text:
Strategic Situation
DURING the first months of 1944, determined thrusts by the Allies were cracking Japanese defenses throughout the Pacific. On land, Japan's hold on Burma was being systematically whittled down; at sea, the United States Fleet was spreading destruction far and wide in preparation for new strategic moves. Submarines were littering the bottom of the Pacific with the wrecks of a large part of Japan's merchant fleet. Frequent and shattering attacks from shore and carrier-based aircraft were tormenting the Japanese from many quarters.
In February 1944 the seizure of Kwajalein, Majuro and Eniwetok in the Marshalls and Task Force 58's strikes against Truk Atoll (16-17 February) and the Marianas (22 February) had profoundly affected the strategic situation in the Pacific Ocean Areas. Seizure of bases in the Marshalls afforded protected, forward-area anchorages for the entire fleet and for the assembly of large amphibious forces, together with sufficient land area for airstrips suited to all types of aircraft.
Strikes on Truk had rendered that important enemy base temporarily useless, had revealed its relative weakness and, coupled with the Marshalls' invasion, made the Japanese Navy realize that its southeastern Pacific bases were untenable. The withdrawal of Japanese naval aviation from Rabaul, a process begun in 1944, was hastened by the Truk raids. The United States "leapfrog" strategy was following a consistently effective pattern.1
The carrier strike on the Marianas, following immediately that on Truk, was conceived as a continuation of pressure which would keep the Japanese off balance in their dispositions and planning. Certainly, a major objective of this particular strike was the desire to gain aerial photographic coverage of the island. The United States had never had complete coverage of the Japanese Marianas and had taken no photographs of Guam since that island's early war capture by the enemy.
Strategically, however, the Marianas strike had the effect of displaying the capabilities of fast carrier task forces in long-range operations and emphasizing to the Japanese that their inner defense line was now seriously threatened. The stage was set for the next major operation in the Central Pacific, by which United States forces proposed to establish themselves firmly in the inner perimeter of Japan's defense. This offensive was to be against the Marianas Islands.
Another carrier raid, one against the Western Carolines (30 March-1 April), though not
influencing selection of the Marianas as an objective or the time of the operation's execution, exerted a vital, direct impact on the entire strategic picture.2
The Marianas form a vital link in an almost unbroken chain of islands extending 1,350 miles southward from Tokyo. Many of these islands are small, rocky, and valueless from a military viewpoint, but others are so located as to provide a series of mutually supporting airfields and bases, like so many stepping stones, affording protected lines of air and sea communications from the home islands of the Japanese Empire to their island fortresses. Capture of the Marianas by United States forces would effectively cut these admirably-protected lines of enemy communication and provide bases from which we could not only control sea areas farther west in the Pacific, but also on which we could base long-range aircraft to bomb Tokyo and the home islands of the Empire.3
Of the 15 islands which comprise the group, only Saipan, Tinian, Rota, and Guam--all in the southern Marianas (150° East longitude, 15° North latitude)--were worthwhile military objectives. The group's northern islands protrude in precipitous, conical peaks from the surrounding seas. Anatahan, for example, is only a fraction the size of Saipan, yet rises over a thousand feet higher. (See Map 1.)
Historical Background
When Magellan discovered the islands in 1521, he was impressed by the sailing ability of the native boys and named the group "Islas de las Velas Latinas" (Islands of the Lateen Sails); but his officers, angered by the natives' thieving habits, called them "Islas de los Ladrones" (Islands of Thieves). The latter name stuck until Queen Maria Anna, second wife of Philip IV of Spain, sent missionaries and soldiers there and, thus, gave the group the name Marianas.
The native Marianas' islanders, the Chamorros, were of small stature, brown-skinned with scanty beards, and had the slanted eyes of the Malay. Through the years, however, the appearance changed; the present Chamorros are ethnically-mixed descendants of the Spanish, Mexican, and Philippine soldiery who garrisoned the islands. The natives' language was permanently influenced by the Spanish domination.
The Marianas remained under Spanish control until 1898. The American cruiser Charleston, entered the harbor of Guam early in the Spanish-American War, accepted the island's surrender, and, thus, provided the United States with a much-needed coaling station for ships en route to the Philippines. After the war, Guam was retained by the United States. In 1899, Spain sold all the other islands of the Marianas and Carolines to Germany for four and a half million dollars. In contrast to the Spanish regime, which emphasized missionary work, the German administration was directed toward economic development.
Shortly after the outbreak of World War I in 1914, Japan seized Germany's Pacific dominions. The League of Nations recognized the seizure and in 1920 mandated the Marianas, with the exception of Guam, to Japan.
Japan set about the settlement and development of these islands in a vigorous fashion. Until 1935, she regularly prepared an annual report for submission at Geneva, in accordance with the terms of the mandate; but after 1935, when she withdrew from the League of Nations, she ceased her reports and let it be known she would not tolerate any challenge to her sovereignty in this part of the Pacific. Between 1936 and the outbreak of the Pacific War, the territory was very jealously guarded against visits by Europeans. It was generally known, however, that by 1938 the Japanese immigrant settlers outnumbered the natives and that, in defiance of the terms of the mandate, Japan was planning powerful naval and air bases throughout the archipelago. Few of their extensive plans reached fruition, however. Japan had long desired possession of Guam, and one of her first moves after the outbreak of war was to seize that island.4
Map 1
Marianas Islands
Saipan, situated some 1,250 nautical miles south by east of Tokyo, was closer to the Japanese Empire than any other large Mandated Island. (See Map 2.) Together with the neighboring island of Tinian (three nautical miles to the southwest), it formed the key point of the Marianas defense and was an important supply base and communication center for the Central Pacific. Tanapag Harbor, on Saipan's west coast, was used as a fueling and supply station for ships en route to and from the Empire. A part of the naval task force for the ill-fated attack on Midway was assembled there in May 1942. Surface patrols for the Marianas shipping routes were based in the harbor.
Two airfields and a seaplane base at Saipan and two airfields on Tinian served as stopover and refueling stations for the aircraft ferry route between Japan and the south. In addition, a large portion of the planes providing air cover for the Marianas were based on the Saipan-Tinian fields.
Though used extensively as a rest and replacement center and as a training area for troops, Saipan lacked the natural facilities of a major naval base. Only a few vessels could find suitable anchorages at Tanapag Harbor.
Irregularly shaped and with its long axis running generally north and south, the island of Saipan is approximately 14 1/5 miles long and 6 1/2 miles wide. Its area is roughly 72 square miles. The east coast of the island is free of coral reefs, except within the limits of Magicienne Bay; the west coast, on the other hand, is almost completely fringed by reefs which extend in width from one-fourth to two miles from the shoreline. Generally, the northern and eastern coasts are clearly defined by cliffs along the shoreline (except in Magicienne Bay and two small areas on Kagman Peninsula's northeastern side); the western coast is lower-lying and offers relatively few natural obstacles to movement inland.5
ASLITO AIRFIELD as seen from the air. Mt. Tapotchau is visible in the background. Magicienne Bay juts from the right of picture. Black smoke at upper left is coming from the Garapan-Tanapag Harbor area.
Almost in the center of Saipan, Mount Tapotchau humps its back against the sky to a height of 1,554 feet. It seems higher, so steep are its sides. This mountain, by all odds the island's key terrain feature, afforded the Japanese excellent observation of the beachhead for 10 days after the landing.
Much of the eastern and northern part of the island is a series of hills and rolling plateaus which tilt sharply down to narrow coastal flats or end abruptly in high cliffs that drop sheer to the sea. The southern and western areas, however, are much flatter, and the land levels off into a coastal plain.
On the southern flatlands, at a point about one mile from the south coast, the Japanese built Aslito Airfield. Its main runway, on an east-west, axis, was 3,600 feet long and 900 feet wide. A second, shorter runway, in the form of an arm, protruded southwestward from the main strip. The field was hard-surfaced with crushed coral rocks.6
Just north of Charan Kanoa and but a short distance inland, the Japanese had half completed a small fighter strip, then abandoned
Map 2
Saipan Island
MARPI POINT AIRFIELD, at Saipan's northern end, was under construction at the time of United States landings.
the project. This strip ran north and south, perpendicular to the prevailing east-west wind. Since such an arrangement is highly undesirable from a pilot's point of view, it is odd that the work was ever begun. This strip was not unique, however, inasmuch as other Japanese airfields, on other islands, were similarly positioned.
At Saipan's extreme northern end, amidst a maze of rocky hills and depressions, there exists a plateau of sufficient size for the construction of an airfield. Here the Japanese were building the Marpi Point Airfield when United States landings interrupted their plans. The shortage of construction equipment, a factor that had hampered work all over the island, slowed progress on this field to snail's pace.
The coastal plain along the western shore contains most of the settlements of Saipan, including the two largest: Garapan and Charan Kanoa. In these two towns were some well-constructed buildings, most of which were made of wood and tile, although, in some of the better structures, masonry was used. A narrow-gauge railroad ran around most of Saipan's coastal areas.
Just inland and behind the town of Charan Kanoa is Lake Susupe, fed principally during the rainy season and becoming very shallow during dry periods. Surrounding the lake is a large swamp, which presented a major obstacle to movement through the area. There are no rivers on Saipan, but two springs exist near Tanapag, on the west coast, and others near
GARAPAN, neat and trim here, was reduced to rubble by United States bombardment. Picture is of northern part of town.
the village of Donnay, on the east coast.7
The climate on Saipan is characterized by two seasons, the dry winter monsoon that begins in November and lasts through March, and the wet summer monsoon that starts in April and ends in late October or early November. These two seasons' temperatures show little variance, but all other phenomena have marked differences.
During the winter monsoon there is a great deal of fair weather, broken occasionally by storms of short duration, but the summer monsoon brings thundershowers and the threat of typhoons.8 An average of one typhoon yearly originates in the area (August or September), but in June and July the local weather is subject to the influence of typhoons originating within 500 miles. Even though Saipan may escape the storm's direct path, these "near misses" often take on the proportions of a considerable gale. The corrugated tin roofs on the native abodes are sometimes flung recklessly about the island by the winds, providing a threat to life and limb.
Annual rainfall at Saipan averages between 120 to 125 inches.9 From November to June, Saipan's monthly rainfall averages from two and one-half to six inches, but from July to October, frequent downpours increase the average to a foot per month. Due to the regularity of its precipitation (275 days per year are rainy),10 Saipan depended largely on rain water, collected in tanks placed under the eaves of buildings, for its domestic water supply. A few wells existed on the island, but these--and the
CHARAN KANOA BEFORE the blow fell. 2d Battalion, 8th Marines after landing north (left) of here, fought along the coast and seized beach area (Green 3) shown.
already-mentioned springs--furnished only a small portion of the population with water.11
The average monthly temperature is relatively constant throughout the year, with 76° in January and February and 80° in June. In the United States, constancy of temperature similar to Saipan's is experienced only by the inhabitants of Key West, Florida. Saipan's hottest days are in June, when the thermometer occasionally climbs to 95°. February brings the coolest weather, with periodic drops to 61°. Relative humidity is high, averaging 78% in winter and 84% in summer.12
Saipan's major industry (under Germany and Japan) was sugar production. The South Seas Development Company (Japanese) operated three large plantations and two sugar mills. Each mill had a capacity of 1,200 tons of sugar cane daily, from which 120 tons of crude sugar were produced. Several plants produced alcohol and liquors from the molasses byproduct. Part of this was converted into synthetic Scotch whiskey, port wine, and four or five other beverage concoctions for Japanese consumption.13
Other than sugar cane, Saipan's agricultural
JAPANESE BOATS photographed off Charan Kanoa pier during Task Force 58's strikes of February 1944. 3d Battalion, 23d Marines, landed on beach shown (Blue 1) on D-Day.
products included tapioca, sweet potatoes, papayas, cotton, and vegetables. None of these was grown in sufficient quantity for export, however. In 1930, a little less than ten percent of the copra collected in the Mandated Islands came from Saipan. This commodity, together with sugar and alcohol, formed the chief items for export. A coffee plantation was established there in 1928, but results were not particularly gratifying.
Fishing was also an important industry. In 1936, nearly four and a half million pounds of bonito and tuna were caught in the Marianas group and shipped to Japan. This, plus small amounts of tobacco and tropical fruit, completed the list of secondary articles for export. The Japanese on Saipan held most of the "white-collar" jobs in the towns, while the Chamorros, for the most part, were farmers, each possessing an average of 15 to 25 acres of land. Also included on the island, apparently as part of a Japanese colonization project, were a large number of Koreans and Okinawans. The latter had been saturated with Japanese propaganda to the effect that they could expect only the cruelest handling from the Americans.14
Japanese Defenses
Saipan was dependent on Japan for imports of foodstuffs (mainly rice), manufactured articles, lumber, building materials, machinery, petroleum products, dry goods and drugs. With the advent of war, these imports became secondary to the more important items necessary for maintenance of the military establishment.
Apparently, however, the shipment of construction material so vitally needed for fortification work was not accorded an early enough priority. This was due, first, to the rapid pace of the United States thrust through the Gilberts and Marshalls and the bypassing of the Central Carolines, which left the Japanese little
STORAGE VAULT for 120mm dual-purpose gun ammunition. Powerfully constructed positions such as this would have been more common at Saipan if Japanese had not been hampered by a shortage of cement and other materials.
time for shipment of these supplies; second, to the devastating effectiveness of United States submarine activity, which was exacting a heavy toll of enemy shipping intended for Saipan;15 and, third, to the incorrect assumption by the Japanese that the next United States objective would be the Palaus, causing them to assign a priority of construction material to those islands.
Time and time again, ships loaded with cement and steel (as well as personnel) had been sent from the Empire only to be sunk by American submarines. The effect of this is indicated in a Japanese document, dated 10 May 1944, entitled "Present State of Supplies and Materiel in the Southern Marianas":
The current freight shortage, which is caused by shipping losses, has deprived the area of much needed materiel. One ship out of three is sunk, and a second damaged, by enemy action.
It was this situation, largely, which caused the Japanese Chief of Staff, 31st Army, to complain to the Chief of Staff, Central Pacific Fleet, that
. . . . we can not strengthen the fortifications appreciably now unless we can get materials suitable for permanent construction. Specifically, cement, barbed wire, lumber, etc., which can not be obtained in these islands. No matter how many soldiers there are, they can do nothing in regard to fortifications but sit around with their arms folded, and the situation is unbearable. I would like this matter of supply of construction materials dealt with immediately.16
That the Japanese defenses were incomplete at the time of our 15 June landings is partially explained by the fact that their defensive installation building plan called for completion about November 1944.17
Another indication that the Japanese time schedule was not adequately keyed to the situation is found in an enemy document, published on 20 May 1944 (less than a month before United States landings), entitled "Outline of Defensive Plan of Northern Marianas Force:"
The various units will so prepare their defensive strength, beginning with the immediate construction of defensive positions, that when they are fully developed they can destroy the enemy landing force on the beach. We will transform these islands into a fortess so that we can expect, absolutely, to hold our airfields. On account of this, although it is tardy, [author's italics] we will complete our field positions by the first ten days in June and thereafter we will rapidly construct permanent defensive positions in strategic places.
It is interesting to note that no specific mention was made of the construction of permanent defensive positions inland. The whole Japanese scheme of defense was committed to "destroying the enemy landing force on the beach."18
As indicated, the Japanese failed to exploit fully the defensive potentialities of Saipan. The island's natural features--including excellent observation, long fields of fire, natural obstacles that canalized movement, cover and concealment--made it nearly ideal from a defense viewpoint.
