The campaign for the Marianas played a vital role in the defeat of Japan. After the capture of Saipan, the next step in this campaign was Tinian. Only three miles away, the island’s nearness to Saipan made its capture essential. Tinian’s relatively flat terrain was ideally suited for the construction of airfields for the new American B-29s, and the Japanese had already constructed several runways at Ushi Point. American control of Tinian would put the home islands of Japan within striking distance of U.S. bombers. The defense of the island was under the command of Col Kiyochi Ogata with 9,000 Japanese troops.
The battle for Tinian had been planned in April 1944. In July, MajGen Harry Schmidt assumed command of the operation, replacing LtGen Holland M. Smith, who took command of the new Fleet Marine Force Pacific. As scheduled, Tinian underwent intensive pre-landing naval air and artillery bombardment. Photo reconnaissance flights and captured enemy documents on Saipan gave a clear picture of the topography of Tinian. It was also during this campaign that napalm was used extensively for the first time. Napalm proved successful in burning off a considerable amount of ground cover.
The choice of a landing site proved to be a difficult problem. Tinian, like Saipan, was rimmed by coral cliffs, varying in height from six to 100 feet, leaving only three possible areas for landing. The best landing site was the beach at Tinian Town. Realizing this, the Japanese had fortified the area heavily. To land there might be as costly as the invasion of Tarawa. The second favorable beach was located at Asiga Bay. This, too, was strongly defended and mined. It was exposed to the trade winds which caused a heavy surf. The third choice was to land at two beaches located on the northwest coast. Both beaches were narrow and crowded with coral, but Japanese defenses were light. One beach was only 60 yards wide and the other was a little more than twice that width. Both beaches were too narrow for a full-scale amphibious assault and presented the danger of congestion of troops and equipment. Based on reports made by swimmers from the Amphibious Reconnaissance Battalion, which reconnoitered both Asiga Bay and the northwest beaches, the decision was made to land on the northwest beaches.
The assault was set for 24 July 1944 (J-Day). It was decided that the 2d and 4th Marine Divisions would land on Tinian, with the Army’s 27th Division held in reserve on Saipan. The 4th Marine Division was to land first on the northwest beaches designated White 1 and White 2. To draw the attention of the Japanese away from the landing, the 2d Marine Division was directed to make a feint off the beach at Tinian Town in an effort to keep the Japanese troops in that area while the real landing was taking place at White 1 and 2.
At dawn on J-Day, the demonstration group’s attack began with the shelling of Tinian Town. The battleship Colorado, light cruiser Cleveland and destroyers Remey and Norman Scott moved in, followed by the transports carrying the 2d and 8th Marines. The landing craft came within 2000 yards of the beach before turning around and heading back to the ships. All returned safely, although Japanese artillery severely damaged several ships. The plan had worked; Japanese attention had been successfully diverted while the assault on the northwest beaches was taking place.
The attack began at 7:45am with two regiments landing abreast in amphibian tractors, the 24th Marines on the left at White Beach 1 and the 25th Marines on the right at White Beach 2. Meeting with some machine gun and rifle fire that in no way compared to the barrage encountered on the beaches of Saipan, the Marines quickly overcame the opposition. By 11:00am all reserve battalions had landed and shortly after that, the division artillery reached the beach. By nightfall on J-Day, all three infantry regiments (23d, 24th, and 25th) of the 4th Marine Division and four pack howitzer battalions of the 10th and 14th Marines were ashore and braced for the expected counterattack from the Japanese. The element of surprise had paid off well. The assault cost a relatively small number of casualties with 15 dead and 225 wounded. Over 15,000 Marines had landed and greatly outnumbered the Japanese defenders. All supplies had received special attention to prevent any congestion on the beaches. According to logistics plans, all supplies were brought across the beaches in tractors and DUKWs (amphibious trucks) and taken directly to division dumps without rehandling.
The Japanese counterattack came the first night. They charged the Marines three times, but the lines held in spite of the fact some Marine companies were down to as few as 30 men. By dawn the Japanese assault was smashed and the Marines began to mop up. On J-Day plus one, the 2d Marine Division arrived from Tinian Town and moved ashore while the 4th Marine Division occupied Mt. Lasso, the highest elevation on Tinian. During the next three days, the Marines moved inland meeting very little resistance and Ushi Point Airfield was taken with no opposition. On 29 July, the two Marine divisions met with stiffer resistance as the retreating Japanese moved south into hills and caves. After these isolated pockets of resistance were destroyed, the Marines moved on Tinian Town. The abandoned ruins were taken the next day and the Japanese withdrew to the southern end of the island.
U.S. forces put the southern area under aerial, naval, and artillery fire in attempt to flush out the remaining enemy troops. Early on 1 August 1944, the 2d Marine Division successfully fought off two banzai charges that seemed to be the enemy’s last gasp. Japanese resistance ceased, and the island was declared secure, although some isolated Japanese troops hiding in caves did keep one Marine regiment tied up with patrol and mop-up activities for months afterwards.
The battle for Tinian was over in nine days. It cost the Marines 384 dead with 1,961 wounded. The element of surprise was the main factor in casualties being so low. This battle, in the opinion of many, was the perfect amphibious operation of World War II.
The role Tinian was to play in the war did not end, however, with its capture from the Japanese. About a year later, the Enola Gay, a B-29 airplane, left Ushi Point Airfield carrying the atomic bomb that was to be dropped on Hiroshima, Japan. Three days later, a second B-29 left Tinian carrying the bomb to be dropped on Nagasaki. The Japanese surrender, ending World War II, followed shortly after that.