The transformation of Tinian

By WILLIAM H. STEWART
Special to the Saipan Tribune

Second of seven-part series

This is a continuation of a series of articles commemorating the 60th anniversary of the end of the war in the Pacific and describes the events that led to the conclusion of hostilities.

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 also scheduled for construction on Guam and Saipan.

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 11 miles of taxiways with “hardstands” sufficient to park 300 aircraft.

The Seabees dug, blasted, scraped and moved 11 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 could form a pyramid two-thirds of a mile in height. Their equipment was kept busy 20 hours a day while welding crews worked to repair bulldozers, shovels and trucks damaged as a result of the rough construction activity. The 15,000 Seabees on Tinian operated a wide assortment of cranes and other equipment including asphalt plants to pave the airstrips. In addition to the airfields they built Quonset huts and other service buildings. 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 the quality of life for the crew 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.

Some 7,300 miles east of Tinian, a plant had been constructed at Oak Ridge, Tennessee in early 1943 for the manufacture of materials for the atomic bombs that would be launched from an island in the Marianas. This huge effort involved 200 prime contractors, 200 million board feet of lumber, 400,000 cubic yards of concrete, 100,000 tons of steel, 750 buildings, 30,000 bachelor quarters, 15,000 family housing units, 55,000 carloads of material and equipment and 12,000 pieces of construction equipment—all in use at the same time. The main building was over a mile long. The facility’s steam power plant generated 238,000 kilowatts and its three boilers produced 750,000 pounds of steam per hour. Fifty railroad cars were required each day to fuel the plant‚s boilers.

The first atomic bomb was assembled at Los Alamos and detonated at Alamagordo, New Mexico on July 16, 1945 at 5:30am. Codenamed “Trinity”, the detonation was a weapons proof shot in preparation for the attacks on Hiroshima and Nagasaki the following month.

SECRET CARGO TO TINIAN

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 USS 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 10 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 26 and its cargo was discharged for what was to be an unknown and unheard of use. For those who could understand, it was Albert Einstein’s 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.

Two days before the Indianapolis arrived on 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 August 3, 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. The ship’s orders were to proceed to Guam and then Leyte in the Philippines for redeployment. Its estimated time of arrival was scheduled for sunrise, Aug. 1. On July 28 the vessel departed Guam and steamed westward 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 second bomb of plutonium had been flown to Tinian by 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 that 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.

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 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. This steel shark was waiting for a kill.

To be continued.

Published in commemoration of the 60th Anniversary of the end of World War II.

William H. Stewart is a military historical cartographer and has mapped many of the World War II Pacific battlefields. He is the author of the books, Saipan In Flames (translated into Japanese) and Ghost Fleet of the Truk Lagoon now in its 6th printing.

Reference sources: Due to space limitations many reference sources have been omitted. This information will be furnished those interested when requested from the author at e-mail: spno@zoomnet.net.