HyperWar: Amphibious Operations: Capture of Iwo Jima [Chapter 5]

Chapter V. Ship-To-Shore Movement
From: Commander Amphibious Forces, United States Pacific Fleet (Commander Joint Expeditionary Force)
The reconnaissance of the eastern beaches was conducted by elements of all four UDT's on the morning of Dog-minus-Two. Seven operating platoons were assigned, each of which was responsible for 500 yards of beach. In addition, four standby platoons were designated and in readiness to render assistance or as replacements. Roger-Hour (the time at which the LCP(R)'s carrying team personnel passed the line of LCI(G) support craft) was designated as 1000.

Fire support was furnished by one LCI(G) and one destroyer in close support of each operating platoon. Five additional LCI(G)'s were stationed in reserve positions, and battleships, cruisers, and additional destroyers delivered continuous area coverage in rear of the beaches.
The beach reconnaissance was completed by UDT personnel in accordance with plan. Swimmers were launched from LCP(R)'s at the 500-yard line, and then proceeded in pairs as close to the water's edge as enemy opposition permitted. Reconnaissance was completed and personnel recovered by LCP(R)'s by 1240. During this period the personnel encountered heavier mortar and small arms fire than has been encountered in any previous operation to date. In spite of this fact, only one man was lost during the reconnaissance.
During the reconnaissance the LCI(G)'s in close support moved in to 11,000 yards, where they immediately began to receive effective fire from enemy mortars and fixed artillery. The personnel of these gunboats returned fire with all weapons and refused to move out until they were forced to do so by matériel and personnel casualties. Even then some returned their stations until again hit. Relief gunboats replaced damaged ships without hesitation. Between 1200 (K) and 1145 (K) 12 LCI(G)'s had been hit. The exact source of the enemy fire could not be determined and it was decided to direct planes to lay a smoke screen along the beach line. For some reason, as yet unexplained, the smoker planes called for by the OpPlan were not on station, so fire support ships were directed to fire white phosphorous along the beach line 1,000 yards inland from the water's edge and on the flanks. The resultant screen was thin, but was apparently effective in reducing the precision of the enemy fire. As it was noted that little enemy fire was being received beyond 1,800 yards out, destroyers in close support were directed to move in to 2,000 yards from the beach. Their rate of fire at suspected and known targets was intensified and the withdrawal of team personnel was covered. During this period the destroyer Leutze was slightly damaged.

The heavy enemy fire drawn by the LCI(G)'s during the reconnaissance of the preferred beaches was not again seen until Dog-Day, although minesweepers and destroyers thereafter and previously came well within range. This lends some support to the conclusion that the Japanese again followed their apparent tendency to hold fire until faced with an actual assault. The approach of 12 LCI craft, which could conceivably carry 2,400 assault troops, preceded by a number of LCP(R), and the fact (known only to the enemy) that the beach profile on the eastern beaches favored the use of large landing craft, would give strength to a belief that an assault was being made. It is therefore recommended that future schemes of maneuver and approach should avoid as much as possible the pattern and suggestion of an assault. In the same vein, UDT personnel in boats should not fire on the beaches except in self defense.
The screen of white phosphorous projectiles on both beaches was of unquestioned value in hampering enemy observation, and reducing the

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precision of direct fire. The smoke similarly hampered our own fire support, but to a lesser degree because of the inability to definitely locate the enemy installations.
It was originally believed that the use of smoke would result in reduced visibility which would seriously hamper the recovery of swimmers. The team captains unanimously reported that their visibility was never reduced below 100 to 200 yards, and that the light smoke provided a screen for their actions without materially affecting the actions of either the LCP(R)'s or the swimmers.
From: Commander Amphibious Group One (Commander Amphibious Support Force)
It is worthy of note that the defenders did not employ heavy guns against minesweepers even when they worked close to the shore. Perhaps this was because the Japanese knew there were no mine fields to defend and considered that damage to minesweepers would not compensate for disclosure of batteries to the fire support ships. When, however, the LCI(G)'s approached the beach in support of the UDT's, it was logical for the Japanese to assume that being landing craft, they were being employed to carry and land troops. The Japanese therefore opened up with everything they had to defeat the supposed landing. It is therefore considered that LCI(G)'s or craft of that general type should not be used to support UDT's working in the vicinity of strongly defended positions, unless the major defenses are assuredly destroyed beforehand, or unless sufficient ammunition is available to permit the same heavy smothering fire as is used in conjunction with an actual landing.
From: Commander Amphibious Force, United States Pacific Fleet (Commander Joint expeditionary Force)