OPEN TRENCHWORKS were employed extensively by the Japanese at Saipan, because they lacked adequate amounts of construction materiel.
Japanese Organization
The Japanese organization on Saipan was extremely complicated; in some cases there were three possible nomenclatures for a single unit. Early in the war, Japanese army organizations were known as "expeditionary forces" and received numerical designations relating to the islands upon which they belonged; thus, the 1st Expeditionary Force was on Saipan, the 6th on Guam, etc. In May 1944, because of numerous inter-island transfers and the influx of reinforcements, the Japanese changed their system of nomenclature. Infantry personnel was organized into "independent infantry battalions" and numbered consecutively. The battalions then became part of "independent mixed brigades," to which were attached one or more battalions of artillery and an engineering company or antiaircraft unit, or both. These brigades were, in turn, assigned numbers. In addition, there were numbered regiments, variously composed, to complicate the picture further.
The intricacies of this organization were either not explained or insufficiently explained to the individual Japanese soldiers, who habitually identified themselves by their original unit names. Certainly the mystery caused United States intelligence agencies more headaches than code names ever could. Thus, with their flair for making the simple difficult, the Japanese delayed United States identification of enemy units and establishment of an accurate order of battle.
American submarines further abetted the
confusion. Numerous ships were sunk in waters adjacent to Saipan with the result that many survivors and stragglers made their way to the island, arriving without records or equipment. In addition, a number of units intended for transfer to more remote stations were trapped on the island by our landings. The order of battle, as now reconstructed, is the result of a careful cross-check of operation orders and maps, quartermaster and mess hall records, tables of organization, field orders, casualty reports, and prisoner of war interrogations.
Saipan's forces were jointly commanded by Vice Admiral Chuichi Nagumo and Lieutenant General Yoshitsugu Saito. Admiral Nagumo, Commander Central Pacific Fleet and 5th Base Force, was an illustrious officer, having established his fame on 7 December 1941, as commander of forces afloat during the Pearl Harbor attack and, later, at Midway and Santa Cruz. His Central Pacific Fleet command was a newly-created administrative unit which, as a practical matter, never progressed beyond the paper stage.
The senior officer in the area, Lieutenant General Hideyoshi Obata, commanding general of the 31st Army and the Army administrative command for the Marianas-Bonins-Marshalls-Carolines, was at Palau on an inspection trip at the time of the United States landings. The actual command of Saipan's defense devolved, therefore, upon Lieutenant General Yoshitsugu Saito, commanding general of the Northern Marianas Army Group and the 43d Division (reinforced).
The two basic army fighting units were the 43d Division (reinforced) and the 47th Mixed Brigade. The former, directly under Saito's command, was composed of three infantry regiments (118th, 135th [less 1st Battalion], and 136th) and additional units to perform transportation, medical, ordnance and communication services. The 47th Mixed Brigade,19 commanded by Colonel Oka, was made up of three independent infantry battalions (316th, 317th and 318th), three battalions of artillery, and an engineer company.
Also important to Saipan's defense but not part of the two major army units were a tank regiment, an infantry battalion, an antiaircraft regiment, two regiments of engineers, and two transportation companies.
In addition to these regularly-assigned army units, there were numerous straggler units. In most cases, these were ill-equipped and poorly-organized and could not participate as efficient fighting organizations. But, certainly, in sniping and infiltrating roles, these units performed valuable service for the Japanese. Army forces on Saipan totalled 22,702.
The Japanese Navy was also well represented, the two principal fighting units being the 55th Naval Guard Force (Maizuru Keibitai) and the 1st Yokosuka Special Naval Landing Force. All naval units were commanded by the combined staff of the Central Pacific Fleet Headquarters and the 5th Special Base Force, both under Vice Admiral Nagumo. In addition to the two major naval forces, there were units to handle details of communication, construction, supply, transportation, pay and routine administration.
Most of the air personnel originally based in the Marianas had left those islands during May and early June to provide air support for the reinforcement of Biak Island, near New Guinea's north coast. Operational losses, as well as disease, claimed a large percentage of these personnel. During the second week in June, the survivors were ordered back to the Palaus and Marianas. Few, however, reached even the Palaus on the return trip, and, apparently, none ever got back to the Marianas. Small detachments of several air organizations remained at Saipan, indicating that the Japanese had planned to send planes back in time to contest a United States incursion. Though the totals changed from day to day, the number of naval (including air) personnel
THESE JAPANESE 8-INCH GUNS still loaded on flatcars, are but three of the scores of weapons unemplaced at the time of United States landings.
on the island on 15 June 1944 was approximately 6,960, bringing the total of Japanese military forces on Saipan to 29,662.20
For the defense of Saipan, the Japanese divided the island into four defense sectors (as shown in Map 3): the northern sector included the northern third of the island to Tanapag; the Navy sector included Tanapag, Garapan and Mutcho Point; the central sector included the western beaches upon which the 2d Marine Division landed on D-Day; the southern sector, by far the largest, included all of the area, Charan Kanoa-Agingan Point-Aslito Airfield-Nafutan Point-Magicienne Bay-Kagman Peninsula. The unit assignments to sectors were:
Northern sector, 135th Infantry Regiment.
Navy sector, 5th Special Base Force (Navy unit).
Central sector, 136th Infantry Regiment (less two companies).
Southern sector, 47th Mixed Brigade.
In addition to those units assigned to specific sectors, a reserve of four infantry companies and two shipping companies was stationed in the Chacha-Tsutsuuran area with orders to "train principally in seaborne maneuvers."' One mountain artillery regiment and
Map 3
Japanese Defense Sectors
one battalion of field artillery, stationed in the vicinity of Mt. Fina Susu, were designated as the "artillery defenses of Saipan." A tank regiment was located in the Chacha-Laulau area. Antiaircraft artillery employed the bulk of its strength to protect Aslito Airfield; a smaller force covered the air over Tanapag Harbor. Most of the service elements were located on the west coast in the Charan Kanoa-Garapan base area.21
By counterattacks, launched during the night from specified points, the Japanese hoped to "demolish the enemy landing units at the water's edge." These thrusts were to employ troops in the vicinity of the area to be counterattacked, plus reserves from other parts of the island if necessary. A plan was prepared in which assembly areas, firing positions, and directions of movement were shown for counterattacks on the most likely areas of United States penetration.
The same plan designated those areas considered strategically and tactically important (See Map 4). A peculiarity of this terrain evaluation is that Mt. Tapotchau did not fall into either category, although that feature certainly dominates most of the island.22
Even the best informed Japanese commanders could not fully appreciate the great need for speed. By 14 June, however, Admiral Nagumo was forced to the conclusion that "the Marianas are the first line of defense of the homeland," and, "it is a certainty that the Americans will land in the Marianas Group either this month or next." The landing on Saipan took place the next day.
Large numbers of heavy weapons (ranging from 200mm mortars to 5-inch coastal defense guns) and literally dozens of searchlights and antiaircraft guns still remained in naval depots or loaded on railroad cars or still packed in cosmoline near partially excavated gun positions. The high ground in the island's center had received little attention in the defensive preparations; and, indeed, beach defenses themselves were in many cases far from complete.
In this small theater, so suitable for the employment of field artillery, the Japanese had neither horses nor adequate vehicles to provide necessary mobility for that arm. Apart from manpower, the only means for moving field guns were rear-drive trucks designed for use on roads, a factor which led to abandonment of a great number of artillery pieces as the Japanese withdrew.
In so far as training in defensive warfare is concerned, Japanese forces displayed a marked deficiency; there was little evidence of organization of the ground, the principal airfield (Aslito) was virtually undefended against ground troops, and their counterattack plans were poorly conceived.23
Despite the apparent deficiencies of the defensive installations and plans, one vital characteristic of a good defense was present--the individual defender was determined to hold the island and was willing to give his life to realize this end. It was this characteristic which would present the greatest difficulty to our forces throughout the battle for Saipan.
High-Level Planning
Casablanca Conferences
As already indicated, the Japanese were
UNDAMAGED 75MM FIELD PIECE captured by the 27th Division. Lacking suitable prime-movers, the Japanese were forced to abandon many artillery pieces.
THE ENEMY, possessing fighting characteristics of which any nation could be proud, generally favored death to surrender. This superior private, among the 3 percent of Japanese soldiers taken prisoner, poses in an internment camp.
well aware of the Marianas' importance in the defense of their homeland. There was almost unanimous recognition that a United States attempt to move into the Marianas area would precipitate a struggle which could decide the war's outcome. Most Japanese felt that, given enough time, the outcome of such a battle would be favorable to themselves.
Some United States planners, notably Admiral Ernest J. King, attached the same importance to the Marianas and, likewise, predicted that an all-out naval engagement would be provoked. Many other top-echelon planners, however, were unconvinced of the necessity for seizing the Marianas. As will be seen, the selection of the Marianas as an objective was in no sense inevitable or obvious; the selection could more accurately be termed a development in the strategic situation. Because the development was an integral part of the strategic planning for the entire Pacific, it will be necessary to discuss the over-all planning which took place.
Although the Joint United States Strategic Committee had begun preparation of a strategic plan for the defeat of Japan in August 1942, this was not completed by January 1943 when the Combined Chiefs of Staff24 met at Casablanca. In fact, there was no final, approved plan in existence for the defeat of Japan at this time. Pre-war strategic plans, while helpful, could serve only as a general guide, since many of the assumed conditions and situations did not obtain. In the absence of a concrete, detailed, written study, Admiral King orally presented to the Combined Chiefs his analysis of the strategic picture. In it he indicated that Rabaul and the Philippines were major objectives, while Truk and the Marianas would constitute vitally important intermediate objectives. The latter islands King considered the "key," because they lay athwart the Japanese lines of communication in the Central Pacific.
From the January 1943 Casablanca conferences emerged a strategic outline, similar in many respects to prewar plans, which was to serve as a framework for later formal, written plans. That framework was this: a line of communications through the Central Pacific to the Philippines would be opened, following a route through the northwestern Marshalls and thence to Truk and the Marianas.25
General Douglas MacArthur, Commander in Chief Southwest Pacific, disliked the Central Pacific route from the outset and made himself voluble on the subject on many occasions. In his RENO I (campaign plan for the Southwest Pacific area), published on 25 February 1943, MacArthur expressed the opinion that the Central Pacific route would be "time consuming and expensive in our naval power and
Map 4
Japanese Counterattack Plan
shipping." In addition, a reorientation of an established front in the South and Southwest Pacific areas would be required and the use of land-based air support would not be possible. On the other hand, MacArthur felt, an approach through the Southwest Pacific, northwestward along the north coast of New Guinea, offered much better chances for success.26
MacArthur's objections notwithstanding, the United States Joint Chiefs presented a plan to the Combined Chiefs at Washington in May of 1943 which concluded that the Central Pacfic route was the better one, since success here would have more decisive strategic results. The British representatives agreed and the Joint Chiefs' proposal was adopted.27
Washington and Quebec Conferences
At the Washington Conference, Admiral King again discussed the Marianas as a specific objective. Speaking in much the same tenor as he had at Casablanca five months before, the admiral described the Marianas as the "key" to the Pacific situation because of their location astride the Japanese Central Pacific communication lines. It appears that the admiral's intense interest in the Marianas stemmed from a realization on his part that the true importance of this target was not unanimously felt. Significant in this connection is the fact that the Marianas had not been prescribed as a specific objective even at this time.28
News of the decisions of the Washington conferences was not happily received in General MacArthur's headquarters. In protest, MacArthur pointed out that the Central Pacific route was a return to pre-war plans, which had not assumed the availability of Australia as a staging base for offensive operations.29 On 3 August 1943, Headquarters Southwest Pacific Area promulgated RENO II, a revision of RENO I based upon limitations imposed by the Combined Chiefs' decisions.30
Further evidence that many officers on the joint planning level were not whole-heartedly convinced that the Marianas were a necessary target is found in the fact that these islands were not mentioned in the written plans which the Joint Chief of Staff took with them to the Quebec conferences in August 1943. Once there, however, Admiral King again mentioned the Marianas, and, in addition, the Combined Staff Planners, a subordinate committee of the Combined Chiefs, listed the Marianas as a possible objective. The result of this was that the Combined Chiefs approved the Marianas as an objective, noting that it might be a "necessary or desirable" campaign. But, in formulating a time schedule for all operations in the Pacific and Far East, the Marianas were again omitted.
Perhaps the most significant decision reached at the Quebec conference was that Rabaul would not be occupied. This departure from previous plans, together with the "approval" of the Marianas, constituted the major changes from the Washington conferences four months earlier.31
General MacArthur was very disappointed by the conclusions reached at the Quebec conferences. The weight of evidence indicated to the general that the Combined Chiefs planned to give the United States Navy responsibility for the prosecution of the war against Japan and that Southwest Pacific operations would be terminated at the Vogelkop Peninsula, New Guinea's western extremity.32
Realizing that General MacArthur was disappointed with the decisions, General George C. Marshall, a member of the Joint Chiefs of Staff, sent MacArthur a lengthy message explaining the decisions and allaying any fears that Southwest Pacific forces were assuming a position of unimportance from the strategic
THREE TOP ADMIRALS look at Saipan. From left to right: Admiral Spruance, who commanded the fleet of which the landing force was a part; Admiral King, who pressed for the operation's execution on the JCS-CCS level; Admiral Nimitz, who allocated ships and troops from his Pacific Forces to take Saipan.
point of view.33
Based upon this message and the decisions of the Quebec conferences, General MacArthur published another revision of his Reno plans, this one called RENO III.34
From what has already been written it may be seen that the selection of the Marianas as a target area was far from a random one. By the autumn of 1943, however, this objective was receiving more prominent mention, if not unanimous agreement. On 6 September 1943, the Joint War Plans Committee, on its own initiative, prepared a study entitled "Outline Plan For The Seizure Of The Marianas, Including Guam." This study was circulated for consideration of the Joint Staff Planners, who agreed at their 99th meeting to inform the Joint Chiefs that the study had been prepared and was available. One interesting feature of this particular study is the prediction that the Japanese fleet would likely contest the move.35 This was not necessarily an original prediction, however, since Admiral King had made it earlier.
Unlike General MacArthur, Fleet Admiral Chester W. Nimitz had found little to protest in the Combined Chiefs' decisions. As Commander in Chief United States Pacific Fleet and Pacific Ocean Area, Nimitz would command operations over the Central Pacific route, designated the main effort. In a letter to the Joint Chiefs of Staff, dated 30 September 1943, Nimitz outlined his garrison requirements for 1944, assuming in his letter that all operations
scheduled or approved by the Combined Chiefs would take place. For planning purposes, operations would advance to the western Carolines (Palau and Yap) by the end of 1944, the latter offensives commencing 31 December. In regard to the Marianas, the letter commented that these would constitute a satisfactory alternative for the Palaus. Thus, the axis of advance through the Central Pacific could follow either the Gilberts-Marshalls-Carolines-Palaus-Philippines axis, or detour northward through the Marianas-Bonins and thence to the Japanese home islands.36
Cairo Conferences
In preparation for the next meeting with their British counterparts, the Joint Chiefs of Staff discussed two matters which would have tremendous weight in the selection of objectives in the Central Pacific. These matters, condensed to single terms, were Truk and the B-29.
