Chapter 5: The Importance of GALVANIC
The Gilberts in American Strategy
To American planners, the capture of bases in the Gilberts marked the beginning of a major effort against Japan, the type of offensive outlined in the ORANGE Plans. The loss of Tarawa, Apamama, Makin, Abaiang, Marakei, and Maiana Atolls did not cripple the enemy, for GALVANIC had not been designed to do so. Although Admirals King and Nimitz believed that a victory in the Marshalls would be more damaging to the enemy than the conquest of the Gilberts, geographical considerations plus slender military resources forced them to strike first at the Gilberts. Both Nimitz, who was willing to undertake any operation that had “a reasonable prospect of success,” and King, who was willing to accept “very considerable calculated risks,” refused to plunge blindly into the mandated islands.1
Not until bombers and photographic planes had penetrated the Marshalls were the American naval leaders willing to risk the ships and men necessary for amphibious operations in that area. The capture of airfield sites in the Gilberts brought the Marshalls within more effective range of land-based planes and enabled the Navy to launch its westward drive. “This operation,” commented Nimitz, “is considered to have been highly successful. Island bases essential to our advance across the Pacific were captured from the enemy with the complete destruction of all his defending forces.”2
As a result of GALVANIC, the Army Air Forces gained four new airfields from which to launch strikes at targets in the Marshalls. At Tarawa, a 6,000-foot runway was built on Betio, while 7,000 and 4,000-foot runways were constructed on Buota. On 15 December, the first bombers, twin-engine B-25s (North American Mitchells), arrived at Tarawa, but neither of the two atoll bases was then ready to handle its full complement of planes. As the year 1944 arrived, heavy B-24s began flying bombing and reconnaissance missions from Tarawa.
In spite of swamps and soft ground, a 7,000-foot flight strip was finished at Makin early in January. Because this runway was built on sand rather than coral, it could not support the weight of B-24s. The Apamama facility, completed by 15 January, boasted 7,000 feet of hard coral surface ideally suited to heavy bombers.3
Although the bases gained as a result of GALVANIC were in themselves important, far more valuable was the experience amassed by American Army, Navy, and Marine Corps commanders. By capturing Betio Island, the men of the 2nd Marine Division had proven that Marine Corps amphibious doctrine was essentially sound. Although the casualty list shocked the American public, the operation was nonetheless a success, for the capture of Makin, Tarawa, and four lesser atolls had neutralized the entire Gilberts group and advanced American might across some 700 miles of ocean. Because the loss of life was confined to so short a period, the impact on civilian morale was especially severe. Almost unnoticed was the possibility that a land campaign over a similar distance, even though comparatively few men fell each day, might in the end prove more costly than a violent but brief assault from the sea. GALVANIC, moreover, did show means by which losses could be reduced in future amphibious operations.
Personnel Problems4
Because Betio was to be taken by a previously specified number of men in what was expected to be a brief but furious battle, corps personnel officers were not concerned with a replacement system, which would be needed in a campaign of longer duration. Routine administration, however, had to be carried on as usual, and at Betio personnel accounting proved a difficult task. Breakdowns in communications, plus the hectic tempo of the fighting prevented the 2nd Marine Division from checking each day on the number of able-bodied men in its ranks. Summaries of casualties and prisoners taken were submitted to VAC immediately after the action, but the confusion of re-embarkation resulted in incomplete and inaccurate returns. To provide more thorough statistics in future operations, VAC urged that periodic G-1 reports be submitted as promptly as possible.
At Butaritari, where 27th Infantry Division headquarters was rapidly established ashore, two periodic reports of losses were prepared. Details of the Apamama venture, however, remained unknown to Holland Smith’s G-1 section. No reports were submitted by VAC Reconnaissance Company until the unit returned to Hawaii.
