The hows and whys of tying in with a Bowline

Ondra Dawn Wall

Bowline enthusiast Adam Ondra, shown here getting super-psyched about bowlines (Photo by Heinz Zak)

If you’ve ever wept tears of inadequacy onto a welded knot after a big whipper (or a series of smaller ones), you’ve probably wondered if there’s a better alternative than the ubiquitous Figure 8. Some climbers opt instead a variation of the bowline, but as an alternative, is it superior? The answer is the same as with many climbing conundrums – it depends.

Although bowlines have been used for centuries (maybe even millennia) in nautical applications, it’s use in climbing is something of an anomaly. This rarity has occasionally created a certain brand of stigma and even led some to denounce the bowline as a death knot. That’s not necessarily true – while the standard bowline is indeed unsuitable for tying in, there are certainly variations which are safe and effective.

But which variations? And why? The internet is pretty much the Wild West in terms of reliable technical information on climbing techniques, more of a repository of opinions than facts. For what it’s worth, let’s try and wade through this particular quagmire and see if we can’t shed some light on this most ancient of climbing questions – should you tie in with a bowline, and if so, which bowline is best?

For reference, I have relied heavily on An Analysis of the Structure of Bowlines by Mark Gommers of PACI (Professional Association of Climbing Instructors). This is a very thorough treatise by a passionate knotsman, so if you’re looking for a more in-depth analysis, you can download his masterwork on the subject here as well as other similar technical manuals. My article is an attempt to condense and summarise this information for the layperson, and I welcome any corrections, inclusions or amendments.

What is a Bowline?

Before we go any further down the rabbit hole, let’s define what we mean by the term “Bowline”.

Even The Ashley Book of Knots, which is considered by most knot aficionados to be vastly more sacred than the Holy Bible, is a little vague on defining exact characteristics of bowlines. These days, experts largely agree that a bowline (or variant thereof) is defined by three essential components:

  • A Fixed Eye (which does not move, as compared to a slipknot)
  • A collar (which captures the standing end), and perhaps most importantly,
  • A nipping loop (which is free to compress with application of load)

In general, when people refer to a “bowline”, they refer to the “standard bowline” as seen in the image above. This knot carries the designating number of #1010 in the Ashley Book of Knots. and was invented for maritime purposes, not climbing. In the interest of disambiguation, this article adopts the following conventions – that “a bowline” refers to any type of knot sharing the characteristics mentioned above, whereas the “standard bowline” refers specifically to the #1010 knot . Variants will be referred to by their respective titles.

What are the advantages of bowlines?

The main advantage of bowlines in a climbing context is that they are easy to untie even after significant loading. Gommers observed that the collar of the End Bound Single Bowline (EBSB) was able to be manipulated under 10kN of force, which is to say that you can place a metric ton of force on the knot and still shift the collar by hand. By way of comparison, a Figure 8 will jam when force on the knot exceeds 4kN.

This means that, for all intents and purposes, the knot is easy to undo under any and all scenarios to be expected in a lead climbing context. I propose that if you have generated a force up to or exceeding 10kN during a fall, you probably have bigger things to worry about then how welded your knot is.

What are the disadvantages of bowlines?

The major disadvantage of the standard bowline is that lacks the security of the Figure 8, given that it has a tendency to work loose unless kept under constant tension. This, of course, is common in a climbing scenario, where the knot experiences alternating periods of tension and slackness, otherwise known as cyclical loading.

The way around this problem is to tie a more secure and stable variant. There are a few, and we’ll examine them in detail soon. The disadvantage to these knots is that they are often harder to tie and harder to inspect. Given that most climbers are more familiar with the Figure 8 as a tie-in knot, most belay partners will generally have no problem identifying faults at a glance. The same can’t be said for bowlines with their seemingly endless variations, and therefore the use of these knots to safeguard a fall carries a higher level of personal responsibility and risk for the user. That said, self-reliance is a key attribute in the sport of climbing, and those who are confident and practiced in tying a bowline should feel no reluctance in its use.

Are bowlines strong enough for climbing applications?

