Note: Use of line and knots or splices to attach Harken hardware is the sole responsibility of the user.
Using Knots to Secure Hardware
Knots listed in Harken instructions are secure knots if tied correctly using Harken supplied line and inspected regularly. It is your responsibility to research and tie knots correctly. Understand these precautions:
- Knots are the weakest link in a line attachment. They often break at about half the breaking load of the line. Keep this in mind when replacing line. Use Harken supplied original line or choose line that is twice the breaking strength of the block. Divide the breaking load of the block by the number of strands and then double this number to account for the loss of strength from the knot. For example, a block with a 544 kg (1200 lb) break load and a 4-strand lashing would put 136 kg (300 lb)on each strand if it were loaded to breaking load. The strand or line needs to be double this or 272 kg (600 lb) break strength or higher. Consult a rigging professional if you have questions on line selection.
- Knots can slip especially with high strength lines. Spectra® or Dyneema®type lines require specialized knots or splices to prevent slipping. For covered lines, a double fisherman's knot works well. For uncovered Spectra®or Dyneema® line use a triple fisherman's knot.
- Knots can be tied incorrectly. An attempt to tie a secure knot can lead to an accident if lines are incorrectly tied. If you are unsure about tying knots consult a professional rigger.
- Splices can be a better alternative to knots if done correctly. Splices should only be attempted by experts or rigging professionals.
Knot tying resources
There are several consult books and websites offering instructions on how to tie knots. One of the many useful websites is Animated Knots linked below.. Carefully read descriptions regarding the knots shown in Animated Knots or other websites offering knot tying technical assistance. Pay careful attention to the sections titled:
2. Knots Weaken Rope
Clicking on the link below takes you out of the Harken Website. Harken is not responsible for the accuracy or content of this site. www.animatedknots.com
Harken Warranty Using Line and Associated Knots and Splices
HARKEN shall not have any liability or responsibility for damages or expenses relating to:
Click here to see our complete limited warranty.