50 caliber machine gun for the four-man crew. The armor thickness was around five inches. The M48 was deployed during the Vietnam War but it was of limited use due to the lack of tank-on-tank battles.

HAI DUONG, Vietnam: When they crashed through the gates of Saigon's presidential palace to end Vietnam's war, the young crew of communist Tank 390 shaped the course of history -- but 50 years on ...