CONTROL
The Iwo Jima operation provided the first test of the amphibious forces' newly formed permanent control organization. This organization was established following the Marianas campaign, where it was realized that proper control of the ship=-to-shore movement of amphibious craft had become a continuing 24-hour a day task, requiring specially trained control personnel and specially equipped control vessels.
The control organization for the Iwo Jima operation consisted of the Transport division, Transport Squadron, and Central (Amphibious Group or Force) Control Officers, permanently assigned to the staff of their respective commanders. This organization now parallels the echelons of both the beach party and the shore party. Control officers were embarked in the same ships as their opposite number in the beach and shore party, giving the maximum amount of time for coordination and understanding of each other's problems prior to the landing.
Each control officer was provided with a control vessel (PCE, PCS, PC, or SC) which had been previously equipped with special communication facilities and provided with a control communication team and advisors from the troops. The control vessels were obtained and equipped, and the personnel trained in their specialized duties, well in advance of the operation. As a result, for the first time the task of controlling the ship-to-shore movement, both during the assault and unloading phases, was handled by "professional." In addition, control equipped craft were provided to the different troop staffs for use as floating command posts.
At the objective the first five assault waves were dispatched as directed by the central control officer, in order to achieve simultaneous landings on all beaches. At the end of that time the two Transport Squadron control officers took control of the dispatching of reserve waves and the furnishing of supplies for the troops as requested by the beach and shore parties, while the central control officer coordinated all control activities.
During the next few days rough sea and weather conditions required that a large part of the activities of the control organization be concerned with salvage of and assistance to landing craft, DUKW's, LVT's and pontoon barges, many of which broached on the beach or drifted out to sea as a result of high winds and heavy seas. All available control vessels were directed to conduct search sweeps in sectors to leeward of Mount Suribachi. It is believed that all personnel were recovered form these drifting craft, but most of the LVT's and DUKW's taken in tow sank before they could be returned. These operations continued until the morning of D-plus-Five, at which time the beaches were suitable for general unloading. At that time the control group was reorganized

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to permit unloading of each of the three transport squadrons present under the direction of its own control officer.
From: Commander Task Group 51.1 (Commander Transport Squadron 11) (Commander Transport Division 31)
For the attack, PC(S)'s or PC's specially fitted with communication facilities and teams are provided. For the landing of the reserve, the special teams and equipment are gone--recommendation: Assign communication teams with necessary equipment to the staff of the Transport Squadron Commander in reserve, who has the necessary control personnel but no communication teams or special equipment.
From: Commander Amphibious Forces, United States Pacific Fleet (Commander Joint Expeditionary Force)

RADAR NAVIGATIONAL DEVICE
The radar navigational device known as VPR [Virtual PPI Reflectoscope (radar)] was employed for the first time during the Iwo Jima assault. This device is designed to fix a vessel's position by apparently superimposing the image of a chart upon the face of a PPI scope, as the result of which the ship's position, indicated at the center of the scope, is "fixed" on the chart.
The equipment was installed in all control vessels at Pearl Harbor and control officers, quartermasters, and radiomen of the ships received instruction both in maintaining a fixed station, and in computing speed-time data to enable the control vessel to arrive at a predesignated point off the beach within a minimum of a few seconds. Both operations are essential in control vessel operations.
Since the installation of VPR in both amphibious force and combatant vessels has been authorized, the following observations may prove of assistance to other commands in the future:

