 Pacific Ocean lies the tiny coral atel of Bikini. It is here that Joint Army Navy Task Force One will conduct the tests with the atom bomb. Not since the discovery of gunpowder has the world wondered over the ability of man to create such an agent of destruction. Anchored in the sheltered waters of the Bikini Lagoon below is an array of almost every type of naval vessel used in the past war. Here is the venerable old carrier Saratoga. The battleship Pennsylvania flagship of World War One USS Nevada was designated the target ship and strategically placed. Being painted a white topside would make her easier to spot from the air. This is the heavy cruiser Pensacola, the heavy cruiser Salt Lake City, and the German heavy cruiser Prince Oigan. The jet battleship Nagato. The light carrier USS independence can be seen on the left. The submarine skate. Attack transports. Freight and cargo ships. LCIs. LCMs. A sample of almost every type of naval vessel comprises this guinea pig fleet. The division of the target ships was based on the directive of the Joint Chiefs of Staff. It required ship damage of 73 ships were assembled. The densest pattern was within a thousand yard radius of the bomb aiming point. Chips within the 500 yard radius were secured by fixed moorings both fore and aft to prevent swinging. These were the heavy cruiser Pensacola, the destroyer Hughes, the Japanese battleship Nagato, the light carrier independence, the submarine skate, the concrete oiler Y.O. 160, and the Japanese light cruiser Sacawa. Ships outside the 500 yard radius were anchored free to swing. From the 1,000 circle to the outer extremity of the target area at 4,000 yards, ships were disposed in a spoke-like pattern consisting of LSTs, LCTs, LCIs, two rows of transports, and one row of destroyers. The heavy ships lying outside the 500 yard circle were the Arkansas, New York, Saratoga, Pennsylvania, and the large German cruiser Prince Oigen. All of the target ships were loaded with ammunition and fuel oil varying from full wartime loading to 10% of normal. Atom... the automatic error is almost incomprehensible to the human mind. In fact, the power of a single bomb was not too well known because there had been but three exploded, none at sea. In this 20th century world of atomic power, man is fully aware that he cannot assume an attitude of indifference to this new elemental force that he had discovered and must prepare against the most important scientific might ever known. These specialists with their strange and complicated scientific instruments will make hundreds of tests measuring temperatures, pressures, and radioactivity, and other experiments analyzing the effects of the bomb on aircraft, armament, ordnance gear, and other paraphernalia. Tied to the decks of the ships in Bikini Lagoon are samples of mechanical equipment and articles of every type and description that the Army and Navy used during the past war. Airplanes, jeeps, food, clothing, trucks, and armored cars. Everything from can milk to tanks will be subjected to the blast. Different animals have been placed aboard the ships to substitute for military personnel. Some were shaved in order that the effects of heat and radiation on their skins could be observed and the results applied to the design of protective clothing. Numerous towers have been erected on Bikini Atoll. Within these steel structures will be housed the remotely controlled photographic, electronic, and other scientific instruments that will automatically record the results of the blast. Atop some of these towers, encased in huge lead vaults, cameras have been strategically placed to capture as much detail as possible. Many types of steel cameras, as well as 16 and 35 millimeter motion picture cameras, shooting both black and white and color film, have been arranged to photograph the explosion during all of its phases and from every possible angle. Other towers and installations on the island will contain the hundreds of delicate instruments that will record data which will be invaluable for future study. In addition to the photographic equipment on land, special cameras will be used under water. Meanwhile on board the carriers at sea, automatic cameras are being installed in the Navy's radio controlled drones. Photographers in other planes with aerial still and motion picture equipment will photograph the blast at various altitudes as they fly around it. Pilots and photographers receive their final instructions here from a veteran naval photographic officer. The atomic explosion will also be observed from a special aircraft. Shortly before able day, when the shore personnel had completed its fast and detailed preparations, Vice Admiral Blandy in command of Joint Army Navy Task Force One makes a last minute personal tour of inspection among some of the installations for radar and other setups which contain the remotely controlled cameras and television apparatus. While the Navy concentrated its efforts at Bikini, the Manhattan Project's scientists at Quajaline were busy assembling the atomic bomb taking special precautions to ensure its safe disposal. Ground crews indoctrinated in the procedure of handling such a weapon. A bombing crew was competitively chosen. Major Swan cut the pilot. Major Wood the Bombardier. The B-29 Dave's dream would carry them to the target. While the bomber is poised on the loading ramp, pilots and