Battle of Rennell Island - Background

Background

On 7 August 1942, Allied forces (primarily U.S.) landed on Guadalcanal, Tulagi, and Florida Islands in the Solomon Islands. The landings on the islands were meant to deny their use by the Japanese as bases for threatening the supply routes between the U.S. and Australia, and to secure the islands as starting points for a campaign with the eventual goal of isolating the major Japanese base at Rabaul while also supporting the Allied New Guinea campaign. The landings initiated the six-month-long Guadalcanal campaign.

The last major attempt by the Japanese to drive Allied forces from Guadalcanal and Tulagi was defeated during the decisive Naval Battle of Guadalcanal in early November 1942. Thereafter, the Japanese Navy was only able to deliver subsistence supplies and a few replacement troops to Japanese Army forces on Guadalcanal. Because of the threat from Allied aircraft based at Henderson Field on Guadalcanal, plus nearby U.S. aircraft carriers, the Japanese delivered these supplies at night, usually by destroyer or submarine, in operations the Allies called the "Tokyo Express." However, these supplies and replacements were not enough to sustain Japanese troops on the island, who by 7 December 1942, were losing about 50 men each day from malnutrition, disease, and Allied ground or air attacks. On 12 December 1942, the Japanese Navy proposed that Guadalcanal be abandoned. Despite initial opposition from Army leaders, who still hoped that Guadalcanal could eventually be retaken from the Allies, on 31 December 1942 the Imperial General Headquarters, with approval from the Emperor, agreed to evacuate of all Japanese forces from the island and establish a new line of defense for the Solomons on New Georgia.

The evacuation was code-named Operation Ke (ケ号作戦), and was scheduled to begin on 14 January 1943. An important element in the plan was an air superiority campaign starting 28 January 1943, to inhibit Allied aircraft or warships from disrupting the final stage of the Ke operation, which was the actual evacuation of all Japanese troops from Guadalcanal.

Allied forces misinterpreted the Ke preparations as the beginning of another Japanese offensive to try to retake Guadalcanal. At the same time, Admiral William Halsey, Jr., the Allied theatre commander, was under pressure from his superiors to complete the replacement of the 2nd Marine Regiment, which had been in combat on Guadalcanal since August, with fresh Army troops. Halsey hoped to take advantage of what he believed was an impending Japanese offensive to draw Japanese naval forces into a battle, while at the same time delivering the replacement Army troops to Guadalcanal. On 29 January 1943, Halsey sent five task forces toward the southern Solomons area to cover the relief convoy and to engage any Japanese naval forces that came into range. These five task forces included two fleet carriers, two escort carriers, three battleships, 12 cruisers, and 25 destroyers.

In front of this array of task forces was Task Group 62.8, the troop convoy of four transports and four destroyers. Ahead of the troop convoy, between Rennell Island and Guadalcanal, was Task Force 18 (TF 18) Rear Admiral Robert C. Giffen, a close support group of heavy cruisers USS Wichita, Chicago, and Louisville, light cruisers Montpelier, Cleveland, and Columbia; escort carriers Chenango and Suwannee; and eight destroyers. Admiral Giffen commanded TF 18 from Wichita. A fleet carrier task force—centered on the carrier Enterprise—steamed about 250 mi (220 nmi; 400 km) behind TG 62.8 and TF 18. The other fleet carrier and battleship task forces were about 150 mi (130 nmi; 240 km) farther back. Admiral Giffen, with Wichita and the two escort carriers, had just arrived in the Pacific after participating in Operation Torch in the North African Campaign. Also, Chicago had just arrived back in the South Pacific, after completing repairs from damage suffered during the Battle of Savo Island almost six months before.