Through the interwar years and into World War II, the Japanese Mandate island of Truk in the Central Caroline Islands had developed a forbidding reputation as an impregnable stronghold, the “Gibraltar of the Pacific,” which was somewhat exaggerated. The Japanese had been very secretive about what they were doing there after having acquired it from the Germans during World War I and kept it under a mandate from the League of Nations. The Japanese had in fact heavily fortified the island. Its strategic location made it the preferred base of the carriers and battleships of the Japanese Combined Fleet in the first two years of the war, and many an intelligence reports for impending battles began with the Japanese marshaling forces at Truk for their next offensive operation. Air and naval forces at Truk could quickly be shifted from there to counter U.S. actions from New Guinea to the Solomons to the Gilberts, Marshalls, Wake Island, and the Marianas. What the Japanese didn’t anticipate was three simultaneous U.S. advances in New Guinea, the Solomons and the Marshalls that resulted in their forces being severely jerked around, wasting a lot of scarce fuel and often being in the wrong place at the wrong time. U.S. submarines, once fixes had been implemented for faulty torpedoes, increasingly found the waters around Truk to be favorable hunting grounds.
The pre-war U.S. concept that carriers should be used in a “hit and run” mode was still deeply ingrained in the U.S. Navy even into 1944. Staying put and duking it out with a large land-based air force was still considered by many to be a really bad idea, not conducive to carrier longevity. However, by early 1944, the Commander of the U.S. Pacific Fleet, Admiral Chester Nimitz, had reached the conclusion that it was time to pierce the aura of Truk and that he had sufficient carrier forces to conduct a major multi-day attack against the Japanese stronghold. With an aggressive carrier task force commander like Rear Admiral Marc “Pete” Mitscher, Nimitz had the right man for the job. As it turned out, Nimitz’s counterpart, Admiral Mineichi Koga, commander in chief of the Japanese Combined Fleet, made the same assessment at about the same time and decided it was time to get the Combined Fleet out of Truk.
The first carrier strike on Truk, designated Operation Hailstone, was scheduled for 17 to 18 February 1944, and timed to coincide with the U.S. landings on Eniwetok (Operation Catchpole) in the western Marshall Islands (see also H-Gram 026-2). Truk (now known as Chuuk, capital of the Federated States of Micronesia) is roughly equidistant from Eniwetok (669 nautical miles) and Rabaul (696 nautical miles) and ships and aircraft operating from Truk represented a significant threat to the Eniwetok operation. The Combined Fleet had deployed to Eniwetok in reaction to the U.S. carrier strikes on Wake Island in October 1943 (and had burned up a huge amount of scarce fuel doing so). Normally, however, due to fuel scarcity and U.S. submarines, the bulk of the Combined Fleet (including Admiral Koga’s flagship, the super-battleship Musashi) remained inside the Truk Lagoon. The lagoon was big enough that naval gunfire from outside the reef could not reach ships anchored inside the lagoon. In the middle of the lagoon, the island of Truk was fairly large, mountainous, and heavily wooded. It was defended by about 7,500 deeply entrenched Japanese troops, and another 3-4,000 Japanese sailors ashore in support functions at air strips, seaplane bases, and repair and logistics facilities. In addition to the considerable anti-aircraft fire that could be put up from the ships in the lagoon, the island was defended by over 40 major-caliber anti-aircraft guns, although the fire control radar intended for those guns had gone down on a transport ship sunk by a U.S. submarine. Of greatest concern to any attacking force was the 300 to 400 Japanese aircraft based at five airfields on the island at any given time. (The number fluctuated considerably as aircraft were shifted around).
In preparation for the strike, two U.S. Marine Corps B-24 Liberator bombers flying from Bougainville in the Solomons conducted a high-altitude, long-range photo-reconnaissance mission (the first) over Truk on 4 February 1944. Although the imagery was incomplete due to cloud cover, plenty of lucrative targets were identified, including one battleship, two aircraft carriers, and five or six heavy cruisers. The Japanese, however, detected the flight and wasted no time understanding its import. Admiral Koga gave the order to clear out. Within days, the majority of the Combined Fleet had shifted to the west to Palau, and the Musashi went all the way back to Japan.
