About Micronesia

History of Saipan & Micronesia (4)

THE ATOMIC BOMB & The SINKING OF THE U.S.S. INDIANAPOLIS (continued)

By William H. Stewart
Military Historical Cartographer

THE EFFORT AT TINIAN
By 1944 the United States had produced a long range bomber that had the capability of flying the round trip distance from the Mariana Islands to the Japanese home islands. In June 1944, the islands were assaulted by U.S. forces for the purpose of obtaining airfields from which to launch the new B-29 Superfortresses against Japan. Airfields were constructed on Guam, Saipan and Tinian.

The construction of the airfields on Tinian was the largest building activity the United States Naval Construction Battalion, (Seabees) had ever undertaken up to that time. They built six huge bomber strips each a mile and one half long and a block wide along with eleven miles of taxi ways with "hardstands" sufficient to park 300 aircraft. The Seabees dug, blasted, scraped and moved eleven million cubic yards of earth and coral on Tinian. This quantity of material would fill a line of dump trucks 900 miles long . Piled on a city block, the earth and coral they moved would form a pyramid two-thirds of a mile in height. Two hundred and twenty dump trucks were kept busy 20 hours a day and 24 welding crews worked to repair bulldozers, shovels and trucks damaged as a result of the rough construction activity. In addition to the airfields they built 173 Quonset huts and 92 other service buildings along with 675 smaller structures. 

Every airstrip was completed on time and none required more than 53 days to build. The Seabee's motto, "We Build, We Fight" and their "Can Do Spirit" distinguished this group as being able to do any kind of work, any place, under any conditions. The efforts of the 6th and 107th Construction Brigades were remarkable. Many Seabee groups would "adopt" an aircraft and when they did so the quality of life for the flyers of the plane improved considerably as the Seabees provided the crew of "their" Superfortress with better Quonset huts, washing machines, better mattresses, ice cream and other comforts of life. The men, equipment and construction material sent to this one island required a degree of logistical support almost beyond comprehension all of which had to be planned, coordinated, assembled and safely transported across the Pacific in hundreds of ships. 

When the work was completed it all had to be repacked and loaded back aboard an armada of naval vessels for transport to still another island where the work would start all over again. 
SECRET CARGO TO TINIAN

Life aboard a United States Navy ship when it is underway soon falls into a customary routine for all aboard and surprisingly, despite days at sea without sight of land, it is not a boring experience. The operation of a vessel underway is an around the clock effort for all aboard usually divided into four hours on watch, (duty station), and eight hours off with the result that one is on watch eight hours in a twenty four hour day. The most critical time for those aboard a warship is when the alarm for General Quarters is sounded calling all immediately to their battle stations. It is at this time that all weapons are manned and ready for action. A time when all aboard are at maximum alert and ready to perform the only tasks for which the vessel was designed - to fight. During the long days at sea, training for that moment is a constant task. 

When not at General Quarters, the food is good, there is a ships library, nightly movies below deck and much work to be done either training to wage war or to keep the vessel clean and painted as protection from the rusting effects of the seas salt spray. The captain alone bears full responsibility for the ship, its discipline and well being. His is the undisputed and only authority. The vessel represents the United States at all times and is a manifestation of Americas national sovereignty. Any attack on an American warship is deemed an attack on America. 

On July 16, 1945 a U. S. Navy vessel left San Francisco for the island of Tinian with a cargo so secret that Harry S Truman, President of the United States and Commander In Chief Of The Armed Forces, had learned about it only some three months earlier and only then after assuming the Presidency upon the death of Franklin D. Roosevelt on April 12th. The Heavy Cruiser Indianapolis was ordered to proceed to the Mariana Islands at all possible speed and in doing so would break all records for crossing 5,000 miles of the Pacific in ten days. The captain had not been informed of the nature of his cargo but was told to keep it under guard at all times. If something happened to the ship that would keep it from reaching its destination he was cautioned to protect the cargo at all cost even if it meant placing it in a lifeboat at the expense of drowning sailors. The vessel arrived at Tinian on July 26th and its cargo was discharged for what was be an unknown and unheard off use. 

The mysterious shipment was the material manifestation of one of the greatest minds in the world and a product of a thought that had first conceived the power of the sun on a university blackboard. For those who could understand it was the mathematical expression that proves that small particles of matter correspond to unimaginable quantities of energy. The formula E = MC2. when applied means that the energy released from a particular mass of material is equal to the weight of the material multiplied by the square of the speed of light expressed in centimeters per second, (the square of 186,000 miles per second). For example, one gram of matter is equivalent to 25 million kilowatt hours or the energy of three thousand tons of coal. At the time very few people on Tinian, if any, knew this. 

