[Illustration: _The positions from which rocket troops launched salvos of 4.5-inch rockets became very unhealthy places, indeed, as Japanese artillery and mortars zeroed in on the clouds of smoke and dust resulting from the firing of the rockets._ Department of Defense Photo (USMC) 111100 ] ] [Sidebar (page 44): Amphibious Logistical Support at Iwo Jima The logistical effort required to sustain the seizure of Iwo Jima was enormous, complex, largely improvised on lessons learned in earlier Marine Corps operations in the Pacific, and highly successful. Clearly, no other element of the emerging art of amphibious warfare had improved so greatly by the winter of 1945. Marines may have had the heart and firepower to tackle a fortress-like Iwo Jima earlier in the war, but they would have been crippled in the doing of it by limitations in amphibious logistical support capabilities. These concepts, procedures, organizations, and special materials took years to develop; once in place they fully enabled such large-scale conquests as Iwo Jima and Okinawa. For the Iwo Jima operation, VAC had the 8th Field Depot, commanded by Colonel Leland S. Swindler. The depot was designed to serve as the nucleus of the shore party operation; the depot commander was dual-hatted as the Shore Party Commander of the Landing Force, in which capacity he was responsible for coordinating the activities of the division shore parties. The timing of the logistics support at Iwo Jima proved to be well conceived and executed. Liaison teams from the 8th Field Depot accompanied the 4th and 5th Divisions ashore. On D+3, units of the field depot came ashore, and two days after this, when VAC assumed control on shore, the field depot took over and the unloading continued without interruption. The V Amphibious Corps at Iwo Jima used every conceivable means of delivering combat cargo ashore when and where needed by the landing force. These means sequentially involved the prescribed loads and units of fire carried by the assault waves; “hot cargo” preloaded in on-call waves or floating dumps; experimental use of “one-shot” preloaded amphibious trailers and Wilson drums; general unloading; administrative unloading of what later generations of amphibians would call an “assault follow-on echelon”; and aerial delivery of critically short items, first by parachute, then by transports landing on the captured runways. In the process, the Navy-Marine Corps team successfully experimented with the use of armored bulldozers and sleds loaded with hinged Marston matting delivered in the assault waves to help clear wheeled vehicles stuck in the soft volcanic sand. In spite of formidable early obstacles--foul weather, heavy surf, dangerous undertows, and fearsome enemy fire--the system worked. Combat cargo flowed in; casualties and salvaged equipment flowed out.