Employment
VPR charts and speed-time charts were drafted en route to the staging point and were reproduced on board U.S.S. Auburn and distributed to all control craft prior to departure for the objective. All AGC's are being equipped with facilities for reproducing these charts.
The dawn approach to Iwo Jima was made, using VPR entirely for navigating the control vessels to the Line of Departure. Current data was obtained by plotting the VPR track when the ship was dead in the water. Best results were obtained from observations of 15 or more minutes.
The first assault wave was tracked to the beach by radar and VPR with reasonable success. Radar tracking of subsequent waves was not possible due to congestion in the area off the beach as evidence in the PPI scope.
After D-day, during rescue and salvage operations, VPR was used to determine the ship's position and facilitate return to the assigned control station. This proved especially valuable during hours of darkness when visual fixes were unobtainable.
In summary, this first extensive use of VPR/NMP navigation in an amphibious operation in the Pacific indicated that VPR/NMP assists the control vessels materially in assuming their proper positions on time. It should be pointed out, however, that VPR was not designed to replace other navigational means, but rather to supplement them. The concept of VPR navigation arose from the need for a means by which ships could make a blind navigation approach to a beach under conditions of poor visibility. VPR does accomplish this within the practical bounds of accuracy. That accuracy depends on (1) the adaptability of the radar gear to VPR modification; (2) the precision of the VPR unit itself; and (3) the skill and experience of the radar operator in obtaining fixes.
The heavy defenses of Iwo Jima which slowed our advance, permitted enemy mortar fire to cover the landing beaches for several days. Consequently, casualties to beach parties were extremely high--about 60 percent. Elimination of hidden enemy mortar positions is a problem confronting the troops and gunfire support ships; the best protection available to beach party personnel is the knowledge of how to defend themselves by the use of arms, digging of slit trenches, etc. Such combat training is already being provided in some measure to beach parties, but this training must be emphasized and implemented to insure that naval beach party personnel are as well prepared to take care of themselves as are combat troops.

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SHORE PARTIES
The composition of the shore party organization had the following disadvantage--many of the personnel were assigned from replacement combat troops of the various troop divisions engaged in the landing and were soon called upon for combat duty prior to arrival of the garrison shore parties. Furthermore, replacement troops received no training whatsoever in shore party duties. This is highly undesirable from both the military and naval standpoint, in that a withdrawal of these combat troops from the unloading organization causes an almost complete cessation of unloading at the beaches, and a consequent serious lack of supplies for the troops ashore, as well as a delay in the withdrawal of transports from the objective, and delay in landing garrison equipment and supplies. It is again recommended that the troop unloading organization be a permanent group especially trained for that task and not subject to withdrawal for other duty except in case of extreme urgency.
From: Commanding General, Headquarters Fourth Marine Division
It is recommended that a permanent organization of size and composition adequate to furnish the basic elements of a Division Shore Party be authorized each Marine Division. The present Pioneer Battalion meets neither of these requirements. A suggested organization to meet the minimum requirements in keeping with the above recommendation is a small Shore Party Regiment consisting of a Headquarters and service Company and two Pioneer Battalions. The composition of each battalion in both equipment and personnel should be similar to those of the present Pioneer Battalion. Headquarters and Service Company of the regiment should be similar in organization to that of the Headquarters and Service Company of the present Pioneer battalion.
From: Commander Amphibious Group Two (CTF 53) and (CTG 51.21)
the shore party problem is without question one of the most important and the toughest problems connected with amphibious operations. Its commander must be an extremely capable, forceful and resourceful officer with great organizational ability. Although the initial assault requirements must necessarily be on call from the separate divisions, it is believed desirable that the Corps shore party assume control from the outset in order to provide the necessary coordination of the supply problem. As at both Saipan and Iwo Jima, difficulties may be experienced on one group of beaches and the entire supply for all troops ashore routed over only one or two beaches. The Corps shore party should be a permanently and separately organized force not subject to the call of any division commander for combat purposes. During this operation the division shore parties were made up largely of replacement troops for the division. This worked fine for a short period but these replacements were soon called up by their division commander, and ultimately resulted in undesirable delays in beach and dump unloading.
All units arrived on schedule and it was apparent as early as 0700 (K) that How-Hour would be met. The only departure found necessary from prearranged plans was the deletion of LCI(G)'s from participation in assault as a result of heavy damage suffered on Dog-minus-Two-Day. The remaining 12 LCS(L)'s rearranged their formation so as to bring all beaches under fire. All preliminary landing preparations proceeded exactly as scheduled. The Gunston Hall, carrying LCT's with tanks embarked, completed launching of her three LCT's at 0740 (k). By 0810 (K) all LST's carrying assault troops had been launched.
All air support units arrived on stations promptly. At 0805 (K) naval gunfire was lifted to permit bombing, rocket, and napalm attacks on landing beaches and beach flanks, and resumed again at 0825 (K).
No gunfire was received in or near transport or LST areas during this period, and transport squadrons were directed to move in 3,000 yards at their discretion.
Assault waves were dispatched on schedule, and landed on all beaches at 0900 (K), the prearranged How-Hour. Only a small amount of gunfire was received in the boat lanes during the approach to the beaches.
The evacuation control LST's launched one pontoon barge each during the morning. These were the only barges launched until Dog-plus Two-Day. LST's carrying LCT's had previously been ordered to prepare to launch LCT's as soon as LVT's were discharged, and to report

