A ring crane is a large construction crane that has a luffing jib.

环式起重机是一种具有变幅臂的大型建筑起重机。

The max distance of the main boom and luffing jib is up to 384 ft.

主臂和变幅副臂的最大距离可达384英尺。

This Demag crane comes equipped with four hoist winches, a boom derrick with two winches, a boom hoist a luffing jib with two winches and a slewing mechanism.

该德马格起重机配备了四个卷扬绞车、一个带两个绞车的动臂井架、一个动臂葫芦、一个带两个绞车的动臂和一个回转机构。