Opening of strand in rotation resistant,low rotation and parallel closed ropes-in extreme circumstances the rope may develop a “birdcage distortion” or protrusion of inner strands.
Note-rotation resistant and low rotation ropes are designed with a specific strand gap which may be apparent on delivery in an off tension condition.These gaps will close under load and will have no effect on operational performance of the rope.
>check sheave and drum groove radii using sheave gauge to ensure that they are no smaller than nominal rope radius +5% ZhongYing recommends that the sheave and drum groove radii are checked prior to any rope installation.
>Repair or replace drum/sheaves if necessary.
>Check fleet angles in the reeving system-a fleet angle in excess of 1.5 degrees may cause distortion.
>Check installation method-turn induced during installation can cause excessive rope rotation resulting in distortion.
>Check if the rope has been cut “on site” prior to installation or cut to remove a damaged portion from the end of the rope.If so,was the correct cutting procedure used?Incorrect cutting of rotation resistant,low rotation and parallel closed rope can cause distortion in operation.
>Rope may have experienced a shock load.