Although GALVANIC represented a greater concentration of naval might than any previous effort against the Japanese, the size of the expeditionary force was limited by the number of transports and trained men available in the Central Pacific area. The 2nd Marine
Division, the only experienced amphibious division that could be assigned to the Gilberts expedition, was given the mission of capturing Tarawa. In order to lessen the risk of loss of valuable ships, the Marines had to assault Betio before landing elsewhere in that atoll. Had the American fleet been strong enough to accept the possible loss of several transports or warships, the assault force could have risked prolonging the action by first seizing islands near Betio and emplacing field artillery to support the storming of the principal objective.
In addition, one Marine regiment had to be retained in corps reserve, thus leaving only two regiments at the disposal of the commanding general of the division. In brief, circumstances forced upon Julian Smith a plan that called for the direct assault by an understrength division against a heavily fortified objective. Although he later was able to employ his third regiment, he could not count on its use and had to rely on aerial and naval bombardment to make up for what he lacked in numbers. The lesson was clear. In assessing operations to seize the atoll, Admiral Nimitz wrote: “Under present conditions, it is necessary to plan for the employment of not less than one division for the capture of an enemy position comparable in strength to Tarawa.”5
Compared to the defending garrison, the force assigned to capture Butaritari was of overwhelming strength. Yet, in the opinion of both Admiral Turner and General Holland Smith, the might of this reinforced regiment could not be dissipated in secondary landings on neighboring islands until Butaritari had been won. After the fall of the major objective was certain, the possible need for further reinforcements at Betio kept General Ralph Smith from employing his reserve battalion as he desired. Not until victory at Betio was assured, could the Army general carry out his plan to trap the remnants of the Makin garrison by landing troops on Kuma Island.
The operations against the Gilberts were the most damaging blows that could be struck against the enemy with the resources then available to Admiral Nimitz. The expedition, no more than equal to its task, was the largest that could have been mounted in the fall of 1943. The GALVANIC force, in comparison to expeditions sent forth later in the war, was small, but these few troops were able to shatter Japanese power in the Gilberts and open the way into the Marshalls.
Intelligence
American intelligence officers, working from photographs taken by submarine and aircraft, were able to locate almost all of the enemy’s defensive installations before the operation got underway. If anything, the interpretation of these photos was too cautious, for several dummy gun emplacements on Butaritari were listed as containing actual weapons. Intelligence specialists, however, failed to foresee the adverse conditions off the beaches at Butaritari. Although the unexpected boulders and coral outcropping there, together with unforeseen tides, complicated
the unloading of men and supplies, these conditions had little effect on the assault landings.
A greater number of oblique photos, taken at irregular hours over a period of several days, might have given a clearer indication of Betio’s regular tides, but no available information could have plotted the freak dodging-tide that occurred on D-Day. When traders and British colonial administrators familiar with the Gilberts failed to agree on tidal conditions, American officers were forced to use a consensus estimate in order to prepare their carefully drawn landing plans. While General Julian Smith felt there was one chance in two that standard landing craft would be able to cross the reef at Betio, he approved a plan that envisioned “a tide that would not float our boats across the reef.”6
More thorough photographic coverage would be needed in future amphibious undertakings, but only prolonged observation could give a hint of the course of eccentric tides. Another partial solution to the problem lay in the use of the Naval Combat Demolitions Units that had been organized prior to the invasion of Kiska. Although the six-man team destined for the Aleutians was inadvertently left behind at San Francisco, Admiral Turner felt that a similar team would have been valuable in destroying underwater obstacles off Betio. In the course of the Pacific war, these units, designated Underwater Demolitions Teams (UDTs), also were employed to collect last-minute information on the depth of water, approaches, and gradients off various objectives.7
During the 76-hour battle for Betio, there was little opportunity to collect, evaluate, and disseminate intelligence information. Most of the Japanese and Koreans preferred death to surrender, and the information provided by the few prisoners had no effect on the conduct of the fighting. At Butaritari, friendly natives confirmed preinvasion estimates of the size of the enemy garrison and its location. In addition, villagers on Kuma Island provided an accurate count of the Japanese in the area, information which helped General Ralph Smith prevent the enemy from retreating along the atoll. Most of the intelligence gathered in the Gilberts, however, was applicable to future operations rather than to the situation at hand.
