OLYMPIC AMPHIBS

Command Ships

CINCPOA OP-PLAN No. 10-45 identified 21 command ships for Operation OLYMPIC. 13 of these were large converted cargo ships, 1 converted small seaplane carrier, 2 converted amphibious transports, and five converted coast guard cutters. Nineteen of these were assigned to the amphibious force. One coast guard cutter (BIBB) was assigned to the Mine Forces and another (CAMPBELL) assigned to ServRon 103..

AMPHIBIOUS FORCES OPERATION PLAN NO. A11-45, which was based on FIFTH FLEET OPERATION PLAN NO. 5-45 allocated those units as follow:

ELDORADO was Admiral Turner’s flagship as the head of the entire Amphibious Force and the Advance Force, which would arrive at the objective area beginning X-8. BISCAYNE, the converted seaplane carrier served as the flagship for Commodore Moosbrugger who was in charge of the destroyer types serving in the screens of the various forces. Also arriving at X-8 were the three main Fire Support Groups, each with its own large command ship. Coast Guard Cutter CAMPBELL would serve as the flagship of the Service and Salvage Group.

The Western Attack Force, Task Force 42 with large command ship ESTES and carrying the 40th Infantry Division would assault Uji Gunto, Kusakaki Shima, Kuro Shima, Kuchinoreabu Shima on X-5. The main purpose of these assaults was to establish fixed radar coverage and fighter direction stations in the Objective Area. On X-4 the Force would assault Koshiki Retto and establish a temporary seaplane base and logistics anchorage. After these tasks were complete the 40th Division would be reimbarked and become a 6th Army reserve.

The smaller Southern Attack Force, Task Force 44 with converted APA CALVERT serving as the command ship and carrying the 158th Infantry Regimental Combat Team was (if ordered) to assault northern Takega Shima on X-3. Alternatively, it was to be prepared to land at any of the 6th Army beaches after X+3. Northern Takega Shima was of interest because it forms the southern portion of Osumi-Kaikyo, the strait between the Pacific Ocean and the East China Sea, just south of Kyushu in the Objective area.

Each of the three main Attack Forces (Third/XI Corps, Fifth/V Amphib Corps, and Seventh/I Corps) would add two additional large command ships, one for the Vice Admiral in charge of the Attack Force and one for the Rear Admiral leading the Transport Squadrons. These forces would begin arriving on X-Day.

Large command ship, COTOCTIN, would lead the floating Reserve Force (IX Corps), that if not needed to reinforce the X-Day landings would assault Kaimondake on X+4.

Converted APA, FREMONT, would lead the reinforcement group, that would arrive as fast as Transron 20 could be released back to the Philippines and returned to the Objective Area.

The CINCPOA plan provided one large (ROCKY MOUNT) and modified three coast guard cutters that are not accounted for in the AMPHIB FORCE plan. The contemporaneous Army Plan has ROCKY MOUNT leading the Reinforcement Force. ROCKY MOUNT served as Admiral Kinkaid’s SEVENTH FLEET Flagship in postwar operations. SEVENTH FLEET was to take over FIFTH FLEET’s remaining missions when Admiral Spruance would be relieved in order to plan Operation CORONET.

AGC 11 ELDORADO TASK FORCE 40   Amphibious Force     Admiral Turner

AGC 18 BISCAYNE TASK GROUP 40.1           Screen Group (Task Flot 5)      Commo Moosbrugger

AGC 11 ELDORADO TASK FORCE 41   Advance Force          Admiral Turner

WGC 32 CAMPBELL TASK GROUP 41.2           Service and Salvage Group               Commodore Hartley

AGC 1 APPALACIAN TASK GROUP 41.3           THIRD Fire Support Group                 Rear Admiral Conolly

AGC 2 BLUE RIDGE    TASK GROUP 41.5           FIFTH Fire Support Group                    Rear Admiral Wright

AGC 7 MT. McKINLEY    TASK GROUP 41.7           SEVENTH Fire Support Group             Rear Admiral Kiland