The sea and sky had dominated the visual world of ship's crew since their departure from Pearl Harbor. Then it appeared on the horizon, a dark brooding mass in the mist of the early morning hours looming out of the sea like a mirage. Off in the distance one aircraft after the other glided through the morning sky, each slowly declining in altitude. At first sight one wondered what they could be, then it quickly became apparent. In a line stretching as far north as the eye could see hundreds of B-29 Superfortresses were returning to the landing fields on Tinian after a fire bombing raid on Japan. 

As the Indianapolis passed the southern end of the island, its destination was now off the starboard side when the order was given to the helmsman, "Come right to 010 degrees", then as all such orders are, it was repeated by the sailor already turning the large, gray wheel on the bridge, "Aye Aye Sir, Right 010 degrees" and the vessel with its secret cargo started its swing to the north to steam up the southwestern side of the island which now accommodated the busiest airfields in the world. With several more course changes the ship made its way into the small harbor. "All engines stop" was signaled on the engine order telegraph as the anchor was dropped in the harbor. 

Two days before the Indianapolis arrived at Tinian, General Carl Spaatz the new commander of Strategic Air Forces in the Pacific was issued his orders, "The 20th Air Force will deliver its first special bomb as soon as weather permits visual bombing after 3 August, 1945 on one of the following targets, Kokura, Hiroshima, Nigata or Nagasaki". These cities were selected since up to this time they had been spared American incendiary attacks so that the full force and impact of the "special" bomb could be observed by the Japanese. 

The Indianapolis discharged its cargo of lead containers and the bomb's firing device at Tinian, placing the bomb components in a small boat which carried the material to the dock. It then hoisted anchor and steamed west, then turned south where it would make a brief call at Guam, an American island recaptured a year earlier from the Japanese and located 120 miles south of Tinian. The ship would then proceed to Leyte in the Philippines for redeployment. Its estimated time of arrival was scheduled for sunrise, August 1st. 

On July 28th the vessel departed Guam and steamed westward at 16 knots toward Asia. The Indianapolis delivered only the material for the first bomb. Fearing that something might happen to the ship before it reached the island, and unknown to any aboard the vessel, material for a Plutonium bomb had been flown to Tinian by separate transports from the United States thus insuring that at least one of the two atomic bombs in the American arsenal would reach the assembly and launch area. 

In breaking the speed record for distance covered between San Francisco and Tinian it is almost certain that this achievement could not have been accomplished if the vessel had engaged in zigzagging maneuvers. The ship was now in waters frequented by enemy submarines. Zigzagging is a common maneuver employed during wartime and particularly when the possibility of enemy submarines could be in the vicinity. It involves steaming on a particular course at one speed for a period of time and then changing to another course and sometimes a different speed and then repeating these changes all the while moving in a forward, although angular movement from a straight base line connecting the point of the vessel's origin with its destination. This technique of seamanship reduces the possibility that an enemy submarine captain will locate the vessel and project its course and speed to a point on the ocean surface in advance of the location where the vessel was first observed for purposes of launching an attack. Zigzagging can be an effective defense against a submarine attack on a surface vessel. 

The vessel was steaming on a Great Circle Route which, either on or below the surface of the ocean, is the shortest distance between two points on the globe. It was along one such route code named "Peddie" that the Indianapolis headed westward on its course between Guam and Leyte. This route intersects with a north- south route between Palau and Okinawa and it was in this vicinity that Captain Iko Machitsura Hashimoto's sleek sea knife lurked in wait for an enemy to devour. The I-58 carried six human driven, suicide torpedoes which could be launched while under water. They were known as Kaitens, or "changing sky". The submarine was also armed with six torpedo tubes.
A STEEL SHARK

In the early minutes of the mid-watch within the Combat Information Center aboard the Indianapolis the crewman peering over the ship's radar had not picked up any object as the sweeping line on the green radar scope circled the seas in a 360 degree scan every few seconds. Nor had the starboard lookout observed the white tell-tale track of incoming torpedoes or the white water "froth" or "feather" trailing a submarine's periscope as it sliced through the water. There was no indication of the mortal danger that would, in a matter of moments, erupt around the Indianapolis and turn the vessel into a flaming inferno. 

Below the ship's main decks in the crew's sleeping quarters those personnel off watch were in bunks stacked along the bulkhead four deep extending from the deck to the overhead. At the end of the passageway the glow of a blue lamp was the only illumination, the smoking lamp was out. The tropical night made the compartments below deck uncomfortably hot and humid. The churning sound of the ship's engines and their vibrations went unnoticed as an accustomed rhythm of a vessel underway. So usual and familiar had the throb of the powerful motors become that it was only when they stopped that it was immediately noticed. The sudden silence would awaken even the deepest sleeper. 

