Naval History and Heritage Command

TF 1 was organized on 11 January 1946. It followed the basic principles employed during World War II to develop amphibious task forces, but incorporated needs of the scientific program. The joint task force staff comprised Army, Navy, and civilian scientific personnel. This joint staff maintained liaison with the War and Navy Departments, the Manhattan Engineer District, and other government agencies.

Commander Joint Task Force 1 [CJTF 1] maintained liaison with two boards of special interest, the Joint Chiefs of Staff (JCS) Evaluation Board and the President's Evaluation Commission. The Evaluation Board was to advise CJTF 1 during preparation for the tests and evaluate test results. The Evaluation Commission was to cooperate with the War and Navy Departments in conducting the tests, and to undertake a study of the tests and to submit its observations to the President along with findings, conclusions, and recommendations.

JTF 1 was subdivided into eight task groups, each of which performed some specific function.

Task Group 1.1 (Technical Group)
Task Group 1.2 (Target Vessel Group)
Task Group 1.3 (Transport Group)
Task Group 1.4 (Army Ground Group)
Task Group 1.5 (Army Air Group)
Task Group 1.6 (Navy Air Group)
Task Group 1.7 (Destroyer Surface Patrol Group)
Task Group 1.8 (Service Group)
Post-Operation Organization and Activities

Headquarters for JTF 1 was on the USS Mount McKinley (AGC-7) (Joint Task Group Flagship).

Task Group 1.1 (Technical Group)

Task Group 1.1 [TG 1.1] was responsible for instrumenting all target ships and target areas. Selected ships assigned to the group were equipped with laboratory facilities to service scientific instruments and record all data. The primary mission of its Drone Boat Unit (Task Unit 1.1.3 [TU 1.1.3]) was to obtain early samples of radioactive water after each test and conduct remotely controlled radiological reconnaissances of the lagoon area after shot BAKER. TG 1.1 also did the following:

A. Operated and performed technical services
B. Observed and measured physical phenomena
C. Furnished technical advice and assistance.

TG 1.1 had the following three task units [TU], listed below with the ships on which they were based.

TU 1.1.1 (Laboratory Unit)

USS Albemarle (AV-5) (Flagship)
LCT-1359
LSM-60 (BAKER surface zero vessel)

TU 1.1.2 (Instrumentation Unit)

USS Avery Island (AG-76)
USS Burleson (APA-67)
USS Cumberland Sound (AV-17)
USS Haven (AH-12)
USS Kenneth Whiting (AV-14)
USS Wharton (AP-7)

TU 1.1.3 (Drone Boat Unit)

USS Begor (APD-127)

Task Group 1.2 (Target Vessel Group)

TG 1.2 did the following:

A. Prepared and placed target vessels for tests
B. Salvaged and provided rescue assistance to damaged, strained, or distressed vessels
C. Evacuated ships at time of tests
D. Furnished boats and boat crews to the boat patrol
E. Provided boats from target vessels for radsafe reconnaissance and transport of initial inspection parties.

TG 1.2 was composed of seven task units [TU] during the testing period. Not all TG 1.2 ships were target ships, although most were. Nontarget ships (*) supported preparation, placement, and salvage of the targets. BAKER target only vessel (**).

Task Group 1.2 (Target Vessel Group) ships participating in CROSSROADS.

Task Group 1.2 (Flagship)

USS Fall River (CA-131) *

Task Unit 1.2.1 (Battleship and Cruiser Unit)

Battleship Division 7 [BATDIV 7]

USS Arkansas (BB-33) (Flagship)
Nagato (captured Japanese battleship)
USS New York (BB-34)

Battleship Division 9 [BATDIV 9]

USS Nevada (BB-36)
USS Pennsylvania (BB-38) (Flagship)

Cruiser Division 23 [CRUDIV 23]

USS Pensacola (CA-24)
Prinz Eugen (captured German heavy cruiser)
Sakawa (captured Japanese heavy cruiser)
USS Salt Lake City (CA-25) (Flagship)

Task Unit 1.2.2 (Aircraft Carrier Unit)

Carrier Division 31 [CARDIV 31]

USS Independence (CVL-22)
USS Saratoga (CV-3)

Task Unit 1.2.3 (Destroyer Unit)

Destroyer Division 31 [DESDIV 31]

