A knot that has been in a rope for over 6 months can cause a real danger. This situation can be a real issue as a knot that’s been in a rope a significant amount of time really weakens the rope if untied.
As you untie a knot that’s been in a rope a long time the rope section where the knot was will remain bent and curly, this is where the weakened rope will be and it will retain a residue memory of the knot, this could cause a mid rope failure if not managed correctly.
Cowtails are a good example of this situation, most people don’t adjust these knots and so they remain in the rope in the same place for months or longer, this is OK as far as the strength of the knot is concerned however you should be untying the knots at least every 6 months to inspect the section of rope.
The moral of the story is regularly move a knot or simply re-tie it each day!
