Tinian Island During the Manhattan Project

Black and white photo of Tinian airfield with several B-29s parked.
B-29s parked at Tinian during World War II.


West of the Phillipines and south of Japan, Tinian is part of the Commonwealth of the Northern Mariana Islands, administered by the United States. Tinian has an area of about 39 square miles (25,000 acres, 101 square kilometers); for comparison, the Los Alamos National Laboratory is close to the same size, covering about 35 square miles (22,201 acres, 90 square kilometers) and Yellowstone National Park is about ten times the size, at 3,472 square miles, about 2.5 million acres or about 9,000 square kilometers. Most of the island is nearly flat, with the highest elevation being 561 feet (171 meters). The population in 2010 was 3,136, and residents are American citizens. The first settlers arrived about 1500 BCE, and later migrations included settlers from the Caroline Islands and Southeast Asia; the resulting indigenous people are known as Chamorros. By the late 1600s it was a Spanish possession and had become a supply station for Spanish, English, Dutch, and French ships to take on food and water. Disease and conflicts reduced the native population from around 100,000 to about 1400 by the 1700s, and they were moved to Guam in 1720. Tinian was sold to the German Empire in 1899. Japan captured it during World War I, and used it for growing sugarcane, coffee, and cotton; the population included over 15,000 Japanese and Koreans, and a very small number of ethnic Chamorros.

Late in World War II the Japanese garrisoned Tinian when they realized its strategic location within bomber reach of their home islands. It was indeed important to the Allies, and they attacked the island on July 24, 1944; the Battle of Tinian lasted through August 1. Of the 8500-man Japanese garrison, only 313 survived, and of the 15,700 civilians, hundreds were killed in crossfire, executed by the Japanese, or committed suicide. On the Allied side, the more than 41,000 Marines suffered 368 deaths and 1921 wounded. This battle was part of the military strategy known as “island hopping,” used to gain locations from which to attack Japan. As soon as the island was seized, the Seabees, the Navy’s construction battalions, began work on the largest airbase of World War II – and in fact the largest airfield in the world at the time. It would become a 40,000-person base, with six 8500-foot (1.5 miles, 2600-meter) runways, hardstands for hundreds of B-29s and other aircraft, and naval facilities including Tinian Harbor. Because the shape of the island was reminiscent of Manhattan, New York, the Seabees laid it out in a pattern, and with place names, based on the city streets there. At one point seven squadrons of the 58th Bombardment Wing used it as a base for flying missions throughout Southeast Asia and into the Japanese home islands. It was one of the bases used by the Twentieth Air Force for operations in 1945 that included firebombing Japanese cities and Operation Starvation, in which mines were dropped in Japanese harbors and shipping lanes to block critical food imports.

Among the more than 500 aircraft that regularly used the long runways were the specially modified Silverplate B-29s of the 509th Composite Group. Although with very few exceptions even their own men didn’t know it, they were a part of the Manhattan Project’s Project Alberta, preparing to carry the atom bombs to targets in Japan. In late April 1945, the 509th began the move from their secret base at Wendover, Utah, to Tinian, where they had their own separate base near North Field. When it reached full strength in May, the 509th numbered 225 officers and 1542 enlisted men. It included staff and arrangements for its own quarters, rations, payroll, and medical care, and its Air Engineering Squadron provided depot-level maintenance for the planes right in the field. There was no need to take them back to the States even for major repairs, and no one but their own people had any need to interact with the highly secret B-29s. The group also included five C-54 Skymaster aircraft, nicknamed “the Green Hornet Line”, to transport personnel and materiel. And their roster at Tinian included 51 scientists, military, and security personnel from the Manhattan Project’s Los Alamos Laboratory, along with two officers from Washington, D.C.

At 2:30 AM on August 6, 1945, the Enola Gay left Tinian for its historic mission to Hiroshima, Japan, carrying the uranium bomb Little Boy. The strike force included a plane each for instrumentation and photography, and three for weather observations. The Enola Gay’s crew included pilot Paul Tibbets, head of the 509th, and Deak Parsons, mission commander, weaponeer, and head of Project Alberta. The crew of the instrument plane included two Los Alamos physicists, future Nobel Laureate Luis Alvarez and future Los Alamos Laboratory Director Harold Agnew. Three days later, on August 9, a strike force led by pilot Charles Sweeny in the B-29 Bockscar and including physicist Lawrence Johnston, carried the plutonium bomb Fat Man to Nagasaki.

After World War II, the hundreds of airplanes returned to the mainland. For a time in the 1980s there were Marine training exercises on the island, and there is still a military presence that is important to the island economy. All the runways but one have fallen into disrepair; that one, on West Field, is part of the Tinian International Airport. North Field is the main part of the National Historic Landmark District, which includes the remains of the bomber base and Japanese fortifications. Two bomb pits built to load the oversized atom bombs into the B-29s have been reopened and sheltered by glazed panels. Although visitation is not heavy, tourism is important to the economy, with attractions including pristine beaches, SCUBA diving, and snorkeling. Tinian is recognized as an Important Bird Area, supporting species including a reddish-brown flycatcher endemic to the Marianas, the Tinian monarch. Besides the runways and bomb pits, historic areas include Shinto shrines and ancient standing stones called latde (or latte, or latdi). These consist of a series of stone columns topped by half-spheres, once part of traditional structures, and are distinctive to Chamorro culture.

  • Rhodes, Richard. The Making of the Atomic Bomb. Simon & Shuster (New York).
  • Kunetka, James. The General and the Genius. Regnery History. 2015.

Manhattan Project National Historical Park

Last updated: September 25, 2023