USS Anderson (DD-411)
USS Hughes (DD-410) (Flagship)
USS Lamson (DD-367)
USS Rhind (DD-404)

Destroyer Division 2 [DESDIV 2]

USS Ralph Talbot (DD-390)
USS Stack (DD-406)
USS Wainwright (DD-419) (Flagship)
USS Wilson (DD-408)

Destroyer Division 3 [DESDIV 3]

USS Conyngham (DD-371)
USS Flusser (DD-368) *
USS Mugford (DD-389)
USS Mustin (DD-413)

Destroyer Division 4 [DESDIV 4]
USS Mayrant (DD-402)
USS Trippe (DD-403)

Task Unit 1.2.4 (Submarine Unit)

Submarine Division 111 [SUBDIV 111]

USS Searaven (SS-196)
USS Skate (SS-305)
USS Skipjack (SS-184)
USS Tuna (SS-203)

Submarine Division 112 [SUBDIV 112]

USS Apogon (SS-308)
USS Dentuda (SS-335)
USS Parche (SS-384)
USS Pilotfish (SS-386)

Task Unit 1.2.5 (Landing Craft Unit)

LST Group 9 [LST GRU 9]

USS LST-52
USS LST-125
USS LST-133
USS LST-220
USS LST-545
USS LST-661

LCI Group 7 [LCI GRU 7]

LCI-327
LCI-329
LCI-332
LCI-620
LCI(L)-549
LCI(L)-615

LCT Group 15 [LCT GRU 15]

LCT-816
LCT-818
LCT-874
LCT-1078
LCT-1112
LCT-1113
LCT-1114
LCT-1115
LCT-1116 *
LCT-1130 *
LCT-1132 *
LCT-1155 *

LCT Group 21 [LCT GRU 21]

LCT-412 **
LCT-414
LCT-705
LCT-812
LCT-1013
LCT-1175
LCT-1187
LCT-1237
LCT-1268 *
LCT-1341 *
LCT-1377 *
LCT-1415 *

Miscellaneous

ARDC-13
YO-160
YOG-83

Task Unit 1.2.6 (Merchant Type Unit)

Transport Division 91 [TRANSDIV 91]

USS Banner (APA-60)
USS Brule (APA-66)
USS Carlisle (APA-69)
USS Carteret (APA-70)
USS Fallon (APA-81)

Transport Division 92 [TRANSDIV 92]

USS Barrow (APA-61)
USS Butte (APA-68)
USS Cortland (APA-75)
USS Crittenden (APA-77)
USS Dawson (APA-79)

Transport Division 93 [TRANSDIV 93]

USS Bladen (APA-63)
USS Bracken (APA-64)
USS Briscoe (APA-65)
USS Catron (APA-71)
USS Fillmore (APA-83)
USS Geneva (APA-86)
USS Niagara (APA-87)

Transport Division 94 [TRANSDIV 94]

USS Appling (APA-58) *
USS Artemis (AKA-21) *
USS Gasconade (APA-85)

Task Unit 1.2.7 (Salvage Unit)

ATR-40 *
ATR-87 *
ATA-180 *
ATA-185 *
ATA-192 *
USS Achomawi (ATF-148) *
USS Chickasaw (ATF-83) *
USS Clamp (ARS-33) *
USS Conserver (ARS-39) *
USS Coucal (ASR-8) *
USS Current (ARS-22) *
USS Deliver (ARS-23) *
USS Etlah (AN-79) *
USS Gypsy (ARSD-1) *
LCT-581 *
LCT-746 *
LCT-1184 *
LCT-1420 *
USS Mender (ARSD-2) *
USS Oneota (AN-85) *
USS Palmyra (ARST(T)-3) *
USS Preserver (ARS-8) *
USS Reclaimer (ARS-42) *
USS Shakamaxon (AN-88) *
USS Suncock (AN-80) *
USS Widgeon (ASR-1) *

An eighth task unit, TU 1.2.12 (Kwajalein Maintenance Force), provide radiological decontamination and ammunition removal and disposal services for the JTF 1 ships moved from Bikini to Kwajalein during August and September 1946. Other activities included rollup of operations at Bikini, radiological survey of marine life around Wotho, Rongerik, and Rongelap islands, preparation of ships for movement to other shipyards, and aid in the training of radiological safety school graduates who had been sent to Kwajalein for practical experience. The unit initially consisted of about 1,500 men base ashore and on assorted small craft as well as the following vessels:

USS Conserver (ARS-39) *
USS Current (ARS-22) *
USS Geneva (APA-86) *
USS Haven (AH-12) *
APL-27 *
LCI-329 *
LCI(L)-549 *
LCI(L)-615 *
YF-753 *

Task Group 1.3 (Transport Group)

TG 1.3 transported personnel and equipment to Bikini Atoll as well as evacuating personnel of the Target Vessel Group. It also furnished boats and boat crews to the boat pool, supplied two AKAs and two LSTs for the construction unit, and transported and quartered the press and observers. This task group was composed of three task units [TU]; their respective ships are listed below.

Task Unit 1.3.1 (Transport Group)

Transport Division 31 [TRANSDIV 31]

USS Bayfield (APA-33)
USS Bexar (APA-227)
USS Bottineau (APA-235)
USS George Clymer (APA-27)
USS Henrico (APA-45)
USS LST-817
USS LST-881
USS Ottawa (AKA-101)
USS Rockingham (APA-229)
USS Rockwall (APA-230)
USS Rolette (AKA-99)
USS Saint Croix (APA-231)

Task Unit 1.3.2 (Press Unit)

USS Appalachian (AGC-1)

Task Unit 1.3.3 (Observer Unit)

USS Blue Ridge (AGC-2)
USS Panamint (AGC-13)

Task Group 1.4 (Army Ground Group)

TG 1.4 was responsible for determining damage to selected Army equipment exposed at varying distances from the detonation point and measuring radii of effectiveness for each detonation. Each of the operating task units had Army equipment on certain ships and on Bikini Island for exposure to the nuclear detonations. Each unit had inspection teams that were assigned to target ships and responsible for loading, securing, maintaining, and inspecting assigned test items. These teams also instructed crews of each target ship concerning exposed test items. Teams were to reboard ships after the tests when ships were radiologically cleared and safe for boarding. TG 1.4 was composed of a headquarters and the following six operating task units [TU]:

TU 1.4.1 (Engineer Unit)
TU 1.4.2 (Signal Unit)
TU 1.4.3 (Ordnance Unit)
TU 1.4.4 (Chemical Unit)
TU 1.4.5 (Quartermaster Unit)
TU 1.4.6 (Air Unit)

Task Group 1.5 (Army Air Group)

TG 1.5, the Army Air Group, composed of provisional Army Air Forces units, was assigned the mission of dropping the ABLE weapon on the target array in Bikini Lagoon. In addition, it furnished aircraft, facilities, and crews for photography, weather reconnaissance, air-sea rescue, cloud sampling, pressure gauge drops, and air transport. The following table lists the numbers and types of Army aircraft used during CROSSROADS and their missions..

Army aircraft, CROSSROADS

Task Unit 1.5.1

1 Boeing B-29 Superfortress (Command)
1 Boeing B-29 Superfortress (Bomb drop)
2 Boeing B-29 Superfortress (Pressure gauge drop)
2 Boeing F-13 Superfortress (Radiological reconnaissance)
3 Boeing B-29 Superfortress (Spare)

Task Unit 1.5.2

2 Douglas C-54 Skymaster (Photographic)
8 Boeing F-13 Superfortress (Photographic)

Task Unit 1.5.3

10 Boeing B-17 Flying Fortress (Drone samplers)
6 Boeing B-17 Flying Fortress (Drone controllers)

Task Unit 1.5.4

20 Curtiss C-46 Commando (Transport)
10 Douglas C-54 Skymaster (Transport)

Task Unit 1.5.6

This unit was combined with TU 1.5.3 before ABLE and BAKER tests.

Task Unit 1.5.7

3 Boeing WB-29 Superfortress (Weather reconnaissance)

Task Unit 1.5.8

2 Boeing B-29 Superfortress (Radio broadcast, press, observation)
Douglas C-54 Skymaster (Borrowed from TU 1.5.4 on shot days)

Task Unit 1.5.9

2 Boeing B-17 Flying Fortress (Air-sea rescue)

B-29s and F-13s, which were B-29s modified for photography, have become intermingled at some points in the historical accounts of Army Air Group operations. The totals for each shown here are correct by most accounts. TG 1.5 was composed of the following 10 task units [TU].