Truk had long been recognized as a formidable enemy stronghold, one which would exact a dear price from attackers. Yet because of its dominance of Central Pacific sea lanes, it seemed to demand seizure. During meetings on 15 and 17 November 1943, the Joint Chiefs probed a possibility which had not before been officially considered: the feasibility of by-passing Truk. Before arriving at a firm decision in this respect it was decided that the United States Navy should launch strong carrier attacks against Truk as soon as possible to determine and test the strength of that mysterious position. The results of these attacks would be the influencing factor in a by-passing decision.37
The Army Air Forces' huge new bomber, the B-29, now being produced in quantity, was scheduled to deliver attacks against the Japanese homeland from bases in China at the earliest possible date. During the November meetings, General Henry H. Arnold, commander Army Air Forces and a member of the Joint Chiefs of Staff, voiced a doubt that had been under discussion by Air Force planners for some time: could the Chinese protect the B-29 bases from Japanese ground capture? General Arnold pointed out that it would be a normal enemy reaction, after the first raids against the homeland, to launch inspired ground offensives toward the China B-29 bases. Fate of the B-29 plans, then, would rest in the hands of the Chinese, in whom General Arnold expressed lack of confidence. Without recommending any drastic rearrangement of plans in regard to the use of China bases, Arnold suggested that these plans be expanded to include use of airfields in the Marianas Islands. These, the general considered, would be next to impossible for the Japanese to recapture, once United States forces were in possession. As an important technical matter, General Arnold assured the other JCS members that the B-29's could carry their maximum bomb load from the southern Marianas to the Japanese home islands.
At last Admiral King was enjoying active support in his long struggle for recognition of the Marianas as a "key" objective. With the added weight thrown behind the project by the Army Air Forces, the question was no longer in doubt. The Joint Chiefs decided that, although the first B-29 raids would be launched from China bases commencing in early June 1944, strikes from the Marianas would start in December of that year.38
Following these mid-November JCS agreements were the late November-early December 1943 meetings in Cairo, Egypt. While the conference--code named SEXTANT--concerned itself chiefly with discussions and decisions regarding operations in Europe, some vital agreements pertaining to Pacific operations were also reached. The Combined Chiefs' "Report for the President and Prime Minister," a summary of agreements and conclusions of a long-range, global nature, was approved and initialed by Roosevelt and Churchill.39 Included
in the report were two documents which were to serve as a foundation for more detailed planning: "Specific Operations for the Defeat of Japan" and "Over-all Plan for the Defeat of Japan."40
The former paper established a time schedule for planning purposes in 1944 and included an operation for the "seizure of Guam and Japanese Marianas" on 1 October 1944 and the initiation of "very long range bombing of vital targets in Japanese 'Inner Zone'41 from bases in Marianas."42 That the time schedule was for planning purposes and not intended as a hard and fast calendar of events, was indicated by an enclosure to the document which pointed out that certain "developments" might make possible a speedup. These "developments" which might permit short-cuts were: first, defeat of the Japanese Fleet at an early date; second, sudden withdrawal of enemy forces from certain areas (as from Kiska); third, an earlier defeat of Germany than 1 October 1944, coupled with an increase in Allied means (such as by acceleration of the assault ship building program); and, fourth, Russia's early collaboration in the war against Japan.43
The other document, "Over-all Plan for the Defeat of Japan," was approved in principle and would be the basis for further investigation and preparation.44
The revised plan, circulated to Nimitz and MacArthur on 23 December 1943, established the strategic concept within the Pacific. This concept prescribed "two series of operations" which would be undertaken concurrently and would be mutually supporting. One of these "series" would be MacArthur's route along the New Guinea-Netherlands East Indies-Philippines axis; the other, Nimitz' route through the Central Pacific, embracing the Mandated Islands. The latter route would be favored where conflicts in timing or means developed, since it promised a "more rapid advance toward Japan and her vital lines of communication," would provide "earlier acquisition of strategic air bases closer to the Japanese homeland," and would be "more likely to precipitate a decisive engagement with the Japanese Fleet." The concept envisaged that both series of operations should progress to a point from which to launch a "major assault" against the Formosa-Luzon-China area in the spring of 1945.45
Campaign Plan GRANITE
Decisions reached at the Cairo Conference, together with the discussions and deliberations of the Joint Chiefs prior to those meetings, provided Admiral Nimitz and General MacArthur with considerable detail for the formulation of their own plans. Some changes in both officers' previous planning was necessitated by the new decisions. For example, the Marianas as an objective was no longer a flexible matter; it was now a definite, scheduled operation. In addition, a carrier strike against Truk had to be executed at an early date.
Admiral Nimitz' campaign plan GRANITE, preliminary draft published on 27 December 1943, planned the Central Pacific operations for 1944. This document tentatively established the sequence and timing of operations for the Pacific Ocean Areas and of Southwest Pacific operations requiring support of major Pacific Fleet units as follows:
Operation Tentative
Target Date
Capture of Kwajalein January 1944. Capture of Kavieng and air attack on Truk 20 March 1944. Capture of Manus 20 April 1944. Capture of Eniwetok 1 May 1944. Capture of Mortlock 1 July 1944. Capture of Truk 15 August. 1944. Capture of Tinian, Saipan, and Guam 15 November 1944.
As may be seen, the Marianas operation was planned as the final and culminating operation of 1944. GRANITE emphasized, however, that the sequence and timing were purely tentative, that if means became available more rapidly than could be anticipated, the program would be accelerated. The plan pointed out, moreover, that a major fleet action, although it might delay amphibious operations for a brief period, would greatly accelerate them thereafter. Likewise, a successful action might, by decreasing the size and strength of forces required to protect lines of communication, justify the omission of an operation even as important as the capture of Truk.46
On 13 January, only 17 days after publication of the preliminary draft, another GRANITE was issued. This one changed certain of the operation dates of the previous draft; operations to seize Mortlock and Truk were moved to 1 August; and, if carrier strikes against Truk should indicate its capture unnecessary, it could be by-passed and Central Pacific forces could move direct to the Palaus (which had not been mentioned in the previous draft) on 1 August. This eventuality would change the first Marianas' landings to the first of November. Of particular interest in this plan is the revelation that, at least for a short time, Admiral Nimitz was thinking in terms of seizing the Palaus and then backing up to take the Marianas.47 This scheme did not reappear in subsequent documents, however.
Representatives of the South, Southwest and Central Pacific assembled at Pearl Harbor on 27 and 28 January 1944 to discuss, coordinate and integrate their planning. In addition to considering a general speed-up of all Pacific operations, the conferees discussed two alternative schedules proposed by Admiral Nimitz:
- Truk, 15 June; Marianas, 1 September; Palaus, 15 November.
- Truk, bypass; Marianas, 15 June; Palaus, 10 October.
The second alternative seemed the most favorable to the assembled officers; but, also, there were many present who favored bypassing the Marianas too. Their reasoning was that the Marianas, because of an almost complete lack of good harbors, would afford poor staging bases. Moreover, they felt that the proposed B-29 operations from the Marianas would not be particularly effective. Further, this group (a decided majority at this conference) felt that the Marianas would be a costly operation, the price of which would not be justified by results achieved.48
While these discussions of the 27-28 January Pearl Harbor conference are interesting, it is apparent that the final decisions in regard to the Marianas had already been made by the Joint Chiefs, and the Truk-by-pass decision would await the results of the carrier strikes.
General MacArthur continued his opposition to the Central Pacific route as late as February 1944, when be sent his deputy, Lieutenant General Richard K. Sutherland, USA, to Washington in a desperate effort to convince the Joint Chiefs that both Truk and the Marianas should be by-passed and that the impetus should be along the New Guinea-Mindanao axis of advance. General Sutherland had been in Washington but a short time when he found it necessary to advise MacArthur that the die was, indeed, cast: the Marianas operation was a certainty; the Central Pacific route was inevitable.49
Also arriving in Washington for conferences with the Joint Chiefs during the month of February 1944 was Admiral Nimitz. The latter pointed out certain factors which had been under discussion at Pearl Harbor a month before: the Marianas did not offer satisfactory bases for the fleet and, if Truk were by-passed, other fleet bases would be required. Nimitz
recommended Ulithi, 400-odd miles southwest of Guam, as an objective, since it would provide an exceptionally good base for the projected offensive against the Luzon-Formosa-China coast area.50
The Joint Chiefs of Staff, for some time, had been looking to acceleration of the entire Pacific offensive, but the Truk imponderable forbade drastic speed-up alterations in existing plans. When, on 17 and 18 February 1944, the Truk carrier strikes51 removed the trappings of mystery surrounding that position, and it was revealed as considerably weaker than supposed, the Joint Chiefs agreed that substantial changes in plans were in order.
Not that the results of the Truk strikes, which indicated that by-passing would be feasible, were the only consideration. Other developments had their influence: the Marshalls operation (30 January-20 February) had been executed with greater speed and less cost than had been anticipated; General MacArthur's Southwest Pacific forces had advanced the invasion of the Admiralties from 1 April to 29 February; MacArthur's RENO IV plan (presented to the Joint Chiefs on 5-6 March) contemplated by-passing the Hansa Bay and Wewak areas and advancing directly to Hollandia; Admiral Nimitz had recommended launching a major amphibious operation against either Truk or the Marianas in mid-June, followed by an assault on the Palaus about 1 October; and, in addition, the Army Air Force was again pressing for early capture of the Marianas.
JCS Directive of 12 March
The culmination of these early-1944 developments and the termination of a number of debates was the Joint Chiefs of Staff directive of 12 March 1944. This directive ordered General MacArthur to cancel the operation against Kavieng and to isolate that island and Rabaul. Hollandia was to be occupied, target date 15 April 1944, using forces originally assigned for Kavieng-Manus with the exception of Marine units assigned for those operations, fast carrier groups and old battleships.
The directive further ordered General MacArthur to return all Pacific Fleet transports, cargo vessels and command ships, which had been allocated for Kavieng-Manus-Hansa Bay, as well as Pacific Fleet combatant vessels, to Admiral Nimitz not later than 5 May. Following seizure of Hollandia, MacArthur was to conduct operations along the New Guinea coast and such other operations as were deemed feasible in preparation for operations against the Palaus and Mindanao.
The occupation and development of the Admiralties was to be expedited, so that suitable bases would be provided for the neutralization of Rabaul, Kavieng, Truk and the Palaus. If additional air base facilities were required, Emirau52 and Mussau were to be occupied and developed.
The same JCS directive ordered Admiral Nimitz to "institute and intensify" aerial bombardment of the Carolines and to conduct carrier attacks on the Marianas, Palaus, Carolines and other profitable targets. The Southern Marianas were to be seized, target date 15 June 1944, and B-29 bases and secondary naval facilities developed there. Admiral Nimitz was also to "provide cover" for General MacArthur's moves against Hollandia and other operations in the Southwest Pacific.
MacArthur and Nimitz were further ordered to coordinate their plans to provide for mutual
support of all impending operations.53
It will be noted that the directive did not include Ulithi, which objective Admiral Nimitz had recommended in his late February visit to Washington. This omission would seem to indicate that the Joint Chiefs felt that the fleet could find satisfactory anchorages within the Palaus.
Immediately after receiving these changes from the Joint Chiefs, Admiral Nimitz sent a secret dispatch (13 March) to major subordinate units directing that the Truk planning cease and that highest priority be assigned to the preparation for the Marianas operation. At the V Amphibious Corps Headquarters, tentative plans for the seizure of Truk had been evolved simultaneously with those for the Marianas, but with Nimiitz' new order, all effort was concentrated on the Marianas.54
On 20 March, the CINCPOA FORAGER Joint Staff Study was issued. This document contained a recapitulation of the Joint Chiefs of Staff directive and set forth the assumptions upon which the Marianas operation was based. Essentially, these assumptions were: first, that Hollandia, the Admiralties, and Emirau had been seized and were available as bases; second, that neutralizing attacks were continuing against enemy air installations at Nauru, Wake, Ponape and in the Marshalls; third that Truk had been subjected to both destructive carrier attacks and sustained bombing from the Marshalls and Bismarcks; and, fourth, that United States sea and air forces had been able to prevent effective use of Truk by major Japanese Fleet units and that United States air superiority and control of the sea in the area of operations had been maintained.
The purpose of the operation, as stated in the study, was to establish bases from which to attack the enemy's sea-air communications, support operations for the neutralization of by-passed Truk, initiate B-29 bombing of the Japanese home islands, and support further offensives against the Palaus, Philippines, Formosa and China. More generally, the purpose was to "maintain unremitting military pressure against Japan" and to "extend our control over the Western Pacific."55
The Marianas operation involved the amphibious assault and seizure of three fortified islands 1,200 miles from the nearest American base and from 4,000 to 7,000 miles from the areas in which troops would be mounted. The Fifth Fleet, the largest ever assembled in the Pacific with control over more than 800 ships, was assigned to transport, land, cover, and support the landing and garrison forces of Task Force 56. The forces of Commander South Pacific, Admiral William F. Halsey, USN, and of Commander in Chief Southwest Pacific, General Douglas MacArthur, USA, were already performing long-range air search and attack missions against the Carolines and Palaus to interdict any enemy threats from
VICE ADMIRAL RICHMOND K. TURNER, commander Joint Expeditionary Force and Northern Attack Force.
those areas. Submarines of Task Force 17 would continue to provide their supporting operations west of the Marianas.
Since the original GRANITE was no longer in effect, a new campaign plan--GRANITE II--was issued on 3 June. The sequence and timing of the projected operations was much changed; the Marianas operation was listed as the first of the period, instead of last. GRANITE II established the tentative schedule of operations as follows:
Operation 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 Amoy56 15 February 1945. orCapture of Luzon 15 February 1945.57
Command Relations
The Joint Chiefs of Staff had designated Admiral Nimitz to command the over-all Central Pacific campaign of which the Marianas was a part. Admiral Raymond A. Spruance, USN, Commander Fifth Fleet, was, in turn, designated to direct all forces engaged in the operation. Charged with command of the Joint Expeditionary Force, which included all task organizations employed in the amphibious operations at all Marianas' objectives was Vice Admiral Richmond K. Turner, USN. The Joint Expeditionary Force was divided into five major and several minor (the latter chiefly garrison) task forces and task groups. The major task groups and forces were: Support Aircraft Headquarters, Expeditionary Troops, Northern Attack Force, Southern Attack Force, and Joint Expeditionary Force Reserve. Rear Admiral Richard L. Conolly, USN, commanded the Southern Attack Force (Guam), while Turner, himself, operating in a dual capacity, commanded the Northern Attack Force (Saipan). Rear Admiral Harry W. Hill, USN, second-in-command of the Joint Expeditionary Force, commanded the Western Landing Group,58 which actually executed the Saipan landings.
Embarked in Admiral Turner's flagship or ashore was the Commanding General, Expeditionary Troops, Lieutenant General Holland M. Smith, who commanded the landing force for the entire Marianas operation. During the assault phase, Smith also commanded garrison troops ashore. His command was exercised at the respective objectives through the Commanding Generals of the Northern and Southern Troops and Landing Forces. General Smith, like Admiral Turner, served in a dual capacity as Commanding General both of Expeditionary Troops and of Northern Troops and Landing Forces. Major General Roy S. Geiger was Commanding General, Southern Troops and Landing Force.
All troops ashore would remain under Holland Smith until Admiral Spruance decided that the capture and occupation phase at a given objective was completed, whereupon command ashore would shift to the island commander. Saipan's island commander was Major General Sanderford Jarman, USA, who, at such time as Spruance directed, would be responsible for base development, civil affairs. and other matters of the island's administration.59 (See Appendix VI for basic organization of high echelons.)
