Red Sun Setting, page 3
The day after receiving the JCS directive Admiral Nimitz sent a secret dispatch to his major subordinates. In it he ordered that planning for the Truk assault be halted and all effort be given to preparing for the Marianas. A week later a CinCPOA Forager Joint Staff Study was issued. In it was outlined the purpose of the operation. Specifically, it was to “establish bases from which to attack the enemy’s sea-air communications, support operations for the neutralization of bypassed Truk, initiate B-29 bombing of the Japanese home islands, and support further offensives against the Palaus, Philippines, Formosa and China.” Generally, it was to “maintain unremitting military pressure against Japan” and to “extend our control over the Western Pacific.”49
A new campaign plan, Granite II, was issued on 3 June. There was a marked difference between this and the original Granite plan, particularly in the timing of operations. The tentative schedule was now:
Operation
Tentative Target Date
Capture of Saipan, Guam, and Tinian
15 June 1944
Capture of Palau
8 September 1944
Occupation of Mindanao
15 November 1944
Capture of Southern Formosa and Amoy
or
Capture of Luzon
15 February 194550
When this plan was issued the invasion of the Marianas was less than two weeks away. The forces on the long winding road to Tokyo were approaching their next stop—the Marianas. Despite the roadblocks, despite the side roads and detours, the Marianas had become vital (inevitably so, given King’s insistence) to the conduct of the war in the Pacific.
chapter 2
Operation A-GO
WITH ADMIRAL ISOROKU YAMAMOTO’S DEATH in April 1943 a successor to the command of Combined Fleet had to be chosen, and the man picked was Admiral Mineichi Koga. While not of the same caliber as Yamamoto, Koga was highly qualified. Though his policies varied little from his predecessor, he was thought to be more conservative, with a cooler temperament.
One of the first operational plans Koga became concerned with was the Z plan. This was prepared in May 1943 and envisioned the use of the Japanese Navy to counter U.S. naval forces threatening the Japanese outer defense perimeter. (This line extended from the Aleutians down through Wake, the Marshall and Gilbert Islands, Nauru, Ocean, the Bismarck Archipelago, New Guinea, then westward past Java and Sumatra to Burma.)1 When their position in the Solomons disintegrated, the Japanese modified the Z Plan by eliminating the Gilberts–Marshalls and the Bismarcks as vital areas to be defended by the Navy. They then based their possible actions on the defense of an inner perimeter (including the Marianas, Palau, western New Guinea, and the Dutch Indies).2
Koga survived Yamamoto slightly less than a year. While retreating from Palau just before TF 58 attacked that anchorage at the end of March 1944, his plane disappeared en route to the Philippines. As great as Koga’s loss was, it was compounded by the loss and subsequent capture of a top secret Z Plan copy and its coding system. Koga’s chief of staff, Admiral Shigeru Fukudome, left Palau separately from Koga on 30 March. In his possession was the Z Plan copy. The two planes ran into a storm (which probably killed Koga) and Fukudome’s crashed just off Cebu. Fukudome was captured by Filipino guerrillas and his precious documents seized. Although the guerrillas soon were forced to give up their prisoner, the documents found their way to U.S. forces via submarine. They were a priceless find. After recovering Fukudome, the Japanese realized that their operations plan was compromised and a new one needed.
Admiral Shigetaro Shimada, Chief of the Naval Staff in Tokyo, immediately began preparing a new plan. Based on a preliminary draft by Admiral Koga, the plan was known as Operation A-GO, and it was under this directive that the Japanese fought the Battle of the Philippine Sea. (Literally, A-GO means the “A” Operation, but for this book a redundant form, Operation A-GO, will sometimes be used.)
Before A-GO went into effect, however, another important change took place in the Japanese Navy. Though the Navy had been a world leader in carrier development, many of its top commanders were battleship or “Big Gun” adherents. However, by early 1944 these commanders had finally accepted the fact that the carrier was the new capital ship. With this realization came a change in fleet organization.3
On 1 March 1944 the First Mobile Fleet (or as more commonly known, the Mobile Fleet) was organized under the command of Vice Admiral Jisaburo Ozawa. Joining the carriers in the Mobile Fleet instead of remaining in separate fleets were most of the first-string battleships, cruisers, and destroyers in the Navy. The Japanese had finally accepted the concept (adopted by the U.S. Navy almost two years earlier) of entrusting a task force including battleships and cruisers to the tactical command of a carrier admiral.
