The LVT-3 was an unarmored tracked landing craft developed for carrying cargo, with a new stern loading ramp for personnel protection and twin Cadillac V-8 Model 42 engines mounted in the side hulls to create more internal cargo space. A total of 2,962 LVT-3s was built for the U.S. Marine Corps, but production problems delayed their combat introduction until 1945 at Okinawa. After World War II, the Marine Corps, facing budget limits and expecting few new amphibious tractors, chose to retain LVT-3 amtracs and LVT(A)-5 amphibious tanks, many of which had not been shipped overseas before the war ended. In 1949 the Marine Corps began modernizing the LVT-3 by adding overhead armor to protect the troop bay, and this 1950 modification produced 1,200 redesignated LVT-3C Bushmasters. The name followed the tradition of naming LVTs after animals associated with water. Bushmasters became the backbone of Marine amtrac units in the Korean War and figured prominently in the landing at Inchon, Marine attacks across the Han River, and the evacuation of Hungnam Harbor after Chinese entry into the war. This example was manufactured by the Borg-Warner Corporation and modified to the LVT-3C by Continental Aviation and Engineering in 1950. It was waterproof, could withstand heavy surf, and had treads designed more for water and sand than for land travel.