crews received their final orders from an Army Air Force officer. This was a photographer's field day and the lens experts selected for this special assignment are given last minute instructions. The B-29 and DC-4 photographic planes bristle with cameras of every type in description. Forty inch telephoto lenses mounted on these unusual cameras resemble huge telescopes. All available sites are employed, plus some special setups never before attempted. If some cameras should miss, certainly others will get the pictures. The exposed film is to be forwarded to the Naval Photographic Science Laboratory for processing, classification and filing, from which center it is available to all authorized agencies of Joint Task Force One. At last the day arrived for test-able. It was July 1st in Bikini, but June 30th in this country. With the atom bomb safely secured in her bomb bay, the B-29 Dave's dream roars down the runway. An anxious moment for the spectators. But the takeoff is without mis-having. Everyone on quad-jouline breathes easier on learning of the bomb's departure. The huge bomber proceeds to the Bikini target escorted by the Air Force Photo Planes. Meanwhile, scores of other aircraft are taking their prearranged positions in the sky above the anchored ships. Some Navy fighter planes have still and motion picture cameras aboard. Others are remote controlled drones with instruments to measure the radioactivity of the air. These will be guided through the cloud column of the explosion. More will circle the area at different altitudes and distances. Everything is in readiness now, and at last the moment has arrived. The bombing plane is nearing the target with its escort of photographic planes. At sea below on one of the ships, Secretary of the Navy Forest Hall is among the observers who patient the arrival of the bomb, and glasses are worn by some, while others hide their eyes. Position. There is the target. Arm away. Arm has been successfully detonated. First you see a blinding flash, then comes the hemispherically shaped cloud that expands rapidly just behind the initial pressure wave. After the smoke clears, the characteristic mushroom cloud begins to form and shoot skyward. The first phase of the bomb burst produces the effect of an exploding derby hat, where the outside edge of the rim outlines the outermost front of the pressure wave at that instant. The cloudy rounded portion of the hat results from what is known as the cloud chamber effect, thing above the clouds and smoke of the explosion. Although obscured during the first two seconds, the ball of fire is still visibly red hot. The maximum temperature reached at the center of this ball, shortly after detonation, exceeds even the temperature of the sun. The mushroom cloud gains altitude with amazing speed. In less than a minute, it has reached a point one mile above the earth. Although a beautiful sight, this swirling boiling mushroom cloud is certain depth to any living thing which approaches too close to its edge. Radioactive fission particles which resulted from the explosion are dispersed throughout the cloud and the deadly radiation from these particles must be avoided until the cloud is thoroughly diffused in the upper atmosphere. In this test, the army, navy, and civilian scientists wanted to find out just how lethal the cloud actually was at various altitudes and various distances from the center. Therefore, under the guidance of the Manhattan Projects, Los Alamos Laboratories, the army air forces installed specially designed filters on four of their B-17 pilotless drone planes so that an airplane could go into the very center of the cloud and bring back samples of the radioactive particles without danger to a human pilot. The navy carried out a similar program utilizing F-6F drones based on the carrier Shangri-La. Only one drone was lost in the entire operation, although it is interesting to note that one other drone was temporarily lost for a considerable time after it had entered the smoke column because it was lifted 6,000 feet in the updraft before it could get through to the other side. As the cloud goes higher and higher, its rate of rise constantly decreases and gradually the tremendous energy of the cloud begins to spend itself. Before the test, there was much speculation concerning the height to which the cloud would rise. Some predicted it might equal the 60 to 70,000-foot altitude reached by the previous Nagasaki cloud. However, at Bikini, the atomic cloud pushed itself to approximately 40,000 feet in a period of 10 minutes and stopped there. Explanation for failure to go higher lay in three facts. First, the atmosphere at Bikini was so wet that a considerable part of the cloud energy was absorbed by the moisture in the air. Second, the bomb was exploded close enough to the surface of the water to permit a certain part of the energy to be transformed into steam by a quenching action. And third, there were no large-scale fires, such as those encountered in burning Nagasaki, to feed the column after its initial rise. After the blast wave from the atomic explosion has spent itself, a reverse or suction wave is created as the air rushes back to the point of burst to fill the vacuum created there. As this air is heated in the vicinity of the fireball, it mixes and rises with the cloud column. Consequently, more air must keep coming into the center of the