Does A Figure-Eight Knot Maintain Its Strength When Wet?

Water Resistance and Knot Performance

When exposed to water, the fibers in a figure-eight knot begin to swell, causing the knot to lose its tightness and strength. This is because water molecules penetrate the fibers, causing them to expand and lose their elasticity. As a result, the figure-eight knot is no longer able to withstand the same amount of load as it would in dry conditions.

Testing Knot Strength in Wet Conditions

Studies have shown that the figure-eight knot can lose up to 50% of its strength when exposed to water. In a study by the British Mountaineering Council, the figure-eight knot was tested in both dry and wet conditions. The results showed that the knot was able to withstand a load of 150 kg (330 lbs) in dry conditions, but only 75 kg (165 lbs) in wet conditions. This significant loss of strength highlights the importance of using a knot that can maintain its integrity in wet conditions.

Alternatives to the Figure-Eight Knot

For applications where the knot will be exposed to water, it is recommended to use a knot that is more resistant to water absorption, such as the bowline or the sheet bend. These knots are designed to maintain their strength and integrity even when exposed to water, making them a better choice for applications such as sailing, rock climbing, and search and rescue.