Because of General Smith's dual role, it was necessary to reorganize the headquarters of the
LIEUTENANT GENERAL HOLLAND M. SMITH, Commanding General Expeditionary Troops and Northern Troops and Landing Force. In the Marianas, General Smith had the largest force commanded by a Marine General up to that time.
V Amphibious Corps to form two staffs so that each echelon would be represented.60 Actually. the preliminary planning was accomplished prior to the reorganization on 12 April, but after that date these staffs became known as the "Red Staff" and the "Blue Staff." The former subsequently became the staff for Commander, Northern Troops and Landing Force and the latter for Commander, Expeditionary Troops. The two groups operated in separate office spaces at Pearl Harbor but had identical sources of information on which to draw as detailed plans were prepared.61
In keeping with principles of concurrent planning, the V Amphibious Corps Staff had anticipated future actions and initiated planning; a rough operation plan for the Marianas was completed as early as 14 March. This served as a basis for the final Expeditionary Troops Plan.62
Available to the Northern Troops and Landing Force for the Saipan landings were the 2d and 4th Marine Divisions, commanded by Major Generals Thomas E. Watson63 and Harry Schmidt, respectively. General Geiger's Southern Troops and Landing Force would be composed of the 3d Marine Division and the 1st Provisional Marine Brigade. In Expeditionary Troops reserve, prepared to land at either objective, was the 27th Infantry Division, United States Army, commanded by Major General Ralph E. Smith. The 77th Infantry Division, United States Army, was to be held in the Hawaiian Islands as strategic reserve and called into the Marianas area after D-plus 20. This time schedule was demanded because it would take that long for ships carrying assault echelons to return from Saipan to Oahu.
Logistics and Administration
The logistical support plan progressed concurrently with operation plans. Early in the planning phase, close liaison was established between all major units in order to transmit
available information without delay. Conferences between key logistical officers insured that uniformity and consistency would prevail throughout the preparation. Experiences in previous operations, availability of shipping space, and the tactical situation, determined initial supply requirements. The Marianas would be a departure from atoll type operations to a campaign on a limited land mass; still, important lessons had been learned which would be invaluable to logistical planning. Initial supplies to be taken by assault forces were as follows:
Class I (Rations) 32 days. Class II (Organizational and Individual equipment) 20 days. Class III (Fuels and Lubricants) 20 days. Class IV (Miscellaneous supplies) 20 days (except medical supplies which were 30 days). Class V (Ammunition) 7 units of fire ground weapons; 10 units of fire for antiaircraft weapons.
Resupply shipments were set up in 3,000-men blocks for 30 days of Class I, II, III, and IV. Items suitable for the block shipment plan were shipped separately in "optional loaded ships." Class V, ammunition, would be loaded in specially designed ammunition ships containing no other type or class of supply. To offset possible losses of initial or resupply shipments, mobile reserves were established in the Marshalls area, subject to the call of the Commander, Expeditionary Troops.
All major units were required to submit a consolidated list of organizational equipment to Headquarters, Expeditionary Troops for screening. This was done to assure that the equipment did not exceed shipping allocations and, also, for the purpose of coordinating the equipment of assault and garrison units to prevent unnecessary duplication.64
Details of hospitalization and evacuation presented at least one major innovation: civilians would need medical care during and after the battle. Our own needs would come first, however. Nineteen AKA's, five AP's, six AKA's, and three LST's were to be available at Saipan for evacuation of casualties. The three LST's had been especially equipped with supplies and personnel to receive casualties from the beach for further transfer to the transports until such time as the tactical situation permitted transports to approach beaches near enough to warrant transfer of casualties direct to the transports. The plan would place one LST off of the beaches upon which the 2d Marine Division would land and one off the 4th Division's beaches. The third LST would relieve whichever LST received 100 casualties first.65
The sequence of building the logistical plan continued with base development considerations. Great quantities of construction material would need shipment to the objective area in order that the base might develop its necessary facilities. Several preliminary conferences were held at CinCPac Headquarters to discuss the amounts and types of materiel needed, shipping required, and related problems. A rear echelon of the Expeditionary Troops G-4 section remained in Oahu to coordinate all activities.
The Marine Supply Service formed the 5th and 7th Field Depots to support Marine units initially and in the ensuing garrison phase. To afford assistance by augmenting the divisions' shore parties, representative portions of the 5th and 7th Field Depots were embarked in assault shipping. Other echelons of the field depots were scheduled to arrive in early garrison shipping.
The rehabilitation plan was conceived with a view to economizing materiel, effort, and shipping. Since the 4th Marine Division would leave the Saipan-Tinian area after the operation and the 2d Marine Division would remain, the 4th would turn its organizational equipment in to the 7th Field Depot for processing, repair, and reissue to the 2d. A similar plan was evolved for Guam, from whence the 1st Provisional Marine Brigade would leave after the operation, while the 3d Marine Division would remain. By this plan, shipping space was conserved and possible damage to equipment enroute eliminated. In addition, man-hours were saved because equipment was not loaded back aboard ships.
To permit coordination and to reduce possibilities of misinterpretation, all major units submitted advance copies of their administrative orders to Headquarters, Expeditionary Troops, for checking and comparison.66
Requirements for shipping in which to embark the Northern Troops and Landing Force were submitted to the Commander of the Northern Attack Force. When the available shipping was provided, NTLF prepared general loading plans and allocated shipping to subordinate units. A schedule for loading, prepared in conjunction with the Navy, fitted as closely as possible the time of availability of the ships and the time desired by the troops. This posed a considerable problem in view of limited harbor facilities from which to mount such a large force. By careful and complete planning, however, the entire force was loaded on time and in the manner necessary to fit the tactical plans.
About a week prior to commencement of loading, the Transport Group Commanders and either the captain or cargo officer of each ship visited the unit whose troops their ships were embarking. This early liaison settled many questions regarding loading arrangements in a most satisfactory manner.67
The work of the G-1 Section of the Expeditionary Troops staff during the period of preparation consisted of its normal functions--supplying replacements to units committed to the operation, attaching reinforcing units to the divisions, organizing specialized units to be employed, alerting units for embarkation, assigning billeting space for staff officers and men aboard ship, and furnishing personnel data required by other sections of the staff.68
Intelligence Information
The Corps G-2 Section was handicapped during the planning stage, as no accurate information concerning enemy installations in the Southern Marianas was available until the carrier strikes of 22-23 February. On the basis of these strikes, intelligence studies were begun. The studies were necessarily incomplete because of inadequate photographic coverage. The carrier photographs of 22-23 February, partly covering Saipan, Tinian and Aguijan, were not supplemented by full coverage until 18 April. Lack of subsequent photographs prior to departure from Pearl Harbor was a source of some irritation to the G-2 Section and greatly complicated its task. Corps had requested photograph coverages on D-minus 90, D-minus 60, D-minus 30, and D-minus 15 days, but this schedule, because of many other demands upon the Navy, could not be completely met. There was, therefore, a consequent lack of timely intelligence information which would have been helpful during the planning and assault phases. At Eniwetok, enroute to the objective, Saipan photographs of 28 May were delivered to the attack force. These were interpreted and disseminated to the divisions' headquarters prior to departure from Eniwetok. The slower travelling LST groups, carrying the initial assault elements, however, had already departed; Marines were required to make their 15 June landings on the basis of 18 April information of the enemy situation.69
These inadequacies in aerial photographic coverage were due to the prevailing naval situation and not to faulty cooperation between Navy and Marine higher echelons. In all instances, the Navy made sincere effort to comply with any and all reasonable requests. It is obvious that Marine planners were desirous of obtaining as many pictures of the objective as possible, and that they would tend to base their requests upon that desire. It is also apparent, however, that the Navy was confronted with a tactical situation which made it virtually impossible to comply with all requests. According to Admiral R.K. Turner, it was necessary for "naval fliers to pick and choose among the very numerous items in Corps requests and then to obtain what coverage they could while fighting battles."70
It is interesting to note that Admiral Spruance, commander Fifth Fleet, gave careful consideration to making a second raid on the Marianas before the actual landings. Aside from the undesirability of pin-pointing the Marianas as the next objective, the scheme was ruled out because of other demands upon available ships.71
The 1:20,000 battle map of Saipan-Tinian-Aguijan was based on the incomplete photograph coverage of 22-23 February and on Japanese charts captured during the Marshalls operation. The contours shown on the map were actually "logical" contours adapted from captured charts and partially revised from existing photographs. Once the map was in use, it was ascertained that these contours were not only inaccurate but that they offered a misleading representation of the basic features of the island. As examples, sheer cliffs sometimes appeared as slopes and box canyons as ravines or draws, a condition somewhat relieved after the 4th Marine Division captured an excellent Japanese map of the island.72 The NTLF G-2 Section made the latter map available to units in time to be used during operations conducted north of the Garapan-Mt. Tapotchau-Magicienne Bay line.73
Another Japanese map, captured by the 8th Marines (2d Marine Division), was found to be especially helpful in that regiment's operations around Mt. Tapotchau. A great deal of care had to be exercised in transposing coordinates from Japanese to the United States maps, however, due to variations in ground forms.74
Estimates of enemy strength prior to the landing on Saipan were considerably below the actual strength encountered. On 9 May the estimate had been 9,000, to 10,000. On 24 May, G-2 Summary No. 20 had increased the estimate:
Should the enemy continue his present rate of reinforcement, it seems logical to estimate that by D-day, combat troops will number 15,000 to 18,000. This estimate does not include "Home Guard" units.
After the operation the count indicated that there were approximately 29,662 combatant Japanese on Saipan on D-Day.75
In all fairness to personnel responsible for divining enemy strength, it should again be emphasized that photographic coverage left much to be desired. Analysis of aerial photographs was one of G-2's best sources; and, since coverage was inadequate, there was a scarcity of detailed enemy information. It should be remembered, however, that a vast expanse of water separated Saipan from the closest United States holdings, and the Navy's problems were many. As the G-2 of the Northern Troops and Landing Force (Lieutenant Colonel Thomas R. Yancey, USA) writes:
Usually, photographic planes accompanied attacking fighter planes on sorties against enemy bases [and] honest effort was made to obtain adequate and complete coverage of the target area. However, during the spring and early summer months in the Marianas area, there are few days when the sky is not partially covered with low cumulus clouds,
obscuring some of the most important installations or key terrain features. . . . This, of course, was unfortunate, but clouds handicapping the photographer provided protection for fighter aircraft.
Strikes against enemy bases were mainly for the purpose of destroying . . . enemy installations, and photographic coverage, while important, was usually reduced to a secondary consideration.76
In addition to difficulties already discussed, the fact that Saipan was serving as a staging area further contributed to the G-2's problems. Many Japanese units were just passing through when the United States blow fell; others were shipwrecked survivors whom fate had guided there. Probably even the Japanese would have found it difficult to determine how many troops they had on the island.
Tactical Plans
As stated before, the CinCPac Joint Staff Study of 20 March 1944 assumed the capture of certain bases for the support of the Marianas campaign. By 22 April General MacArthur's Southwest Pacific Forces had successfully effected the capture of Hollandia and the Admiralties, and the 4th Marines had occupied Emirau. The following day Admiral Nimitz published his Operation Plan 3-44 for the Marianas. Subsequently, orders were issued by the Commander, Fifth Fleet (Admiral Spruance) and by the Commander, Joint Expeditionary Force (Vice Admiral Turner). The mission of Task Force 56 (Expeditionary Troops) was to capture, occupy and defend Saipan, Tinian and Guam, and to be prepared for further operations.77
That part of the mission pertaining to Saipan and Tinian was assigned to the Northern Troops and Landing Force (NTLF) with the following major units being assigned:
Corps Troops (Administrative and Service Elements).
1st Battalion, 2d Marines.
2d Marine Division (Reinforced) (less 1st Battalion, 2d Marines) (plus 1st Battalion, 29th Marines).78
4th Marine Division (Reinforced).
XXIV Corps Artillery.
Saipan Garrison Force (Task Group 10.13).
Tinian Garrison Force (Task Group 10.12).79
In Expeditionary Troops reserve, prepared for commitment on Saipan, Tinian, or Guam, was the United States Army's 27th Infantry Division. This division prepared 21 separate plans for possible employment on any of the three islands, 16 of these in anticipation of Saipan landings. As the planning of higher headquarters progressed, a few plans were discarded.80
Concurrent planning was the rule; the day following issuance of the Expeditionary Troops plan, NTLF Operation Order 2-44 (Tentative) was published. This plan and a later one (Operation Plan 3-44, issued on 1 May 1944) ordered the two Marine divisions to land on Saipan's western beaches in the Charan Kanoa vicinity, 2d Division on the Red and Green Beaches (north of Charan Kanoa) and 4th Division on the Blue and Yellow Beaches (facing the town itself and the area south of it). After the simultaneous landing, both divisions would advance rapidly inland to objective O-1, the first dominating ground inland. Thereafter, the 2d Division would push up and seize Mts. Tapotchau and Tipo Pale, while the 4th Division would shove across to the island's east coast, capturing Aslito Airfield on the
PREFERRED BEACHES ON SAIPAN. Reef demanded that the ship-to-shore movement be executed in amphibian tractors.
way. (See Map 5 for scheme of maneuver.)
As part of the same plan, the 1st Battalion, 2d Marines (Reinforced), was ordered to "land on the night of D-minus 1-D-Day, on selected beaches of Magicienne Bay, move rapidly inland, seize Mt. Tapotchau81 before daylight, and defend same until relieved."
This mission, intriguing to the imagination, was later fortunately cancelled. Not, however, before the battalion had altered its organization to fit assigned shipping (six destroyer transports), or before its supplies and heavy weapons were embarked aboard two escort carriers (with plans to parachute-drop needed items from torpedo planes), or before it had completed considerable specialized training. As will be seen, these arrangements caused much inconvenience.82
Even with the cancellation of the mission, the 1st Battalion, 2d Marines, remained as an immediate subordinate unit of the Northern Troops and Landing Force with orders to "be prepared after How-hour [author's italics] to land on order on selected beaches of Magicienne Bay, or on other beaches to be designated."83 (For a detailed analysis of the original mission and its subsequent cancellation, see Appendix V.)
Both divisions, it will be noted, had been ordered to "seize Objective O-1" after landing. This objective embraced the first commanding
ground inland from the beaches, a distance varying from 1,200 to 1,500 yards in the middle and tapering to the beach on both flanks. It was essential that this line be occupied rapidly, since, until then, no relief from the enemy's direct fire weapons could be expected. Every man was impressed with the fact that the high ground was the immediate goal and that this should be seized as soon as possible. As will be seen, however, the two divisions, though actuated by the same purpose, chose different means to achieve this end.
A diversionary demonstration, beginning shortly before the actual landing and continuing sometime thereafter, was to be conducted in the area northwest of Tanapag Harbor.84 This effort, for the purpose of diverting enemy reserves and supporting fires from the area of the actual landing, would be afforded added realism by supporting fires from Fire Support Unit Four (TU 52.17.4), including battleships Maryland and Colorado, light cruiser Louisville and four destroyers.85
The divisions wasted no time after receipt of the NTLF Operation Plan. Soon, tentative plans were submitted for approval. Actually, the divisions had carried on planning, based on tentative drafts and conferences, before receipt of the formal NTLF plan. The 2d Division planned to land with the 6th and 8th Marines86 abreast, 6th over the Red Beaches, 8th over the Green Beaches.
