fire-escape knot

Noun

 * 1)  A series of evenly spaced overhand knots in a rope, which make it more secure for climbing or descending. Often used for fire escapes and jib boom foot ropes on rigged sail ships. Also known as the Philadelphia knot.

Usage notes

 * Although a series of knots, it is referred to in singular because the series is initially tied as one repeating hitch knot pulled out to form the series.