After Betio was secured, Japanese language officers of the 2nd Marine Division scoured the island in search of enemy documents. The most important find was a set of plans and specifications for some of the defenses encountered on the island. This document and the examination by engineers of shattered emplacements enabled the Americans to build sample blockhouses and test their durability. Such experiments led to improvements in naval gunfire techniques and infantry tactics
in time for the Marshalls operation.8
Of the prisoners questioned by 2nd Division intelligence specialists, only Ensign Kiyoshi Ota was able to provide valuable information. He testified that although air strikes had destroyed two or three protected installations, the men in shelters or covered fortifications were safe from both bombs and naval shells. In his opinion, naval gunfire had devastated antiaircraft emplacements, shattered communications, but failed to destroy concrete structures. The ensign, however, was impressed by the effective on-call fire delivered by destroyers posted in the lagoon. Since the building where Ota was stationed was destroyed by a tank-infantry team, his testimony indicated both the importance of coordination between infantry and armor as well as the need for a more accurate and powerful preparatory naval bombardment.9
Command and Communications
The command relationships decided upon for GALVANIC satisfied neither Holland Smith nor Ralph Smith. Before the expedition sailed, the Marine general had pointed out that, although nominally a corps commander, he had no troops under his tactical control. The Army general felt that, since he had not been free to alter his tactical plans without Admiral Turner’s approval until after the naval officer had directed him to assume command ashore, the commander of the landing force was for the most part “a conduit for the issue of orders”10 by the assault force commander.
Ralph Smith, however, was quick to admit that an amphibious operation was a type of combat in which the concern of the Navy for its ships might conflict with the scheme of maneuver ashore. Obviously, some sort of compromise was necessary. In the general’s opinion, “the successful execution of an amphibious operation is dependent not on who or what component of the armed forces commands, but on the mutual confidence between all commanders and a comprehensive understanding of the problems faced by each.”11 Apparently, there was no lack of confidence and understanding, for Turner’s system of command was adequate to the situation at both major objectives.
The difficulty in transmitting orders and information rather than any weakness in the command structure caused confusion and needless delay at both Makin and Tarawa. Because there was little opposition at the beaches of Butaritari, communications failures did not jeopardize the success of the 27th Infantry Division assault troops. Radio contact between ship and shore was reliable enough, but elements of the assault battalions at times had difficulty in exchanging messages.12
As a command ship for the Tarawa operation, the battleship Maryland
proved an unhappy choice. Transmitters, receivers, and antennas, installed in a compact area, interfered with each other, severely hampering communication efficiency. In addition, the concussion from the 16-inch guns of the vessel ruined some of the more delicate pieces of radio equipment. Admiral Hill recommended that, as a temporary expedient, the number of radio channels in use be drastically reduced, but the problem of ship-to-shore communications could not be solved until specially designed command ships were introduced in the Central Pacific.
The communications difficulties extended to transports and landing control craft as well. There was an evident need for better facilities, better trained control personnel, and a more systematic command setup. As a result of lessons learned, the transport group, and later the transport squadron commander, “was given a greatly enlarged staff and made responsible for ‘traffic control’ off the beaches. With the better communications facilities made available to him, he was,” in the words of the transport commander at Tarawa, “the logical one to be charged with this duty.”13
Once ashore on Betio, the Marines continued to have communication troubles. Batteries in the MU radio, the handset carried by platoon leaders, wore out too quickly to suit the men who depended on these sets. Officers in the division complained that the TBX radios were susceptible to water damage, but VAC analysts held that the case containing the radio was watertight if assembled properly. Neither division nor corps, however, had a kind word for the TBY, and Admiral Hill’s headquarters recommended that this piece of equipment be replaced by its Army equivalent. Waterproof bags or cartons also were needed to protect telephones and switchboards during the ship to shore movement. Because each used a different type of radio, contact between infantrymen and tank commanders was uncertain.14
Tactical Lessons
The most important feature of the assaults upon Betio and Butaritari was the role of the amphibian tractor as an assault craft. Prior to GALVANIC, LVTs had been used to haul supplies from transports to dumps inland of the beaches, but the conquest of the Gilberts marked the first time that these vehicles had carried the first wave of troops. The tractors proved so successful in their new role that Holland Smith came to believe that LVTs were vital to the amphibious assault.
