This article is an in-depth look at caving cowstails used for SRT. There is a huge variety of carabiners, ropes and knots to consider, as well as the different styles of knotted and stitched lanyards. I have written this page to focus on the ‘normal’ unequal length, twin-leg cowstails that are commonly used for UK single rope technique in caving and mine exploration, but there are still variations on these from person to person. I’ll discuss the broad choices we are faced with for each element, and cite sources or link to other websites for more information. Where I have a personal preference I will state it as such and explain why. There are all sorts of reasons why a reader may choose to deviate from what I show here, but that is for the experienced user to decide based on their preferences and intended uses. For anyone looking for general info on cowstails for their SRT setup, then this article is aimed at you. There is an accompanying ‘how to’ video for this post which is down towards the bottom of the page.

What We Use Cowstails For In SRT

The use of cowstails for caving and mine exploration can be generally split down into 3 headings; Protection, Progression & Positioning.

Protection

Simply put, the cowstail is a link between our harness and the rigging or other anchor point. Should we slip or lose our grip when moving around at height, the cowstail connects us to something and prevents us taking a fall. During rescues or some SRT manoeuvres, we might rely on the cowstails for our protection as we remove or reposition other items of our SRT kit from the rope.

Progression

When progressing along a rope traverse, or between anchor points, to remain safe from the risk of a fall we will need to ensure we always have at least one attachment. A single cowstail would need to be unclipped and reclipped, leaving us exposed to a fall if we slipped during the transition. The use of two cowstails allows us to move one to the new anchor point while the other remains attached to the previous anchor, meaning we are never completely disconnected when at height.

Positioning

One of the biggest differences between vertical caving and rock climbing is that cavers hang on their kit as part of normal use. Climbers will only do so if they fall, as pulling on your rope or anchors is generally considered cheating! Cavers hang on their ropes, bolts and cowstails to get around the environment they are in and limit the chance of a fall occurring whenever possible. The SRT kit is designed to be hung on in use, including the cowstails. This is essential for some rope manoeuvres, and makes steep or hanging traverses less strenuous.

Cowstails are used during access to and from pitches and across traverses. We also use them during mid-rope manoeuvres like rebelays and knot passes. I’d suggest that if you’re not yet familiar with the ways a cowstail is used during SRT then you are best investing your time in structured training before coming back here to consider what cowstail is best to buy. Understanding how they are used will inform you of what option might be best for you.

Falling Onto Cowstails

Avoid it if you can! Right, let’s get this out there straight away. The only way to eliminate all risk of dangerous impact forces on the human body, or injuries resulting from swinging into the rock, is to never get into a position where you can fall any significant distance onto your cowstails. Whenever we are able to, we will hang on our cowstails, but this is not practical or possible in some situations or manoeuvres. We therefore need to recognise the limits of what we can safely do with our cowstails. Summarising this in a few paragraphs is not easy and will necessitate some generalising.

It’s not the fall that kills you, it’s the stopping. The shorter the distance we have to decelerate in, the greater the Impact Force. Hitting concrete or rock at the bottom of a fall will result in a very rapid deceleration and if the potential energy of the fall is high enough, a catastrophic Impact Force will occur. Falling onto your cowstails and being caught by a harness is also potentially a rapid deceleration event. To keep potential Impact Forces to safe levels we need to limit the distance that we could fall onto our cowstails, and use a cowstail setup that would be safe if we were to fall the small distances that cannot be avoided. The accepted teaching in the caving world is that cowstails should never be used in a situation above Fall Factor 1, and ideally always below that. Practically this means that we should always be positioned below the anchor that our cowstails are attached to.

The French caving school EFS conducted a series of drop tests on different types of cowstails in 2006. This has been translated into English and can be viewed or downloaded from the link below. The table is taken from page 31 and is the average results for drop tests at FF1 with an 80kg mass using comparable 11mm rope (except the webbing cowstails). Where the table states a ‘Barrel Knot’, this is a Poachers Knot variation with 2 turns. There are more details about the knots later in this article. For context, 6kN is the maximum ‘safe’ force a user is permitted to receive when using Fall Arrest equipment during Work at Height activities in the UK.

