However, the auxiliary lock is not equipped with tow haulageequipment, so double lockage tows require special pull boat assistance.
但是，辅助船闸没有牵引设备，因此双闸拖轮需要有特殊的牵引船协助。
2
Research on continuous ore drawing and haulageequipment for underground metal mines has widely been done in main foreign countries with mining industry.