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readiness. Six of these completed launching prior to sunset, making a total of nine LCT's in the water Dog-night.
LCT's and LSM's carrying tanks were called in to the beach commencing about 0920 (K), and all beached and discharged successfully in spite of enemy gunfire. The tanks, however, encountered great difficulty in moving inland from the beaches. Four LSM's were hit by shellfire while beached but were able to retract under their own power.
TransDiv 32 with one RCT of the Third Marine Division embarked, arrived in the area at 1000 (K). Reembarkation of LVT's in parent LST's commenced at about the same time. Reembarkation continued until early afternoon, at which time all were aboard with the exception of those being used for emergency supply. Loose sand on beaches and heavy enemy fire combined to make unloading of equipment very difficult. Only emergency supplies were landed on Dog-Day. Transports moved in to Area ZEBRA in early afternoon.
During the first day all BLT's of the Fourth and Fifth Marine Divisions, together with half of the division artillery, were landed against increasingly heavy opposition. Initial losses in amphibious vehicles were moderate. No air attacks took place, although unidentified planes caused an alert in the early evening.
Night retirement was conducted in general accordance with previous plans and directives. A total of 11 fire support ships, 7 transport types, and 21 LST's remained at the objective overnight. All LSM's and control craft remained at the objective overnight throughout the operation. No unloading took place during the night, except into LSM's alongside heavy ships remaining at the objective.

BEACH PARTIES
Although operating under unusually difficult conditions at Iwo Jima and under heavy enemy gunfire, it is considered that the coordination between beachmaster and the offshore control vessels was not satisfactory. The following specific points require improvement:

A simplified visual system of calling boats to the beach must be provided. This must include lights for night signalling and range lights for the beaching of larger craft.
A more positive means must be established by control vessels of determining at night what landing craft are in their vicinity waiting for beaching instructions. Particularly during the early phases of assault, night signalling is dangerous and must be kept to a minimum. Radio communication proved only partly satisfactory. On one beach the control officer had an LCPR tender which cruised th area and contacted orally each arriving craft. This proved very satisfactory.
All requests from the troops on shore for materials or supplies must be channelized through the control vessels. In this operation as in preceding ones, there has been a marked tendency for troop commanders to send their requests direct to the ships concerned or to the higher echelons without notification to the control officer and embarked trop representative. This results in loaded craft arriving at the control vessel without any knowledge for their need on the part of the control officer.

The beach condition at Iwo Jima stressed the weakness of our present beach party organization. Practically all members of the beach parties were engaged in their first combat experience. The beach conditions were unusually tough and would have challenged the resourcefulness and efficiency of the most highly trained organization. Successful beach operation under these conditions is an extremely difficult task and it is believed essential that permanent organizations be set up to handle this problem.
Initially it is recommended that a small group of key beach party personnel be constituted and trained in all angles of rough water work and that during an operation they be placed in complete charge of the beaches, supplemented by the required personnel of existing beach parties now aboard transports. Ultimately an organization should be built up corresponding more or less to that of the underwater demolition teams. Such an organization would become highly skilled in beach party work, and would develop a high morale and esprit de corps which is now definitely lacking in beach party organizations. When an operation was in prospect, beach party units would be designated for each beach from this organization. During an operation these beach parties would remain in control of the beaches until such time

