Rock Climbing Knots: The Double Bowline Vs. the Figure Eight
Since its beginning, roped climbing has been dependent on the art of knots. While there is a great amount of literature demonstrating how to tie knots, specifically for boy scouts and sailors, there is not much research about the safety of knots specific to rock climbers. Although a climber’s relationship with a knot can be as simple and inconsequential as lacing up his or her approach shoes, a climber's life depends on the reliability of his or her tie-in (the knot linking the rope to the climber’s harness) and other knots used in anchor building. This article will focus specifically on two of the most common tie-in knots.
Double Bowline or Figure Eight?
You’ve probably realized that there are a few different knots that climbers use to tie in: mainly the figure eight and the double bowline. But which is better, safer, more reliable?
You could spend hours mining mountaineering and climbing forums for an answer, but you'll quickly come to realize that these forum commentators repeat themselves A LOT and that no one seems to have any real proof or data except "I use it and I haven't died yet." Occasionally they provide a link to a source that mysteriously no longer exists. So which one wins the seemingly deadlocked debate, the double bowline or the figure eight?
Do you prefer a double bowline or a figure eight?
Every knot, no matter how perfect, weakens the rope. Some knots are considered stronger than others in that they do not cause as much uneven stress on the core of the rope. A rope almost never breaks within the knot itself, but at a point just outside of the knot where the weight load of the knot is actually distributed.
The figure eight is a stronger knot than the double bowline, but the double bowline is still more than strong enough to protect a climber on reasonably safe equipment. We need to take into consideration other factors besides knot strength in order to make a choice between the two.
Pros and Cons
The Figure Eight
Very likely you were taught to tie in with a figure eight when you first began climbing. Most guides and instructors will teach this knot to beginners because:
- it is easy to visually check to see if it is tied correctly
- it will usually still protect the climber if it is tied incorrectly.
Some of the disadvantages of the figure eight are that:
- it takes two steps to tie and untie
- the knot can be difficult to untie after working a route or taking a lead fall.
The Double Bowline
Many experienced climbers swear by the double bowline. These double bowline converts love that the knot:
- is easy to untie, even after taking a large lead fall,
- absorbs more energy in the event of a fall making for a softer catch and less wear on the rope,
- they don't have to remember to take out the figure eight before pulling the rope through after a lead pitch.
Some concerns about the double bowline are that:
- it may possibly untie itself (though many people believe that this can be avoided by tying a water knot just above the double bowline),
- it is more difficult to tell if it is tied properly at first glance,
- if the double bowline is tied incorrectly it would offer no protection to the climber.
Many climbers are mistrustful of the double bowline, and you will hear various fears about the safety of the double bowline that are largely unsupported by research. I believe a lot of the fear comes from a basic confusion: the bowline in its simplest form is not safe for climbing. However, the double bowline is a safer variation of the bowline.
For an article all about bowline variations, and a variation that the author believes is even better than the double bowline or “Yosemite” version, click here.
So Which is Better?
Sorry for those of you who need a definitive answer, but I have to conclude that the choice between the double bowline and the figure eight is a matter of preference. While both knots are safe and acceptable for almost all climbing situations, I would say that the figure eight is overall safer than the double bowline, especially for beginners. However, there are many advantages to the double bowline for lead climbers and the safety rating is well within the range of acceptable risk.
Unfortunately, there are a lot of myths and not much peer reviewed research on these knots under the pressures they would likely endure in a typical rock climbing belay system (dynamic force, such as a fall, as opposed to static force). Most of what has been tested is the strength of the knot, which is only one of the safety factors to consider in a knot. Even more disturbing is the shadyness of the research that is available to the climbing public. Here are some of the sources I took information from.
Great Literature About Tying Climbing Knots
I highly recommend this easy to follow, superbly written and illustrated guide to knots. It is by an experienced climber and it's perfect for all levels of climbers. Chances are that you do not know all 35 knots that rock climbers should know!