The unlucky Japanese light cruiser Agano was delayed departing Truk due to previous damage. Agano had been hit by a torpedo from a U.S. Avenger during the strike on Rabaul on 11 Nov 1943 (see H-Gram 024) and while being towed to Truk for repairs was hit by a torpedo from Scamp (SS-277). (Agano’s escorts fought off an attack by Albacore, SS-218, the same day). Finally leaving Truk for Japan on 16 February, Agano was hit by two of four torpedoes from submarine Skate (SS-305) but remained afloat until the morning of the following day, during which the Japanese destroyer Oite rescued 523 of Agano’s 726-man crew. However, Oite was torpedoed and sunk during the U.S. airstrikes on Truk on 17 February, during which all but 22 of Oite’s crew and all of the survivors of Agano were lost. (Of note, Skate had put a torpedo into the super-battleship Yamato off Truk on Christmas Day 1943, sending the seriously damaged Yamato back to Japan for repairs.) By 17 February the only Japanese ships left in Truk were two light cruisers, eight destroyers, and about 50 other auxiliaries, cargo ships, merchant ships, and patrol and service craft.
The commander of the U.S. Fifth Fleet, Vice Admiral Raymond A. Spruance, personally assumed command of Task Force 50, shifting his flag from the heavy cruiser Indianapolis to the new battleship New Jersey. Spruance was selected for his fourth star just before the raid on Truk and was actually promoted just afterwards. The Fast Carrier Force (TF 58) was under the command of Rear Admiral Marc A. “Pete” Mitscher, who had relieved Rear Admiral Charles A. Pownall after the Gilbert Islands operations, embarked on Yorktown. The U.S. Force consisted of four new Essex-class carriers––Yorktown, Essex Intrepid, and Bunker Hill––plus Enterprise and four light carriers Belleau Wood, Cabot, Monterey, and Cowpens, along with more than 500 aircraft. In addition, six new fast battleships, ten cruisers and 28 destroyers rounded out the force. TG 58.4, under the command of Rear Admiral Samuel P. Ginder, with Saratoga, Princeton, Langley, and escorts was detached from TF 58 to cover the landings at Eniwetok (Operation Catchpole), where they commenced strikes on 16 February 1944.
On 12/13 February 1944, three fast carrier task groups departed Majuro Atoll (recently captured in the Marshall Islands) and topped off from five tankers before making a high-speed run toward Truk. These task groups included TG58.1, Commander Carrier Group 1, Rear Admiral John W. Reeves consisting of Enterprise, Yorktown, Belleau Wood, three light cruisers, and one anti-aircraft cruiser; TG 58.2, Commander Carrier Group 2, Rear Admiral Alfred .E. Montgomery, consisting of Essex, Intrepid, Cabot, three heavy cruisers, and one anti-aircraft cruiser; and TG 58.3, Commander Carrier Group 3, Rear Admiral Frederick C. Sherman, consisting of Bunker Hill, Monterey (future U.S. President Lieutenant Gerald Ford in crew), Cowpens, and battleships North Carolina (BB-55), Iowa (BB-61), New Jersey (BB-62, Vice Admiral Spruance embarked), Massachusetts (BB-59), South Dakota (BB-57), Alabama (BB-60), and two heavy cruisers.
TF 58 reached the launch point 90 nautical miles northeast of Truk on 17 February and commenced launching an hour and a half before dawn. The first strike was a 72-plane fighter sweep from the five U.S. fleet carriers, which caught the Japanese by surprise, the Japanese having just stood down after two weeks of high alert following the B-24 reconnaissance mission. The advance fighter sweep was a new technique devised by Rear Admiral Mitscher. About 45 Japanese fighters scrambled into the air only minutes before the U.S. fighters arrived overhead, and about another 45 were able to get airborne during the course of the fighter sweep. Over 30 Japanese fighters were shot down and 40 more destroyed on the ground by strafing––all for a loss of four U.S. fighters. The fighter sweep was followed immediately by 18 Avengers dropping incendiary and cluster fragmentation bombs (another innovation) on Japanese dispersal areas. By the afternoon, no Japanese fighters were challenging the U.S. air raid. Of about 365 Japanese aircraft at Truk when the raid began, only about 100 survived, the rest having been shot down or destroyed on the ground.
Commencing at 0443, the five light carriers began a staggered launch, resulting in a near continuous stream of strike aircraft (another innovation) arriving over Truk during the morning. During the course of the day there were 30 distinct U.S. airstrikes, delivering 369 1,000-pound bombs, 498 500-pound bombs, and 70 torpedoes. Many of the attacks went against Japanese shipping in the lagoon. The commander of Bombing Ten (VB-10), future Rear Admiral James D. Ramage, sank the merchant tanker Hoyo Maru. An Avenger from Intrepid’s Torpedo Squadron 6 (VT-6), flown by Lieutenant James E. Bridges, hit the ammunition ship Aikoku Maru, which blew up with such force it obliterated the ship and, unfortunately, Bridges’ aircraft and aircrew, too; all three were lost. The Japanese destroyer Fumizuki suffered a near miss, but the crew could not control the flooding and she sank the next day. The destroyer Tachikaze had run aground on 4 February and was still immobilized when she was hit by a torpedo and sunk. The destroyer Oite was hit and sunk as related above. The destroyer Shigure, survivor of numerous battles (and sole survivor of two) survived yet another, although she suffered serious damage with a bomb hit in her No. 2 turret, killing 21 and wounding 45.