Cowstail Variation (using 11mm dynamic rope)	Average Force from test results at Fall Factor 1 when dropping an 80kg mass
Figure of Eight Knot – Barrel Knot	5.64 kN
Figure of Eight Knot – Figure of Eight Knot	5.75 kN
Overhand Knot – Barrel Knot	5.90 kN
Overhand Knot – Overhand Knot	6.44 kN
Sewn Loop – Barrel Knot	6.52 kN
Sewn Loop – Clove Hitch	6.81 kN
Sewn Loop – Figure of Eight Knot	7.30 kN
Sewn Loop – Sewn Loop	9.00 kN
Petzl Spelegyca Webbing Sewn Cowstail	10.99 kN

For a fall factor 2, there were fewer tests done during this project, but the cowstails made entirely from knotted rope produced the lowest forces compared to stitched ones.

Bob Mehew and Roy Rodgers have been conducting tests on cowstails for years using the BCA drop tester and static rigs. They are in the process of preparing this data for publication and I will add links to this once it becomes available. From what I have seen of it, the performance of knotted cowstails in their results is consistent with the EFS test results, and I do have permission to share one chart from their draft report. This shows the peak force for cowstails made from different knots when dropped at FF1 three times in succession. The ‘Barrel Knot’ is the 2 turn Poachers Knot described later in this article. Note that all the first drops produced a force of under 6kN.

What about the minimum breaking strength of cowstails, is this something we need to be concerned about if we can fall onto them? Well yes, but mainly no. Providing the equipment we use to construct our cowstails is designed for what we’re doing with it, we use it in an appropriate way, and retire it before it becomes overly worn or damaged, then the ultimate breaking strength is not something that we need to be concerned about for normal use. It will certainly be a higher force figure than is safe for us to receive on our body. The weakest item is always the pink squishy user wearing it. Safety equipment like ropes, carabiners or cowstails need to be sourced via a reputable retailer or manufacturer. In the UK there are product safety standards that goods need to meet to ensure they are safe for their intended use. For PPE that is designed to protect us against serious injury or death, the items will also need to have been independently assessed to meet those standards by a Notified Body. Achieving this certification allows the manufacture to put a CE or UKCA mark and safety standard (usually ‘EN….’ or ‘BS EN….’) on the item. In order to trust the legitimacy of the markings and given specifications for the items we use, we must trust the source. Buying from open marketplaces like eBay and Amazon is a risk, so go to a trusted retailer of caving gear or check if your intended retailer is listed as an official stockist for that brand. Cheap gear is tempting, but you have to ask why is it so much cheaper than other brands? Don’t trust your life to bargain knock offs, get legit kit and use it correctly and then you don’t ever need to worry if your tails (or harness, or carabiners, or ropes….) are strong enough.

Types of Cowstails

Most cavers will create their own bespoke set of cowstails from rope and knots, but there are some who use manufactured lanyards with stitched terminations. Here I’ll talk about the different types of cowstails and lanyards that are currently available, and whether they might be appropriate for SRT use.

Lanyards With Shock Absorbers

For large falls (above FF1), there simply is no safe way to catch the body without the use of full body harnesses and dedicated energy absorbing devices like Fall Arrest (EN355) or Via Ferrata (EN958 / UIAA 128) Lanyards. In UK industry, the safety standards that cover work at height lanyards limit their length to a maximum of 2m (EN355). Lanyards designed to arrest a fall must be able to limit the energy transmitted to the body via a full body harness to under 6kN. This force is still high enough to hurt and cause some bruising, but is generally not enough to cause significant injury. Fall arrest lanyards must keep the user under 6kN even when they take the largest possible fall that could be taken on those lanyards, which is 4m if using a 2m lanyard (Fall Factor 2). In order to pass certification, these fall arrest lanyards include a force dissipating element, known colloquially as a ‘shock pack’. This is a webbing device constructed in a way that tears apart in a predictable way when it hits a trigger force and gives a greater distance to decelerate in. This trigger force (c 2kN) can be reached in smaller falls at or below Fall Factor 1. When arresting a fall, these lanyards can potentially extend up to 1.75m beyond their original length. Via Ferrata lanyards operate on a similar principle, but conform to a different safety standard and have slightly different test requirements, but would be similarly impractical for caving use.

Both Fall Arrest and Via Ferrata types of lanyard are generally unsuited to caving use as they are expensive, bulky, require significant clearance heights to accommodate elongation during deployment, and are not normally designed to be hung from. Another consideration is that once it has deployed, the lanyard is then unsafe to continue to use, meaning you might be without a lanyard to exit the cave/mine.