column, thus causing the effect you see in these pictures of the ship array, where the air rushing into the center of the cloud column carries with it the smoke of the burning ships. In order to obtain complete photographic records, photo aircraft pursued the cloud and took pictures of it as long as possible while it drifted slowly to the southwest. Gradually, it became diffused to such a degree that the chase had to be abandoned. One thing was certain, however, the dangerous radioactive particles in the cloud had become so widely scattered that no longer was there any danger to the surrounding area. In just a moment, you will see two views of the atomic bomb explosion taken from the observer ships, approximately 20 miles from Bikini Lagoon. The second view provides another excellent example of the cloud chamber effect, which is produced for a very simple reason. Bikini was almost saturated on July 1st, and when the pressure wave hit the air, it was compressed and heated. After the pressure front passed, the resultant expansion of the air cooled it below saturation point and caused formation of the expanding fog cloud you have seen in each view of the explosion. Atop a 100 foot tower on Bikini Island, over three miles from the point of burst. You can see the shock wave coming toward the camera. Watch those palm trees in the foreground. Lens in the lagoon. These cameras were started in motion by remote control radio signals emanating from a board laboratory ships many miles away that a timing watch has been placed within view of the camera in order to afford the scientists a means of studying the speed relationships of the various phases of this explosion. The epicenter of the detonation of the bomb was approximately 650 yards from the USS Nevada. At this point, the transports Gilliam and Carlisle, the destroyers of Lamson and Anderson and the Japanese cruiser Sakawe were sunk. The following ships sustained serious damage. Nevada. Independence. Salt Lake City. Skate. Y. O. 160. L. E. M. Number one. Pensacola. Arkansas. L. S. T. 52. Crittenden and the A. R. D. C. The next ships to be seen were only slightly damaged. Negato. Banner. Pennsylvania. Skipjack. Apagone. Park. Butte. Dawson. Prince O'agon. Wilson. Stack. Ryan. Hughes. And the L. C. T. eight seventy four. These were the first pictures taken from surface craft, which made their way into the target area as soon as the danger from radioactivity had passed. The three ships visible here are an A. P. A. The Salt Lake City and the independence. The smoke from the light carrier independence is from burning torpedo warheads in the torpedo storage on the hangar deck in the foreground. Numerous salvage tugs and radiological reconnaissance vessels are taking water samples from the lagoon for testing. We say the Nevada. Negato. Saratoga. Troop transports freight and cargo ships and other vessels in the array as the camera sweeps across the target fleet. This ship the U. S. S. Pennsylvania was about eighteen hundred yards from the epicenter of the bomb blast. Wreckage was slight and limited to minor superstructure damage. The fire burning in midships was in supply samples stowed on this stick and was not of a serious nature. In the background a salvage tug is seen fighting a small fire on the heavy cruiser Salt Lake City. This ship the U. S. S. Saratoga was about twenty six hundred yards from the epicenter. The only damage sustained was a small fire topside and a minor operating mechanism of one of the airplane elevators. Prince Oigan was about seventeen hundred yards from the epicenter. This ship sustained minor topside damage only. This is the U. S. S. Pennsylvania again after the fire had been extinguished. This view shows her starboard side which was away from the blast and which sustained topside damage. This ship the Japanese battleship Nagato was about eight hundred fifty yards from the epicenter. Damage was limited to topside fixtures and superstructure which were considerably battered and broken. The epicenter sustained only slight damage topside. Is the secretary of the Navy in the foreground is a shattered mirror which had been placed on the deck along with other equipment to be tested. This troop transport received extensive superstructure damage. The smokestacks radio and radar antenna and supports together with various other light topside structures were broken or buckled. These animals survived the blast but died later from the effect of radio activity. This ship the U. S. S. was about six hundred fifty yards from the epicenter. These pictures were taken from the side nearest the blast and show the superstructure wreckage. The paint on this side was scorched but did not burn. This view shows a portion of the unarmored deck after which was pushed down by the explosion. Aircraft and quarter master supplies placed on this deck were considerably damaged. Concrete oiler Y. O. one sixty which was located about four hundred yards from the epicenter. The concrete hole was undamaged but the superstructure was almost completely demolished. The U. S. S. Arkansas was about six hundred fifty yards from the epicenter and sustained extensive damage to topside fixtures and superstructure. Lake City was one thousand yards from the epicenter. Superstructure wreckage was considerable. Both stacks were wrecked and antenna and other fixtures were bent over or broken. Kola was located about