» Bambi Bucket: Long-line Selection

Bambi Bucket: Long-line Selection

Dec 16 2009

Problems caused by improper long-line:

Bambi bucket should not spin when it uses a proper long-line and connected to a fixed hook. If an improper long-line is used, a bucket may start spinning at the moment when the bucket is pulled out of the water with full load of water, and continues to spin backward and forward. When a swivel hook is also used, the bucket does not spin when it has a full water load, but it starts spinning again at the moment when it dumps water.

Causes:

The root cause of this problem can be traced to the long-line being made from a regular cable, instead of a non-rotating cable. Regular cable has a tendency to rotate itself forward or backward when a tensile load is added to the cable or is released from the cable, due to the nature of the manufacturing method of the cable. The rotating torque it creates will make the bucket spin if the long-line is mounted to a fixed hook. The reacted torque on the fixed hook is significant and may even damage the hook. After changing fixed hook to swivel hook, it seems that the bucket with a full water load stops spinning, but it is the swivel hook that will spin instead of the bucket. The torque required to make the bucket with full water load spin is much higher than the torque required for the swivel hook to spin. However, the bucket starts spinning again when it dumps its water load. The torque required to make the empty bucket spin may be similar or less than the torque required for the swivel hook to spin.

Solutions:

Change the long-line to a non-rotating long-line and mount the long-line to a fixed hook. The non-rotating long-line is made from non-rotating cable, which will not create a torque when a tensile load is added to the cable or released from the cable. Attached information sheets provide more detail of the non-rotating cable.

Notes:

The suspension lines of the bucket may need to be changed if they have been twisted, as the damage will be permanent and the suspension lines will continue to cause spinning even after the long-line has been changed from rotating type to non-rotating type.

Recommendation:

If the bucket has been spinning, we recommend that when the long-line is changed, the suspension lines are also changed.

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Dec 16 2009