As valuable as the tractors had been, they were not perfect. Greater speed, additional armor protection, and a ramp for discharging troops were the improvements suggested by VAC.15 At
the time of GALVANIC, an armored amphibian tractor mounting a 37-mm gun, the LVT(A), and an amphibious 2½-ton truck, the DUKW, were in production. Even though neither of these types had undergone an adequate combat test,16 corps recommended that a battalion of armored tractors, two companies of the new DUKWs, and two battalions of ordinary LVTs be assigned each division in future assault landings.17
The fighting on Betio centered around pillboxes and shelters built of either steel and concrete or log and coral. Many of the flamethrowers which the Marines used so effectively against these installations had been made available by the Army Chemical Warfare Service detachment in Hawaii.18 In spite of the help of the Army, there were not enough flamethrowers at Betio, so VAC recommended that in the future one such weapon be assigned to each rifle platoon. In addition, the Army, Navy, and Marine Corps agencies in Hawaii began cooperating in the development of a flame-throwing tank.
The Sherman tanks and the half-tracks, which also mounted high-velocity 75-mm guns, proved effective against the lighter Japanese installations. Because the 37-mm guns of the light tanks could do little damage to prepared fortifications, Holland Smith’s headquarters recommended that these vehicles be replaced by the heavier Shermans. Pack howitzers, which had to be wheeled into position by their crews, were not as effective in delivering direct fire against pillboxes as were the more maneuverable tanks and self-propelled guns.
Demolitions had proved so deadly that corps recommended the issue of one demolitions kit to each rifle squad. Flamethrowers, demolitions, and armor had enabled Marine infantrymen to close with and kill the enemy by means of grenades and rifle fire. Grenades, in fact, were so valuable that VAC urged still greater emphasis on the offensive or concussion type. Perhaps the most important lesson learned was that the destruction of a Japanese garrison as skillfully entrenched as the defenders of Betio was a task that required teamwork as well as courage.
Because units tended to become intermingled during the amphibious assault, individual Marines might find themselves commanded by a stranger. Under these adverse conditions, the riflemen had to fight as part of a hastily organized team. In the opinion of corps operations officers, this kind of teamwork could only result from the self-discipline, resourcefulness, and initiative of every unit leader. Leadership, then, would continue to be stressed in future training.19
Artillery and Naval Gunfire
Had circumstances not forced him to do otherwise, General Julian Smith would have seized the islands adjacent to Betio, emplaced artillery on them,
and shelled the main objective before attempting to storm it. The need to capture Betio as quickly as possible prevented him from landing elsewhere in the atoll prior to the principal assault, but a study of the operation indicated the soundness of the original idea. Although Holland Smith’s headquarters had no choice but to veto such tactics at Tarawa, the corps headquarters now urged that every effort be made in future operations to land artillery on lightly defended islands within range of the major objective.20
At Betio in particular, great things had been expected of the preparatory naval bombardment. Representatives of V Amphibious Force, V Amphibious Corps, and the 2nd Marine Division, had contributed their knowledge to the drafting of a naval gunfire plan. As a result of their combined efforts, a greater weight of metal was hurled into each square foot of Betio than had rained down on any previous amphibious objective, but the bombardment, awesome as it seemed, did not kill enough Japanese. The VAC commander noted, however, in his report on the operation that “without naval gunfire the landing could not have been made.”21
GALVANIC taught naval gunfire officers that, when the requirements of a surprise attack did not preclude it, adequate preparation required days rather than hours of precision bombardment. To fire for two or three hours, much of the time shifting from one sector to another, was not enough. The sturdiest Japanese installations, many of them dug into the coral sands, could be penetrated only by a base-fused, armor-piercing shell plunging at a steep angle. Instead of the armor-piercing type, comparatively ineffective point-detonating, high-capacity ammunition was used at Betio. Although the training and rehearsals for GALVANIC had helped, especially in the accurate delivery of on-call fire, still more training was thought necessary. A simpler and more effective target designation system needed to be developed.22 In the future, the officers of every supporting ship should know just what was expected of their guns. The ideal solution to the problems posed by the fortifications at Tarawa appeared to be the early arrival of the objective of thoroughly trained fire support units stocked with the proper ammunition, a deliberate bombardment designed to shatter possible strongpoints, additional shelling by destroyers and landing craft during the assault, and finally the accurate delivery of whatever fires the troops ashore might request.23