The 4th Marine Division would employ the 23d and 25th Marines in the assault, the 23d landing over the Blue and the 25th over the Yellow Beaches.
For the demonstration at Tanapag Harbor, the two divisions would use infantry elements not committed to the initial assault. These included the 2d Marines and the 1st Battalion, 29th Marines, from the 2d Division, and the 24th Marines from the 4th Division.87
In the event that later intelligence information indicated that the Charan Kanoa (preferred) beaches were too strongly defended to permit landings, an alternate plan was conceived. This plan contemplated landings to the north of Garapan on beaches Black and Scarlet. The 2d Division, in the event this plan were used, would land on Black Beach at H-Hour, followed three hours later by the 4th Division, which would land on Scarlet Beaches in Tanapag Harbor.88 Some excellent submarine photographs made careful study of the alternate beaches possible, and all hands were as well briefed on this plan as the preferred one.
Since the preferred beaches on Saipan were fringed by a reef and since it would be impossible to negotiate a crossing of the reef in conventional landing craft, the landing plan contemplated the use of LVT's (Landing Vehicles, Tracked, often called "amtracs") as the principal assault vehicle. LVT's were to be transported to the objective aboard LST's (Landing Ships, Tank). Sufficient LVT's were allocated to allow for the preloading and direct landing of assault units as well as one reserve battalion for each division. By making other LVT's available after arrival in the transport area and by executing transfer operations from landing craft to LVT's, it would be possible to land the bulk of the two divisions in these vehicles. LVT battalions were assigned as follows: 2d Marine Division--2d, 5th and 715th Amphibian Tractor Battalions (the latter an Army Battalion); 4th Marine Division--534th and 773d Amphibian Tractor Battalions (both Army) and the 10th Amphibian Tractor Battalion, less its Company A and plus Company C of the 11th Amphibian Tractor Battalion.
Preceding the first wave of troop-carrying LVT's would be a wave of armored amphibian tractors (LVT(A)'s), each of which mounted
a 75mm howitzer in an armored turret. These vehicles were to cover the landing and movement of assault waves to O-1. Preceding the 2d Marine Division was the 2d Armored Amphibian Battalion, while the Army's 708th Amphibian Tank Battalion would provide a similar mission for the 4th Division.89
The 10th and 14th Marines (artillery regiments of the 2d and 4th Marine Divisions, respectively) were each assigned four LST's for the operation. One LST was capable of lifting the howitzers and about 275 men of one artillery battalion. The remaining personnel was carried in transports (AKA's). Of this latter group, some were transhipped from AKA's to LST's at Eniwetok Lagoon for the final leg of the trip. Organic motor vehicles of the artillery regiments, with drivers, were carried to the objective in cargo ships (AKA's).90
The 10th Marines loaded all four of its organic battalions (two battalions of 75mm pack howitzers, two battalions of 105mm howitzers) in LST's. The pack howitzers were preloaded in LVT's and the 105's in DUKW's (amphibious trucks, normally called "ducks"). The 10th Marines had been reinforced with the 2d 155mm Howitzer Battalion, V Amphibious Corps, whose guns, ammunition and equipment were loaded aboard three AKA's and most of the personnel aboard APA's.91
The 14th Marine Regiment was organized into five battalions, the 1st and 2d armed with 75mm howitzers; the 3d, 4th and 5th with 105mm howitzers.92 The 14th Marines used three LST's to lift the three battalions of 105mm howitzers pre-loaded in ducks. The fourth LST allotted them carried 75mm pack howitzer ammunition. The two pack howitzer battalions of the 14th Marines were loaded aboard transports. It was planned that the 75's would land after transfer from landing craft (LCVP's) to ducks which would return after landing the 105mm battalions. This part of the plan was not carried out, however, due to the slow return of the ducks after debarking the 105's, and the 75mm battalions were subsequently landed in LVT's.93
Training and Rehearsal
As over-all plans for the Marianas operation evolved and specific tactical plans developed, the concurrent assembly and preparation of forces was being accomplished. Initially, training of units was general in nature; but, as more detailed information relative to the scheme of maneuver, the terrain features, and the enemy forces became available, the program was supplemented to conform to the expected character of the operation.94
For a period of several months prior to the operation, Headquarters, V Amphibious Corps, prepared participating elements so that a state of advanced readiness would exist prior to the target date. This preparation involved filling existing personnel shortages, provisions for supply and logistical support of assault and garrison elements, and an extensive training program. The latter involved a period of overall instruction, a period of amphibious training and, finally, full-dress rehearsals.
The divisions and separate elements were issued training directives based on Corps standing operating procedures and experience gained in past operations, designed to prepare the units for their assigned missions. Emphasis was placed on individual and small unit training
Map 5
Plans for Landing
(which had paid such big dividends in previous campaigns), on the integration of the infantry-tank-artillery-engineer team, and on the use of the battalions, regiments and entire divisions as units. All weapons were fired in problems involving units the size of a squad to a division. Exercises were conducted both day and night in terrain varying from that of jungle and cane fields to that typical of larger volcanic land masses.
Several key Japanese phrases, like "Tay-oh-ah-geh-tay-deh-tay-kai" (put up your hands) and the Japanese equivalents of "hurry up," "come out and we will give you food and water," etc., were introduced into the vocabularies of all hands with the hope that some of the routine conversational exchanges would not require the services of an interpreter. These lessons were administered to the Marines at their most receptive time: before the evening movie.95
The phases of general training culminated for all divisions in a period aboard ship. The 2d Marine Division conducted amphibious maneuvers during the period 12-31 March on beaches at Maalaea Bay, Maui, with all of its elements participating. Similar training was conducted in the same area by the 23d and 25th Marines of the 4th Marine Division during the period 13-26 April. The 24th Marines and 4th Division Troops participated in several preliminary boat exercises, using the facilities of the Maui Amphibious Training Center. During the later part of April, the 27th Infantry Division executed its shipboard training at Maui. The elements of the Corps Special Troops were instructed initially by Corps; but once attached to divisions, these elements participated in division training to familiarize them with their roles and to acquaint them with the infantry units with which they would operate.96
The divisions did not accomplish their training without difficulty, however; the 2d Division's camp on the island of Hawaii and the 4th Division's camp on Maui were incomplete in many respects. Considerable time was necessarily spent making these camps liveable. At Camp Maui, the ubiquitous red clay caused much annoyance. In dry weather, everything was covered with red dust, in wet weather, with red mud. Camp Tarawa, the 2d Division's camp at Kamuela, was located near vast, sprawling lava fields, and movement through these was dangerous. Many sprained ankles and bruised knees resulted from marches over the jagged gray eruption.
On the credit side of the ledger, both divisions had ample room to conduct firing exercises. The artillery regiments of the two divisions, in particular, enjoyed the wide open spaces which allowed them to spread out and fire at long ranges. Much attention was devoted to coordination and integration of the various arms throughout the period of preparation.
One device which proved very fruitful was that employed by the 2d Marine Division at the culmination of its training program. This was a "walk through" rehearsal, executed on dry land but using the identical scheme of maneuver to be employed at Saipan. As explained by Major General Thomas E. Watson, the division commander:
In preparation for the exercise, the successive phase lines which had been designed to control the advance of the Division from the landing beaches to the Force Beachhead Line were laid out on the ground exactly to scale. In front of the staked-out beaches were marked the adjacent water areas over which the ship-to-shore movement was to take place off Saipan. Over this terrain game board the entire division was moved in accordance with the time schedule calculated for the actual assault and employing the scheme of maneuver designed for the attack. In this manner, every officer and man learned the part he was to play in the landing and came to appreciate the time and space factors involved. Yet, only a few commanders and staff officers of the thousands of men who participated in this rehearsal actually knew the real name of the target.97
Both Marine Divisions had previous amphibious combat experience; the 2d at Guadalcanal and Tarawa, the 4th at Roi-Namur. Portions of the 27th Division had served with the V Amphibious Corps before; the 165th Infantry Regiment during the Gilberts operation at Makin and the 106th in the amphibious assault against Eniwetok Atoll. The XXIV Corps Artillery was newly-organized, its 155mm gun battalions being former coast artillery units. All eight amphibian tractor battalions assigned (four Marine and four Army) were well trained. Of these, one of the Army battalions and two of the Marine battalions had previously experienced combat.
Concurrently with the final training and preparation for the rehearsal and final embarkation of the assault forces, the garrison forces were assembled. Major General Sanderford Jarman, USA, was assigned as Commanding General, Saipan Garrison Force, and Major General James L. Underhill, USMC, as Commanding General, Tinian Garrison Force. In close harmony with the plans of the assault and naval forces, these units prepared for their missions. The 864th Antiaircraft Artillery Group under Colonel Kenneth M. Barager, USA, part of the Saipan Garrison Force, was ordered to land with the assault forces on Saipan to "furnish antiaircraft protection in the zones of action of the 2d and 4th Marine Divisions."98
On 17 May a full-scale Corps landing was undertaken at Maalaea Bay, Maui. The 2d and 4th Marine Divisions landed abreast with a tactical problem ashore to simulate the actual planned scheme of maneuver to be employed on Saipan. Owing to the habitation of Maui, no live ammunition could be fired there. On 19 May, another exercise was undertaken at Kahoolawe, Hawaiian Islands.99 Troops boated in LVT's approached to within 300 yards of the beach under actual naval gunfire bombardment and aerial support but did not land. Immediately following this rehearsal, shore fire control parties of the Landing Force landed on Kahoolawe and conducted fire missions with their initially assigned fire support ships.100
Similar rehearsals were conducted by the 27th Infantry Division with the naval elements of the Joint Expeditionary Force Reserve between the 20th and 24th of May. As plans for a special commitment of the 1st Battalion, 2d Marines, were still under consideration, that unit with Company A of the Corps Amphibious Reconnaissance Battalion conducted a separate final rehearsal at Hanalei Bay, Kauai. Air drops of supplies, made during this exercise, proved the method employed satisfactory.101
Three unfortunate operational accidents occurred during the rehearsal phase which resulted in two dead, 17 missing and 16 injured.102 Aboard LST 485, which was transporting a portion of the 2d Battalion, 8th Marines, men were sleeping in a Landing Craft Tank (LCT 988) which was secured on the deck of the LST. The weather was rough and the strain on the cables was too great; at 0230 on the morning of 14 May the craft was pitched overboard with the sleeping men aboard. Nineteen men were either missing or killed, and five were injured as the craft was rammed and sunk by the next LST in column.
Similar accidents occurred aboard LST's 71 and 390, when LCT's 999 and 984 slipped overboard. Losses on these two, however, were not as great. LCT 999, its ramp door closed, suffered little damage and was towed back to
Pearl Harbor. LCT 984, however, had its ramp and engine doors open when launched and became so badly waterlogged that it capsized and sank slowly, assisted at the end by gunfire. The search for survivors continued throughout the night, and many were rescued.
An investigation of the accidents revealed that insufficient and perhaps, improper securing, plus the fact that at least two of the LCT's were carrying heavy loads of fresh water, may have been chiefly responsible for the accident. The weight of extra ammunition for the LCT's 4.2-inch chemical mortars may also have been a contributory factor to the mishaps.103
The rehearsals proved particularly valuable in the training derived from the ship-to-shore movement--involving over 700 LVT's--and in the test of the overall communication plan. Critiques were held following the rehearsal, and minor defects that had been discovered were pointed out and corrected in so far as practicable. Benefit was derived from the experience and familiarization gained by various elements of the Joint Expeditionary Force actually working together under circumstances closely paralleling those expected during the actual operation.
When the rehearsal was completed on 19 May, the bulk of the force returned to Pearl Harbor and Honolulu for rehabilitation. One-half of the LST's with embarked assault troops, however, remained at Maalaea Bay, Maui. With such a large force at Pearl Harbor, sufficient facilities and space for exercising the troops were not available. It was possible, however, to bring small units ashore each day for recreation. At the same time, the remainder of the loading was accomplished.104
On 21 May, with ships tightly clustered at Pearl Harbor readying for the final approach to the objective, disaster struck.
LST 353, tied up at West Loch unloading its 4.2-inch mortars and ammunition for those weapons, suddenly, unaccountably, burst into flames and exploded.105 Black smoke billowed wildly from the scene, shattering explosions rent the air as the fire spread to five more LST's. Other ships in the vicinity of those doomed hastily got underway to prevent further spread of the destruction. Marines and sailors aboard the burning ships dived into the water, leaving weapons, clothing and equipment behind in their frantic efforts to escape. Many swam ashore with only a pair of trousers or shorts left of their possessions.
As the fires continued, small ships equipped with fire-fighting apparatus moved in close to LST's and tried to subdue the inferno. Personnel watching the catastrophe stood with nervous anticipation, fearing further explosions which would mean almost certain death for the fire fighters. Their devotion to duty excited the admiration of all onlookers. Perched precariously on their tiny red craft, these men moved closer than safety or common sense would dictate. Continuous small blasts sprayed the area with fragments of shells and pieces of equipment, and there was no assurance that the entire area might not go up in one gigantic explosion at any moment. But the fire fighters remained stubbornly at their posts.
In the end, they could not save the ships that were burning, but they were successful in preventing a spread of the damage. By dark, six LST's were lost106 with heavy resultant casualties in personnel and equipment. By good fortune, however, most of the amphibian tractors and DUKW's had debarked from the ships for routine checkups ashore prior to the fire.
As the LST's were transporting assault troops and in view of the imminence of the operation, the losses were especially critical. The 2d Marine Division lost a total of 95 men and the 4th Division 112 in this disaster. Rumors were rife that sabotage had caused the disaster, but an investigation failed to reveal that it was other than an unfortunate accident.107
Immediately following the explosion, all agencies concerned were called into action to assist in caring for the injured and surviving troops. Clearing stations were organized through which survivors were directed to the hospitals or to the Transient Center, V Amphiibious Corps. Replacements had to be supplied as soon as possible. This was accomplished promptly from personnel at the Replacement Center.108
The LST's were to have sailed on the morning of 24 May, less than three days after the costly fire. It was apparent that a delay in departure would be demanded. But for how long? The gears of the attack machine were meshed to an established target date; delays could upset the smooth timing. Concern along these lines was soon relieved, however, as efficient staff work paid off. Ships, personnel, equipment and supplies were replaced in four short days and LST's sailed only 24 hours late, with the lost day being made up en route.109
Movement to the Objective
The Northern Attack Force departed from Pearl Harbor in echelon. The slow-moving LST groups with assault troops, LVT's and artillery embarked, left on 25 May. Attack Group One, embarking the remainder of the 4th Marine Division and Headquarters, Expeditionary Troops, sailed on 29 May. Attack Group Two, with the 2d Marine Division and Headquarters, Northern Troops and Landing Force embarked, left Pearl Harbor on 30 May. Other echelons of Garrison Forces and resupply shipping were scheduled to depart at later dates.
