the same time that the first wave had begun their attacks, the Japanese aircraft carriers launched a second wave consisting of eighty-one dive bombers, fifty-four high-level bombers, and thirty-six fighters. As Helenas anti-aircraft guns got into action, they helped to fend off further attacks from the second strike wave while other men worked to control flooding by closing the many watertight hatches in the ship. The heavy anti-aircraft fire was credited with disrupting the aim of several Japanese bombers, which failed to hit the vessel with an estimated four near misses. Of these, one struck the pier while the other three landed in the water on her starboard side.