单项选择题
Electric cargo winches have an overload safety device which normally cuts the current to the winch motor（）.
A.after torque causes line pull to exceed the rated capacity of the winch
B.before the line pull reaches the rated capacity of the winch
C.when the line pull reaches the breaking strength of the fall
D.before the safe working load of the fall is reached
相关考题
-
单项选择题
Damaged bulkheads often take a permanent set which is independent of the panting or bulge caused by water pressure. To control this，you should（）.
A.install shoring so the shoring supports the damaged bulkheads without pushing on them
B.install shoring so that it pushes on the damaged bulkhead while supporting it
C.use jacks or chain falls to remove the set before installing shores
D.place sandbags by the bulkhead without installing shores -
单项选择题
Buckler plates are（）.
A.triangular-shaped plates connecting the bull chain to the topping lift
B.metal plates secured over the tops of the hawsepipes
C.faired shell plates with curvature in two directions
D.sheets of dunnage used to prevent heavy cargo from buckling the deck plates -
单项选择题
Bilge keels are fitted on ships to（）.
A.assist in drydock alignment
B.improve the vessel's stability
C.protect the vessel from slamming against piers
D.reduce the rolling of the vessel
