Along this line 20,000-ton coal trains can reach a length of over 7 km pulled by powerful electric locomotives over an extraheavyduty track and driving down operating costs.
大秦线上运行的两万吨运煤列车长度可达7公里，由大功率电力机车牵引，大大降低了运营成本。
2
Its extraheavyduty bearings are designed to maximize its operational life.
其额外的重型轴承的设计最大限度地发挥它的运行寿命。
3
Objective To summarize the cure experience of 1500 case extra-heavyduty, heavy duty craniocerebral injury patients.