En route to the objective, every individual was thoroughly briefed on the plans for the attack on Saipan. Schools and staff exercises were conducted, lectures were given; photographs, relief maps, terrain models and charts had been prepared and furnished all units. Every individual was completely informed of the detailed plans for the attack. The force arrived at Eniwetok Lagoon for final staging between the 6th and 11th of June.110
The troop-carrying limitations of LST's precluded the comfortable embarkation of complete tactical units for the lengthy voyage from Hawaii to Saipan. Though each of these vessels carried sufficient amphibian tractors to lift an entire rifle company, they failed to provide adequate sleeping spaces for the full complement of troops. It was therefore ordered that surplus personnel, who could not be thus accommodated, travel from Hawaii in the comparative comfort of AP's and transfer to appropriate LST's at Eniwetok. Tactical advantages of arrival at Saipan as integrated assault units warranted the overcrowding during the last six days of the trip, and despite the fact that the Marines were packed like sardines during this period, there is no evidence that fighting efficiency was impaired.111 At all times crews and maintenance details for embarked LVT's and LVT(A)'s were billeted in LST's bearing their vehicles.112
Naval Gunfire and Air Bombardment
While LST's and transports carrying assault forces churned toward Saipan, preparatory bombardment of targets areas had begun. On the afternoon of 11 June, Vice Admiral Marc A. Mitscher's Task Force 58113 initiated three and one-half days' intense bombardment of Saipan, Tinian, Guam, Rota and Pagan.
Originally, softening of the target was to have begun to 12 June; but this was changed when Admiral Spruance approved Mitscher's recommendation that a fighter sweep be executed on the afternoon of the 11th. Mitscher gave as the principal reason for this alteration the desirability of varying the pattern of strikes and taking advantage of the opportunity for surprise. "Heretofore," reported Mitscher after the operation, "all of our carrier attacks had been made in the early morning. It was believed that the enemy had become accustomed to this and would expect us to continue this practice."114
While the carriers were still 200 miles east of the islands, a 225-plane fighter sweep surprised the Japanese in the Marianas and destroyed 150 planes in the air or on the ground. This crippling blow depleted the local air strength by about one-third and thereafter prevented the enemy from reacting in strength. The United States advantage, once gained, was never lost. "Control of the air," reported Admiral Nimitz, "had been effected by the original fighter sweep on 11 June."115 The tactic of the afternoon strike had proved feasible and, according to the commanding officer of one of the participating air groups, was "an excellent innovation . . . . "116
On 12 June the serious bombing began; Saipan and sister islands felt the impact of tons of high explosives dropped upon airfields and installations. The 13th brought a resumption of the rain of bombs. With most of their planes either burned on the ground or missing in action, the Japanese responded only with sporadic dusk and night attacks during this preliminary phase of the operation.
The inability of the enemy to foresee the imminent danger to the Marianas left two vulnerable convoys in the area when Mitscher's Task Force entered. The first of these, a formation of 20 ships, fleeing on a northerly course 125 miles west of Pagan Island, was attacked on the afternoon of the 12th by planes of Rear Admiral William K. Harrill's Task Group 58.4 To the south, 135 miles west of Guam, the other convoy (six ships) became the target for a special attack mission sent by Rear Admiral Joseph J. Clark, commanding Task Group 58.1. Between the two attacks 12 cargo ships, three submarine chasers, and one patrol-torpedo boat were sunk.117
Surface ships of TF 58 began to bombard Saipan on 13 June (D-minus 2). The fast battleships fired their main and secondary batteries for nearly seven hours into the western coast of Saipan and Tinian, turning the
impact areas into scenes of desolation. Aircraft, aviation facilities, antiaircraft emplacements, coast defense guns, canefields and enemy installations of many types were struck. At night, the persistent harrassing fires of TF 58's destroyers denied the Japanese even an hour's relaxation. This "around the clock" shelling prevented last minute improvement and repair of positions and greatly complicated the enemy commanders' tasks of readying their commands.118
The enemy's reaction to Mitscher's strikes of 11-12-13 June is indicated by the diary account of a Japanese tank noncommissioned officer, Tokuzo Matsuya:
11 June--At a little after 1300, I was awakened by the air raid alarm and immediately led all men into the trench. Scores of enemy Grumman fighters, began strafing and bombing Aslito Airfield and Garapan. For about two hours, the enemy planes ran amuck and finally left leisurely amidst the unparalleledly inaccurate anti-aircraft fire. All we could do was watch helplessly.
12 June--With daybreak enemy planes (even more than yesterday) made a sudden attack. The all day strafing and bombing was much heavier. It must have caused great damage at Garapan and Aslito Airfield.
13 June--At 0930, enemy naval guns began firing in addition to the aerial bombing. The enemy holds us in utter contempt. If only we had a hundred planes or so.119
Sitting in a ringside seat on Tinian (six miles south of Saipan), an unidentified Japanese noncommissioned officer wrote in his diary on 12 June:
Of all the tens of Japanese planes one can't see even one during a raid. The planes which cover the sky are all the enemy's. They are far and away more skillful than Japanese planes. Now begins our cave life. Enemy planes overhead all day long--some 230 in number. They completely plastered our airfields. . . . Where are our planes? Not one was sent up. Our AA guns spread black smoke where the enemy planes weren't. Not one hit out of a thousand shots. The Naval Air Group has taken to its heels.120
As already indicated, Admiral Mitscher's Task Force inflicted considerable damage and contributed much to the eventual successes on Saipan, but its effectiveness was limited by several factors which are worthy of note. First, the seven fast battleships were required to remain beyond the range of shore batteries and outside possible mined areas. In regard to this, Admiral Spruance has written ". . . the broad shelf to the westward of the island gave minable depths. As the minesweepers did not arrive and start sweeping until D-1 Day (14 June), the fast battleships obviously ought not to steam through what might be mined waters to conduct their bombardment."121
As a result, fires were delivered from ranges in excess of 10,000 yards. Experience in the Gilberts, Marshalls and Eniwetok had taught that ships must close the range and fire direct fire, spotting from the ship itself, if complete destruction of installations, and fortications were to be realized. In contrast to the desired employment, there were instances of battleships firing 5-inch 38 at ranges in excess of 16,000 yards--too great for destruction of point targets.
The fast battleships, as a group, lacked the training and experience necessary for effective shore bombardment.122 This type of firing, involving methodical, patient, adjustment, was fundamentally different from the firing necessary to succeed in an engagement at sea. Where ships had not received specific training in shore bombardment, their effectiveness on this mission was considerably reduced. Task Force 58, of necessity, had devoted the bulk of its training and thinking to fighting surface engagements, with due emphasis on speed and maneuverability. Consequently, the special difficulties attendant to the destruction of small land targets had received but scanty attention. Both in size and distinctiveness, a well-camouflaged pillbox presented an entirely different type of target than an enemy ship.
Since TF 58 was dependent on air spotters for adjustment of its fires, it follows that these
UNDAMAGED JAPANESE PILLBOX harmonizes with surrounding terrain. Such inconspicuous targets received scant attention from bombarding ships. Only those positions receiving direct hits were silenced.
spotters should be adept in locating and recognizing important enemy ground installations and defenses. Spotters, in most cases, lacked the vital training necessary to develop this ability and, consequently, directed fire on obvious buildings and terrain features which made interesting but unprofitable targets. A case in point is the sugar mill at Charan Kanoa. This building, a prominent landmark, easily identified, had been riddled with shot and shell. The Japanese, however, were not inside, nor were they using the mill for military purposes.
In addition to those reasons already given, the effectiveness of TF 58's bombardment was further limited because of an overemphasis on covering all assigned areas. (so-called "area-shooting") to the neglect of specific point targets within those areas. Intercepted radio transmissions indicated that ships often shifted to new targets without applying the air spotter's last correction and adjustment.123
A comment by Admiral Spruance in regard to the employment of the fast battleships for shore bombardment is pertinent:
The use of the fast battleships . . . was done with a view to increasing the number of large bombardment shell that could be carried in the heavy ships . . . without too great a reduction in the armor piercing rounds that the [fast battleships] must carry for fleet engagement. This served a useful purpose, but it was never intended to take the place of the close-in fire of the [old batleships] to which it was a useful preliminary.124
On 14 June (D-minus 1) fire support ships of the Northern and Southern Attack Forces (TF's 52 and 53), under the command of Rear Admiral Jesse B. Oldendorf, arrived off Saipan and joined TF 58 in a blasting bombardment
SUGAR MILL IN CHARAN KANOA, an obvious target, received more naval gunfire than it deserved. Smokestack provided one ingenious Japanese an observation post for several days after United States landings.
of beaches and installations. For the D-minus 1 and D-Day naval gunfire preparation, Admiral Turner divided the islands of Saipan and Tinian into seven fire support sectors and assigned a fire support unit to each. (For sectors and ships assigned to each, see Map 6.) Fire Support Unit Eight was not assigned a specific sector for the D-minus 1 bombardment and was to "deliver counterbattery fire only as required." On D-Day, with its ammunition supply virtually intact, Unit Eight would move into the western portion of Sector 6 and deliver "intense enfilade fire at the Charan Kanoa beach installations."
Ships firing in critical Sector 1 (which included the preferred landing beaches) would furnish covering fire for mine sweepers and underwater demolition teams as well as to "destroy beach defenses . . . particularly including Afetna Pont." These ships were also to destroy all buildings and installations at Charan Kanoa except those facilities that might later be converted to our own use.
The six destroyers of Fire Support Units Two and Three would participate in the D-Day bombardment only. On D-minus 1, these ships would afford protection to the advancing LST's and transports of TF 52. It will be noted that sectors 2 and 3 were smaller segments of sector 1, with the range very much reduced. The reason for this preponderance of power off the western coast was that the Charan Kanoa beaches had been selected as preferred landing areas.
Fire Support Unit Four, in addition to covering mine sweepers and underwater demolition teams operating within its sector, would prepare the alternate landing areas for possible use and cover the Demonstration Group.
Fire Support Units Five, Six and Seven would destroy enemy guns and installations lying within their sectors.
In addition to the specific targets assigned, supports ships were to "fire all unburned cane fields (using WP projectiles) within their sectors."125
Map 6
Fire Support Sectors
The bombardment of 14 June generally proceeded acording to plan; certain alterations, however, were demanded by the development of the situation. Rear Admiral Howard F. Kingman's Fire Support Unit One experienced difficulty in destroying Japanese installations on Afetna Pont; combined fires of Birmingham and Indianapolis throughout the morning failed to achieve destruction or, indeed, even complete neutralization, inasmuch as mortar fire, apparently emanating from the point, constantly menaced the ships. Because of this situation, Admiral Kingman issued orders to Tennessee, California and Birmingham to concentrate on Afetna Point during the afternoon instead of assigned targets in Charan Kanoa. In addition, two strafing-bombing strikes were placed on the point during the afternoon. The result of all this was that defense positions appeared to be neutralized but not destroyed.126
Fire Support Unit Four (commanded by Rear Admiral Jesse B. Oldendorf, who also commanded the Task Group) did not experience the expected opposition from Flores Point or from Maniagassa Island, and Maryland and Colorado were therefore directed to concentrate on Japanese batteries in the vicinity of Mutcho Point. The cruiser Louisville took over the missions formerly assigned the two battleships.127
Rear Admiral Robert W. Hayler's Fire Support Unit Five covered its assigned sector on Saipan's east coast, though it experienced difficulty in locating enemy installations. This unit was assigned to remain off Saipan, delivering harrassing fires throughout the night of 14-15 June, while the remainder of the task group retired to the westward.128
Operating in Sector 6 was Rear Admiral Walden L. Ainsworth's Fire Support Unit Six,129 covering its assigned area without special incident. One point of interest, however, is found in the fact that the battleship Pennsylvania, after firing at Nafutan Point (on the southeast tip of the island) for approximately eight hours, failed to achieve complete neutralization. Almost as soon as the Pennsylvania's fire ceased, a Japanese shore battery impudently opened fire upon, but failed to hit, the cruiser Montpelier. This again illustrated that neither destruction nor neutralization was guaranteed even by relatively long periods of bombardment.130
Fire Support Unit Seven, commanded by Rear Admiral George L. Weyler, bombarded the west coast of Tinian throughout the day in accordance with its instructions, while Rear Admiral Charles T. Joy's Fire Support Unit Eight observed Tinian's east coast to protect Unit Six from Japanese shore batteries.131
With the arrival on 14 June of the old battleships, cruisers and destroyers of the Joint Expeditionary Force, the quality of the shore bombardment improved greatly. The reason for this was no mystery; these ships had devoted considerable time to shore bombardment, both in training and battle experience. During the rehearsals at Kahoolawe, a month prior to the operation, the old battleships had received valuable experience. They knew the necessity of slow, painstaking adjustment in shore bombardment, that merely covering an area was not sufficient. At Tarawa, where the development of the technique was still suffering growing pains, the fallacy of area-shooting was clearly revealed. Methodical pin-pointing of targets, complex bookkeeping, careful weighing of priorities, and studious damage assessment are requisites to efficient shore bombardment.132
While the old battleships practiced, TF 58's new battleships had been far at sea executing raids, with little or no opportunity to train in
shore bombardment. This, plus the aforementioned range restriction, resulted in area-shooting rather than systematic pin-pointing.
Even with the improvement of shore bombardment beginning with the arrival of the old battleships, however, certain factors limited a really effective preparation. First and foremost was the shortage of time with respect to the very large number of targets. Since the older battleships did not arrive until D-minus 1, allowing them to participate in only one day of preliminary bombardment (as distinguished from the D-Day fires), it is apparent that adequate time for these ships did not exist. Second, was a failing already discussed in relation to TF 58--lack of training of air spotters in distinguishing important targets ashore. (Here, again, obvious targets attracted entirely too much attention.) Third, was the necessity that support ships of TF 53 (Fire Support Units Six, Seven and Eight) conserve ammunition for the bombardment of Guam, expected to take place within a few days. On D-Day another restrictive would be added--targets farther than 1,000 yards inland were to be attacked only by aircraft until H-Hour. Although done in the interests of employing both supporting arms to the maximum without using precious time coordinating their efforts, it resulted in some targets escaping the fires of the weapon best suited for their destruction.133
Operation reports mention a number of reasons which contributed to prevent satisfactory neutralization or destruction of targets on Saipan--the size of the island, the large number of defensive installations, the enemy's excellent use of camouflage, and the mobility of many of his weapons.134 These same characteristics, however, could as well apply to many other islands (Guam for example), and do not represent conditions peculiar to Saipan.
Operating under cover of naval gunfire three underwater demolition teams (UDT's)135 moved close inshore during daylight of 14 June to perform their hazardous tasks. There, with eyes anxiously searching for signs of enemy activity, skilled hands prodded the reef floor for obstacles, mines, and the like. Once found, such obstacles had to be removed or destroyed. Teams were assigned as follows: Beaches Red Two and Three and Green One and Two--UDT #5; reef at the north side of Tanapag Harbor, leading to Beaches Scarlet One and Two (alternate plan beaches)--UDT #6; Beaches Blue One and Two and Yellow One and Two--UDT #7.
UDT #5 (covered by California and Birmingham,) and UDT #6 (covered by Maryland, Colorado and Louisville) proceeded according to plan, neither team suffering casualties. For the men of UDT #7, however, it was a different story; heavy fire from Beaches Blue and Yellow greatly complicated their tasks. To assist them, Tennessee and Indianapolis laid down an intense 5-inch and 40mm barrage along the beaches but were unable to neutralize enemy positions sufficiently for UDT #7, to conduct a complete reconnaissance. Hostile fire notwithstanding, UDT #7 executed its reconnaisance to the following distances from beaches: Blue One--Waterline; Blue Two--75 yards; Yellow One--Reconnaissance impossible except lip of reef; Yellow Two--100 yards.
