History Friday: MacArthur’s Amphibious Fighting Style & Operation Olympic

One of the biggest problems with World War II (WW2) military histories is the issue of “lanes.” WW2 history writers tend to focus on their one thing, use the institutional historical narratives of their particular military theater and service and then make some appalling inaccurate statements of fact without understanding the wider background. Yet, they are in the generally understood narrative limits of the historical “lane” and everyone nods in agreement. This is an especially difficult problem with understanding MacArthur’s South West Pacific Area (SWPA) institutional culture and amphibious fighting style, as compared to the both the the European and Mediterranean Theaters of Operation (ETO and MTO) and the Central Pacific style that dominates the post-war amphibious operations narrative.

For example, there were more and larger US Army run amphibious landings in WW2 than US Navy (USN) and United States Marine Corps (USMC) Central Pacific Drive, yet there is very little real examination or understanding of them as amphibious operations compared to the US Navy’s Central Pacific drive. Very few WW2 history writers try and trace the development of a military concept across several military theaters and see how it is expressed in various theaters’ institutional culture and war fighting styles. This is a vital methodology in understanding the ground truth of what happened.

For the research I am doing on the canceled invasion of Japan, knowing that US Army amphibious experience is absolutely essential to understand the orders for Kyushu invasion, since the US land based air forces were planning to replicate and improve on the Normandy D-Day aerial bombardment by dropping 200,000 tons of bombs on Kyushu in Oct 1945 plus another 80,000 tons of conventional bombs (180KT total!) on the Nov 1, 1945 X-day landing. (By way of comparison, Hiroshima was a 15KT nuclear blast.) US Army Air Force Generals Spaatz & Doolittle were commanding 20th & 8th Air Force to deliver that tonnage. That tonnage was in General Hap Arnold’s diary as a promise to MacArthur in the summer of 1945, yet USMC historians investigating Operation Olympic speak of the low density of naval fire support there would be on X-day compared to Okinawa and Iwo Jima, like that aerial bombardment didn’t exist!

SWPA M-18 Hellcat Landing in the Philippines
SWPA M-18 Hellcat Landing in the Philippines

This column on “MacArthur’s Amphibious Fighting Style” will use that “tracing an idea across historical lanes” methodology to compare and contrast the various American WW2 amphibious fighting styles with short “thumb nail” descriptions so you can understand this problem with the WW2 historical narrative and appreciate the coordination issues for the “canceled by atomic bomb” Operation Olympic landing in Japan.

The final major amphibious landing Europe was Operation Dragoon. The landings in Southern France, several weeks after the D-Day landing in Normandy, were the climactic expression of the ETO/MTO amphibious war fighting style. It was a “Power and Deception” style characterized by the following :

* An Allied coalition command structure with multiple large national contingents (US, French, British)
* Overwhelming land-based air-power with minor carrier support
* Overwhelming capital ship surface sea-power projected a few hundred miles
* A predominantly shore-to-shore landing ship troop movement (via Landing ships LCI(L), LST and LCT)
* A foe with land based reinforcement requiring both deception and an anti-transportation campaign to isolate
the battlefield
* A circumscribed naval gunfire program, because of that land mechanized force reaction time
* Large (Division plus sized) airborne delivered ground force component
* The substitution of medium/heavy bombers for Naval Gunfire in fortification destruction
* A requirement for a great deal of small littoral combatant (MTB’s and corvettes) combat power
* An evolved electronic warfare capability to deal with German radio guided bombs and radar

In contrast, the Central Pacific amphibious style, the Tarawa landing through Okinawa, was a Sea-centric “Power” style characterized by:

* Naval centric “joint” warfare where the Navy was always first among equals and most staff work was done under
Adm. Nimitz’s eyes
* Overwhelming US Navy sea power projected thousands of miles
* Ship-to-shore movement with large amphibious ships (APA, AKA, LSD) dropping off LCM & LCVP landing craft and
LVT landing vehicles
* Overwhelming naval air supremacy with minor land based air support
* No enemy ground reinforcement due to air and sea superiority
* No role for littoral MTB type small craft. The LCI(L) was converted to a inshore gunboat for the role.
* Little electronic warfare capability until faced with Japanese radar equipped night torpedo bombers in
October 1944

