This knot is used by firemen in case of fires, for example imagine a scene where the ladder on the firetruck messes up, but people need to get down a five story building or more. All they have is a long piece of rope, they can safely get down with a secure knot like the fire-escape knot. So, why not learn it, it's easy to do, and hard to untie if you tie it tightly.
This is from the American Boys Handbook.
Step 1: Get Your Rope
First grab a piece of rope, and bend it like this to make a loop in it. Follow every step to the smallest detail.