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Adjustable hitch knot

The taut line hitch is an adjustable loop knot for use on lines under tension. It is useful when the length of a line will need to be periodically adjusted in order to maintain tension. It is made by tying a rolling hitch around the standing part after passing around an anchor object. Tension is maintained by sliding the hitch to adjust the size of the loop, thus changing the effective length of the standing part without retying the knot. It is typically used for securing tent lines in outdoor activities involving camping, by arborists when climbing trees, for tying down aircraft, for creating adjustable moorings in tidal areas, and to secure loads on vehicles. A versatile knot, the taut line hitch was even used by astronauts during STS 82, the second Space Shuttle mission to repair the Hubble Space Telescope.

The adjustable loop forms of the rolling hitch and Magnus hitch, in addition to being called either of those two names, have also come to be known variously as the taut line hitch, or midshipman's hitch.

Ashley uses the name midshipman's hitch for this variation. Based on rolling hitch #1735, this version is considered the most secure but may be more difficult to adjust after being heavily loaded. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half hitch around the standing part. Continue by passing the working end over the working part, around the standing part again and back through the loop formed in the first step. Make sure this second wrap tucks in between the first wrap and the working part of the line on the inside of the loop. This detail gives this version its additional security. Complete with a half hitch outside the loop, made in the same direction as the first two wraps, as for a clove hitch. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary.

Based on rolling hitch #1734, this version is the one most often seen named taut line hitch, typically in non nautical sources. It is the method currently taught by the Boy Scouts of America. The earliest Boy Scout Handbook to include the taut line hitch was the 5th edition, published in 1948. However it illustrated #1855, the variant shown above. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half hitch around the standing part. Continue with another wrap inside the loop, effectively making a round turn around the standing part. Complete with a half hitch outside the loop, made in the same direction as the first two wraps, as for a clove hitch. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary.

Based on Magnus hitch #1736, this is exactly as above but with the final hitch in the opposite direction. It can be more tricky to snug up, since both lines emerge from the same side of the hitch, but it has less tendency to twist under load. Pass the working end around the anchor object. Bring it back alongside of the standing part and make a half hitch around the standing part. Continue with another wrap inside the loop, effectively making a round turn around the standing part. Complete with a half hitch outside the loop made in the opposite direction than the first two wraps, as for a cow hitch. Dress by snugging the hitch firmly around the standing part. Load slowly and adjust as necessary. This is the form most commonly used for aircraft tie down. One taut line hitch is tied 15–30 cm from the aircraft and adjusted for tension, then a second taut line hitch is tied 5–20 cm further from the aircraft and finished with a half hitch. Wind induced lift tends to pull the knot tighter, gust induced oscillations tend to damp out, and once the half hitch is undone, pushing the lower working rope up easily releases both hitches even amid icing.

Once snug and set, the hitch can be adjusted as needed. To tighten the line with respect to a load attached to the standing part, the user can grasp the standing part with one hand inside of the loop and pull toward the anchor object. The hitch may be grasped with the other hand and as slack develops within the loop, the hitch slid away from the anchor object, taking up the slack and enlarging the loop. To loosen, the hitch may be slid toward the anchor object, making the loop smaller and lengthening the standing part.