MacArthur’s SWPA amphibious style was an innovative land-sea-air or “Triphibious” style, largely because he had so few resources and no other choice. The SWPA theater did what it could with what it had. The style was characterized by:

* A “Service Coordination & Cooperation” command style with MacArthur as the final arbiter of operations and strategy
level decisions and the flag level principals being scattered over thousands of miles of territory during the planning and
decision making punctuated by occasional command conferences of the service principals or their representatives.
* Limited land based air power providing contested local air superiority from distant bases
* Very limited sea power
* Predominantly shore-to-shore amphibious movements done by US Army engineer boats, and impressed Aussie small craft before
the Army engineers arrived.
* Enemy reinforcement after landings via barge traffic from the close shore
* Air transport reinforcement and resupply
* Limited air drop delivery of Airborne troops (Regiment sized) covered by air-laid smoke screens
* MTBs had a key role with land based air power in isolating the battlefield night and day respectively
* Hard terrain constraints on operations for air and sea power
* Extreme sensitivity to casualties, especially amphibious sea lift that caused…
* Covert placement of Radar and signals intelligence units prior to landings

Fighting Styles As Executed
Most SWPA amphibious landings had abrieviated shore bombardment with a heavy accent on rockets from landing ships and US Army Engineer landing craft, 6 inch and 5 inch naval gunfire. The SWPA amphibious ships and craft always loaded light, with vehicles filled with supplies on LSM and LSTs for quick debarkation at roughly 0730 to 0830 in the morning, and a very quick withdrawal (often by 1200) compared to Central Pacific amphibious assaults which _started_ at 1030 after days of intense shore bombardment with battleships and air strikes. This was due to SWPA assaults generally having only contested local air superiority from distant land bases, as compared to pure air supremacy from local carrier task forces in the Central Pacific drive, with no prospect of replacement of amphibious shipping if lost.

The ETO/MTO naval gunfire support and landing times were closer to that of SWPA than the Central Pacific drive as they had to worry about combined arms mechanized attacks on the first day. Both Army theaters used the DUWK amphibious truck heavily, the USMC in the Central Pacific, used DUKW’s very little. Both Army dominated theaters used naval gunfire as “neutralization” and not “destructive fire” as in the Central Pacific. Army Air Force bombers were used to destroy beach positions instead of naval gunfire. The lower the bombers operated, the more successful they were and Kenney’s mediums and heavies always flew low. That was one of the reasons Utah beach on D-Day was less casualty prone than Omaha beach. The low level medium bombers of 9th Air Force hit German defenses at Utah, and the three divisions of 8th Air Force heavy bombers flying high with radar bombing missed at all the others…twice!

All three of these amphibious styles would be drawn upon for the final assault on Japan, Operation Olympic. Yet look at all the ink, and now electrons, spent looking at the Central Pacific assaults (See notes & sources below) with the majority of WW2 amphibious experience, the US Army’s, being flat ignored.

Now you know I advocate “crossing the lanes” to research the canceled Operation Olympic amphibious assault at the end of the Pacific War.

List of Column Acronyms:
AKA – Attack Cargo Ship
APA – Attack Transport
DUKW – 6X6 Amphibious Truck
LCI(L) – Landing Craft Infantry Large
LCVP – Landing Craft Vehicles and Personnel
LCM – Landing Craft Mechanized
LCT – Landing Craft Tank
LSM – Landing ship Medium
LSD – Landing Ship Dock
LST – Landing Ship Tank
LVT – Landing Vehicle Tracked
MTB – Motor Torpedo Boat
RCM – Radio Countermeasures, the WW2 name for early electronic warfare

Notes and Sources:

Books —

Joseph H. Alexander Storm Landings: Epic Amphibious Battles in the Central Pacific Naval Institute Press, @April 6, 2009, ISBN-13: 978-1557500328

Robert Amory, Jr., SURF AND SAND: the Saga of the 533d Engineer Boat and Shore Regiment and 1461st Engineer Maintenance Company 1942-1945 @1947, Andover Press, Ltd., Andover, Massachusctts, U.S.A.

