Iwo Jima's soft volcanic ash and steep terraces. In addition, American troops used the LVTs to transport casualties from the front lines to evacuation sites on the beaches. The 75 mm howitzer on the LVT-4 provided important fire support as the Marines slowly advanced across the island. Okinawa This was the largest landing in the Central Pacific drive. The new LVT-3, a redesign of internal arrangements, was used successfully through the long Okinawa campaign. Over 1000 LVTs took part in the Battle of Okinawa. Europe In Europe, LVTs were mainly used for landings and river crossing operations as well as assaults in swampy zones. By the end of 1943, 200 LVT-1s had been delivered to the British Army for training in preparation for future operations in Europe. The U.S., British, and Canadian armies used the Buffalo in the 1944 Battle of the Scheldt in the Low Countries, during Operation Plunder crossing of the Rhine in March 1945, along the Po River in Italy, across the river Elbe, and in a number of other river crossing operations. LVTs were used in the Normandy landings, but their use by the United States was limited as the US Army doctrine in Europe viewed the Sherman DD as the answer to assault on heavily defended beaches. LVT-2s were used to help unload supplies after the landings on Utah Beach from the cargo ships off the coast to the beach and through the nearby swamps. For the Rhine crossing, the British 21st Army Group had some 600 Buffalos available, most of them used to transport the assault infantry. As mud was expected to hamper the Sherman DD tanks, some LVTs were armed with a 20 mm cannon and two machine guns to give fire support until bridges could be constructed across the river. The "Specials" were under the 79th Armoured Division (which operated and coordinated the use of all specialist assault vehicles), that also provided Buffalos fitted with "Bobbin" carpets to create temporary roadways over the mud. The US Army used LVT-2s and LVT-4s in Europe in small numbers in 1944–45 for river crossing operations. LVT-2s and LVT-4s were used by US troops on the Roer River crossing in 1945. US Army LVT-4's were also used by 752nd Tank Battalion to ferry 88th Infantry Division troops across the Po River in Italy in April 1945. Five LVT-4s were supplied through Lend-Lease to the Soviet Red