AGC 12 ESTES     TASK FORCE 42              Western Attack Force                           Rear Admiral Davis

RAGC 32 CALVERT  TASK FORCE 44             Southern Attack Force                        Rear Admiral Briscoe

AGC 8 MT. OLYMPUS TASK FORCE 43             THIRD Attack Force                        Vice Admiral Wilkinson

AGC 14 TETON TASK GROUP 43.1 THIRD Transport Group  Rear Admiral Hall

AGC 10 AUBURN TASK FORCE 45             FIFTH Attack Force                          Vice Admiral Hill

AGC 13 PANAMINT TASK GROUP 45.1 FIFTH Transport Group  Rear Admiral Reifsnider

AGC 4 ANCON TASK FORCE 47              SEVENTH Attack Force                  Vice Admiral Barbey

AGC 9 WASATCH TASK GROUP 47.1          SEVENTH Transport Group   Rear Admiral Noble

AGC 5 CATOCTIN TASK FORCE 48              Reserve Force                                 Rear Admiral Rodgers

RACG 44 FREMONT TASK FORCE 49             Reinforcement Force                 Rear Admiral Struble

Landing Ship Vehicle

CINCPOA OP-PLAN No. 10-45 identified all six LSVs for Operation OLYMPIC. The six ships were originally designed as minelayers, but delivered as transports. For Operation Olympic the Army (Annex 6 to FO 74, 28 July 1945) assigned these ships to carry headquarters units and independent units assigned to higher headquarters; 2 to SIXTH Army HQ and 1 each to I Corps, V Amphib Corps, IX Corps. SIXTH Army designated one of their LSVs as a Command Ship.

LSV 1 Catskill

LSV 2 Ozark

LSV 3 Osage

LSV 4 Saugus

LSV 5 Monitor

LSV 6 Montauk

Landing Ship Dock

CINCPOA OP-PLAN No. 10-45 identified sixteen LSDs for Operation OLYMPIC. These ships had a long well deck that could carry a variety of landing craft; 14 LCM (1 medium tank), 3 LCT (5 medium tanks), 41 LVT, or 47 DUKW. The LSDs were assigned to the assault divisions only: 3 to the 1st Cavalry Division(+), 2 each to the 25th Infantry Division, 33rd Infantry Division, 43rd Infantry Division, 2nd Marine Division, 3rd Marine Division, 1 each to the 40th Infantry Division, 81st Infantry Division, and 98th Infantry Division. Many of these units would make a quick turnaround with cargo from Okinawa.

Typically the LSD’s would carry a tank company to the objective area. That company would be paired with one or two assault battalions.

LSD 1 Ashland

LSD 2 Belle Grove

LSD 3 Carter Hall

LSD 4 Epping Forest

LSD 5 Gunston Hall

LSD 6 Lindenwald

LSD 7 Oak Hill

LSD 8 White Marsh

LSD 13 Casa Grande 

LSD 14 Rushmore 

LSD 15 Shadwell 

LSD 16 Cabildo

LSD 17 Catamount

LSD 18 Colonial

LSD 25 San Marcos

LSD 26 Tortuga

Transports (APA, APH, & AP) & Attack Cargo Ships (AKA)

CINCPOA OP-PLAN No. 10-45 identified 209 Attack Transports (APA), 17 Transports (AP), and 84 Attack Cargo Ships (AKA) assigned to fourteen Transportation Squadrons for OLYMPIC. In addition five APAs were designated for casualty evacuation, three APHs would bring troops to Kyushu and then be reconfigured hospital ships, ten AKAs were available but not formally assigned to squadrons and six AKAs were dedicated for transport of ammunition. With the LSDs and LSVs this was practically all the assault shipping available to the U.S. Navy.

The APA was a troop transport equipped to carry landing craft. A Haskell Class APA carried two LCMs, one open LCPL, one covered LCPL (Captain's Gig), two LCPRs, eighteen LCVPs. Similarly the AKA was a cargo ship equipped to carry landing craft. A Tolland Class AKA carried fourteen LCVPs and eight LCMs.

