Double overhand knot

The second tuck makes the end spiral around itself. When it is set, the two wraps roll around each other into an elongated, barrel-shaped knot. It is longer and thicker than the single overhand and therefore less likely to slip through openings.

Because the wraps nip each other, it also holds well in slick cord. The same property makes it hard to untie after loading: the wraps pull together into a compact bundle. For a stopper, its bulk matters rather than its tensile strength.

The same basic form is found in other knots: two double overhands, each tied around the other rope, make the double fisherman's bend, a well-known bend.

The key is setting it slowly. At first pull only gently on both sides and watch the two wraps settle around each other. A neatly set double overhand shows two slanting, parallel wraps forming a tidy spiral – not a jumble of crossed strands.

Only when the shape is right do you pull hard. If you set it too fast, the wraps end up twisted and messy, the knot becomes lumpy and holds less well. Leave a sufficiently long tail and don't trim it too short.

The double overhand is ideal as a stopper on thin cord, as a lump that must not slip through an eyelet or hole, and as a backup for the tail behind other knots – for example on the bowline, where the tail can be secured with it around the neighbouring loop leg.

It is unsuitable where the knot must come undone easily later, and it only stops slipping if the opening is clearly smaller than the knot. For thicker rope that will be reused, the figure-eight or stevedore knot is more pleasant.

As a stopper the double overhand fails in almost only two ways: it is pulled through an opening that is too large, or a tail trimmed too short slips out while setting. Both can be avoided by choosing the spot deliberately and leaving a long tail.

After heavy loading it can hardly be untied. Don't try to pry it open with a knife – you risk cutting yourself and the rope gets damaged. Better to flex, knead and be patient, or simply leave the knot in on a non-critical piece of rope. None of the knots in this atlas is meant for life-safety use – not for climbing, abseiling, rescue or holding and lifting people. Life-safety use only after proper training with certified equipment.

First tie a single overhand but don't set it. Take the end around a second time and through the same loop. Hold both sides loosely and pull apart very slowly – watch the spiral form. Repeat until the shape comes out neatly every time.

A third tuck gives an even thicker, barrel-shaped knot that sometimes serves as a grip or marker on thin cord. The double overhand is one of the oldest and simplest bulking knots; in English books you also find it under names such as 'barrel knot' or 'blood knot', although these do not always mean exactly the same knot.