Because the preliminary hammering of Betio had not achieved the spectacular results hoped for, the importance of naval gunfire to the success of the operation could easily be underestimated. The 3,000 tons of explosives that blasted the island caused many casualties, disrupted Japanese communications, and enabled the first three assault waves to gain the beaches without meeting organized resistance.24 Once these Marines were ashore, the enemy rallied to inflict serious casualties on succeeding waves. This seemingly remarkable recovery was due in part to the lifting of naval gunfire where the LVTs were some distance from shore. Out of the entire task force, only the pair of destroyers in the lagoon could see the progress of the amphibian tractors and time their fires accordingly. The other fire support ships halted their bombardment according to a prearranged schedule that did not take into account the distance yet to be traveled by the assault waves. To prevent the premature lifting of preliminary fires, Admiral Hill’s staff recommended that destroyers take up positions from which they could track the incoming waves and thus keep firing as long as the friendly troops were not endangered.25
Logistics
The original logistical plan for the Betio operation, though carefully drafted and based on previous amphibious experience, proved unrealistic. A beachhead was needed for the unloading of supplies and evacuation of casualties, but at Betio the Marines fought through the first day with their backs against the sea. Not until the long pier was pressed into service as a transfer point was there room to store or sort cargo. Even if space had been available ashore, landing craft could not have crossed the reef to reach the island. The carrying of supplies from the end of the pier, a point accessible to LCVPs and LCMs, to the front lines was best done by LVTs. Casualties were evacuated in the same vehicles that brought food, water, and ammunition to the embattled units. Wounded Marines were placed in the tractors and carried to the end of the pier where they were given emergency treatment and transferred to landing craft for the journey out to the transports. A naval officer in a minesweeper at the line of departure was given control over boat traffic, and the improvised system worked quite well. The Navy and Marine Corps officers responsible for beachhead logistics, when confronted with an unforeseen difficulty, had responded to the challenge.
The waters off the pier were usually dotted with landing craft waiting their turn to unload. This congestion was due to the conflicting needs of the Navy and Marine Corps as well as to the fact that supplies had to be funneled along the pier. The Marines wanted items landed in the order of their importance, but the Navy had to unload the transports as rapidly as possible regardless of the value of the cargo to the attacking
troops.26 The longer the transports remained at the objective, the greater the danger to these valuable ships from Japanese planes and submarines. In their eagerness to aid the assault troops, the ship crews were often too cooperative. As the commander ashore on D-Day noted:
In their enthusiasm, they did not load what I wanted, they just loaded. By the time they got a message from me requesting certain items the boats were already filled with other material. Tarawa made SOP [Standing Operating Procedure] that the Navy would not unload supplies except as requested by the landing force commander ashore. ... Items that come ashore must be in accordance with the requirements of those ashore.27
Although pallets, a few of which were used at Tarawa, were recommended for adoption, Marine planners pointed out that not all bulk supplies could be lashed to wooden frames. During the early hours of the assault, or when the beachhead was narrow and under fire, supplies would have to be landed rapidly and in comparatively small quantities. Once the beachhead had been won, these platforms appeared to be one of the best means of speeding the movement of cargo from the transports, across the beaches, and to inland dumps.
