The Constrictor Knot

[JerseyCity Frankie]

I’m a big fan of the Constrictor Knot. It’s a very useful knot for fixing a line to a spar such as in the case of a stay or backstay attaching to a topgallant masthead on small models or on lighter lines on larger models. Its got a low profile and its easy to tie and when tightened it constricts as advertised. Clifford Ashley apparently invented it and its number 1249 in his book. It’s also mentioned in the original Ship Modelers Shop Notes in a Merritt Edson essay on page 187. Unfortunately the illustration included in Shop Notes tends to make the knot look difficult to tie. In fact most descriptions of the knot fail to show how easily it can be tied. Its litterly just a loop that is twisted once into a figure eight and the two lobes thus created are folded together to form the knot which can be slipped over the end of the spar in question. If the knot has a drawback it is that once tightened it can be very difficult, if not impossible, to untie. This photo shows the steps involved in tying it and below I will break down the individual steps. It may appear complex but it really boils down to a few simple hand moves.

[JerseyCity Frankie]

It’s a natural for ship model builders in that you can tie it in your hands even in very small line. In these photos I’m using heavier line in order to make it visible. First form an overhand loop. Note that in the photo there is a prominent loop and the two ends of the line. For the purposes of this demonstration you should think of the two ends of the line as a horizontal bar that will always remain straight. This imaginary bar is never manipulated with the fingers, only the loop is involved in tying the knot.

[JerseyCity Frankie]

The hardest part of tying the knot: twist the loop into a figure eight. With the left hand you flip the bottom left part of the loop, say 7:00 on a clock face, up to the 11:00 position which forms two lobes. Note that the left hand is "under" the "bar".

[JerseyCity Frankie]

Pull the left hand lobe under the bar leaving the right hand lobe over the bar.

[JerseyCity Frankie]

The final move is to fold the right hand lobe down OVER the bar using the twist you put in the original loop as the hinge. So you form a loop, twist it once, and each side of the loop is folded over each sides of the “bar”. Now you have the finished knot and you can drop it over the end of whatever spar you want to tie it around. Tighten by pulling on both ends of the "bar" at the same time.

[Ulises Victoria]

Interesting! Would it be too much to ask to see photos of the knot used in a practical application, such like those you describe?

 

Thanks in advance.

[JerseyCity Frankie]

Here is the finished knot drawn up on a cylinder. Its nearly the same knot as the Clove Hitch but it stays tight when you pull on the ends and I actually find it easier to tie. If your tying a pair of shrouds or backstays you can tie it in the center of the line and the ends can lead port and starboard. 

[capnharv2]

Thank you for the photos! I'm a big fan of the knot too-except I've never been able to tie it. Now, at least, there's hope.

 

One good use is as a temporary seizing. Clove hitches can slip-this won't.

 

I've seen it used on broken tillers to hold them together.

 

Harvey

Edited October 23, 2013 by capnharv2

[Ulises Victoria]

Thanks. I see it now.

[SteamWake]

Huh end result looks like an over/under double half hitch.

 

Never seen that one, thanks!

[pompey2]

I use this know quite a bit. Often for the first ratline to shroud knot being more secure that a clove hitch.

In those instances you dont have a free end (ie spar end) to drop the know over.

But it is pretty easy to tie the clove hitch first, then pass one end (of the ratline in this example) back through the knot.

I dont have access to anything at the moment to show where the line passes through the knot but the animated knots site shows it.

 

Nick

[jud]

About half the time that I use a clove hitch, I can tie it and throw it over the end of something, or to make a temporary halter from a rope by twisting the large loops around each other once and adjusting to fit, a half hitch once on will keep it in place if you expect a storm. learned that from an old cowboy when I was a kid and he had me tying the clove hitch using two hands without using the ends of the rope. Lay the rope over your right hand holding with your thumb, palm up. Left hand, palm down, thumb pointing away from the body, holding the rope so it runs under the left thumb straight out to the right through the right hand. Now twist both hands counter clock wise and lay the loops together and you have a clove hitch, The crossings will be down, but playing with the constrictor knot discovered that you can turn the crossings of the clove hitch up, then tuck the end coming out to the right under the inside loop, closest to the body clove hitch loop, and turn it into a constrictor. Once the movements become automatic in taking a hold of the rope so you can twist counter clock wise, tying the clove hitch and the constrictor can be done quickly. Now I need to find a way to tie the constrictor around  a pole or ring.

jud