Task Unit 1.5.1 (Tactical Operations Unit)

TU 1.5.1 trained crews, prepared equipment for the tests, airdropped the test ABLE weapon, set up the air search radar in the Bikini area, and provided radar analyses of practice bomb runs. It also operated two B-29s that dropped pressure gauges during each test. In addition, after each detonation it tracked the radioactive clouds and sampled air around the clouds. The unit was based on Kwajalein Island.

Task Unit 1.5.2 (Army Air Photographic Unit)

TU 1.5.2 conducted air photographic operations and furnished aircraft for radiological reconnaissance flights. It was stationed on Kwajalein Island.

Task Unit 1.5.3 (Instrumentation and Test Requirements Unit)

TU 1.5.3 and TU 1.5.6 (Army Drone Unit) were combined before the operation began. It was responsible for providing the B-17 drone and B-17 drone-controller aircraft for cloud-sampling operations. The drone mission required that the unit provide and maintain special equipment for sampling and for drone control operations. This included special cameras mounted in the drones. This unit was located on Enewetak Island.

Task Unit 1.5.4 (Air Transport Unit)

TU 1.5.4 provided airlift for personnel, supplies, and equipment between Roswell Army Air Field, New Mexico, and the Pacific Test Area. It also provided air shuttle service among Kwajalein, Bikini, and Enewetak Islands. Both C-46s and C-54s were available. This unit, stationed on Kwajalein Island, was responsible to assist in evacuating Enewetak Island in case of radiological danger to personnel on that island.

Task Unit 1.5.5 (Air Service Unit)

TU 1.5.5 serviced and maintained Army aircraft on Kwajalein Island. In addition to service and maintenance personnel, the task unit had engineers, military policemen, and weather-forecasting personnel.

Task Unit 1.5.7 (Army Air Weather Reconnaissance Unit)

TU 1.5.7 had three WB-29 aircraft with crews trained in weather reconnaissance. It flew long- range weather reconnaissance missions before each test. This unit was located on Kwajalein Island.

Task Unit 1.5.8 (Air Orientation Unit)

TU 1.5.8, based on Kwajalein Island, was responsible for accommodating visitors, observers, the press, and news broadcasters. It flew these groups in two B-29s and two borrowed C-54s to witness CROSSROADS detonations.

Task Unit 1.5.9 (Air-Sea Rescue Unit)

TU 1.5.9 was initially part of TU 1.5.3 but was made a separate unit before testing started. It had two B-17 aircraft (called "Dumbos") for air-sea rescue and provided coverage between Enewetak and Bikini. The unit was based on Enewetak Island.

Task Unit 1.5.10 (Headquarters, Air Unit)

TU 1.5.10 contained the command and staff elements of TG 1.5. It was based on Kwajalein Island and operated the task group headquarters. It was also known as Hq TG 1.5.

Task Group 1.6 (Navy Air Group)

TG 1.6 had three different functions: drone plane and drone boat control, aerial photography, and seaplane transportation. TG 1.6 was composed of four task units [TU]:

TU 1.6.1 (Drone Carrier Unit)

[Task Element] TE 1.6.11

USS Shangri-La (CV-38)

[Task Element] TE 1.6.12

USS Charles P. Cecil (DD-835)
USS Furse (DD-882)
USS Newman K. Perry (DD-883)
USS Turner (DD-834)

[Task Element] 1.6.13

(Navy Field Recovery Subunit, Naval Air Base Roi-Namur, Kwajalein)

[Task Element] TE 1.6.14

Air Development Squadron 2 (VX-2)

TU 1.6.2 (Photo Carrier Unit)

USS Saidor (CVE-117)

Plane guard destroyers from TE 1.6.12 were assigned.

TU 1.6.3 (Seaplane Unit, Naval Air Base Ebeye Island, Kwajalein)

Patrol Seaplane Squadron 32 (VPB-32)
Air-Rescue Squadron 4 (VH-4)
Carrier Aircraft Service Unit (Fleet) 34 (CASU(F)-34)

TU 1.6.4 (Seaplane Tender, Bikini)

USS Orca (AVP-49)

Shangri-La carried drone aircraft and operated off Roi Island, Kwajalein, where an airfield was used for landing and experimenting with drone planes. Between tests, Saidor operated from Bikini Lagoon with drone boat control and photographic unit personnel on board. Except on ABLE and BAKER days, Orca was stationed at Bikini as a terminal and service unit for transport seaplanes. The ship maintained seaplane runways and furnished overhaul servicing required for all planes on turn-around service.