Some Japanese ships tried to escape and were sunk by waiting submarines, while others were either blocked in the lagoon by U.S. air attack or set upon by U.S. surface ships as they attempted to flee. The light cruiser Naka was caught trying to flee 35 nautical miles west of Truk by several waves of Helldivers and Avengers from Bunker Hill and Cowpens and was hit by a bomb and a torpedo, breaking in two and sinking with the loss of 240 crewmen (210 were rescued).
As U.S. Navy aircraft were slaughtering Japanese auxiliaries and merchant ships inside the lagoon, Vice Admiral Spruance led an “around-the-atoll cruise” (TG 50.9) on 17 February to catch leakers, bombarding shore installations as it went. Consisting of the new battleships New Jersey and Iowa, the heavy cruisers Minneapolis (CA-36) and New Orleans (CA-32) (all survivors of the Tassafaronga debacle in November 1942), and four destroyers (covered by combat air patrol from the light carrier Cowpens), TG 50.9 caught the light cruiser Katori. That ship, the auxiliary cruiser Akagi Maru, two destroyers Maikaze and Nowaki), and a minesweeping trawler Shonan Maru No. 15 had left Truk before the attack but had not gotten far enough away. Aircraft from several carriers had already pounded the small group. The Akagi Maru was hit by three bombs, causing several large explosions, and she was abandoned. Despite her own damage, Katori took on a number of survivors from Akagi Maru, although all would be lost when Katori itself went down. All told, 788 crewmen and 512 passengers on Akagi Maru were lost.
Although aircraft could have finished off Katori, which had already been hit by one torpedo and as many as seven bombs, Spruance wanted a surface engagement, so Mitscher waved off further air attacks on the damaged light cruiser. Aviators, and some of Spruance’s own staff, viewed Spruance’s decision as reckless. (I can only imagine that from the bridge of an Iowa-class battleship, Spruance felt pretty invincible.) Spruance directed Minneapolis, New Orleans, and two destroyers to engage the Katori. The destroyers Bradford (DD-545) and Burns (DD-588) fired several salvos of torpedoes at Katori, all of which missed. Katori responded with a torpedo salvo of her own, which also missed. Eventually Iowa fired 46 16-inch and 124 5-inch shells at the Katori hitting her multiple times, yet she continued to fight valiantly until the end, her guns still firing as she rolled over and sank. Although there were survivors of Katori in the water, none were rescued by the U.S. or the Japanese. In the end, there were no survivors from her crew of about 300 nor were there any from those previously rescued from Akagi Maru.
As Katori met her end, the destroyer Maikaze valiantly stood by the Katori and got off a salvo of torpedoes at the Iowa and New Jersey that might have hit but for a timely warning from U.S. aircraft overhead. The New Jersey maneuvered and the torpedoes passed just ahead. VADM Spruance remarked, “That would have been embarrassing” (had the torpedoes hit). Like Katori, Maikaze absorbed tremendous punishment but kept firing until she was finally finished off by the U.S. cruisers, going down with all-hands. In the meantime, the little trawler Shonan Maru No. 15 put up a valiant fight against the destroyer Burns. The Japanese trawler continued to fire even as she went under, also with all hands.
The Nowaki, on the other hand, made good her escape and was able to open considerable distance during the melee with Katori and Maikaze. New Jersey and Iowa pursued, and opened fire at the extreme range of 34,000 to 39,000 yards, straddling Nowaki several times and hitting her with splinters. The last salvo, at a range of 22 miles, is believed to be the longest-range gun shot at an enemy ship. (Nowaki would be sunk by torpedoes from the destroyer Owen in the Philippines on 26 October 1944.) The surface engagement ended when Burns was directed to dispatch a Japanese submarine chaser, the CH-24, which opened fire on Burns with her single 3-inch gun. Despite her valiant but futile gesture, CH-24 didn’t last long. Burns attempted to rescue about 60 Japanese survivors in the water, who vigorously resisted being rescued. Whaleboats from Burns were able to haul about six unwilling Japanese out of the water. With the remainder refusing rescue, but close enough to Truk that they might be rescued by the Japanese, the Burns dropped three depth charges onto the survivors, ensuring they would not live to fight another day.