Below the the surface it had been ten days since the submarine I-58 had cast off all lines and slipped out of the harbor of Hirao, Japan. It had traveled south to a point in the western Pacific where it lingered on station astride an imaginary line connecting the island of Guam and Leyte Gulf in the Philippines, a route which was the shortest distance between these two American naval bases. The large, three hundred foot long, cruise-type submarine fitted and designed for trans-Pacific patrols moved silently through the dark waters like a hungry steel shark stalking its prey. Its teeth were six bow torpedo tubes. Inside this metal tube was a crew of 119 men and 11 officers among them the thirty six year old captain, a graduate of Eta Jima Naval Academy, Commander Iko Machitsura Hashimoto. Powered by two, one thousand eight hundred horse power electric motors and, when fully loaded with eight hundred tons of fuel, the under-sea vessel also had on deck a compartment large enough for a float plane which could be catapulted along a fifty foot slanting runway although the I-58 did not carry any aircraft on this mission. When surfaced the monster was capable of cruising 15,130 nautical miles at a speed of fourteen knots and could remain submerged for eighteen hours at four knots. Its safe diving depth was three hundred twenty eight feet and when alarmed or threatened, it could dive to periscope depth in seventy seconds. The air was foul in the great black, steel beast when the captain gave the order to come to periscope depth. 

As the water was blown from its tanks the vessel began its rise upward from the depths. "Up periscope " came the command and the shaft that was to provide its only view of the world above water moved toward the overhead in the conning tower of the command center of the submarine. Captain Hashimoto pulled down the handles and placed his hands on the focusing instrument and slowly began turning a full 360 degrees to view the world of water above the ship. He saw no sign of an intruding vessel or aircraft. "Down scope - surface", he ordered. And once again the ballast tanks were blown of the excess sea water it had aboard to maintain depth. 

The bow of the I-58 broke the surface and as the sea rolled over its deck in white swirls of froth, the stern became parallel with the surface and water left the deck. The captain climbed the ladder, spun the wheel on the water tight hatch above him and climbed out into the fresh air of the dark night, inhaling deeply the ocean air free of diesel fumes. He stood with binoculars to his eyes and made a visual sweep of the sea around him. In less than fifty seconds with a half moon darting in and out of intermittent cloud cover which occasionally illuminated the surface he spotted a dark object on the surface. Peering into the night he saw the silhouette of a ship at a distance of thirty thousand yards. Calculating his position and the target's bearing, he

Back down the hatch he dropped, turning the wheel on the hatch that would seal the interior from the on-rush of water that was sweeping over the bow - he jumped to the deck of the conning tower. Outside water rushed over the ship as it sank beneath the waves, down, down, it drifted in a world of silence - until upon reaching periscope depth he ordered, "Up Periscope". With that he waited as the submarine moved into position. The order rang through the ship, "Prepare to fire torpedoes and launch Kaitens" . Those members of the crew that were to serve as human torpedoes prepared their equipment. 

It took about ten minutes to swing the submarine around and steady on a course heading toward the target after roughly estimating the surface vessel' s course and speed - he then barked, "Speed twelve knots and the I-58 continued to approach the unsuspecting Indianapolis. During this period he called for the Target Identification Book and mistakenly thought he recognized the vessel as a battleship. All the while sub sounding gear was being used to determine any change in the target's course and speed. As his heart pounded with anticipation, Captain Hashimoto then set up the problem on his director, placing in the estimates and waiting to give the order to fire. 

It became apparent that the target was approaching off his starboard bow and he waited until the target approached within a distance of fifteen thousand yards which was now an indistinct blur in the periscope he was still unable to determine if the target was zigzagging or if it was a battleship - he only knew that it was a large vessel, then he gave the order that all aboard waited for. "Fire" Hashimoto barked - and at that moment the first of six torpedoes were pushed through the submarine's bow tubes. Quickly, five more oxygen propelled, Type 95 torpedoes with their magnetic warheads left the submarine at a spread of three degrees, all speeding toward the black silhouette Hashimoto had seen through the periscope. The metal fish raced at a speed of forty eight knots at a depth of twelve feet all directed at the ship which was well within range of the 880 pound warheads of the torpedoes. 

As the torpedoes left the submarine the ship "bounced up" as it was relieved of the weight, "Down scope", came the order so as to keep the ship from breaking the surface. Then he waited as the seconds ticked by, waiting, waiting, tick, tick, tick, tick, as he watched the second hand sweep around the time piece - counting off everyone's measured life span in a way never to be recalled - a measured cadence of the universe leading all men on each individual journey to eternity. "Up Scope" he ordered and the steel cylinder which was his eyes revealed a flash of fire and in its light he also saw two plumes of water forward of the ship's bridge rising from the water like giant, white geysers, then he heard the sound he was waiting for, "Boom" - followed by - "Boom" and again in the instant of a breath another, "Boom", "Boom" - "no vessel could possibly survive this devastating attack", he thought. It was 12:15 A. M., Monday, 30 July, 1945 and so recorded in the submarine's log.

Continue with: History 5 (sinking USS Indianopolis)