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Winches sheaves and purchases for flexible steel wire rope
Winch drums
This page explains what winch drums are, and includes how to wind and spool them.
Winch drums
Drums are the pulling mechanism that spool and store surplus wire. The braking mechanism is connected to either the drum or the gearing, which is joined to the drive mechanism.
Correct anchorage will contribute to safety and longevity of winch rope operation.
Winch drums
Winding
Multi-layer winding requires a smooth transition from the bottom to the second layer. This is achieved by "riser pieces" which guide the rope onto the second layer and prevent damage.
Grooved drum
Spooling
Wire ropes should be spooled onto a drum under pre tension, approximately 10% of the line pull of the winch. This is to make sure rope is laying correctly, not loose. When a load is lifted, loose rope can pull down into lower layers and become damaged.
Spooling
9:29
Liebherr - Measures to extend the service life for hoist ropes
The capacity of drums and storage reels
This formula can be used to work out whether the winch drum has enough capacity to take the amount of rope needed in a purchase:
Formula for capacity of drums and storage reels
Reel capacity when winding ropes onto empty reels
Use this table for how to calculate reel capacity when winding ropes onto empty reels:
Factors K - Used in calculating drum and reel capacities
| Rope diameter MM | Factor K | Rope diameter MM | Factor K |
|---|---|---|---|
| 1.6 | 45.646 | 20 | 0.690 |
| 3 | 26.539 | 22 | 0.600 |
| 3.5 | 21.067 | 26 | 0.466 |
| 4 | 17.010 | 28 | 0.372 |
| 5 | 11.977 | 32 | 0.296 |
| 5.5 | 8.953 | 36 | 0.247 |
| 6 | 6.417 | 38 | 0.208 |
| 8 | 4.311 | 40 | 0.172 |
| 10 | 3.082 | 44 | 0.150 |
| 11 | 2.321 | 48 | 0.131 |
| 13 | 1.804 | 52 | 0.116 |
| 14 | 1.445 | 54 | 0.103 |
| 16 | 1.184 | 58 | 0.092 |
| 18 | 0.987 | 60 | 0.081 |
| 19 | 0.834 | 64 | 0.058 |
How to calculate reel capacity for when winding ropes onto empty reels
The formula is based on uniform rope winding and will not give correct figures if rope is wound unevenly on the reel.
The amount of tension applied when spooling the rope will also affect the length. The formula is based on the same number of wraps of rope in each layer. This is not strictly correct, but does not result in appropriate error unless the width (B) of the reel is quite small compared with the flange diameter.