Daniel E Barbey MACARTHUR’S AMPHIBIOUS NAVY: SEVENTH AMPHIBIOUS FORCE 1943-1945 United States Naval Institute @1969 ASIN: B0006BZ1D4

Merrill L. Bartlett ed. Assault from the Sea: Essays on the History of Amphibious Warfare Naval Institute Press @1993 ISBN-13: 978-0870210761; See articles “Preparations for the Amphibious Invasion of Normandy, 1944” BY SUSAN H. GODSON; “Amphibious Aspects of the Normandy Invasion” BY HANSON W. BALDWIN

JOHN W. HUSTON Ed, “American Airpower Comes of Age: General Henry H. “Hap” Arnold’s World War II Diaries, Volume 2,” Air University Press Maxwell Air Force Base, Alabama, January 2002 page 335

Sunday, June 17, 1945 [Luzon, Philippine Islands]

“He [MacArthur] did not understand our plan for employing B-29s in Japanese operations, destruction of 30 Jap cities and their industries, 200,000 tons [of bombs] a month to destroy targets in invasion area and 80,000 tons on invasion day. He liked it. [once it had been explained?]

Gordon Rottman (Author) , Peter Dennis (Illustrator) US World War II Amphibious Tactics, Army and Marine Corps, Pacific Theater Osprey Publishing (November 11, 2004) ISBN-13: 978-1841768410

Gordon Rottman (Author) , Peter Dennis (Illustrator) US World War II Amphibious Tactics: Mediterranean & European Theaters Osprey Publishing (September 26, 2006) ISBN-13: 978-1841769547

Ed Simmonds and Norm Smith, “ECHOES OVER THE PACIFIC: An overview of Allied Air Warning Radar in the Pacific from Pearl Harbor to the Philippines Campaign,” Radar Returns 39 Crisp Street Hampton Vic 3188 Australia, Internet Edition – November 2007,ISBN 0 646 24323 3

Dissertations —


Government Documents —


Chapter 14 “RCM IN THE EUROPEAN AND MEDITERRANEAN THEATERS” SUMMARY TECHINICAL REPORT OF DIVISION 15, NDRC, VOLUME 1, RADIO COUNTERMEASURES, Office of Scientific Research and Development, Vannevar Bush, Director, DIVISION 15 Chief C.G. Suits, Washingtion DC 1946

Chapter 15 “RCM IN THE PACIFIC THEATER OF OPERATIONS” SUMMARY TECHINICAL REPORT OF DIVISION 15, NDRC, VOLUME 1, RADIO COUNTERMEASURES, Office of Scientific Research and Development, Vannevar Bush, Director, DIVISION 15 Chief C.G. Suits, Washingtion DC 1946

Eighth Air Force Tactical Development August 1942 – May 1945,” 9 July 1945 Prepared by Eighth Air Force and Army Air Forces Evaluation Board (European Theater of Operations), page 143

“D-Day : On D-Day itself 1,350 bombers of the Eighth Air Force formed up in 225 squadrons of six aircraft each. This huge force made a Tire-dawn assembly and followed the route which would give them a right- angle attack on the “beach targets. This would give the H2X overcast “bombing equipment a clearly defined line at the “beach, minimizing risk of bombing our own troops. Over 1,000 of the bombers attacked beach installations, while small forces attacked Caen and alternative targets.
Because of overcast weather, extra safety factors had been added to prevent bombing of friendly troops. This resulted in placing the weight of our bombs 300 to U00 yards behind the beaches.”