four hundred fifty yards from the epicenter. This ship sustained serious superstructure wreckage. Both stacks were a total wreck and numerous other topside structures were badly damaged. The submarine skate was located about three hundred yards from the epicenter. The light fixtures, periscopes and superstructure were demolished but the pressure hull and conning tower remained intact. An interior machinery was undamaged. The Japanese light cruiser Sakao was located about one hundred fifty yards from the epicenter of the bomb burst. This cruiser was heavily damaged topside and the hull ruptured aft, causing her to slowly flood. Although the Sakao was commissioned only 18 months ago, she is considered by the Japanese to be a victory model and is not of modern construction. The hull, for example, was entirely riveted. Her superstructure, after the midships and above the main deck, was completely demolished. She capsized to port and sank the day following the bomb burst. This is the light carrier independence, which was about six hundred yards from the epicenter. This ship was severely damaged by the primary blast action of the bomb. Last struck the independence on the port side, blew in the light sideplating between the hangar and flight decks and pushed up the center of the flight deck like a rooftop and overboard. The top of the island was completely blown off. Gun spawnsons and guns on the port side were severely damaged. The watertight integrity of the hull remained intact. No fires occurred except among the torpedoes on the hangar deck aft. This class carrier was built on a basic cruiser type hull. The port side external plating was light blister shell plating and became deeply fluted between longitudinal frames as a result of the bomb burst. Similarly, the hangar deck plating is a light false deck built over the heavier hangar deck. The damage to the starboard side away from the blast was less severe. Although damage to some of these ships is impressive, it must be remembered that these experiments are not a contest between bombs and ships, but an earnest effort to determine what changes must be made in the future design and construction of ships, dispersion of bases, tactics and strategy in this new age of atomic power. It was an extremely busy one for the technical and scientific personnel attached to Joint Task Force One. During this time, the immense task of making detailed and comprehensive inspections and the recording of data resulting from test Able was completed and in addition the entire target ship array was reoriented. The basic premise which determined the target ship orientation for test Baker was the Joint Chiefs of Staff Directive, requiring that the ships be so disposed as to secure graded damage from maximum to minimum. The primary purpose of test Baker was to secure precise ship damage and instrumentation measurements resulting from an atomic bomb explosion just under the surface of the water. Of the 84 target vessels, 40 ships were placed within one mile of the bomb detonation point and 20 ships were placed within one half mile. The obsolete Arkandian carrier Saratoga were secured for an act by fixed moorings presenting their full length to the explosion in order that maximum damage would be insured. The Arkansas was placed about 250 yards from the bomb and the Saratoga about 700. These distances were carefully estimated so that at least one and probably both of these heavy ships would be deliberately sunk. In order to properly determine the shock effect of the underwater explosion against submerged submarine hulls, six of these craft were suspended underwater at varying depths. These pictures show the operation of submerging the skip jack. The method used was to secure heavy concrete mooring blocks to each boat. Buoyancy tanks were then slowly flooded until the concrete blocks rested on the bottom of the lagoon. Varying lengths of chain were used between the concrete blocks and the six submarines in order to hold each boat at its desired depth. Two additional submarines were left on the surface, one of which was the skate damaged in test able. In test Baker photographic procedure was similar to that followed in test able. Many types of cameras and especially motion picture cameras were encased in huge lead vaults atop photographic towers erected on three islands in the lagoon. All of these cameras operate automatically. These specially designed enclosures built of reinforced concrete to withstand the shock of the primary blast action are lined with thick sheets of lead to protect against radiation from the bomb burst which would otherwise fog sensitive films. To further protect the film from the effects of radiation sliding lead panels built over the camera ports and designed to close automatically will seal the vaults making radioactive penetration impossible. Flown from Rondjerick to witness the historical event is King Judah ruler of Bikini. It was he who unselfishly gave his island to the United States in order that these experiments could be conducted. King Judah has been invited aboard the command ship of Operation Crossroads to meet Vice Admiral Blandy. The LSM 60 was designated as the target suspension vessel for the Baker Day test. The equivalent of a bomb bay was cut in the tank deck and through this opening the bathysphere carrying the atomic bomb was lowered into the sea. The bomb was held