.jpg)
JibCap’s Scuttlebutt #3 Halyard Knots or Nots
We all know that knots, bends, loops, and splices weaken the line in which they are made. When knotted line is strained to its breaking point, it almost always fails at the knot or close to it, unless it is defective or damaged elsewhere. In most situations, forming loops and bends is far more practical than using line splices, even though the splice can maintain nearly the line's full strength. Prudent sailors allow for a large safety margin in the strength of line chosen for a task due to the weakening effects of knots, aging, damage, shock loading, bend radius, etc.
Determining a precise strength value for a particular knot is difficult because many factors can affect a knot efficiency test: the type of fiber, the style of line, the size of line, whether it is wet or dry, how the knot is dressed before loading, how rapidly it is loaded, whether the knot is repeatedly loaded, and so on. Yachting Monthly has a good article on knot strength or knot efficiency. https://www.yachtingmonthly.com/sailing-skills/strongest-sailing-knot-30247
The advantage of using the eye splice is that it retains approximately 80+% of the line strength. The disadvantages are halyard splices can be difficult to make during ‘on the water situations’, especially with older line and it is likely the broken splice will slip through the mast opening because of the splice’s small profile.
The only ‘knot’ that comes close to the eye splice is the ‘Double Fisherman’s Loop’ which retains line strength at approximately 80%. The advantages of the ‘Double Fisherman’ Loop’ is that it is easy to make under all circumstances and should this knot part, it is likely it will NOT pass through the mast opening because of its much larger profile. https://www.youtube.com/watch?v=01Qp-z0T2NE
One last note on halyard splices and ‘knots’, consider using a plastic thimble or something similar to increase the bend radius of line around the shackle as much as possible. Lines are significantly weakened if they are taken around tight turns. The entire load comes on the few fibers on the stretched outer edge of the turn and they break. Even a 5:1 radius (the radius of the bend compared to the diameter of the line) results in a loss of about 15-20 percent of the line strength.
If you have a maintenance tip you would like to share with your fellow Sailors, please email tom@jibcap.com If we post it, we will send you a JibCap Tee as a token of our appreciation.
Determining a precise strength value for a particular knot is difficult because many factors can affect a knot efficiency test: the type of fiber, the style of line, the size of line, whether it is wet or dry, how the knot is dressed before loading, how rapidly it is loaded, whether the knot is repeatedly loaded, and so on. Yachting Monthly has a good article on knot strength or knot efficiency. https://www.yachtingmonthly.com/sailing-skills/strongest-sailing-knot-30247
The advantage of using the eye splice is that it retains approximately 80+% of the line strength. The disadvantages are halyard splices can be difficult to make during ‘on the water situations’, especially with older line and it is likely the broken splice will slip through the mast opening because of the splice’s small profile.
The only ‘knot’ that comes close to the eye splice is the ‘Double Fisherman’s Loop’ which retains line strength at approximately 80%. The advantages of the ‘Double Fisherman’ Loop’ is that it is easy to make under all circumstances and should this knot part, it is likely it will NOT pass through the mast opening because of its much larger profile. https://www.youtube.com/watch?v=01Qp-z0T2NE
One last note on halyard splices and ‘knots’, consider using a plastic thimble or something similar to increase the bend radius of line around the shackle as much as possible. Lines are significantly weakened if they are taken around tight turns. The entire load comes on the few fibers on the stretched outer edge of the turn and they break. Even a 5:1 radius (the radius of the bend compared to the diameter of the line) results in a loss of about 15-20 percent of the line strength.
If you have a maintenance tip you would like to share with your fellow Sailors, please email tom@jibcap.com If we post it, we will send you a JibCap Tee as a token of our appreciation.