The APAs and AKAs came in two sizes. Large APAs carried 1200-2000 troops with 1200-4700 tons of cargo; small APA carried 850-1000 troops with 400-600 tons of cargo. Most of these ships carried an infantry battalion to the objective. Large AKAs carried 4400-5275 tons of cargo and as many as 250 troops. Small AKAs carried 980 tons of cargo and 54 troops. The ships were highly fungible and switched squadrons frequently.

AMPHIBIOUS FORCES OPERATION PLAN NO. A11-45 identified the transportation squadrons assigned to specific army units as follows:

  • TransRons 16, 19, & 20 was assigned to move XI Corps as a part of the Third Attack Force, Task Force 43.

  • TransRons 12, 13, & 24 was assigned to move V Amphibious Corps as a part of the Fifth Attack Force, Task Force 45.

  • TransRons 15, 17, & 18 was assigned to move I Corps as a part of the Seventh Attack Force, Task Force 47.

  • TransRons 11, 21, & 22 was assigned to move IX Corps as part of the Reserve Force, Task Force 48.

  • TransRon 14 was assigned to move 40th Infantry Division as a part of the Western Attack Force, Task Force 42.

  • TransRon 20 was to be quickly returned to the Philippines, become a part of the Reinforcement Force, Task Force 49 and deliver the 11th Airborne Division Kyushu.

  • TransRon 23 was available, but not assigned to any identified land unit.

SIXTH ARMY FIELD ORDER 74, 28 July 1945 outlined the planned use for these assets without being ship specific as follows:

Western Attack Force, Task Force 42, PhibGroup 13

X-5, TransRon 14, 40th Infantry Division, from Panay

  • 12 APA(L)

  • 2 APH (RIXEY, TRYON) (Identified in Amphib Plan A11-45)

  • 4 AKA(L)

  • 1 LSD

  • 9 APD

Southern Attack Force, Task Force 44, PhibGroup 14

158 Infantry RCT, from Legaspi

X-3

  • 1 APA(L)

  • 1 AKA(L)

  • 19 APD

THIRD Attack Force, Task Force 43, 3rd Phib Force

SIXTH Army

X-Day

  • 1 LSV from Manila

X+1

  • 1 APA(L) from Manila or Batangas

  • 1 APA(S) from Batangas

  • 1 LSV from Manila

X+2

  • 1 APA(L) from Manila or Batangas

  • 1 AKA(S) from Batangas

X+4

  • 1 APA(L) from Batangas

  • 1 AKA(L) from Batangas

  • 1 AKA(S) from Batangas

X+7

  • 1 APA(L) from Manila or Batangas

  • 1 AKA(L) from Batangas

X+11

  • 1 AP from Batangas

X+15

  • 1 AP from Batangas

1st Cavalry Division + 112 Cavalry RCT from Batangas

X-Day

  • 12 APA(L)

  • 3 APA(S)

  • 3 AKA(L)

  • 3 AKA(S)

  • 3 LSD

43rd Infantry Division from Lingayen

X-Day

  • 12 APA(L)

  • 4 AKA(L)

  • 2 LSD

Americal Division from Cebu

X+2

  • 12 APA(L)

  • 1 APA(S)

  • 4 AKA(L)

  • 1 AKA(S)

XI Corps

X+1

  • 1 APA(L) from Manila

X+2

  • 1 APA(L) from Batangas

  • 2 AKA(L) from Batangas

  • 1 AKA(S) from Batangas

X+4

  • 1 APA(S) from Manila

  • 1 APA(S) from Batangas

  • 1 APH (PINKNEY) (Identified in Amphib Plan A11-45)

X+7

  • 2 APA(S) from Batangas

FIFTH Attack Force, Task Force 45, 5th PhibFor

2nd Marine Division from Saipan

X-Day

  • 12 APA(L)

  • 3 AKA(L)

  • 1 AKA(S)

  • 2 LSD

3rd Marine Division from Guam

X-Day

  • 12 APA(L)

