Wet Rope Strength

A wet rope is not dangerously weakened for rappelling compared with a dry rope.

Wet rope strength.

Test 2 is the wet test with figure of eight knots. Test 1 is the dry test with figure of eight knots. Any bend tighter than 4 reduces the strength of rope because they stress the rope in flexure the fibers weaker direction. Manufacturers results for knotted tensile strength throwbag rope values with an overhand knot.

Static strength is most important when rappelling and ropes can have up to a 30 percent strength loss there. One boater will talk about tensile strength while the other will talk about working load. In sterling s tests an 11 mm drycore rope held 11 falls dry and seven falls wet. Strength is the tensile strength from the manufactures specifications without knots.

Each of these measurements has different uses and here we re going to give. But again for toproping this isn t an issue. A wet rope is not dangerously weakened for rappelling compared with a dry rope. Static strength is most important when rappelling and ropes can have up to a 30 percent strength loss there.

But a wet nylon rope is also weaker than a dry one. According to sterling rope a non dry treated rope can lose 70 percent of its strength and a dry treated rope can be 40 percent weaker when wet. Rope strength is a misunderstood metric. However when wet it is possible to see as much as a 70 percent reduction in dynamic performance which is important when taking a lead fall.

Both of these are important measurements and it s worth learning how to measure and understand them.