在每年运行300亿英里的过程中,美国200万辆铁路货车要发生数千起脱轨事故,在1970年就有5602起。脱轨的原因虽然是多种多样的,但历史上仍然有一半是由于设备或线路故障所造成的。这些脱轨事故的损失虽不能确切知道,但可估计,在每年18000—33000万美元的总损失费用中,因设备和线路故障引起的脱轨给铁路造成的直接损失约达6000—6500美 In the course of 30 billion miles a year, there are thousands of derailment accidents in 2 million U.S. railway wagons, up from 5602 in 1970. Although the causes of derailment are varied, half of the history is due to equipment or line failures. Although the loss of these derailment accidents can not be fully known, it can be estimated that the direct loss due to derailment due to equipment and line failures to the railway amounts to about 6000-6500 U.S. dollars per year for the total loss of US $ 180-33 million