Engineers of the Southwest Pacific 1941-1945. Vol IV. Amphibian Engineer Operations Government Printing Office (GPO), @1950, ASIN: B007RFF1X2
On-line at:

“Medium Bomber Operations 1 January – 28 August 1944” Headquarters 12th Air Force, 12 April 1945 (Operations Strangle and Dragoon) Acessed from Combined Arms Research Library Digital Library.

“NAVAL GUNFIRE SUPPORT OF AMPHIBIOUS OPERATIONS: PAST, PRESENT, AND FUTURE” by DONALD M.WELLER, Major General, USMC (Ret.), March 28, 1978, Naval Sea Systems Command Headquarters, U.S. Marine Corps NAVAL SURFACE WEAPONS CENTER Dahlgren, Virginiia 224148, DTIC Accession number ADA051873, pages 12 & 15

The differing strategic environments in the Central Pacific and Normandy dictated differing techniques. U.S. control of the sea and air in the Pacific and the limited size of the island objectives eliminated the requirement for surprise. Consequently, all Central Pacific operations after Tarawa were characterized by 2 or more days of preliminary operations devoted to destruction of Japanese island defenses, including coastal defense guns. The heavy guns of battleships and cruisers firing at point-blank ranges (2000 to 5000 yards) pulverized and eliminated these weapons.

In the Normandy invasion, the essential requirement for surprise ruled out pre-D-day firing, although some air attacks were directed against coastal weapons prior to D day without significant reduction in their capabilities. On D-Day, each of the 23 coastal defense batteries covering the seaward approaches to the Invasion beaches was assigned to a heavy-gun ship, either cruiser or battleship. These ships, firing from positions 10,500 to 30,000 yards offshore, were able to suppress the coastal batteries, thereby preventing any significant interference with the landing operation, although, unlike the Japanese batteries, few were actually destroyed. Admiral Moon, the Amphibious Attack – Force Commander for Utah Beach (one of the two on which U.S. forces landed), explained the success of the naval guns as follows:
“It was significant that at least through the first week of the operation, no battery could be considered destroyed unless captured. There were several instances of positions which were believed, on the basis of air and sea observation, to have been destroyed yet guns in these positions subsequently opened fire. In some of these cases, there is evidence that casements protected the guns against lethal damage although they were rendered inoperative during the bombardment and for many hours thereafter. The latter was probably the case at Crisbecq, which battery was one of the most important on the east coast of the Cherbourg Penisula. The position contained two 210mm guns in casements, one 210mm in an open emplacement, and six 88mm dual purpose in open revetted emplacements. The casements had roofs of reinforced concrete 12 1/2 feet thick and walls ranging from 10 to 16 feet. This position had been subjected, both before and after D-day, to especially heavy air and naval bombardment. The guns in casemates were undamaged except for minor fragmentation scars, the casemates themselves were also entirely unscratched even by close misses. On the other hand, all communication leading to them from the observation post and rangefinders were disrupted which probably rendered accurate fire extremely difficult. All the other guns in the battery which were not enclosed were destroyed or nearly so.2″”

Seventh Amphibious Force Command History, 10 January 1943 – 23 December 1945, DANIEL E. BARBEY, Vice Admiral, U.S. Navy, Commander Seventh Amphibious Force. On-line at:

Internet Documents:

“The Air Command Post Afloat”

The U.S. Army Air Forces in World War II, D-Day 1944, Air Power Over the Normandy Beaches and Beyond, by Richard P. Hallion Air Force Historian, Air Force History and Museums Program 1994

Chapter 2, V [Marine] Amphibious Corps Planning for Operation Olympic and the Role of Intelligence in Support of Planning, by Major Mark P. Arens, USMCR [MCIA]

Naval gunfire support to the V Amphibious Corps during the initial landings included four old battleships, three heavy cruisers, four light cruisers, and eleven destroyers.(17) In comparison, the bombardment of Iwo Jima was carried out by six old battleships, five heavy cruisers and ten destroyers. While the Corps landings on Kyushu were to cover a larger area and against more difficult terrain, in effect less naval gunfire support was to be provided.
17. V Amphibious Corps, Naval Gunfire Operations Report, Occupation of Japan, 30 November 1945, 3.

