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How to Install a Wire Rope Thimble

by Will Charpentier

Wire rope clips are used to put a thimble into the end of a wire rope. There are specific calculations that tell you how many clips you need, how far apart each clip must be from other clips, how much of the wire rope you will have to wrap around the thimble, where to place the thimble and how much of the wire rope's length goes to securing the eye that wraps around the thimble. Once you get past the arithmetic, the "nuts and bolts" of the work are just that.

Multiply the wire rope diameter by three and add 1 to the result; round up if the answer is fractional. Use a small adjustable wrench to remove the nuts from the u-bolts of this many rope wire clips. For example, if the diameter of the wire rope is 0.5 inches, then: 0.5 x 3 = 1.5, plus 1 equals 2.5, rounded up to 3.

Measure the length of the thimble and multiply this measurement by 2.5 to determine the size of the eye. Multiply the wire rope diameter by 6, multiply that result by the number of wire clips from which you've removed the nuts and add the size of the thimble: so if our thimble is 1 inch long, then 2.5 x 1 = 2.5; the wire rope is 0.5 inches in diameter, so 0.5 x 6 = 3. Three times 3 wire rope clips equals 9 and 9 + 2.5 = 11.5, the number of inches of wire rope that you will wrap back over the thimble and under the wire rope clips.

Subtract the length of the thimble from the number of inches of wire rope that you will wrap back over the thimble: 11.5 = 10.5. Measure 10.5 inches from the end of the wire rope, mark this location with a permanent marker and set the thimble's narrow end on that mark. Wrap the wire rope tightly over the thimble.

Push one of the U-bolts from the wire rope clips downward onto the line you wrapped over the thimble. Get the wire rope clip as close to the thimble as possible and slide the roddle over the legs of the U-bolt. Thread the nuts onto the legs of the U-bolt and tighten them with the wrench.

Once more, multiply the diameter of the wire rope by 6. The result is the distance between the first u-bolt and each of the remaining u-bolts. If the wire rope is 0.5 inches in diameter, the second u-bolt should be 3 inches from the first and the third, 3 inches from the second.

Items you will need

  • Small adjustable wrench
  • Wire rope clips

Warning

  • Never use less than three wire rope clips, regardless of the calculations.

References

About the Author

Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.