Trucker's hitch

The rope runs from the first anchor to the loop, then from the end around the second anchor and back through the loop. Between the loop and the second anchor there are now two strands of rope side by side, pulling together. That is the principle of a simple pulley system: several strands share the work, and your pull on the end is redirected and multiplied.

In theory the gain would be considerable; in practice rope-on-rope friction eats a large part of it. But that friction has an advantage too: it briefly holds the tension while you tie off with your other hand. A clip in the loop reduces friction and spares the rope, but the tension slips back more easily while you tie off.

The loop is the heart of the system and usually its weakest point. It should be made with a knot that forms a fixed loop and keeps its shape under load – an alpine butterfly or figure-eight loop is reliable. After tensioning, check: has the loop kept its shape, or has it distorted or shifted? A simple slipped loop is quicker, but it can capsize, i.e. flip over under load and fall apart, or jam so hard that you can barely open it.

The loop belongs roughly an arm's length short of the second anchor, so you have enough travel. The two half hitches for tying off go around both strands below the loop and are snugged up tight towards it. Leave a decent length of tail behind them. If you tie the last hitch with a bight (“slipped”), you can release the whole thing later with one tug.

The most common problems: a loop made with an unsuitable knot that falls apart under load; a loop sitting too close to the anchor, so it bottoms out before the line is taut; and finishing hitches tied around one strand only instead of both, so they slip.

Over time, wear adds to this. Where rope runs over rope, friction creates heat and the loop chafes. If you re-tension often, look at it regularly and move the loop to a fresh spot. It becomes dangerous when very thin cord is tensioned extremely hard: the cord can snap or the anchor can fail, for example a rotten branch or a loose peg.

The trucker's hitch is ideal for a tarp ridgeline that should stand taut so the tarp does not sag and water runs off well. You can also use it to lash luggage or a cover onto a roof rack or trailer – in addition to suitable straps.

It is no substitute for certified tie-down straps on the road; many countries have rules on securing loads, so check local rules. Nor is it for life-safety purposes: life-safety use only after proper training with certified equipment. If a line does not really need to be drum-tight, a simpler adjustable hitch is often enough.

A heavily tensioned rope stores energy like a drawn bow. If it breaks or the anchor fails, it snaps back – together with peg, branch or clip. So never stand in line with a heavily tensioned rope, protect your eyes, and only tension as hard as you really need to.

Check the anchors first: a healthy, reasonably thick tree is good; a thin or dead sapling is not. With trees, put something under the rope so the bark is not damaged. And after rain or wind, check that everything is still in place: some ropes stretch when they get wet, others shrink.