20 thoughts on “History Friday: MacArthur’s Amphibious Fighting Style & Operation Olympic”

  1. The terrain at Utah has to have had a major role in the casualty level. It is flat, the chief obstacles being the flooded marshes inland. The airborne assaults were to capture the causeways over those marshes.

    Omaha Beach has 200 foot bluffs behind it and the passages were blocked by huge obstacles. I have some photos of those two beaches here.

    Much of the problem at Tarawa was the reef which caused the landing craft to stop a long way from the beach. The Navy had failed to anticipate a neap tide that stranded the Higgins boats far offshore.

  2. Mike K,

    The primary killer’s of American infantry on Omaha Beach were German infantry machine guns and mortars located in open trenches of those bluff’s between the fortifications.

    Had the 8th Air Force dropped from 5,000 feet visually like the 9th Air Force medium bombers, rather than 20,000 feet by radar, most of those German infantry would have been dead.

    The other issue with the Omaha landings, vice Utah, was the rocky shingle on the beaches that immobilized wheeled and tracked vehicles.


  3. BTW, the picture of the M-18 Hellcat tank destroyer leaving from a US Coast Guard manned LST is one of the minor mysteries of the Pacific War.

    The troop list for the Cebu Philippines landing _does not_ include any elements of the M-18 Hellcat equipped TD battalions in the Philippines.

    The US Army LVT battalion involved in the Cebu landing was a former TD battalion, so they may have picked up an M-18 somewhere.

  4. I hope your book, or at least a subsequent post will compare the differences between Army Pacific Campaign casualties and USMC casualties. I have read the Army’s were markedly less.

  5. Trent, were MacArthur’s plans for invading the Japanese home islands influenced by his SWPA experience. It seems Olympic and Coronet would have been more like the European invasions in scale and method.

  6. >>>Trent, were MacArthur’s plans for invading the Japanese home islands influenced by his SWPA experience.

    Short answer — Yes.

    Longer answer — the last Borneo invasion was seen by MacArthur’s command team as a testing ground for the Olympic invasion.

    >>>It seems Olympic and Coronet would have been more like the European invasions in scale and method.

    Another short answer — Yes it would.

    Longer answer — General Kenney was going to use Ie Shima and Okinawa much like the USAAF used Sardinia and Corsica for the invasion of southern France, Operation Dragoon.

    The largest unexamined issue was Kenney was planning to use three pilots for every airplane on Ie Shima and Okinawa. The normal USAAF unit had something like 1.2 pilots per plane. This meant that plane counts of those islands should be more properly thought of as “logistical slots” that many more planes and pilots operated through from the larger air depot in the Philippines.

    Meanwhile, Arnold and the Bomber Mafia were plotting back in Washington DC with the Joint Chiefs of Staff to replace Kenney’s medium and light bomber forces with B-29’s…which would be controlled by the Strategic Army Air Forces under Generals Arnold and Spaatz.

    Admiral Turner’s plans for using USAAF air units had significant order of magnitude errors.

  7. I’ve read that advice given to European commanders, by Pacific veterans, was often ignored.
    Also – a little off subject; however, could we have made our main landings in Southern France? They gave us a tremendous amount of support.

  8. >> MikeK Says:
    >>Trent, General McNair got a close view of high altitude heavy bomber accuracy.
    >>It was brief but intense.

    Heh. Too True.

    The interesting thing about the 8th Air Force bombing was the 2nd order effects of it.

    Horrible as the casualties at Omaha Beach were, they should have been a lot worse due to the number of US infantry pinned on the beach, amount of German artillery and the number of concrete protected forward observers the Germans had. The 8th Air Force bombings are a big reason the German infantry observers on the beach didn’t have that artillery.

    The Germans were very dependent on wire communication for directing their artillery as they lacked FM radio. This meant behind every infantry company position on the beach, there were long runs of telephone and telegraph wires running for miles, most of which were above ground.

