Operation Forager logistics
Operation Forager, the American invasion of the Mariana Islands in June and July 1944 during World War II, was the largest amphibious operation of the Pacific War to that date. It involved the movement and support of a fleet and 166,000 ground troops over extremely long distances. Intervention and disruption by Japanese air and naval forces was anticipated. This meant that not only did the forces ashore have to be supplied with enough resources to continue operations if unloading was interrupted, but a fleet of warships had to be maintained at sea for up to four months.
A crucial problem was the provision of sufficient shipping. A shortage of ships and cargo space forced units to leave some vehicles and equipment behind, and some units had to travel on separate ships from their equipment. Unloading was facilitated by the use of wooden pallets, but not all cargo ships had the space or equipment to accommodate them. On Guam the reef prevented landing craft from directly accessing the beach and pallets had to be broken up and stores transferred to DUKWs or Landing Vehicles, Tracked, (LVTs) on the reef.
Two dozen replenishment oilers were on hand to enable the fleet to refuel at sea. For the first time in the Central Pacific Area, the Japanese targeted oilers. With the fleet at sea for over four months, many stores aboard ran low. These were replenished by general stores issue ships carrying 5,000 different items. The Battle of the Philippine Sea and staunch Japanese resistance ashore on Saipan and later Guam resulted in a longer campaign than anticipated, with increased calls for naval gunfire support, and consequently prodigious ammunition consumption. Most resupply ships were not vertically loaded, which made retrieving the most urgently needed items more problematic. Ammunition ships were called forward to replenish the fleet off Saipan while the battle still raged on shore, a risky action as Japanese air attacks occurred almost every day.
After the battle, the Mariana Islands were developed into a major naval and air base. Hospitals on the islands received wounded from the Battle of Iwo Jima and the Battle of Okinawa. Boeing B-29 Superfortress bombers were based on the islands and conducted air raids on Japan, including the bombing of Tokyo on 10 March 1945 and the atomic bombings of Hiroshima and Nagasaki.