- DECLASSIFIED l1 Authority - 79 This in nder Young the following information in for use in the commentary in feet Baker it classified secret As scheduled at 0335 Bikini time on 25 July bomb of the thneaki type wee detonated below the surface of Lagoon the Lagoon at this point was 180 feet deep The bomb was suspended from the LSM 60 near the center of the target array the DOE HAS no oeaacnon 1 0 orcmsemcnno - N COORDINATION REQUIRED exploeion wee of predicted violence and in en destructive no 20 000 tone of THE RAYMOND A CARPENTE rho visible phenomena of the exploeion by civilian and Manhattan Project phenomenologiete attached to Joint Task Force 1 At the moment of a done which showed the light of incandescent material within was upon the surface of the Lagoon The blunt wave was followed by an opaque cloud which rapidly enveloped about half of the terget array the cloud vanished in about two eeoondo to reveal an predicted a column of ascending water A study of photograph taken from a certain engle indicate that the column of water lifted the 26 000 ton battleship Arkansas for a brief interval before the vessel plunged to the bottom of the Lagoon Ehe diameter of the column of water was about 2 200 feet and it rose to the height of a little over one mile in a matter of few seconds spray rote to much greater height The column of water contained several millions tone of outer For nevernl minutes after the column reached maximum height water fell back forming on expending cloud of spray which engulfed about half of the target array surrounding the been of the column was well of foaming voter several hundred feet high I have outside the water column about 1 000 feet from the center of explosion jfwere 80 to 100 feet in height These waves rapidly diminished in nice as they proceeded outward the higheet wave reaching the beach of Bikini Island which we miles from the point of explosion were approximately 7 feet in height Woven did not pass over the inland and no material damage occurred there DECLASSIFIED rho explosion produced intense radioactivity in the waters of the Lagoon Part of this was by reason of the neutron bombardment of the sodium in the salt contained in sea water but the water was further dangerously contaminated by fission products from the bomb itself Radioactivity immediately after the burst is estimated to have been equal to many hundred tone of radium A few minutes exposure to this intense radietion at its peak would withina brief interval have incapacitated human beings and have resulted in their death in days or weeks Great quantities of radioactive water descended upon the ships from the column or were thrown over them by waves ibis highly lethal radioactive water constituted such a has rd that after four days it was still unsafe for inspecting parties operating within a well established safety margin to spend any useful of time at the center of the target area or to bosrd ships anchored there As in test A the array of target ships for teet 3 did not represent a normal anchorage but were designed instead to obtain the maximum data from single explosion Of the 8k chips and small craft in the array to were anchored within 1 mile and 20 within about 1 2 mile of the point of explosion ve major ships were sunk the bottleehip Arkansas immediately and the heavy hull aircraft carrier Seretogs after seven and a belt hours A leading ship a landing craft and he oiler sank immediately The destroyer Hughes in sinking'condition and the transport Felice badly listing were later beached The submerged submarine Apogcn wee coat to the bottom emitting air bubbles and fuel oil and one to three other submarines are believed to have sunk Five days after the burst the badly damaged Japanese battleship Rognto sunk It was found impossible immediately to inspect damage to hell power plant and machinery of the target ship because of radioactive contamination The operetion of Joint Task Force I in conducting the test hes set a pattern for close effective coaoperetion of the armed services and civilian scientists in the plehning and execution of this highly technical operation MoreoVer the genes have provided valuable training of personnel in 3013 operat1onj requiring Mane use-net in of efforts DECLASSIFIED Authority i Although lethal results might have been more or less equivalent the radiological phenomena accompanying the We burnt were markedly different In the case of the air burst bomb it teamed certain the unprotectod pox-normal within one mile would have suffeer high camlitieo by intonue neutron and gamma radiation on well an by blunt and heat Ihoae surviving immediate a oat 1would not have been momma by radioactivity persisting after the burst