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as the garrison forces took over, thereby eliminating the confusion and inefficiency now existing at that period resulting from beach parties being withdrawn when their ships leave.
From: Commander Transport Squadron Sixteen
At the time the Squadron Beachmaster landed, all beaches were under continuous enemy mortar, artillery, and small arms fire. Fire on RED ONE, however, was not as heavy as on the other two beaches. RED ONE was therefore the best beach at the time over which supplies could be delivered. "Priority Cargo" was called for and unloaded by hand at the water's edge wherever a place not under water could be found along the narrow beach strip.
Before the Shore Party could get the cargo up over the terrace or install exits, make cut-throughs, lay matting, and establish roadways, to do so, the beach strip became piled and jammed with various types of cargo due to the fact that it was the best beach and "Priority Cargo" was being rapidly landed in response to demands. For a time, in addition to its own share, Beach RED ONE was not only receiving cargo which would normally be distributed between the three beaches but it was also receiving cargo destined for the support of the Fourth Marine Division as well as the Fifth Marine Division, due to the impossibility of working YELLOW and BLUE Beaches. During D-Night, and part of D-plus-1-Day, a large portion of the ammunition received had to be packed up to the lines by hand because sufficient LVT's were not available.
One factor which tended toward confusion in unloading and delay in getting boats into and off the beach was the frequent and everchanging demands for priority cargoes. In many instances, before boats loaded with requested priority cargoes could be landed and unloaded, the priority had changed to another type of cargo. This was due to the fact that BLT Commanders, Beachmasters, and Control Officers were by-passing both the Shore Party Commander, and the Logistics Officer, in ordering supplies to the beach.

Early delay in unloading was caused by landing craft of all types retracting to avoid enemy fire and by personnel also seeking cover from enemy fire, air rads, etc. This, however, was partially corrected by the issuance of specific orders that no type of landing craft, once it had reached the beach, was to retract until it had been completely unloaded and that unloading was to continue regardless of air raids.
Additional delays were caused by cranes, dozers, and tractors sinking into the sand or breaking down and necessitating additional equipment to pull them clear. In addition it was necessary to tow self-propelled vehicles across the beach strip. Even DUKW's had to be towed to the second terrace. In many cases, heavy vehicles required two or three dozers or tractors in tandem to get them across the beach. Failure to unload LVT's at the dumps promptly caused delay in their availability at landing craft waiting to be unloaded. Additional delay which became accumulative and of considerable importance over a period of time was caused by the repeated interruptions of operations by sniper fire and the time lost in rounding up personnel to resume work after its cessation. Another factor was the greatly diminished shore party personnel available at night and the difficulty of keeping such working parties intact.
Night unloading was also hampered somewhat during the early phase by the stationing of LVT(A)'s along the beach at sunset for defense purposes against counterattack.
Later considerable delay in unloading LCT's was caused by the necessity of the LCT's retracting repeatedly in order to obtain new footing as a result of being carried down on obstructions. In addition, small boats in a number of instances were badly loaded with pallets athwartships, cargo nets overloaded, etc.

From: Commander Task Unit 53.4.1 (Commander LSM Group Thirteen)
A northeasterly wind of about 6 knots and a moderate sea on D-day were favorable for landing on the eastern beaches. The combination of intense enemy fire and the steep beach gradient broached and wrecked numerous LVT's, LCVP's, and LCM's at the surf line. When the LSM's beached, it was difficult to spot a beaching location

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where the surf line and the beach beyond were clear. The beach and shore parties were dug in right down to the waters edge, which caused further congestion. All six tank loaded LSM's discharged their cargoes rapidly and thereby avoided casualties from enemy fire while on the beaches.
The shore party LSM's which, by the nature of the vehicles and equipment carried required more time to unload, suffered several personnel casualties because of the longer period on the beaches. These LSM's were ordered to beach by the control vessels but were ordered to retract by the beach party before any appreciable unloading had been completed. This occurred not only on the initial beaching but on some of the subsequent beachings before these LSM's had completely discharged their preload. It is believed that if the equipment was not wanted on the beach at the time, the beachmaster should have so informed the control vessels which could have held the LSM's at the line of departure until they were needed. The control vessels in some instances directed these LSM's to beach on certain beaches, and the LSM's after beaching, were ordered by the beachmaster to retract and land on some other beach.
The LSD's and ARL's performed great service for LSM's and enabled the ships to continue operations and in some cases to remain afloat. The Belle Grove, LSD 2 was kept filled with one LSM after another, replacing screws and repairing underwater damage. Damage above the water line and engineering casualties were repaired by the ARL's. As stated above transports assisted in repairing ships alongside when possible. Without the above repair facilities it is doubtful whether more than half of the LSM's could have carried through the unloading phase, and it is quite possible that some might have been lost had they been ordered to continue operating without repairs.

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