Tip for untying jammed knots
Posted On: 2020-08-15

How to Untie Tight Knots

Are you looking for an easier way to untie jammed-up knots?  One way is to quickly twist the parts of the rope just outside the knot back and forth as you push in slack.

The reason this works is because of the phenomenon of compound sliding.  For an example, set a book on a slight incline on which the book will stay put.  Now, start pushing the book sideways with a
pencil, and you'll notice that it'll start sliding down the ramp even though it couldn't before.  Friction forces act opposite of local relative velocity, so tranverse motion takes very little force to occur.

This also accounts for why it is easier to insert a plug gage in a hole if you twist as you push.

Therefore twisting rope going into a jam back and forth will help the rope give slack where you need it.

(It also helps to avoid jam-prone knots to begin with, such as the overhand knot, the overhand loop, the figure-eight loop, the fisherman's knot (water knot), grapevine knot,  and others.  An ounce of prevention…)