Ashley No. 2242, Prolong Knot

Day 348: I went and put my foot in it. Talking to the Hobby Hall officials at the Puyallup Fair, I mentioned that I'd like to put in a display of marlinespike seamanship next year without considering the fact that I've given away most of the work I've done. Now I'm up against it: I have to produce the goods! To that end, I'm starting big with a Prolong Knot mat which will be the central feature of the display.

The Prolong Knot is so named because it may be extended indefinitely by adding additional bights in multiples of three. The minimum number of bights for a Prolong is four; subsequent additions give 7, 10, 13 and so on. It is a fairly simple knot to double (here doubled three times) for a nice doorstep mat. "Doubled three times?" you ask. "Don't you mean quadrupled?" No, doubling is the term for retracing the route of the rope, and each time the rope repeats its path, it is said to be "doubled again," thus when four complete circuits have been made, it is said to have been "doubled three times" (the original knot and three repetitions).

This particular mat measures 18" x 9" and required forty feet of 3/8" sisal rope to manufacture. It took about two hours to complete. A single knot is worked loosely at first, and then as it is doubled and redoubled, excess rope must be worked out until it is nicely formed and lays flat. Upon completion, the raw ends of the rope are seized (wrapped) and stitched into place on the reverse. In more compact work, a pointed metal tool called a marlinespike (marlinspike or marlingspike) is used to adjust the rope, hence the name "marlinespike seamanship," i.e., the sailor's art of knot-tying. There are a number of books available on the subject, but the Ashley Book of Knots is considered to be the ultimate reference.