At 0956, Commander UDT #7 requested smoke to screen rescue of survivors--including seven wounded. For this screen, the destroyer Wadleigh fired 87 rounds of 5-inch 38 white phosphorous. The battleship Tennessee also fired several white phosphorous rounds along the beach to assist in the evacuation. This constituted the Navy's only use at Saipan of screening smoke for other than screening transport areas and anchorages.136
No one was disappointed to find that preassault demolitions would be unnecessary at Saipan. But, despite the lack of obstacles, the UDT's were able to provide some valuable information to the landing force, information concerning reef conditions, depths of water, channels, surf, tide, current, and defenses on the beach.137
More information in this connection had been acquired on 13 June (D-minus 2) by Commander William I. Martin, USN. Leading his torpedo-bomber squadron (VT 10) from the carrier Enterprise in strikes against beach defenses, Martin's plane was downed by Japanese antiaircraft fire near the radio station north of Charan Kanoa. Although his two crewmen were killed, the commander swam out to the reef. While awaiting rescue, he noted down a number of pertinent facts regarding tidal conditions, depth of water over the reef, and nature of the reef floor. This report was transmitted to the landing force prior to D-Day.138
Also jotting down notes was Japanese noncommissioned officer Tokuzo Matsuya. In his diary entry for 14 June, he reveals bitterness at the failure of Japanese planes to appear over Saipan, coupled with very realistic philosophy:
Where are our planes? Are they letting us die without making any effort to save us? If it were for the security of the Empire, we would not hesitate to lay down our lives but wouldn't it be a great loss to the "Land of the Gods" for us all to die on this island? It would be easy for me to die but for the sake of Japan's future I feel obligated to stay alive.139
Actually, this NCO saw through the picture more completely than did most of his superiors, who thought that it was just a matter of time until the mighty Japanese air arm asserted itself.
The imposing array of sea power off Saipan might have frightened a less persistent foe to silence, but the Japanese periodically emerged from cover to answer the challenge. In most instances their shells only churned the water, but twice on 14 June they found their intended mark. Destroyer Braine (of Fire Support Unit Seven) and battleship California (of Fire Support Unit One) were hit by one shell each while engaging in shore bombardment. Though neither ship suffered critical damage, the shelling had its effect; Braine's number 2 torpedo mount and after fireroom were put out of commission by a 6-inch shell from Tinian, and California's main battery director and forward radar were rendered inoperative by an exploding missile (estimated 105mm) from Saipan. The destroyer had three men killed and 15 injured, the battleship one killed and nine wounded.140
It should be noted that preliminary bombardment of Saipan was limited to carrier and surface strikes. There was no land-based air support prior to the landing. While land-based air assisted the operation indirectly by attacks on other islands, none could be employed against Saipan itself because of distances involved. Also, there was no possibility of artillery support prior to the landing from lesser islands within suporting range, as had been possible at Kwajalein, Roi-Namur, and Eniwetok. There was no continued preparation of any sort over an extended period of time, such as that which was to prove so effective in the preparation for the Guam and Tinian operations.141 In this connection, General Holland
Smith later wrote: "The initial mistake was this: we did not soften up the enemy sufficiently before we landed."142
Saipan was the most heavily defended of the three islands, despite the fact that the Japanese defensive preparations were incomplete at the time of our landing. One may only speculate on how much more costly the operation would have been if the Japanese defensive plans had reached fruition. Likewise, we may only speculate on how much less costly it would have been if preparatory fires had been adequate.143
Related Covering Actions
The scope and extent of the Saipan venture demanded that many areas in the Pacific be at least temporarily neutralized, so that the Japanese would have false clues as to the target area and so that our approach and landing would not be strongly contested by enemy aircraft. This build-up was vital to success.
Among the far-removed covering actions were the operations of the Eleventh Army Air Force, flying from its bases in Alaska and the Aleutians against Japanese installations in the Kurile Islands. This unit's raids, mounted in the face of harsh Arctic conditions, affected the Saipan operation in an indirect--yet important--manner; a portion of the Japanese air force was diverted from the Central Pacific and sent to defend the icy north.144
Wake and Marcus, which flanked on the north our approach to the Marianas, were the targets for a carrier raid almost a month before the Saipan landings. This raid, under the tactical command of Rear Admiral Alfred E. Montgomery, USN, was designed both to neutralize the threat to the projected supply line from the Marshalls to the Marianas and to indoctrinate several new air groups. Three carriers participated--Essex, Wasp and San Jacinto.145
Wake and the by-passed atolls were methodically bombed by the land-based Army planes of Major General Willis H. Hale, USA, acting under the general direction of Vice Admiral John H. Hoover, USN. Truk, also, was kept neutralized by these forces in coordination with land-based planes from the South and Southwest Pacific.146
More intimately keyed to the target date were the strikes on the Palaus. Executed by aircraft of MacArthur's Southwest Pacific Forces, the bombardment began on 3 June; from 9 June until the Saipan landings these islands and others in the western Carolines were harassed daily. This activity minimized possibilities of trouble from the south and southwest.
To prevent the Japanese from staging aircraft through the Bonins in the north, two task groups (Clark's 58.1 and Harrill's 58.4) of TF 58 departed Saipan on 14 June for an attack. This move was the deepest penetration of Empire waters ever made by a carrier striking force up to this time. In the teeth of a growing gale, fighter sweeps and bombing missions were launched against Iwo Jima, Chichi Jima and Haha Jima; and, despite airborne opposition and unfavorable flying conditions, the mission was accomplished and the effectiveness of the Bonins as an aircraft staging area was greatly reduced.147
Final Approach of the Northern Attack Force
Details of staging at Eniwetok Lagoon, meanwhile, had been completed on time, and the Northern Attack Force departed by echelon on the 8th, 9th and 10th of June. The
entire movement to the objective was uneventful, the weather was pleasant, and no portion of the Northern Attack Force was detected. During the movement of the attack force to Eniwetok, while there, and in the subsequent move to Saipan, radio silence (except on very high frequency) prevailed.148
LST's with assault waves embarked and transports of the Joint Expeditionary Force arrived at the target area before dawn of 15 June. Strategic surprise appears to have been gained, but the bombardment which had begun on 11 June, together with the work of the Underwater Demolition Teams, denied any hope of tactical surprise.
The armada now in position off the western coast of Saipan was tremendous. One hundred ships were required to transport the Northern Landing Force, plus four to five times that number of supporting vessels.149
Personnel aboard those ships had been much heartened during their approach by an optimistic dispatch from Admiral Mitscher (whose Task Force 58 had been pummeling Saipan and sister islands for several days): "Keep coming, Marines; they're going to run away." But, on an island only fourteen and one-fifth miles long and six and one-half miles wide, there isn't much room to run--if, indeed, one wished to run.
Table of Contents ** Previous Chapter (Foreword) * Next Chapter (2)
1. The basic concept of the "leapfrog" strategy was to seize those islands essential for our use, bypassing many strongly held intervening ones which were not necessary for our purpose. The disparity between our naval power and that of the enemy made it virtually impossible for the Japanese to support the garrisons of bypassed islands, and these bases became innocuous. (Though considerable effort was required to keep them that way.)
2. USSBS, The Campaigns of the Pacific War, 204, hereinafter cited as Campaigns. The War Reports, Admiral King's Report, 586, hereinafter cited as King. Ltr from Adm R. K. Turner to CMC, 4Jan50, hereinafter cited as Turner.
3. King, 589.
4.The foregoing account of the historical background is a synthesis of the following sources: Pacific Islands Under Japanese Mandate, Tadao Yanaihara, 8-28; The Pacific Islands Handbook, 1944, R. W. Robson, 150-151; Encyclopedia Brittannica, Vol. XVII, 4-5; JICPOA Information Bulletin 7-44, "Marianas," 5; Smithsonian Institution War Background Studies Number Sixteen, Peoples of the Western Pacific, Micronesia, and Melanesia, Herbert W. Krieger, 35.
5. G-2 Study of the Southern Marianas, V Amphibious Corps, 21, hereinafter cited as G-2 Study. JICPOA Information Bulletin 7-44, 50.
6. Unlike other Japanese airfields, Aslito had no provision for turning circles, but wide runways afforded sufficient space for this function. Jutting to the north from the center of the main runway was the larger of two service aprons. This apron, 900 feet long and 600 feet wide, gave access to the three main hangars. About 250 yards to the east, a secondary apron (900 feet by 165 feet) fronted two small hangars.
7. Northern Troops and Landing Force, G-2 Report, 74, hereinafter cited as NTLF G-2 Report. G-2 Study, 23.
8. JICPOA Information Bulletin 7-44, 51-52.
9. This is double the amount that annually falls on New Orleans, our wettest city; is triple that of New York City, Washington, D. C. and Philadelphia; five times that of Omaha; six times that of San Francisco; and dwarfs the fall at Yuma, Arizona by 33 times. Smithsonian Miscellaneous Collections, World Weather Records, Vol. XC, 316-356, hereinafter cited as World Weather Records.
10. Though this seems like considerable rain, Saipan gets the least of any island in the region (Carolines, Marianas, Palaus). Sailing Directions for the Pacific Island, Vol. 1, 566.
11. G-2 Study, 27.
12. JICPOA Information Bulletin 29-44, Weather Survey for Carolines and Marianas, 2-3. World Weather Records, 331.
13. After D-Day this production stopped, but the flies did not. Making the most of the situation, these insects embarked on a veritable orgy of feasting and reproduction.
14. JICPOA Information bulletin 7-44, 58-60.
15. Report on Japanese Defense Plan for the Island of Saipan, Southern Marianas, prepared by the Engineer, Expeditionary Troops (TF 56), July 1944, 1, hereinafter cited as TF 56 Engineer's Report.
16. CINCPAC-CINCPOA Item #9652.
17. NTLF G-2 Report, 6.
18. Task Force 56 (Expeditionary Troops), G-2 Report, hereinafter cited as TF 56 G-2 Report, 7.
19. This unit was the original Saipan garrison force and prior to the change of its name had been called "1st Expeditionary Force." In his order of 8 June 1944, LtGen Obata had ordered that the 47th Independent Mixed Brigade be transferred to Tinian and relieve the 50th Infantry Regiment of the task of defending that island. The 50th would then go to, and defend, Rota. The transfer was to commence about 15 June 1944, but United States landings on that date disrupted Obata's plans. CINCPAC-CINCPOA Item #9645.
20. NTLF G-2 Report, 66-69 and App. J. For a detailed Order of Battle, with strengths of individual units, see Appendix VIII.
21. Ibid., 8-9. It will be noted that the 118th Infantry Regiment was not assigned a specific mission. This unit arrived during the first week in June and, therefore, was too late for the defense order. Its presence, however, afforded General Saito a sizeable reserve to use wherever he chose.
22. Ibid., 8-9.
23. TF 56 Engineer's Report, 1-2.
24. These were the American and British Chiefs of Staff meeting together. It is pertinent to note that, in the war with the most amphibious characteristics of any in history, no senior United States Marine was included on the high planning level.
25. CCS 56th Meeting, 14Jan43.
26. RENO I, 25Feb43.
27. JPS 67/4; JCS 287 and 287/1; Minutes JCS 76th and 80th Meetings.
28. TRIDENT, 21May43. 92d Meeting.
29. Radio message, CINCSWPA (Gen MacArthur) to WARCOS (Gen G. C. Marshall) C-3302, 20Jun43, CM-IN 13149.
30. RENO II, 3Aug43.
31. CCS 373, 18Aug43, Appreciation and Plan for the Defeat of Japan: Minutes CCS 110th Meeting. 17Aug43.
32. Radio message, CINCSWPA to WARCOS, C-6131, 28Sep43, CM-IN 19656.
33. Radio message, WARCOS (for JCS) to CINCSWPA 8079, 2Oct43, CM-OUT 630.
34. RENO III, 20Oct43.
35. JPS 264, 6Sep43.
36. Ltr from Adm C. W. Nimitz to the JCS, 30Sep43, subject: "Garrison Requirements in the Central Pacific Area."
37. The Truk strikes had the additional purpose of covering the landings at Eniwetok.
38. JCS 123d and 124 Meetings, 15 and 17Nov43.
39. Churchill classified the report as a "masterly survey of the whole military scene" and gave his opinion that when military historians came to adjudge the decisions of the SEXTANT conference, they would find them fully in accordance with the "classic articles of war." SEXTANT, 5th Plenary Meeting.
40. "Report to the President and Prime Minister," CCS 426/1. CCS 136th and 137th Meetings, 5th Plenary Meeting.
41. The "Inner Zone" included: Japan proper, Manchuria, Korea, North China, Karafuto (Japanese Sakhalin) and Formosa.
42. "Specific Operations for the Defeat of Japan." CCS 397 revised.
43. Enclosure to CCS 397 (revised).
44. "Over-all Plan for the Defeat of Japan," CCS 417 and 417/1. CCS 130th, 134th and 137th Meetings. 1st and 2d Plenary Meetings.
45. Ibid.. CCS 417/2. 23Dec43.
46. GRANITE, 27Dec43, 7.
47. GRANITE, 13Jan44.
48. Radio Message, CINCPOA to CINCSWPA, 070521/Z Jan44, CM-IN 8330; Radio Message, CINCSWPA to WARCOS, C-1217, 21Feb44, CM-IN 1443; Memo from Col W. L. Ritchie to Gen T. T. Handy, 4Feb44, subject: Brief of Pacific Conferences, Pearl Harbor 27-28Jan44; General Kenney Reports, George C. Kenney, 347-349.
49. General Marshall's Incoming-log; telephone conversation between Gen R. K. Sutherland (in Washington) and Gen R. J. Marshall in Brisbane, WD Telecon 192, 15Feb44.
50. JCS Memo for Information No. 200, 7Mar44, subject: Sequence and Timing of Operations, Central Pacific Campaign, a report by CINCPOA. Supplementary minutes, JCS 150th Meeting, 7Mar44.
51. This was the occasion for a message from the British Chiefs of Staff: ". . . warm congratulations on the brilliant success of the operations in the Pacific which have culminated in the devastating bombardment of Truk and have led to the dismissal of Field Marshal Sugiyama and Admiral of the Fleet Osami Nagano. . . . May Truk be but the prelude to even greater successes on the way to final victory in the days that lie ahead." JCS 148th Meeting 22Feb44.
52. Plans for the seizure of Emirau were well underway before the Joint Chiefs' 12 March directive. The 4th Marines (reinforced) landed on Emirau 20 March 1944. See Marine Corps historical Monograph "Bougainville and the Northern Solomons."
53. JCS 713/4, 12Mar44.
54 Task Force 56 (Expeditionary Troops), G-5 Report, 1, hereinafter cited as TF 56 G-5 Report.
55. CINCPOA, FORAGER Joint Staff Study. 20Mar44.
56. This operation, never actually executed, would have employed all of the Marine Divisions except the 3d; the 1st and 2d Marine Divisions would have constituted part of the Formosa assault force, landing on 15 February 1945; the 4th, 5th and 6th Divisions were to seize the port of Amoy, China, on 7 March 1945.
57. GRANITE II, 3Jun44. 9-13 and 25-26.
58. The Western Landing Group was composed of the Northern Troops and Landing Force, Assault Transport Group, LST Flotillas, Control Group, Gunboat Support Group, Beach Demolition Group, Beachmaster Group, LST Flotilla, and the Pontoon Barge Unit.
59. Amphibious Operations, Invasion of the Marianas. Commander in Chief United States Fleet, P-007, 1-9, hereinafter cited as COMINCH P-007.
