This is going to be a bumpy ride. It has been debated for years and lately the argument has been heated. So, I guess it is my turn to throw my hat into the ring and see how much backlash I get. This is still something I am researching so please let me know of any reliable resources that you might shed further light on this topic.
Lets start out with a metaphor. Two cars: a minivan and a sporty convertible. One is known and loved. It has room for 7 in its roll cage and a reliable yet sluggish automatic transmission. The other is not as widely used but often coveted. It has a drop top and a zippy 6 speed manual. Assuming that both vehicles are in brand new condition, which one is safer?
The Figure 8 and Double Bowline cage match has picked up some steam with the recent accident involving John Long and an incomplete bowline knot. Many have taken the pulpit and proclaimed that the Double Bowline is a dangerous knot and should be banned from climbing gyms. Let's look at the arguments...
The Case Against the Double Bowline:
Strength- The Double Bowline knot technically weakens the rope more than a Figure 8 (*Numbers vary but all concur that the Figure 8 weakens the rope less.)
Simplicity- The Figure 8 is easily recognizable and therefore easy to check giving climbing partners a no-brainer check. The Double Bowline seems more complicated to check and may confuse a climbing party making it difficult for partners to correctly double check.
Safety Record- The properly tied figure 8 has, to my knowledge, a 100% safety record while the Double Bowline has at least been associated with several high-profile climbing accidents.
In Defense of the Double Bowline:
Strength- All knots weaken the rope by a certain percent, some more than others. Even by having a higher percentage of rope weakening, the strength of a well-maintained rope terminated in a Double Bowline is still well within the range of acceptable safety.
Simplicity- Some might argue that the Double Bowline is in fact a simpler knot to tie (one can do it without looking) and, after untying, it does not leave any knot in the rope to get snagged in anchors when pulling it after a lead. Climbing partners do question it when they don't understand it. But shouldn't that questioning prompt deeper investigation of the correctness of the tie-in point and therefore a more thorough double check?
Safety Record- While the Double Bowline has been accused of associating itself with climbing accidents, I have not been able to find one documented case of a properly tied and backed up Double Bowline failure. John Long and Lynn Hill both attribute their falls to not completing their knot, which could happen with any knot if the climbing team is distracted.
The THEORIST in me looks at the strength, the safety record, and the foolproof nature of the Figure 8(it even works moderately well when not finished) and quickly comes to the conclusion that it is the only knot that anyone should ever use for climbing. Using any knot that has inferior stats would be dumb.
However, my inner PRAGMATIST has a slightly different opinion. I know that in climbing, different challenges call for different solutions. I know that all knots have advantages and disadvantages. I know that each knot has a unique set of features that could be handy in certain scenarios. (For example: In joining two rope for rappel, the EDT weakens the rope by around 50% but is skilled at avoiding flakes and cracks) Maybe there is a time when the features of a slightly weaker knot could be advantageous?
So, which knot do I use? I use both depending on the type of climbing, terrain, partners, weather, and rope. I use the Figure 8 in prolonged climbing situations, or when I have new partners, or when the rope is thick or frozen. I use the Double Bowline for shorter climbs, with pliable ropes, experienced partners, or when I am going to be pulling rope through a fixed set of anchors so I don't forget to undo my starter knot. IT DEPENDS.
Which Car is Safest?
Obviously the safest car is the one left in the garage. But climbers are creatures of action; sloth does not become us. We need to choose one car to get to the crag. Even the minivan with the five star safety rating could be operated by a texting teenager, and the relatively more dangerous convertible captained by an incredibly alert and responsible motorist.
At the end of the day, I would argue that, all other things being equal, the safest car is the one with the best driver.
*Please feel free to contact me if you are aware of any resources that might help shed light on this issue. Lets continue the conversation as we learn together.
Climb Smart MN is a grassroots approach to climbing education based on community and charitable giving. For information on donation based climbing lessons visit ClimbSmartMN and follow us on Facebook. With over ten years of climbing instruction, coaching, and guiding experience, Chris Hesselbein strives to better the climbing community through personalized technique and safety education.