A month passed after Koga’s death before a new commander of Combined Fleet was named. He was Admiral Soemu Toyoda, a sarcastic, but brilliant and aggressive officer. He raised his flag on the light cruiser Oyodo, anchored in Tokyo Bay, on 3 May. Toyodo received the A-GO plan from Shimada the same day and immediately issued the general order for Operation A-GO.
As with so many of the previous plans, A-GO envisioned a “decisive” fleet action. This time the “decisive battle areas” were deemed to be the Palaus and the Western Carolines. It was in these areas that the Mobile Fleet, along with heavy land-based air, would be concentrated. If by chance the U.S. fleet attacked the Marianas, its ships would be pounced upon by land-based planes in that area. Then the enemy would be lured into the areas where the Mobile Fleet could defeat him. There “a decisive battle with full strength (would) be opened at a favorable opportunity. The enemy task force (would) be attacked and destroyed for the most part in a day assault.”4
Vice Admiral Jisaburo Ozawa, the redoubtable commander of the Mobile Fleet during the Battle of the Philippine Sea. (U.S. Navy)
The framers of the A-GO plan were nothing if not optimistic: “As soon as the enemy is damaged, he will be pursued. The strongest air force that can be used will be immediately deployed at land bases and ceaseless air attacks will be waged day and night. . . . Complete success is anticipated.”5
In conjunction with Operation A-GO, Admiral Shimada came up with a plan to use planes from the home islands. This plan was known as TO-GO. The land-based naval planes of First Air Fleet or Base Air Force were to have an important role in this plan. Prior to the “decisive” battle these planes were to destroy at least one-third of the enemy carriers. Deployment of these planes started 23 May and was completed by early June. However, because of the proposed battle area, the majority of the aircraft were stationed in the Carolines–Philippines area. Only 172 aircraft were based at the point of attack, the Marianas.6 However, a number of planes from the Hachiman Air Unit in Japan could be sent into the Bonins (including Iwo Jima) and thence south to the Marianas if danger developed there. Clearly, the Japanese placed a great deal of faith in their land-based planes for the coming action. However, though TO-GO was good theory, it failed miserably in practice.
The Japanese had every reason to hope, even to pray, that the “decisive” battle would be fought in the Palaus—Western Carolines area. They were running out of fuel for the Navy! Even though an enemy attack on the Marianas was not out of the question, there was not enough fuel for the Mobile Fleet to steam there and fight a battle. American submarines had recently been making Japanese tankers special targets and they had been doing very well at it. In the first five months of 1944 the U.S. subs had sent twenty-one tankers to the bottom. The oil Japan and her Navy so desperately needed was not reaching the Home Islands.
Oil was available to the Navy from the Borneo oilfields of Tarakan and Balikpapan—oil pure enough to be delivered unprocessed directly into the ships’ fuel bunkers. But this unprocessed oil was also highly volatile and therefore dangerous to use. Also, it contained some impurities that tended to foul boilers. For these reasons it was ordered that this oil be processed by refineries in Sumatra and Borneo before being issued to the Mobile Fleet.
Following the distribution of the A-GO plan, senior staff officers from all the concerned commands met on Saipan between 8 and 11 May. During discussions of the plan the disturbing question of a possible American attack on the Marianas came up. At first the high command ruled out the possible sortie of the Mobile Fleet to the Marianas because of the fuel situation. The nagging problem remained, however. Toyoda, therefore, decided to take the admittedly daring step of authorizing the use of unprocessed Borneo oil for the Mobile Fleet units. With this fuel the Fleet would now be able to give battle off the Marianas. But the use of this volatile fuel would have a serious effect on the Mobile Fleet during the Battle of the Philippine Sea. To be nearer the supply of oil the Mobile Fleet began congregating at Tawi Tawi in mid-May. This fine anchorage is on the westernmost island of the Sulu Archipelago, only 180 miles from Tarakan.