Like the little CH-24, the counter-attack by the Japanese was valiant but feeble. At 1900, six or seven Kate torpedo bombers, retrofitted with radar, attacked the U.S. carrier force. Intense U.S. anti-aircraft fire kept most of the Kates away. One made a concerted attack, and an attempt to intercept it with a night fighter guided by a radar-equipped Avenger failed. At 2211, the Kate put a torpedo into the starboard quarter of the Intrepid, jamming her rudder, killing 11 and wounding 17, and forcing her to withdraw for several months of repairs.
Between midnight and dawn, Mitscher pulled another innovation out of the hat, launching the first night carrier bombing attack against shipping in U.S. carrier history. Twelve specially-equipped TBF-1C Avengers from Enterprise’s VT-10, carrying four 500-pound bombs each, conducted a night strike on remaining shipping in Truk Lagoon. In 25 runs, the Avengers scored 13 direct hits and 7 near misses (plus two direct hits on islets mistaken for ships) which actually accounted for about one third of the hits on ships achieved by the entire force during two days of strikes. Despite the November 1943 loss of Navy ace and Medal of Honor awardee Butch O’Hare in the first attempt at night intercepts by U.S. carrier fighters, the Enterprise continued to be the leader in night battle tactics development; after the Battle of the Philippine Sea in June 1944, Enterprise would be designated as the night strike carrier, tasked with developing and executing tactics for night fighting.
Violating the “and run” part of long-standing “hit and run” carrier doctrine, at dawn on 18 February, aircraft from Enterprise, Yorktown, Essex, and Bunker Hill attacked Truk again. Meeting no air opposition, the carrier planes bombed and strafed airfields, hangars, storage tanks (with 17,000 tons of fuel that went up in smoke), and ammo dumps with great effect. By the time the U.S. strikes ended, U.S. carriers had flown 1,250 combat sorties, dropping 400 tons of bombs and torpedoes on shipping and 94 tons on land targets. The Japanese had lost between 250 and 275 aircraft and 75 percent of their supplies on Truk. Japanese warship losses included two light cruisers, four destroyers, two submarine chasers, one auxiliary minesweeper, and a motor torpedo boat. Additional ships sunk included three auxiliary cruisers, 16 Navy transport ships, three Army transport ships, one freighter, two submarine tenders, and––probably most valuable––five tankers. Damaged ships included two destroyers, two submarines, a repair ship, a seaplane tender, a submarine chaser, and a target ship. One additional cargo ship was also damaged.
The cost to the United States of Operation Hailstone was one fleet carrier damaged, one battleship slightly damaged, 25 aircraft lost, and 40 dead. A number of U.S. aircrew were rescued by submarine. In one case, a Kingfisher float plane launched from the heavy cruiser Baltimore, flown by Lieutenant Junior Grade D. F. Baxter, flew right into the lagoon and rescued an Essex Hellcat pilot that had been shot down on the morning fighter sweep of 18 February, while nine other Hellcats held a Japanese destroyer at bay. The submarine Searaven (SS-196) also rescued the entire three-man crew of a Yorktown Avenger.
The Japanese never again used Truk as a major fleet anchorage, and the devastating carrier attack was a huge blow to Japanese morale (and a big boost to U.S. carrier pilots’ morale and confidence). At the time of the attack, Allied commanders had not yet decided whether Truk would need to be invaded or could be bypassed. On 12 Mar 1944, Admiral Nimitz made the decision to bypass it.
Of the Marshalls campaign and the raid on Truk, Navy historian and Rear Admiral Samuel Eliot Morison would write, “Courage and determination the Navy had shown from the first, but in the Marshalls it demonstrated mastery of the art of amphibious warfare; of combining air, surface, submarine and ground forces to project fighting power irresistibly across the seas. The strike on Truk demonstrated a virtual revolution in naval warfare; the aircraft carrier emerged as the capital ship of the future, with unlimited potentialities.”
(Sources for this section include Rear Admiral Samuel Eliot Morison’s History of U.S. Naval Operations in World War II, vol. VII, Aleutians, Gilberts and Marshalls. Also: The Admirals: Nimitz, Halsey, Leahy and King: The Five-Star Admirals Who Won the War at Sea, by Walter R. Borneman, 2012; The Fleet at Flood Tide: America at Total War in the Pacific, by James Hornfischer, 2016. Additional sources include Naval History and Heritage Command Dictionary of American Fighting Ships [DANFS], for U.S. ship histories and combinedfleet.com for Japanese ship histories.)
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