At Betio, supplies piled up on the beaches, for enemy opposition and a shortage of manpower prevented the shore party from functioning as planned. A single pioneer battalion from the engineer regiment was not equal to the task, and the Marines from certain of the rifle companies, men who were supposed to be sorting and moving supplies, had joined in the fighting, leaving their work to be done by whomever the shore party officers could press into service. In the opinion of the corps G-4 section, the shore party machinery was in need of overhaul, for the pioneer unit was not large enough to do its work without reinforcement. Until the table of organization could be revised, Marines from service rather than combat units should be detailed to aid in the logistical effort.28
The evacuation of casualties became increasingly efficient as the beachhead was expanded. On the first day, the wounded were placed in rubber boats and towed by hand to the edge of the reef where they were transferred to landing craft for the journey out to the transport area. Later, LVTs became available to evacuate the wounded to boats waiting at the end of the pier. Although the supplies of morphine, sulpha drugs, splints, dressings, and plasma proved adequate, the collecting platoons did run short of litters. At Tarawa, the doctors and corpsmen did a heroic job. The major recommendation to result from the operation was that hospital ships be assigned to task forces charged with seizing heavily defended atolls.29
The Role of Aviation
Both defense against air attack and the close support of ground troops were entrusted to carrier planes flown by Navy pilots. One force of carriers stood ready to intercept Japanese planes striking from the Marshalls. Other carriers protected the Makin task force and attacked targets ashore, while a third group performed the same tasks at Tarawa. Except for unsuccessful night attacks on the retiring task forces, the enemy offered no serious challenge to American air defenses.
Air support at Tarawa, in the opinion of both Navy and Marine Corps officers, suffered many of the ills that had plagued naval gunfire support. The strikes made prior to the assault accomplished little, for not enough bombs were delivered, and those dropped were not heavy enough to damage Japanese emplacements. On D-Day, because of severe communication difficulties, there had been poor coordination of the aerial effort with the progress of the assault waves toward the beaches. The planes scheduled to attack at dawn arrived late, and those which were to support the landing were early, their pilots unaware of a postponement of H-Hour. Although the beaches were strafed just before H-Hour, the attack was not effective, for the Japanese, who had taken cover in air raid shelters and pillboxes, were immune to harm from machine gun bullets. Later in the operation, while supporting units ashore, the aviators had difficulty in locating their targets.
These shortcomings indicated, among other things, that effective air support was impossible unless the pilots and ground troops had trained as a team. Marine Colonel Peter P. Schrider, VAC air officer, was convinced that the division and its supporting carriers should train together for two or three days—the longest possible time at this stage of the war.30 Holland Smith recommended that Marine aviators thoroughly schooled in the principles of direct air support should be assigned to escort carriers and included in any future amphibious operation undertaken by a Marine division. If this request could not be granted, he continued, the Navy airmen selected for the task should be carefully indoctrinated in the tactics they would employ.31
Air operations at Tarawa led to certain changes in doctrine, which would benefit soldiers and Marines storming other beaches. Unless dive bombers were attacking a particular target which might be obscured by smoke and dust, there was no need to suspend naval gunfire while the planes executed the strike. No danger of shells striking aircraft existed as long as the pilots pulled out of their dives at an altitude higher than the maximum ordinate of the naval guns. In addition, the practice of scheduling the final aerial attack in relation to H-Hour was judged to be unrealistic. Those planes assigned to maintain the neutralization of the beaches just prior to the assault should begin their attack when the landing craft were about 1,000 yards from the objective and continue the bombing and strafing until the assault waves were approximately 100 yards from shore.
Finally, since machine gun fire had proved ineffective against beach defenses, some sort of gasoline bomb was needed, a device which would insure that the defenses remained silenced during the last few minutes of the ship-to-shore movement.32
Not only were important lessons learned from GALVANIC, but many necessary changes in amphibious tactics and techniques were made almost immediately. By the time of the Marshalls operation, for example, naval gunfire would improve in both accuracy and volume. On the other hand, the war had reached the Marianas before effective coordination was achieved between air strikes and naval gunfire. As one study of amphibious warfare has phrased it, “Tactically, Betio became the textbook for future amphibious landings and assaults.”33 In the flames of Tarawa was tempered the sword that would cut to the heart of the Japanese Pacific empire.