In a word, yes. Some have made spurious claims as to the inherent weakness of bowlines, but it should be remembered that all knots weaken cordage to some extent. During his relentless examination, Gommers tested the breaking strain of the EBSB and observed it to be approximately 75% as strong as the minimum breaking strength of the cordage as quoted by the manufacturer (Sterling, for those playing at home). When compared with the Figure 8, which has been observed by many tests to be 75-80% as strong as the minimum breaking strength, this represents slim to no difference. Nothing to see here, folks.

What are the methods of failure?

There are two main methods of failure with the standard bowline, and these methods of failure can help point us in the right direction when deciding which variants might be more suitable.

The first is when the tail works its way through the knot, either by cyclical loading, ring loading or slack shaking, all of which occur in varying amounts during climbing. The second is through rupture or failure of the nipping loops. Of the two, the latter is a less important consideration given the strength assessments made above, but it is still worth note. Bowline variants which are suitable for climbing solve both problems by some combination of the following methods:

  1. Securing the tail (either by virtue of the knot itself or in conjunction with a Double Overhand AKA Half Fisherman’s)
  2. Showing resistance to ring loading
  3. Increasing the number of strands captured by the nipping loop (which increases friction on the tail, as well as increasing the radius of the loop and thereby lessening the stress caused to cordage by sharp bends)

Only “secured” bowlines should be used in life-critical applications, and the standard bowline is not one of these. By definition, any knot that requires additional tail manoeuvres (e.g. tying a Double Overhand) to lock down the structure is not inherently secure, and only those which are inherently secure by virtue of the knot itself are suggested later.

There has also been a proposed method of failure in which the collar “capsizes”, similar to the failure method observed on the Offset Overhand Bend (AKA Euro Death Knot). This, however, has not been observed and replicated in any manner which would conclusively confirm this method.

Which variations are suitable for climbing applications?

Let’s take a look at which bowline variants which have been proven to be stable and secure. All offer ease of untying after loading, and therefore they present themselves as viable alternatives to the Figure 8.

Scott’s Simple Lock Bowline

Scott’s Simple Lock Bowline

Source: An Analysis of the Structure of Bowlines, Mark Gommers

Lee’s Locked Yosemite Bowline

Lee's Locked Yosemite Bowline

Source: An Analysis of the Structure of Bowlines, Mark Gommers

End Bound Single Bowline

EBSB Bowline

Source: An Analysis of the Structure of Bowlines, Mark Gommers

Each of these bowline variants has been tested and shown to be secure… but that doesn’t mean you shouldn’t test them yourself! Before trusting your life to any of these knots, you should verify their efficacy in a safe environment and ensure that you are thoroughly familiar with their construction.

Look, should I tie in with a Bowline or not?!

Personally, I still use a Figure 8. It’s not because of any prejudice or phobia, it’s simply what I know best – I am confident that I can tie a Figure 8 correctly, even when I’m exhausted and it’s dark and there are boogiemen around. But that all comes down to muscle memory and familiarity. If you’re committed to forming that same familiarity with a secure bowline variant, then there is no good reason you shouldn’t.

If the style of climbing you enjoy most doesn’t involve regular falls (e.g. ice climbing, mountaineering, adventure trad), you probably don’t need to make the change. But if you find yourself climbing hard sport and projecting a great deal, you might find a bowline to be a superior choice.

Ryan Siacci, Esq.
February 2019

Remember, folks – climbing is dangerous! The above information should not be considered a definitive work, but rather an overview. Mistakes and omissions are possible, and the use of the information contained in this document does not imply responsibility to the author for death, injury or harm that may result. Always test your knots before use and consult a professional climbing guide for guidance.

2 Replies to “The hows and whys of tying in with a Bowline”

  1. Great article Ryan, really enjoyed the read! You mentioned this in passing towards the end, but I’ve not heard of it being studied in detail – how vulnerable are the different tie-in knots to misidentification/incorrect tying? Has anyone attempted to quantify failure rates through incorrect knot tying by knot type?

    1. Thanks, I’m glad you enjoyed it! I generally write whatever nonsense I feel like writing, so writing technical stuff with researching and fact checking is much more time consuming, but the results are rewarding.

      Your question is a very good one. Reliable climbing data is thin on the ground, and my guess (without actually knowing 100%) is that the reliable data on that particular chestnut will probably not exist. Leave it with me and I will see if I can uncover anything useful! Thanks for the idea 🙂

Thoughts? Opinions? Cries of dissent?