Ozawa’s own Carrier Division (CarDiv) 1, consisting of the fine new 29,300-ton armored-deck carrier Taiho, plus the veteran heavy carriers Shokaku and Zuikaku, sailed from Lingga Roads south of Singapore, where it had been training for over two months, on 11 and 12 May. (For the coming battle Ozawa would wear two hats: one as commander of the Mobile Fleet; the other as CarDiv 1 commander.) On the 11th CarDiv 2, comprising the 24,140-ton sister ships Junyo and Hiyo and the converted 13,360-ton Ryuho, and CarDiv 3, with the 11,262-ton Zuiho and the 11,190-ton former seaplane tenders Chitose and Chiyoda, left the Inland Sea. After fueling their destroyers at Okinawa, these two divisions proceeded to Tawi Tawi, arriving on the 16th.
The air units assigned to each carrier division were the 601st, 652nd, and 653rd Naval Air Groups. These were largely green organizations. The 601st had been shattered at Rabaul in November 1943 and, newly reformed, did not join CarDiv 1 until February 1944. The 652nd had also been smashed at Rabaul in January and was not reformed until March. Carrier Division 3’s 653rd Naval Air Group was an entirely new outfit, having been formed about the first of February.
These air groups were sorely lacking in training time, ranging between only two to six months. Training at Tawi Tawi for these inexperienced groups was hampered considerably by the lack of a suitable airfield there. Flight training had to be cancelled in May, and the air groups would consequently not be ready for the impending battle. An important factor in these units’ training was that most of the crews would be flying newer and “hotter” aircraft—D4Y Judy dive bombers, B6N Jill torpedo planes, and the improved Zeke 52 fighters. So, with its pilots lacking time in their new aircraft, combat experience, night qualifications, and coordination between (and within) their groups, the outlook for the air arm of the Mobile Fleet was not a happy one. And besides the lack of an airfield, there was another big disadvantage to Tawi Tawi—one the Japanese were to learn the hard way. It was easily accessible to submarines.
The movement of the Mobile Fleet to Tawi Tawi did not go unnoticed by the Americans. The capture of the Z Plan had already given intelligence officers of Vice Admiral Thomas C. Kinkaid’s Seventh Fleet an inkling of coming events. On 11 May they commented, “A powerful striking force is believed to be gathering in the northern Celebes Sea, using anchorages in the vicinity of Tawi Tawi. It is believed that the assembly of this force will be completed by 15 May.”7
Although close to the facts, this was still just speculation on the Americans’ part. More hard evidence was needed. This evidence was beginning to trickle in, however. The submarine Lapon, patrolling off the west coast of Borneo, spotted at least three carriers, five cruisers, and a number of destroyers steaming by about six miles away on the morning of 13 May. The sub couldn’t get into an attack position but was able to send a contact report that evening.
Movements of the Mobile Fleet, May to 16 June 1944.
Following the Lapon report, Commander Submarines Southwest Pacific (or in Navy lingo, ComSubSoWesPac) ordered the Bonefish, skippered by Commander Thomas W. Hogan, to take a look at Tawi Tawi. Hogan brought his sub south from the Sulu Sea, where he had been patrolling, at full speed. Early on the morning of the 14th Hogan spotted a convoy of three tankers and three destroyers. It appeared they were heading for Tawi Tawi. Creeping up on the convoy, Hogan fired five torpedoes from 1,300 yards. Two of them hit—one in a tanker and one in the 2,090-ton destroyer Inazuma, which went down. The remaining destroyers pounded the Bonefish for a time, but the sub was able to slip away.
A little before noon the next day, while the Bonefish was lying submerged some forty miles northwest of Tawi Tawi, a large group of ships passed by, headed for the anchorage. Possibly the force that the Lapon had seen, it contained one large carrier, two battleships, many cruisers, and about ten destroyers. Hogan got off a contact report that night.
Hogan was not finished looking over Tawi Tawi. The next day he moved in closer, raised his periscope, and saw a sight mouthwatering for a submariner: “Six carriers, four or five battleships, eight heavy cruisers, light cruisers, and many destroyers.”8 But the Bonefish had only one torpedo left, so this would remain but a tantalizing target. Hogan moved south during the night and sent out another report. Two enemy “tin cans” must have been listening, for they immediately came out after the Bonefish. Hogan took his sub deep, however, and was able to evade his attackers.
