A cutter suction dredger moves around the spud during operation，and the cut width is decided by the swing angle, which would be reduced in severe environment by the effects of external loads and the restriction of winch忆s capacity.
Computation and analysis for environment load and its effects on capability is carried out for a cutter suction dredger operating
in rapid section of Yangtze River，and methods are proposed for determination of operating environment and equipment capability in the preliminary design stage.