Manufactured Stitched Lanyards

These are lanyards or cowstails that have stitched terminations instead of knots, although some might require a knot or hitch to attach it to the harness. These are becoming more common to see on SRT kits but it should be recognised that for many of these lanyards, we might be using them outside of their intended uses. Sport cavers can ultimately choose to use anything they want however they want, although I’d strongly advocate only using equipment as the manufacturer intended it to be used. For those LCMLA or CIC holders who go to work underground, we must ensure that we are using appropriate equipment as it is intended to be used, or risk the wrath of the insurance companies or regulators when something goes wrong.

When used appropriately, some stitched cowstails and lanyards are potentially suitable for SRT caving use, however there are some drawbacks to consider. Testing shows that knotted rope cowstails produce lower Impact Forces for the same falls when tested against stitched cowstails (EFS lanyard testing report). This extra shock absorption in knotted cowstails is in part due to the tightening of the knots, which the stitched lanyards do not have. So even with correct use, the stitched tails do not give the softest catch out of the alternative options available to us. Some models allow you to adjust the lengths of the 2 legs to suit the user, others do not. When the legs are fixed and not perfectly suited to you, this can compromise the efficiency of your manoeuvres or certain rescues. Another downside for many is the cost of stitched lanyards and cowstails like these. The price of fixed lanyards without carabiners can be 5 to 10 times greater than the equivalent amount of rope used to create knotted cowstails. On the plus side though, the manufactured cowstails are generally more compact on the harness D-ring, and the addition of an adjuster on one or both legs can make them very useful for hanging traverses, pitch heads and more advanced uses like bolting and aid climbing. I personally use a single leg adjustable lanyard to supplement my normal knotted twin leg cowstails for some trips and tasks.

Lanyards Designed For Sport Use

Dynamic rope or webbing cowstails that are manufactured for use in cave and mine exploration, canyoning, mountaineering, adventure parks, or as personal anchors in climbing, are not capable of dissipating significant Impact Forces. Sport lanyards conforming to the UIAA 109 standard (‘Belay Lanyards’) must be able to withstand forces generated in a Fall Factor 2 fall without breaking during their testing, but they have no shock absorber to reduce the force that reaches the user. In testing they only need to limit the peak force to under 10kN on the first test drop, which is potentially enough to break your pelvis or cause other significant injuries when using a normal caving sit harness. A Fall Factor 2 catch onto a cowstail will exceed the ‘safe’ 6kN figure, probably by quite a way. A Fall Factor 1 onto a stitched dynamic could also likely result in a force above 6kN (in laboratory testing with steel masses). In real use, the force would probably be less than the testing shows because the human body can deform, the harness moves, and the anchor point for the cowstail is often rope or a knot which can also absorb energy via stretching. At the time of writing, all of the stitched cowstails made of rope or webbing that are sold for sport use (including the adjustable type) that I am aware of, state the user must always remain below the anchor, i.e. under a FF1, and many state they must be kept taut during use. If you intend to use pre-made stitched termination cowstails for caving, you should always use them in a way that would keep the Fall Factor below FF1 or risk serious forces hitting your body if you did fall.
Many of the cowstails that fall into this category are only designed for use at a belay station or during an abseil with the user physically hanging on it during use. Some manufacturers produce twin lanyards that are approved for use on a lifeline or traverse, so we might consider some lanyards of this type to be suitable for use in caving. It is important to really research any stitched lanyard or cowstail before you buy it so that you know it is safe and approved for what you intend to do with it. The only lanyard that I am aware of specifically produced for caving SRT manoeuvres and progression along a traverse is the Petzl Spelegyca.

The Spelegyca is CE approved, but the Petzl website does not show which, if any, standards it conforms to. This does not mean it is unsafe, it just means that Petzl have defined the use and specification of it as an item of PPE, which has been approved by a Notified Body, but it has not been tested against a specific standard. Stitched webbing lanyards like the Petzl Spelegyca don’t have shock absorbers like EN355 Fall Arrest lanyards and the webbing itself is effectively zero-stretch. When compared with Dynamic rope (stitched and knotted) cowstails, they deliver a significantly higher Impact Forces in an FF1 test. When used under the anchor, or for positioning, as they are intended to be, the Spelegyca will be perfectly okay to use though and I don’t wish to give the impression that they are unsafe for caving.