    This is what Admiral Moon said of the Normandy shellings in the foot notes above:

    …The casements had roofs of reinforced concrete 12 1/2 feet thick and walls ranging from 10 to 16 feet. This position had been subjected, both before and after D-day, to especially heavy air and naval bombardment. The guns in casemates were undamaged except for minor fragmentation scars, the casemates themselves were also entirely unscratched even by close misses. On the other hand, all communication leading to them from the observation post and rangefinders were disrupted which probably rendered accurate fire extremely difficult. All the other guns in the battery which were not enclosed were destroyed or nearly so.2″”

    The 8th Air Force bombings that missed the Omaha beach emplacements and killed a lot of cows — and not a few Frenchman — behind the beaches also destroyed most of the German infantry’s wire communications to its guns, and the battleship and cruiser naval gunfire plus tactical air strikes prevented their repair the first day of the D-Day invasion.

    The use of B-29’s over Kyushu in the same role would be much more effective for a number of technical and tactical reasons. The 8th Air Force would have SHORAN radio navigation in October/November 1945 and they would also have radio proximity fuzes for their bombs. The B-29’s of 8th Air Force would be able to deliver more payload, more accurately in any weather, with 10-times the fragmentation effectiveness to carpet bomb the back slopes of the hills overlooking the Kyushu beaches, where the Japanese guns were going to be.

    When they were done, the Japanese would have neither wire nor long range radio communications for the use of indirect fire artillery due to the B-29 carpet bombing fragmentation beaten zones.

    Unobserved indirect artillery fire that wasn’t coordinated and whose guns had to keep ducking back into caves from American aircraft and naval gunfire counter-battery fire efforts would be neither accurate nor effective.

  9. >>VXXC said:
    >>I hope your book, or at least a subsequent post will compare the
    >>differences between Army Pacific Campaign casualties and USMC casualties.
    >>I have read the Army’s were markedly less.

    There are a lot of doctrinal reasons for that fact, that I will touch on in later columns.

    The best place to go to understand that are the following;
    1) the Army 81st Infantry Division and USMC 1st Marine Division after action reports for the Battle of Peleliu, AKA Operation Stalemate II,
    2) The 6th Marine Division after action report on the final assault on Sugarloaf on Okinawa, and
    3) The final Marine assaults by the 8th Marine Infantry Regiment on Okinawa.

    The Pacific Army and USMC ground units were developing a systematic doctrine of set piece assault to deal with Japanese cave positions, such that they only had to be taken once, not the 14 times the 6th Marine Division did at Sugarloaf.

  10. In current events (relatively), the USMC were the branch fighting hardest to keep one or two battleships in the fleet to support their landings.

    Only a battleship’s 16 inch guns could be effective against casement-emplaced guns covering a landing beach and even then, only so much. Maybe the new hyperbaric bombs would more effective but only as anti-personnel weapons against the gun crews.

    The Navy is now pumping for very long range naval guns but that still leaves a close in-shore heavy weapon gap.

  11. Trent, I am emailing you a picture of my father washing an M-18 on Mindoro in late 1945. He was then executive officer of the 86th Division’s reconnaissance company, having been transferred to it from the 96th Division as he didn’t have enough points to go home with the 96th.

    They used it to deliver mail as there were still a lot of Japanese hold-outs.

  12. Trent – you seem well versed in this subject. I had read somewhere that there were actually 2 “spheres of influence” in the Pacific divided between MacArthur and Nimitz.

    MacArthur had the inner sppere – Nimitz the outer sphere

    Any truth to that?

    Of course when one thinks of amphibious landings in WW2 one things of the Marines – interesting that the Army had their ways, too.

  13. Bill,

    I am not quite sure what you mean by this:

    “MacArthur had the inner sppere – Nimitz the outer sphere”

    MacArthur had Australia and the Navy did not. A great deal of American strategy in the Pacific was built on that fact.