60. Col Robert E. Hogaboom, who served as Assistant Chief of Staff, G-3, of the Northern Troops and Landing Force during the Marianas Campaign, points out that General Smith actually had a triple status at the time: "First, he was the administrative commander for certain designated Marine Forces in the Pacific; second, he was Commanding General, Expeditionary Troops; and third he was Commanding General, Northern Troops and Landing Force. Accordingly, General Smith initially had three staffs functioning under his command. One staff under a deputy commander remained in Pearl Harbor to conduct administrative matters during the campaign. A second staff, Expeditionary Troops staff, was embarked in the flagship of the Expeditionary Force and remained aboard that ship throughout the operation. A third staff, Northern Troops and Landing Force, initially embarked on the flagship of Rear Admiral Hill, went ashore on Saipan directly under General Smith." Ltr from Col R. E. Hogaboom to CMC 30Apr47.
61. Northern Troops and Landing Force Report, 2-3, hereinafter cited as NTLF Report.
62. TF 56 G-5 Report, 1.
63. The 2d Marine Division was commanded by Major General Julian C. Smith until 10 April 1944 when General Watson assumed command.
64. Task Force 56 (Expeditionary Troops), G-4 Report, 2-11 hereinafter cited as TF 56 G-4 Report.
65. Task Force 51, Operation Plan A10-44, Annex H, Medical, 2. Each of the three LST's had one doctor and eight hospital corpsmen aboard. Since this number was inadequate to care for the expected number of casualties, two doctors and 16 corpsmen would be transferred to each LST after arrival in the transport area.
66. TF 56 G-4 Report, 11-15.
67. NTLF Report, 7-8. This procedure was not possible in all instances, however; two transports assigned to the 2d Marine Division were on the west coast of the United States at this time. Ltr from Col R. J. Straub to CMC, 13Jan50.
68. Task Force 56 (Expeditionary Troops), G-1 Report, 1, hereinafter cited as TF 56 G-1 Report.
69. TF 56 G-2 Report, 1-2. Some fine submarine photographs (taken by the Greenling) of the target area were available; but the preferred landing beach areas on Saipan were not included.
70. Turner.
71. Ibid.
72. The exact time and place of this capture are not indicated in records consulted, but the time is assumed to be in the period D-Day to D-plus 6, during which time the advance was toward the east coast.
73. TF 56 G-2 Report, 4. These maps were reproduced by the 64th Engineer Topographic Battalion.
74. Ltr from BrigGen C. R. Wallace to CMC, 27Dec49, hereinafter cited as Wallace.
75. NTLF G-2 Report, App. A and B, 7.
76. Ltr from LtCol T. R. Yancey, USA, to DirPubInfo, 8Jul49, hereinafter cited as Yancey. This officer was one of several United States Army officers who served on the Corps staff.
77. Task Force 56 (Expeditionary Troops), G-3 Report, hereinafter cited as TF 56 G-3 Report, 2.
78. The 1st Battalion, 29th Marines, had been attached to the 2d Marine Division to fill the vacancy created when the 1st Battalion, 2d Marines, was assigned a special mission under landing force control (see below). Formed from personnel of the 2d Division, the 1st Battalion, 29th Marines, was later to join the 29th Regiment (6th Marine Division) for the Okinawa campaign. This "orphan" unit remained with the 2d Division throughout the Saipan operation.
79. Task Force 56, Operation plan 3-44 (26 Apr 44), Annex Able, Task Organization. For the detailed Task Organization, see Appendix VII.
80. 27th Infantry Division, G-3 Report, 6, hereinafter cited as 27 Inf Div G-3 Report.
81. At first glance it may appear that there was duplication in the mission assigned to the 2d Division and the 1st battalion, 2d Marines, inasmuch as both were instructed to seize Mt. Tapotchau. It should be pointed out, however, that the battalion could seize only the summit of the mountain, leaving the expansive slopes to the division. Elements of the 2d Division were to move up and join the battalion at the peak.
82. Ltr from LtCol W. B. Kyle to DirPubInfo, 13Nov48, hereinafter cited as Kyle.
83. NTLF Operation Plan 3-44, Change No. 1.
84. NTLF Operation Plan 3-44.
85. Task Unit 52.17.4 Report, 7.
86. Throughout this monograph, the designation "8th Marines," "23d Marines," etc., will be used rather than Regimental Combat Team 8 (RCT 8), RCT 23, etc. Thus, reinforcing troops (which make a regiment an RCT) are considered included in the 8th Marines (23d Marines) designation. In like manner, the 1st Battalion, 2d Marines, is used rather than BLT 1/2.
87. 2d Marine Division Report, Section V, 2-3, hereinafter cited as 2d Mar Div Report. 4th Marine Division Report, Section VI, 13, hereinafter cited as 4th Mar Div Report.
88. NTLF, Operation Plan 4-44 (3May44).
89. NTLF Opn Order 3-44, Annexes A and K. 2d Armored Amphibian Battalion Operation Order No. 2.
90. 4th Mar Div Report, Annex C, 2. 2d Mar Dir Report, Section II, I. Ltr from LtCol H. N. Shea to CMC, 13Jan50, hereinafter cited as Shea.
91. 10th Marines Report, I, hereinafter cites as 10th Mar Report. The Field Artillery Journal, Mar-Apr 48, "Amphibious Artillery," Maj E. J. Rowse.
92. Technically the 5th Battalion had already been designated "4th 105mm Howitzer Battalion, V Amphibious Corps"; but, since it was administratively and operationally attached to the 14th Marines, it was most often referred to as the 5th Battalion. After the Tinian operation the unit received 155mm howitzers, and its designation was changed to "4th 155mm Howitzer Battalion, V Amphibious Corps," under which name it participated at Iwo Jima. Ltr from LtCol D. E. Reeve to author, 11Aug49, hereinafter cited as Reeve.
93. 4th MarDiv Report. Annex C, 11. Interview with LtCol F. J. Karch 6Jan49, hereinafter cited as Karch.
94. TF 56 G-3 Report, 3.
95. By the time these expressions had received the treatment of a Brooklyn accent, with occasional profanity added, the effect was both humorous and confusing. Later, many Marines became quite wrathful when the Japanese could not understand them.
96. TF 56 G-3 Report, 4-5. 4th MarDiv Report, Section 3, 6.
97. Ltr from LtGen T. E. Watson to DirPubInfo, 9Jun49, hereinafter cited as Watson.
98. NTLF Report, 4-5.
99. Kahoolawe, just south of Maui and east of Lanai, absorbed more rounds than any island in the Pacific--and looked the part. Under Marine officer supervision, thousands of rounds of naval ammunition were expended monthly, concurrently providing training for ships and shore fire control personnel. In this manner, naval gunfire officers participated in firing exercises with the ships they would control in combat. Ships that were available to fire the Kahoolawe course were unmistakably superior in shore bombardment technique to those that were not. Courses similar to the one at Kahoolawe were located at San Clemente and in the Guadalcanal area. Marine Corps Gazette "Naval Gunfire Training in the Pacific," Jan 48, LtCol R. D. Heinl, Jr. Turner.
100. TF 56 G-3 Report, 5-6. TF 56 Naval Gunfire Officer's Report, 8, hereinafter cited as TF 56 NGF Report.
101. Kyle, 3. TF 56 G-3 Report, 6.
102. TF 56, G-1 Journal, 16 May.
103. Joint Expeditionary Force Report, TF 51, Encl A, 2, hereinafter cited as TF 51 Report. Annual Sanitary Report For The 2d Marine Division 1944, 91.
104. TF 56 G-3 Report. 6-8. NTLF Report, 5-6.
105. At the time of the explosion, LST 353 had on board the only LCT with 4.2-inch mortars that had not gone overboard on the tragic night of 14-15 May. An investigation, following the accidental launchings, had concluded that the excessive weight of 4.2-inch mortar ammunition was a contributory factor in the mishaps. This, plus the fact that it was too late to get more craft fitted with 4.2-inch mortars anyway, caused Admiral Turner, commander Joint Expeditionary Force, to order the project's abandonment. LST 353 was in the process of complying when the accident occurred. Turner.
106. These were LST's 39, 179, 480, 43, 69 and 353. The latter three had LCT's aboard which were also lost in the disaster.
107. TF 51 Report, Encl A, 2. 2d Mar Div Report, Sec. VI, 1. 4th Mar Div Report, 11. Interview with Col M. C. Horner, 13Jul49.
108. TF 56 G-1 Report, 2-3. The commanding officer of the 23d Marines, the regiment that suffered heaviest in this accident, commented that though the replacements were adequate in numbers, they "were not trained to carry out the functions of those lost." Ltr from MajGen L. R. Jones to LtCol G. D. Gayle 8Feb50, hereinafter cited as L. R. Jones.
109. NTLF Report, 8.
110. Ibid., 9. Eniwetok was also used as an assembly and staging point for all shipping moving to and from the Marianas. A convoy and routing organization was set up to control ships of all types, and was designed to prevent an undesirable congestion of ships in the Marianas, while at the same time making promptly available in that area such ships as were required. Fifth Fleet, Final Report on the Operation to Capture the Marianas Islands, 2, hereinafter cited as 5th Fleet Final Report.
111. Aggressiveness was perhaps increased. After six crowded days aboard an LST, many Marines were ready to fight anybody.
112. 2d Mar Div Report, Sec. II, 2.
113. TF 58 contained eight large carriers (Hornet, Yorktown, Franklin, Bunker Hill. Wasp, Enterprise, Lexington and Essex), eight light carriers (Bataan, Cabot, Belleau Wood, Monterey, Princeton, San Jacinto, Cowpens, and Langley), seven new (fast) battleships (Alabama, South Dakota, Indiana, New Jersey, Iowa, Washington and North Carolina), 13 cruisers (Boston, Baltimore, Canberra, Oakland, San Juan, Santa Fe, Mobile, Biloxi, Vincennes, Houston, Miami, San Diego and Reno) and 58 destroyers. From its 16 carriers, TF 58 could provide an air fleet of 900 planes. Fifth Fleet Operation Plan 10-44, 12-13. The Navy's Air War, Aviation History Unit OP-519B, DCNO (Air), edited by Lt A. R. Buchanan, USNR, 204-205, hereinafter cited as The Navy's Air War.
114. CTF 58 ser. 00388, 11Sep44, 31. Some histories have mentioned the reason for the speed up was that a Japanese search plane had spotted the Task Force as it sortied from Majuro and that Mitscher had decided to move as rapidly as possible. Admiral Spruance, however, says that this is incorrect. "A Japanese search plane . . . made a high altitude reconnaissance of Majuro a day or two before Task Force 58 sailed and again about three days after it had gone." This had no effect upon the change in the fighter sweep, however. Ltr from Adm R. A. Spruance to CMC, 17Jan50, hereinafter cited as Spruance.
115. CINCPOA Operations in the Pacific Ocean Areas, Jun44, 30.
116. Yorktown, ser. 0020, 29Jun44, 52.
117. The Navy's Air War, 205-206; King, 590; "Japanese Naval and Merchant Ship Losses During World War II By All Causes," Joint Army-Navy Assessment Committee (JANAC), 12 and 60-61, hereinafter cited as JANAC.
118. King, loc. cit. Naval Gunfire Support in the FORAGER Operation, 10, hereinafter cited as FORAGER NGF Report.
119. CINCPAC-CINCPOA Item #10,238.
120. CINCPAC-CINCPAA Item #11,405.
121. Spruance.
122. The exception that proves the rule: LtCol Joseph L. Stewart, Assistant G-3, NTLF, comments that "the North Carolina [one of the fast battleships of TF 58] was one of the best shooting ships I ever fired." Ltr from LtCol J. L. Stewart to CMC, 9Jan50.
123. FORAGER NGF Report, 2-10. NTLF, Naval Gunfire Report, 5, hereinafter cited as NTLF NGF Report.
124. Spruance.
125. Task Force 52 Attack Order A11-44, Annexes A and C.
126. Task Unit 52.17.1 Report, 6-7.
127. Task Group 52.17 and Task Unit 52.17.4 Report, 7.
128. Task Unit 52.17.5 Report, 1-3.
129. Admiral Ainsworth was also in command of Task Group 52.10, which included Fire Support Units Six, Seven and Eight. Ships of these three units were from the Southern Attack Force, earmarked for fire support at Guam.
130. Task Group 52.10 and Task Unit 52.10.6 Report, 1.
131. Task Unit 52.10.7 Report, 2. Task Unit 52.10.8 Report, 2.
132. Marine Corps Gazette, "Naval Gunfire Support in Landing," Sep45, Maj R. D. Heinl, Jr., 42.
133. FORAGER NGF Report, 11.
134. Ibid., COMINCH P-007, 3-2.
135. Each team consisted of approximately 16 officers and 80 men, all Navy except for one Army and one Marine liaison officer per team.
136. A detailed smoke plan had been prepared which included the screening of the front and flanks of boat waves; except as stated, however, the plan was not used. Adm Harry W. Hill, Commander Western Landing Group, stated that smoke was not used in the ship-to-shore movement because it was unnecessary. "Smoke is a double-edge weapon. Though it screens the enemy's observation, it also greatly complicates control and coordination. We felt that more was to be lost than gained by the use of smoke in the ship-to-shore movement at Saipan." Interview with Adm Hill on 20Sep49. To this, Adm Turner adds: "Actually, at Saipan we had too much smoke during the landing. The ship bombardment set up a heavy wall of smoke, due to the light off-shore breeze, that did not dissipate until after about the second wave had landed. Turner.
137. Details of UDT operations at Saipan are a synthesis of the following sources: COMINCH P-007, 4-1 and 8-1; Task Force 52 Attack Order A11-44, Annex G, 1-2; Task Unit 52.17.1 Report, 5-6.
138. Naval Air Operations In the Marianas, Naval Aviation History Unit OP-501D, C-32, hereinafter cited as Naval Air Operations In the Marianas.
139. CINCPAC-ClNCPOA item #10,238.
140. Fifth Fleet, Initial Report on the Operation to Capture the Marianas Islands, 15-16, hereinafter cited as 5th Fleet Initial Report. TF 51 Report, Encl L, 1.
141. This opinion is not shared by Adm Turner, who writes: "After a great deal of thought, I have come to the conclusion that the prolonged bombardments of Guam and Tinian actually had very little good effect. . . . In any case, it would have been unwise and impracticable, from the standpoint of major tactics, to have had a longer preparatory period for Saipan. . . " Turner.
142. Coral and Brass, Gen H. M. Smith, 162, hereinafter cited as Coral and Brass.
143. Analysis of these inadequacies in preparatory fires is drawn from hindsight, a much easier procedure than determining--before an operation--what the needs will be. In this connection, VAdm Harry W. Hill has written: "It is my recollection that during the planning period everyone was pretty well agreed that the naval gunfire, while not greatly in excess of requirements, certainly appeared to be adequate for the job." Ltr from VAdm Hill to CMC, 12Jan50.
144. The War Reports, Second Report of the Commanding General of the Army Air Forces, Gen H. H. Arnold, 388, hereinafter cited as Arnold.
145. The Navy's Air War, 204.
146. Arnold, 384-385. A History of the United States Navy, Dudley W. Knox, 555, hereinafter cited as Knox.
147. The Navy's Air War, 206.
148. Task Force 56 (Expeditionary Troops), Signal Officer's Report, 8.
149. COMINCH P-007, 1-3 and 5-4. TF 56 G-3 Report, 13.