Question 1

Why is nylon rope generally preferred for anchor rodes and mooring lines, rather than polyester (Dacron)?

Accepted Answer

Nylon stretches significantly under load, absorbing shock loading from waves and snubbing — exactly what's needed to protect ground tackle and cleats from sudden jerking loads Nylon's elasticity is the whole point for anchor and mooring use — it stretches under a sudden load (a wave lifting the bow, a gust snatching a mooring line) and absorbs the shock rather than transmitting a sharp jerk straight to the cleat or anchor. Polyester's low stretch is actually why it's preferred for halyards and sheets instead, where you want minimal stretch for sail control.

Question 2

You need to make up a mooring line to leave permanently rigged on a cleat. What is the correct way to secure it so it can be released quickly under load if needed?

Accepted Answer

A full turn around the base of the cleat, then figure-of-eight turns across the horns, finished with a locking hitch — this holds securely under load but can still be freed even when the line is under tension A round turn plus figure-of-eight turns finished with a locking hitch is the standard cleating method — it grips securely under load through friction, but because it isn't a jamming knot, it can still be released even when the line is under real tension, unlike a line simply wrapped or a knot that jams tight.

Question 3

What happens to a rope's breaking strength at a knot compared to its rated straight-line breaking strength?

Accepted Answer

A knot can reduce a rope's effective breaking strength significantly — often by a third or more, depending on the knot and rope type — because the tight bend concentrates stress unevenly across the fibres Every knot reduces a rope's effective strength to some degree because the sharp bend loads the outer fibres far more than the inner ones, rather than sharing the load evenly the way a straight pull does. This matters most with high-strength ropes like HMPE, where the loss at a knot or splice can be dramatic and isn't always obvious from the rope's straight-line rating alone.