Lanyards Designed for Work at Height

Rope lanyards produced for work at height either conform to EN354 or EN358 lanyard or positioning device standards.
EN354 lanyards are designed for static loading and are tested to ensure their minimum breaking strength exceeds 22kN. There is a dynamic test for this standard which involves a 100kg mass being dropped FF2 onto the lanyard. The lanyard must survive the test, but no forces are recorded. Forces in a fall like this could be significant and potentially fatal for a user.
EN358 lanyards are designed to support a user in suspension, or ‘Work Positioning’. They have to pass a static test of up to 15kN but have no slippage on adjusters up to 4kN. The dynamic test involves a 1 meter drop with the test weight and just like the EN354 lanyards, they only need to survive the drop and not break, with no forces recorded.
Just on the basis of the standards then, it would appear that no work at height lanyard conforming to these standards is suitable for caving use where a potential fall of up to FF1 might occur. However that is just the standard test thresholds and the lanyard might be manufactured to exceed those requirements. Some manufacturers do allow the use of lanyards like these on lifelines in their instructions and so we might consider some lanyards of this type to be suitable for use in caving. As stated above, you should research what you are looking at buying to make sure it is safe and approved to use in the way you want to use it.

Lanyards with Adjusters

Single and twin leg lanyards are available with length adjustment devices for both sport and work environments. These may be certified under a mix of UIAA 109, EN354 and EN358 standards, and their intended uses vary greatly. The inclusion of an adjuster on the lanyard leg does make these very attractive for use in caving if you can stomach the cost. Most adjustable lanyards are only approved for use for suspending the user, but some are intended for use when progressing on a lifeline or traverse. As with the other stitched lanyards and cowstails above, not all will be suitable for caving use but some may be so. It is important to select the right tool for the job. Lanyards with adjusters do not generally have replaceable ropes, so if you are using one of these and the rope wears out or becomes damaged, you will have to replace the whole item.

I have compiled some information relating to stitched lanyards with and without adjusters. The PDF table shows all of the variations that I could find and what use they are certified for and designed for according to the manufacturer’s website and user instructions. The table was put together in January 2024 and changes may have occurred since, so always consult the current manufacturer information for any product that you are considering for purchase.

Knotted Rope Cowstails

Stitched cowstails are certainly becoming more common amongst cavers, but cowstails formed from knotted rope are still the most popular and cost effective way to make a set of bespoke cowstails for use on your SRT kit. Having to ‘manufacture’ the cowstails yourself does mean that you need to understand what type of rope, knots and carabiners will be required. The available choice of components is large and can be confusing, so we will look at the requirements and options for each element separately below. If you are starting to put together your own SRT kit, then knotted rope cowstails are the best type to start with and hopefully when you have finished studying this section you will be comfortable to source and make your own set.

When comparing webbing, knotted rope and stitched termination cowstails, knotted cowstails consistently performed better on the first drop during testing. The knots tighten up during the fall and increase the extension of the rope during the catch, which results in lower Impact Forces compared to stitched cowstails. Regularly hanging on knotted cowstails will however cause the knots to tighten over time, so the periodic untying and retying of your knots is needed for this benefit to be retained. Remaining under the anchor during use will always be the best defence from high Impact Forces resulting from falls onto cowstails, but for the softest catch that we can realistically achieve, knotted rope cowstails are the best option.

Styles of Knotted Cowstails

Earlier I discussed the use of cowstails falling into the 3 broad headings of Protection, Progression and Positioning. How you put your cowstails together will affect how safe and efficient they are for doing those 3 things.

Protection of the user is mainly down to the correct use of the cowstails, i.e. remaining below your anchor, and that is best covered through practical training with a competent person like a caving instructor. Additionally, to make sure we have the right level of security we need to make sure that we are using suitable components to make our cowstails, and that is discussed more below.

Safe Progression between anchors relies on us having two cowstails legs that can be moved independently. These two legs could be made of separate sections of rope each attached to the harness D-ring, but it is more common to use a single length of rope to make one twin-legged set of cowstails. A carabiner is tied into each end of a section of rope, and a knot is used in the middle of the cowstails to attach them to our harness D-ring. The main advantage of this all-in-one style is that it uses less rope than two single leg cowstails, and a single knot attached to the harness is less bulky than two separate ones. For efficient progression between anchors, we need cowstails with legs that are sufficiently long enough to make the transitions straightforward, whilst not being so long as to be a risk to us if we fell onto them. Optimal rigging for traverses would generally position them around shoulder to face height when we are stood on a ledge, so cowstails rarely need to be any longer than that. If you are hanging from them after a slip, you would still be able to reach the traverse rope or anchor you are clipped to, which would not be the case if your cowstail legs were longer than your own arms can reach. I have witnessed cavers needing to ascend with their jammers up their own overly long cowstail leg so that they can reach the traverse rope and pull up to recover themselves. This is both inefficient and unnecessarily tiring. That thought nicely leads us to the third use….