Task Group 1.7 (Destroyer Surface Patrol Group)

TG 1.7 performed the following tasks during CROSSROADS:

A. Furnished radsafe patrols
B. Anchored one ship at Bikini Atoll lagoon entrance, except when it was evacuated, and supplied arrival information to incoming vessels
C. Advised the Senior Officer Present Afloat (SOPA) about each arrival and departure from Bikini Lagoon
D. Deployed two destroyers to act as approach markers for the bombing aircraft in test ABLE.

TG 1.7 was composed of only one task unit [TU], TU 1.7.1 (Destroyer Squadron Unit), and contained the following ships:

Destroyer Division 71 [DESDIV 71]

USS Barton (DD-722) (Flagship)
USS Laffey (DD-724)
USS Lowry (DD-770)
USS O'Brien (DD-725)
USS Walke (DD-723)

Destroyer Division 72 [DESDIV 72]

USS Allen M. Sumner (DD-692)
USS Ingraham (DD-694)
USS Moale (DD-693)
USS Robert K. Huntington (DD-781)

Task Group 1.8 (Service Group)

This task group had the following responsibilities:

A. Base facilities and services including repair, fuel, water, mail service (USS LST-861); general supply, provisions, hospital, and recreation (USS LST-388)
B. Island commander functions for land areas of Bikini Atoll, such as policing recreational areas, conducting shore patrol, and controlling boat traffic at landings
C. Boat services
D. Medical and hospital services
E. Quarters and laboratory facilities on USS Fulton (AS-11) for the Oceanographic Wave Measurement Group
F. Surveys in accordance with the Oceanographic Survey Plan
G. Construction in accordance with Logistics Plan
H. LCI shuttle service between Bikini and Kwajalein atolls
I. Evacuation of Rongerik Atoll population if necessary.

TG 1.8 was composed of the following six task units [TU]:

TU 1.8.1 (Repair and Service Unit)

USS Ajax (AR-6)
ARD-29
ATA-124
ATA-187
USS Cebu (ARG-6)
USS Chikaskia (AO-54)
USS Chowanoc (ATF-100)
USS Coasters Harbor (AG-74)
USS Creon (ARL-11)
USS Dixie (AD-14) (Flagship)
USS Enoree (AO-69)
USS Fulton (AS-11)
USS Hesperia (AKS-13)
USS Limestone (IX-158)
USS LST-388
USS LST-861
USS Munsee (ATF-107)
USS Phaon (ARB-3)
USS Pollux (AKS-4)
USS Quartz (IX-150)
USS Severn (AO-61)
USS Sioux (ATF-75)
USS Sphinx (ARL-24)
USS Telamon (ARB-8)
USS Tombigbee (AOG-11)
USS Wenatchee (ATF-118)
USS Wildcat (AW-2)
YC-1009
YF-385
YF-733
YF-734
YF-735
YF-752
YF-753
YF-754
YF-990
YF-991
YF-992
YO-132
YO-199
YOG-63
YOG-70
YW-92

TU 1.8.2 (No units assigned)

TU 1.8.3 (Dispatch Boat and Boat Pool)

USS Gunston Hall (LSD-5)
LCI(L)-977
LCI(L)-1062
LCI(L)-1067
LCI(L)-1091
LCT-1361
LCT-1461
PGM-23
PGM-24
PGM-25
PGM-29
PGM-31
PGM-32
USS Presque Isle (APB-44)
USS San Marcos (LSD-25)

TU 1.8.4 (Medical Unit)

USS Benevolence (AH-13)
USS Bountiful (AH-9)

TU 1.8.5 (Survey Unit)

USS Bowditch (AGS-4)
USS James M. Gillis (AGS-13)
USS John Blish (AGS-10)
YMS-354
YMS-358
YMS-413
YP-636

TU 1.8.6 (Construction Unit)

53RD Construction Battalion (later, Construction Battalion Detachment 1156)

TU 1.8.7 (Rongerik Evacuation Unit)

USS LST-871
USS LST-989

Post-Operation Organization and Activities

Source: U.S. Defense Nuclear Agency. Operation Crossroads, 1946. Washington: Defense Nuclear Agency, 1984.

29 September 1998

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