Knots for joining ropes

Reef knot (square knot) and why not to use it for loads

What it is for: tying two ends of the same rope around something: bandages and slings (see chapter 7), bundles, the mouth of a bag, a rolled-up tarp.

1. Right over left and under (a half knot, like tying your shoelaces).
2. Left over right and under.
3. Check. Each end comes out on the same side of the other's bight and the knot lies flat. If the ends come out crossed diagonally, you tied a false knot or "granny knot": undo it.

Sheet bend (single and double)

What it is for: joining two ropes, even of different thickness or material, quickly and in a way that is easy to untie. The double is more secure with slippery or wet rope, or ropes of very different thickness.

1. Make a bight with the thicker rope (A). Hold it with one hand.
2. Pass the working end of the thin one (B) through the bight, from below to above.
3. Go around both legs of the bight with B from behind.
4. Pass B under itself, but over the bight. Do not return it through the inside of the bight.
5. Double: before passing it under itself, make a second full turn around the bight following the first.
6. Tighten by pulling the standing parts. Both working ends should end up on the same side of the knot.

Double fisherman's knot

What it is for: joining two ropes of the same thickness permanently, and closing a length of cord to make a prusik loop. It almost never unties after being loaded.

1. Overlap the two ends, one pointing opposite the other, with enough overlap to tie both knots.
2. With A's working end, make two turns around both ropes, moving toward A's standing part.
3. Pass A's working end through both turns and tighten. It is a double knot around rope B.
4. Repeat with B's working end around A, in the opposite direction.
5. Pull both standing parts until the two knots come together. On one side you see two "X"s; on the other, four parallel turns. Leave long tails.