AUGUST 1, 2024 – The end of July marked the 80th anniversary of the invasion of Tinian, completing the campaign to capture the Marianas Islands during Operation FORAGER. Seizure of the Marianas Islands enabled a strategic land-based bombing campaign as well as providing naval basing to efficiently tighten the blockade of the Japanese Home Islands.
Operation FORAGER also represented incremental progress in the war, as the Northern Marianas Islands were considered part of the Japanese Home Island Defense Area.
Although many consider the Marianas landings, and especially the Tinian assault as predominantly Navy-Marine Corps operations, that oversimplification could not be further from the truth. Evidence of the Army’s active participation can be found throughout the landing force detailed to take Tinian.
First off, the Theater Army of the Pacific provided much of the operational planning, specialized manpower skills, heavy weapons, logistics, Combat Medical support, signal, engineer, and other theater-level enabling capabilities that made the operation possible.
Operation FORAGER was planned, organized, trained for, and extensively rehearsed beforehand on select Hawaiian bases throughout O’ahu, Maui, Kaho’olawe, and the Big Island, with new assault troops benefiting from the specialized training packages taught by Soldiers at Army-run training facilities and schools’ purpose-designed and constructed to replicate the combat conditions anticipated in the Marianas. There, infantry, artillery, engineers, and tank crews mastered the techniques and procedures for reducing enemy obstacles and fortifications, practicing until perfection.
After the campaign, many participants reflected on the high level of preparation for the campaign, saying it felt as though they’d experienced it all beforehand.
Among the 70,000 assault troops that took part in FORAGER, more than one-third were Army, which also provided most of the combat service support, medical support, and an artillery Corps. Of the 415 LVTs that carried the assault troops from Saipan to the Tinian landing beaches, 225 (or 55%) were operated by Soldiers from four Army Amphibian tractor battalions, accompanied by Army amphibious tanks.
Many of the Soldiers of the 534th, 708th, 715th, and 773d Amphibian Tractor Battalions had made combat assaults during both the Saipan and Guam invasions; Tinian was their third assault landing made during July 1944 alone. Troops from the 27th Division and the 477th Amphibian Truck Companies, as well as the 708th Amphibious Tank Battalion provided more than half of the 140 DUKW amphibious trucks, and eighty tanks, and the extra crews needed to resupply and support the Tinian assault troops.
The assault on Tinian was favored with the most prolonged preliminary artillery bombardment than any other Central Pacific Island in the war. That fire support was largely provided by the XXIV Corps Artillery, consisting of 13 battalions with 156 guns. The artillery groupment consisted of two 155mm gun battalions, three 155mm howitzer battalions, and eight 105mm howitzer battalions, which provided a steady, 24-hr a day firing of an average of 1,509 fire missions of 24,536 rounds daily.
Spotting was provided by an organic group of nine spotting observation aircraft, so many that it prompted the building of a separate runway to accommodate them on Saipan. Two of the Army’s 155mm Arty battalions went ashore with the Marines, firing almost 50,000 rounds in support of the operation during the three weeks of combat. Air support was provided by dedicated squadron of Army P-47 aircraft, which averaged 175 sorties a day. Army bombers dropped 69 tons of ordnance on Tinian targets. The Army also provided two Field Hospitals and three Portable Surgical Hospitals, plus several engineer and signal units.
The 8,000 Japanese defenders fought tenaciously for every inch of ground, considering it Japanese soil. The ferocity of battle led to one of the highest casualty rates among American troops. Tinian was also the site of a major night counterattack, in which more than 2,500 Japanese soldiers fanatically attacked friendly defensive positions.
By the time Tinian was declared secure on 1 August, about 500 of the 8,000 Japanese defenders remained alive. Cleaning them out lasted through September. Even as the fighting in the south was still being carried out, a massive engineering effort was underway in the north part of the island, where four east-west runways were being constructed to take advantage of the seasonal wind patterns. In a few short months the first squadron of America’s newest long-range bomber, the B-29, landed in the Marianas and went to work with a vengeance. American forces now owned an ideal airbase, only 12 flight hours away from Tokyo.
By early 1945 Tinian housed the largest air force base in the world, and hundreds of planes daily departed to drop their deadly payload over Japan. Significantly, it was from Tinian’s Ushi Point Airfield, the farthest northerly runway, that the Enola Gay took off on 6 August 1945 to drop the first atomic bomb on Hiroshima, which hastened the end of the war. And the U.S. Army played a key role in getting us to that point in time.
By Dr. Mike Krivdo