  • 4 AKA(L)

  • 2 LSD

5th Marine Division from Hawaii

X-Day

  • 12 APA(L)

  • 3 APA(S)

  • 4 AKA(L)

V Amphib Corps

X-Day

  • 2 APA(L) from Maui

  • 1 LSV from Maui

  • 1 APA(S) from Hawaii

  • 1 AKA(L) from Oahu

X+2

  • 1 APA(L) from Maui

  • 1 AP from Maui

  • 1 AKA(S) from Maui

  • 1 APA(L) from Hawaii

  • 2 AP from Hawaii

  • 1 AKA(L) from Hawaii

  • 1 APA(S) from Oahu

  • 1 AKA(L) from Oahu

  • 2 AKA(S) from Oahu

  • 2 AKA(S) from Guam

  • 1 APA(L) from Lingayen

X+4

  • 1 APA(L) from Lingayen

  • 1 AP from Lingayen

  • 2 AP from Leyte

X+7

  • 1 APA(L) from Lingayen

X+11

  • 1 APA(L) from Lingayen

  • 2 APA(S) from Lingayen

SEVENTH Attack Force, Task Force 47, 7th PhibFor

25th Infantry Division from Lingayen

X-Day

  • 14 APA(L)

  • 5 AKA(L)

  • 2 LSD

33rd Infantry Division from Lingayen

X-Day

  • 14 APA(L)

  • 4 AKA(L)

  • 2 LSD

41st Infantry Division from Zamboanga

X+2

  • 14 APA(L)

  • 6 AKA(L)

I Corps from Lingayen

X+1

  • 1 LSV

X+2

  • 2 AKA(L)

X+4

  • 3 APA(S)

X+7

  • 2 APA(S)

  • 1 AKA(S)

RESERVE Attack Force, Task Force 48, PhibGp 11

98th Infantry Division from Oahu

X+3

  • 8 APA(L)

  • 2 APA(S)

  • 3 AKA(L)

  • 2 AKA(S)

  • 1 LSD

81st Infantry Division from Leyte

  • 12 APA(L)

  • 1 APA (Casualty Evac) (THOMAS JEFFERSON)(Identified in Amphib Plan A11-45)

  • 2 APA(S)

  • 2 AKA(L)

  • 1 LSD

77th Infantry Division from Cebu

X+5

  • 9 APA(L)

  • 2 APA(S)

  • 4 AKA(L)

IX Corps

X+3

  • 1 LSV

X+4

  • 2 APA(L) from Leyte

  • 2 APA(L) from Lingayen

X+5

  • 1 APA(L) from Leyte

  • 1 APA(L) from Oahu

  • 3 AKA(S) from Leyte

X+7

  • 1 APA(L) from Leyte

  • 1 APA(S) from Leyte

  • 1 AKA(S) from Leyte

  • 1 APA(S) from Lingayen

  • 1 AP from Lingayen

  • 3 AKA(L) from Lingayen

  • 1 APA(L) from Cebu

Most of these units were planned to make a second trip to Kyushu from the Philippines or Marianas on X+22 (11th Airborne Division), X+25, X+30, or X+35.

In the medical Annex, SIXTH ARMY FIELD ORDER 74, 28 July 1945 was specific regarding the assignment of APHs and Casualty Evacuation APAs as follows:

SEVENTH Attack Force

  • APA 13 J.T. Dickman

  • APA 170 Gosper

THRID Attack Force

  • APH 2 PINKNEY

  • APA 26 SAMUEL CHASE

FIFTH Attack Force

  • APA 21 CRESCENT CITY

WESTERN Attack Force

  • APH 3 RIXEY

  • APA 1 TRYON

RESERVE Attack Force

  • APA 30 THOMAS JEFFERSON

As only one casualty evacuation APA is accounted for in the long list above, it may be that four of these five APAs are included without reference to their full function.

