自有铁路以来,铁路货车就不断向大型化发展。在北美、巴西、澳大利亚、苏联和南非,好多年以前就已经开始采用总重超过100吨的货车了。其中最突出的是美国。大型货车是铁路为了适应提高运输能力和改善铁路运输的经济性的要求发展起来的。但是,由于经济上和技术上诸因素的制约,货车的吨位并不能无限制地增大。虽然大多数国家目前正在以积极慎重的态度继续发展,然而从美国的情况看来,货车的大型化似乎已经达到目前技术水平的极限,在运用中暴露出不少问题。 Since its own railway, railway wagons have been continuously enlarged. In North America, Brazil, Australia, the Soviet Union and South Africa, trucks weighing more than 100 tons have been used many years ago. One of the most prominent is the United States. Large trucks are developed for the railway in order to meet the requirements of improving the transportation capacity and improving the economy of railway transportation. However, due to economic and technical constraints, the tonnage of trucks can not be increased indefinitely. Although most countries are continuing their development with a positive and cautious attitude at present, from the perspective of the United States, it seems that the large-scale truck has reached the limit of the current technological level and exposed many problems in its operation.