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KNOTS & SPLICES

Sheet Bend

The way to join two lines of different size — a bend that holds where a square knot will not.

INSPECT BEFORE LOAD · NEVER EXCEED WLL

Rope, splices and hardware are only as good as their condition. Inspect before every use and retire on evidence.

Sheet Bend — nautical chart line drawing

Specification

TypeBend — joins two lines
Strength retention55–60%
Easily untiedYes when slack
Suitable diameterDifferent sizes OK
Jam riskLow
Common errorWorking ends on opposite sides

Technical parameters

Retention55–60%
Retention (double)≈ 65%
Tie time15–25 s
Tails left≥ 10 × diameter
Works withUnequal diameters
FailsWhen slack and shaken
TieLoad

Overview

A sheet bend joins two ropes end to end. One line forms a bight, the other passes up through the bight, around behind both parts of it, and tucks under itself. The essential detail is that the two working ends must come out on the same side of the knot, where the load will keep them pressed together rather than pulling them apart.

Its particular virtue is that it works between lines of different diameters, which the square knot does not. Joining a heavy dock line to a light messenger is exactly what a sheet bend is for. Doubling the bight before you tie it — a double sheet bend — adds security and is worth doing in anything slippery or heavily loaded.

Strength retention is modest, around fifty-five to sixty per cent, and a sheet bend in two lines of very different stiffness can shake loose when slack. It is a utility bend, and it should be backed up or doubled where the load matters.

Safety notes

  • Both working ends must exit on the same side. If they do not, the bend is unreliable and can spill under load.
  • Use a double sheet bend for anything slippery, small or heavily loaded.
  • Never join two lines to make a fall-arrest or life-safety system. A bend is always a weak point.

Using it well

  • Load it once by hand to seat it before trusting it; a sheet bend sets visibly.
  • Where diameters differ a lot, put the bight in the thicker line.
  • For a semi-permanent join, finish each tail with a stopper knot.

Suited to

Joining unequal linesUtility workTemporary repairMessenger lines

Typical applications

Joining linesUtilityRepair
Figures are typical catalogue values for new equipment, quoted for comparison and planning. They are not a guarantee for any specific product or any specific load. Always work to the manufacturer’s stated working load limit and to the regulations that apply where you sail.

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