The concrete ballast units are packaged in 20-inch containers with twist locks, making them easily transportable.
混凝土道碴单元包装在带有扭锁的 20 英寸集装箱中,方便运输。
英语百科
Twistlock
A twistlock and corner casting together form a standardized rotating connector for securing shipping containers. The primary uses are for locking a container into place on container ship, semi-trailer truck or railway container train; and for lifting of the containers by container cranes and sidelifters.