Landing Ship Tank (LST), Landing Ship Medium (LSM) and Landing Vehicle Trac (LVT)

CINCPOA OP-PLAN No. 10-45 identified 559 LSTs and 400 LSMs for Operation OLYMPIC. The mass produced LST and LSM were the workhorses of Allied amphibious warfare carrying anything and everything to the objective. In beaching configuration the LST could carry 500 tons of cargo; the LSM 150 tons. For port to port shipments the LST could carry 2100 tons. Other key LST capacity planning constraints included 7,437 SqFt. of area and 92,958 CuFt. of space. Typical loads for the LSM were 5 medium or 3 heavy tanks, or 6 LVT's or 9 DUKW's.

A particular assignment of the LST was to transport the initial waves of the assault. Each LST carried a reinforced infantry company boated in tracked landing vehicles (LVT). LVT’s could carry 24 combat loaded personnel or 4 tons of cargo. The LVTs were assigned to an an Amphibious Trac Battalion, which typically supported two reinforced infantry battalions in the initial assault waves. For OLYMPIC each Army assault division was provided an Amphibious Trac Battalion.

LSTs also carried amphibious tanks (LVT-A) armed with a 37mm gun or 75mm howitzer. These were mixed with LTVs in the initial waves of the assault. The four companies of the 780th Amphibious Tank Battalion would accompany the assault waves of the I Corps’ 25th Infantry Division and 33rd Infantry Division and XI Corps’ 1 Cavalry Division, and 43rd Infantry Division. Similarly, a company of the 708th Amphibious Tank Battalion would accompany each of IX Corps’ assault divisions, the 81st Infantry Division and 98th Infantry Division as well as the 40th Infantry Division of the Western Attack Group. The fourth company of the 708th Amphibious Tank Battalion was assigned to the 158th Infantry RCT, which did not have a boated regular Tank Company available.

Unlike the Army units, each of the Marine assault divisions (2nd and 3rd) had two Amphibious Trac Battalions and two two Amphibious Tank Companies assigned. This would permit twice as much assault infantry to come ashore in LVT’s in the V Amphibious Corps area. As a result the number of LSTs assigned to the Marine assault divisions was proportionally larger than the Army divisions and the number of LSMs assigned to the Army units was in turn much higher than their Marine counterparts.

Destroyer Transports (APD)

CINCPOA OP-PLAN No. 10-45 identified eighty nine APDs for OLYMPIC. Most of the 4 stack conversions were no longer serving as active APDs. For the most part these were new BUCKLEY or RUDDEROW class destroyer escorts that had been converted or modified during construction into a light, relatively fast troop transport that could carry 162 troops and their equipment. Twenty eight of these ships were tasked with moving portions of the 40th Infantry Division and 158th Infantry RCT in the Western and Southern Attack Groups. Twenty one ships were committed to transport and support Underwater Demolition Teams. The remainder would likely be assigned to screening forces in an escort destroyer role.

LCS(L) (3)

CINCPOA OP-PLAN No. 10-45 identified 110 LCS(L) for OLYMPIC. 130 LCS(L) were produced; as such, most of the surviving ships were assigned to OLYMPIC. LCS Flotillas nominally were assigned 36 LCS in three groups and six divisions. LCS Flotillas 3, 4, & 5 were so organized and would be assigned to each of the major Attack Forces. LCS Flotilla 1 had been assigned to the Seventh Fleet and was slightly smaller. It was slated to support the Western and Southern Attack Forces in their preliminary operations, the Fifth Attack Force on X-Day, and the Reserve Attack force subsequently.

These 250 ton gunships designed mission was to provide close in fire support for amphibious landings. The latest production models were armed with three twin 40mm mounts, four 20mm cannons, four 50 caliber machine guns, and ten Mark 7 rocket launchers. Earlier units had either a single 3”gun or a single 40mm in the bow position.

At Okinawa the 40mm was found to be the most effective weapon against Kamikazes. LCS gunships, with as many as six 40mm were found to be a very helpful addition to destroyers on radar picket stations. The OLYMPIC Amphibious plan would continue/expand this practice. The Amphib Plan called for sixteen radar picket locations each with three destroyers and four LCS.