  14. Trent – by “sphere’s” I mean the distance from the Asian land mass – MacArthur had as a responsibility an area closer to Japan, Philippines, Australia and Nimitz had a responsibility from the eastern boundary of MacArthur westward.

    Of course what I read may have been BS – but each was responsibility for the complete planning – amphibious landings on…

    Max Hasting’s book Retribution is an interesting read on the last year of the Pacific War – he makes some assertions that I questioned – such as, the B-29 was so expensive at over $600K / plane – that LeMay felt first to use it and justify it (when a blockade might have been effective) – but this – and his companion book on the European theater, Armageddon, are interesting…

  15. Bill,

    The Central Pacific Drive was a shorter geographic route to Japan than from Australia.

    The issue in the Pacific War was before about January 1944, the best _logistical route_ was the one that used Australian supplies.

    After January 1944, it was a political question of whether we re-took the Philippines on the way to Japan or took Formosa/Taiwan.

    MacArthur won that decision from the US Navy, despite FDR being the most pro-Navy president in the history of the Republic.

  16. “FDR being the most pro-Navy president in the history of the Republic”

    This is fascinating, and is an under-appreciated aspect of FDR’s thinking and action.

    Nonetheless, he seems to have been a pragmatist when it came to inter-service squabbles. He wanted to win the war, first, last and always.

  17. Trent – an interesting assertion in Max Hasting’s Retribution, is that both the Philippines, and Palau (a nearly forgotten and bloody island) were unnecessary. At least it is the author’s assertion that MacArthur had a personal stake in the Philippines and his larger strategy of “island hopping” – letting Japanese garrisons starve and wither on the vine, was brilliant.

    Of course, for Mac Arthur’s strategy to be successful, he needed the successes of the US Navy.

    With the benefit of hindsight perhaps Hastings was right.

  18. Bill,

    Max Hasting’s Retribution is badly flawed regards the Philippines for a lot of reasons(most of the following is from a future column rough draft) —

    First, and a generally unknown fact, was the Southern Philippines was very important for Japanese Army logistics in the Pacific. Davao, Mindanao in the Philippines was a center of manufacture of Japanese Army powered barges and small wooden freighters, called “Sea Trucks” in WW2 documents. The following is from page 32 of the 1947 United States Strategic Bombing Survey report titled “The Fifth Air Force in the War Against Japan” —

    Losses in larger and faster ships, and the necessity of maintaining such vessels on the main routes of supply to Empire, caused the Japanese to resort to smaller shipping for inter-theater troop movements and supply. The “Sea Truck,” a small wooden ship of stylized construction (100/300 tons), became a most important factor in his surface movement from early 1943. The power barge was also made and used in large numbers. These vessels were manufactured at Soerbaja, Davao, and other places beyond our range of attack. They were used on long sea hauls at times, movement being traced from Philippines to Halmaheras and New Guinea in such vessels. They were used almost entirely in redistribution from supply termini in the combat zones. Fishing vessels, luggers, and prahus were also extensively used in intertheater supply and were capable of moving effective tonnage by their numbers and the ability to hide in small inlets. This small shipping became an increasingly important target for Fifth AF and regular hunts were made for it until its movement ceased.

    MacArthur’s 5th Air Force did not have enough planes or supplies to wipe out those facilities without killing a lot of innocent Filipinos and denying both his own own troops in Luzon, and those with the American fleet at Okinawa, badly needed air support. This was particularly important in terms of suppressing Japanese airfields on Formosa sending Kamikaze’s to Okinawa April – June 1945. Every long range bomber strike sent to Davao, had it been by-passed, would have been one diverted from Formosa during that time.

    Second, in the Pacific War, logistical “opportunity costs” were measured in terms of Amphibious sea lift and merchant shipping tonnage. The reason for this was tied into the issues of shipping capacity, port capacity and the organization of amphibious assaults.

    US Navy historians including Samuel Elliot Morrison denigrate Mac’s moves in the Southern Philippines, the Visayan passages specifically, while glossing over the logistical realities of MacArthur’s coastal shipping. This line of argument lets the Navy off the hook for how badly they went out of their way sabotage MacArthur on shipping and naval support (This story and a number of others I intend to expand on in later columns).