To help the Bonefish keep Tawi Tawi under surveillance, two more subs (the Puffer and Bluefish) were ordered into the area. While approaching Tawi Tawi on the morning of the 22nd, the Puffer, under the command of Lieutenant Commander Frank G. Selby, found a group of vessels on training maneuvers. Two flattops and three destroyers could be seen as Selby crept in. Carefully setting up on one carrier, Selby was startled when the other carrier swept by, only 500 yards astern. Breaking off the attack, Selby brought the Puffer around for another approach. Finally, at a range of 1,400 yards he fired a spread of six torpedoes. Although one, and possibly two, torpedoes hit the Chitose, they apparently were duds and did no damage to the carrier. All that Selby and the Puffer got for their effort was a good working-over by the escorts.
The Puffer made up for the attack on the Chitose by sinking two ships on 5 June. The 4,465-ton Takasaki and 7,951-ton Ashizuri were valuable ships designed to operate with the carrier forces, furnishing the flattops with supplies while at sea. They even provided aircrew quarters and aircraft repair facilities.
Another submarine, the Cabrilla, visited the Tawi Tawi area a few days after the Puffer’s action with the Chitose. During an attack on a group of three carriers and three battleships maneuvering outside the anchorage, the sub’s skipper apparently took too long a look at his targets. The sub was suddenly depth-charged by a plane, and was violently shaken up. The enemy vessels were able to retire safely to Tawi Tawi.
U.S. submarine operations in this area had been reasonably successful so far and were far from being finished. One important result of the subs’ attentions was that the Mobile Fleet’s maneuvers were curtailed considerably in the month before it sailed for battle. On the other hand, Japanese submarine operations during A-GO can hardly be considered successful. At least twenty-five enemy subs were used for scouting and supply purposes in the operation; seventeen were sunk. No useful information was obtained and not one American ship was even damaged.
The Japanese began their submarine operations on 14 May, the day the Bonefish moved into the Tawi Tawi area. Still convinced that an American attack would be aimed at the Palaus, the Japanese set up a scouting line (the NA line) of seven submarines starting at a point about 120 miles northeast of the Admiralties. Other subs were stationed in the Marshalls and Marianas area. The NA-line submarines were decimated by U.S. hunter-killer groups (particularly that of the England). Other Japanese submarines suffered equally poor results.
The I-176 was on a supply mission to Bougainville when it was pounced on by the destroyers Haggard, Franks, Hailey, and Johnston. After holding the sub down for about twenty hours, the destroyers began taking turns on attack runs. Following five separate attacks, the Franks began another run shortly after midnight on 17 May. A full depth-charge pattern was sown, and the unfortunate sub was blown up and sunk northeast of Green Island. One sub down. The RO-42, patrolling off Eniwetok, survived three salvos of hedgehogs (a type of throw-ahead projectile more accurate than the conventional roll-over-the-side depth charge) from the destroyer escort Bangust on 10 June, but could not survive a fourth. Two down. While steaming on the surface north of the Admiralties on 11 June, the RO-III was surprised by the destroyer Taylor. After taking numerous 5-inch and 40-mm hits, the Japanese boat crash-dived and was put under permanently by the “tin can’s” depth charges. Three down. On 16 June the destroyer escort Burden R. Hastings made contact with a surfaced submarine about 120 miles east of Eniwetok. The sub suddenly submerged, and the destroyer escort fired two hedgehog salvos followed by four depth charges. A violent explosion accompanied the second salvo, and the depth charges finished the job of breaking up the enemy vessel. At daylight an aluminum nameplate with RO-44 written on it was found. Four down.
In the Marianas the Japanese were no luckier. A picket line manned by the I-10, I-185, and I-5 was set up east of Saipan, but it did not last long. The I-5 simply disappeared, the I-185 was sunk by the destroyers Chandler and Newcomb on 22 June, and the I-10 came out on the short end of a battle with the destroyer David W. Taylor and destroyer escort Riddle on 4 July. Three more vessels had been crossed off the list of operational Japanese submarines.