at the desired depth until detonation by means of specially designed winches. When everything was in readiness aboard the LSM 60 the scientists and military personnel left the ship and a careful check was made of their departure so that no stragglers were left. The signal flag yoke was too blocked on the halyards indicating that no personnel were aboard. After Dr. Warner fused the bomb rear Admiral Parsons deputy commander for technical direction took a last look at the LSM and went over the side into a waiting picket boat. Having left the target array the Admiral comes aboard the USS Mount McKinley flagship of Operation Crossroads. Everything has been placed in readiness and he submits his report to Vice Admiral Blandy. Aboard the firing ship USS Cumberland Sound members of the Los Alamos group of the Manhattan Engineer District entered the timing laboratory where radio transmitters and specially constructed instruments for detonating the bomb are located. The timing laboratory scientists pass into the master control room. Dr. Marshall Holloway leader of the Los Alamos group unlocks and personally throws one of the master transmitter switches. The timing laboratory is a complex interlocking system of radio transmitters, time recorders and scientific apparatus. As each hour approaches generators are started transmitters warmed up, graph cards on time recorders changed and everything made ready for the blast. Each hour minus two minutes is broadcast from the ship and all hands stand by. Sitting in the central console switchboard with the microphone is Dr. Ernest Titterton assistant to Dr. Holloway. As he announces each hour minus 30 seconds Dr. Holloway throws the 30 second switch. Dr. Titterton at the automatic firing panel board prepares to broadcast the last 15 seconds. 15, 10, 5, 4, 3, 2, 1. The blast is photographed from the Mount McKinley and King Judah displays a marked interest in the proceedings. These pictures of the ascending water column show the expanding cloud of spray at the base of the column moving outward and enveloping the ships in the target array. Great quantities of radioactive water from the column descended upon the decks of the nearby vessels and ship hulls a mile away were drenched by the wall of foaming water. Here is an army Air Force drone approaching the cloud column. Still another view of the explosion recorded from a photographic tower on McKinney shows the column composed of millions of tons of water rising at an initial rate exceeding the speed of sound. The water and spray from the explosion will fall for several minutes. Here again is an excellent photographic portray of the boiling, foaming wall of water engulfing the ships in the foreground. This highly lethal spray was intensely radioactive partly by reason of the neutron bombardment of the sodium in the salt contained in seawater. It is estimated that radioactivity immediately following the burst was equal to hundreds of tons of radium. An expanding cloud of spray and fog several hundred feet high may be seen moving out from the center of the detonation. This cloud eventually covered the entire target array. Waves outside the water column about one thousand feet from the center of the explosion were eighty to one hundred feet in height. These waves rapidly diminished in size as they proceeded outward. When reaching McKinney had a height of approximately seven feet. Visible on the surface of McKinney lagoon is an oil slick leaking from ruptured oil tanks principally from the battleship Arkansas. Three major ships were sunk. The Arkansas immediately the aircraft carrier Saratoga after seven and a half hours and the Japanese battleship Nagato after five days. Several small craft were also sunk. Immediately after the burst radiological reconnaissance drones were sent into the lagoon. Despite the presence of radioactive contamination radiological safety patrols immediately entered the lagoon for preliminary appraisal of the damage. Landing parties armed with Geiger counters which register any unsafe concentration of radioactive particles. Go ashore at McKinney to recover the camera film and the data recorded by the scientific instruments. Meanwhile an inspecting party headed by Admiral Blandy General Kepner and Admiral Parsons surveyed the damage in the target array. Shown here is the Japanese battleship Nagato which flooded and capsized five days after the blast. The light carrier independence sustained severe superstructure damage in test able and no additional apparent topside damage was visible after test Baker. The heavy cruiser Salt Lake City the destroyer Hughes in sinking condition was beached. The Saratoga sustained heavy underwater hull damage and listed badly. Other ships surviving the Baker day blast were the submarine skate the submarine pilot fish the heavy cruiser Pensacola a troop transport and a small yard oiler the Saratoga taking on more and more water slowly sink stern first the operation of joint Army Navy task force one in conducting the tests has set a pattern for close effective cooperation of the armed services and civilian scientists in the planning and execution of this highly technical operation. It has also provided valuable training of personnel and joint operations requiring great precision and coordination of efforts. This preliminary photographic report has covered the period of time through Baker plus one day.