    Mindanao was also infested with both Japanese radars and suicide small boats (Called Q-Boats in the SWPA) which threatened MacArthur’s small freighter convoys and small boat distribution sea lines of communications. The following is from page 651 “Engineers of the Southwest Pacific, 1941-1945 – vol 4” on the combat between Japanese suicide boats and the US Army’s Amphibious Engineers in the Southern Philippines. The text I clipped below can be found on the Hathi Trust digital library at this link.

    Boat Missions.
    Boat operations by 533d EBSR craft in Davao Gulf included a shore-to-shore landing on 15 May on Samal Island, which lies offshore from Davao. (See Maps Nos. 31 and 33.) Japanese artillery on Samal had proved harassing and occasionally destructive; an enemy shell on one occasion struck a portable surgical hospital and killed 7 men and wounded 9. To destroy the Japanese gun emplacements the 3d Battalion, 19th Infantry, was transported to Samal in LCM’s and LVT’s of Company B, 533d EBSR, the expedition being supported by 2 LCM gunboats. The Japanese were hunted down in the island’s rocky interior or were forced to flee to the mainland. Later in May the LCM’s of Company ? were employed to support the advance of the 24th Division along the coast northeast of Davao. The boats were frequently under fire by small arms and light artillery.
    LCM gunboats and rocket craft were also employed in daylight attacks upon Japanese Q-boat hideouts on the east coast of Davao Gulf.395 A 5-day raiding mission to destroy Japanese radar installations in southern Mindanao marked 533d EBSR boat operations in late May and early June.

    Third, MacArthur’s issues with port capacity and workforce shortages brings us to the way freighters were packed in WW2. There were four ways to load a freighter.

    1. Amphibious Landing Combat loaded with equipment/supplies stacked in the hold for rapid debarkation in order of use in an amphibious assault.
    2. Theater Unit loaded with organization equipment and units placed on the same ship or in multiple ships in the same convoy.
    3. Commercial loading with minimal weapon dis-assembly, consistent with freighter space availability & center of gravity, with unit loads of equipment spread over several convoys weeks or months apart.
    4. Maximum freighter space utility with vehicles and equipment requiring a factory or depot assembly at the other end to reassemble the major weapons systems involved.

    Every amphibious landing had to take freighters loaded out as in #2 through #4 above, unload them. Then combat load the contents into Amphibious assault shipping, plus some number of the freighters that were unloaded. Then stage the shipping out in convoys in order of use at landing. In terms of shipping space, Amphibious combat loading was less than 1/2 the efficiency of commercial loading and 1/4 the shipping efficiency of “factory reassembly loading” above. (Shooting Blanks or Dirty Little Secrets of WW2)

    The typical amphibious assault in WW2 was in three echelons:

    1. The Assault echelon with 70% or less of the vehicles and 100% of the infantry.
    2. The follow-on echelon that filled out artillery and other combat support. Then finally,
    3. The third echelon that completed the rest of the Assault Division and higher level assets for things like heavy Ordnance repair, usually in 1st echelon assault landing shipping making a 2nd round trip.

    Even if the Southern Philippines ports were “logistically barren” in terms of supplies after capture. They were still highly useful in future operations to have available against Japan to in order to unload and repack shipping for an invasion. If only for the real estate available to unload and water resources. Since the Southern Cebu City, Cebu and Iloilo on Panay were the second and third largest cities respectively in the Philippines at the time. They had lots of valuable port real estate and water.

    One of the forgotten logistical issues of the Central and South Pacific islands were that they were especially low on fresh drinkable water. You needed water for those 2nd and 3rd echelon servicemen waiting for their reinforcement convoy as well as the port clearance work force.

    Which brings up the final thing Southern Philippine ports had addition to port capacity.

    They had Filipino port workers as “force multipliers” for a chronically short of bodies SWPA Army Service force.

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