Positioning (hanging) on cowstails is a necessary part of some SRT manoeuvres and is a great way of saving energy on hanging traverses with few or no footholds. Having our cowstails short enough so the carabiner remains in reach when we are hanging from them is essential for this. As mentioned above, optimal rigging places the traverse rope at around shoulder to head height, so the longest our cowstails need to be is that. Symmetrical length cowstails are viable in some environments like the fixed rigging in certain mines that have easy pitch heads reached from good ledges, but most SRT routes will require you to hang while you get on and off a pitch head. To make hanging pitch heads or traverses easier, we could have really short cowstail legs to position ourselves level with the traverse, anchor point or knot that we are clipped to. Short cowstail legs would also allow us to keep rebelay loops shorter, and limit the force of shock loads that might occur if a rebelay anchor fails. The problem with having two very short cowstail legs is that you then become limited in how far you can reach between anchor points. Clipping past a butterfly knot on a traverse may not be too much of a challenge, unless the rigging is really high, but moving from a traverse out to the centre of a Y-hang knot may become more awkward. To give us the best of both worlds, most cavers make use of asymmetrical leg cowstails. One leg is shorter and this is the one we generally use for positioning, and the other is longer to facilitate easy reaching to the next anchor point, or is left attached but slack when the short cowstail is removed before we complete an SRT manoeuvre or ‘2-inch test’ at the top of an abseil.

Another style to mention here briefly is the IRATA style of rope cowstails. These are essentially used in the same way as caving cowstails, i.e. for positioning, protection and progression below the anchor point (<FF1). Due to the requirements on having two independent points of contact at all times, rope access cowstails usually consist of three legs. They can be constructed from separate sections of rope or using individual stitched lanyards, but much like caving cowstails, the most efficient and cost effective way of doing this is with a single length of rope. Two of the legs are long, and the third is really short. IRATA manoeuvres are very similar to SRT, but with more points of contact needed, but the use of the cowstails is broadly the same. There is more bulk on the harness D-ring, which can be an issue for that crowded point on SRT kits, but some people prefer this setup (often those from rope access backgrounds who are used to it).

Some people like to use adjustable cowstails, mostly just on the longer leg, but occasionally on both. The advantage here is that you can quickly turn an asymmetrical set of cowstail legs into two short legs for challenging traverses. The disadvantage is cost and a sacrifice of some shock absorbency because you have not got as many knots in the cowstails. Like the IRATA setup mentioned above, the adoption of these configurations is probably best left to a time when you have enough experience of the use of cowstails to know they are going to be beneficial to you. For SRT caving in the UK, asymmetrical knotted rope cowstails are the norm for most people.

The best way to understand the impact that the different configurations of cowstails have on efficient SRT is for you to get some training from an appropriate person.

Choice of Rope

For knotted cowstails we must use Dynamic climbing rope. Specifically a rope that conforms to EN892 and/or UIAA 101. Under this safety standard there are three different classifications of Dynamic rope; Single Ropes, Half Ropes and Twin Ropes. The BMC has produced an excellent guide to Dynamic ropes for climbers which can be read here, and it saves me having to go into all the differences between the classifications in this article. In short, a Single Rope is designed to be used on its own, Half Ropes and Twin Ropes must always be used as a pair. As we can fall or be supported on either leg of the cowstail and not both at once, we are using the rope as a single line.

• Static Elongation of less than 10% with 80kg of weight – This low figure is a benefit to us when we hang on our cowstails, as they will not stretch so much that we don’t end up where we wanted to be positioned. The lower the Static Elongation figure for your rope, the less the stretchy it will be when hung on.
• Dynamic Elongation of up to 40% when tested using an 80kg mass at FF 1.7 – When we fall onto the cowstails, we want them to stretch to reduce the Impact Force of the fall. The higher the Dynamic Elongation figure, the more the rope stretches and the softer the catch. The Peak Impact Force figure derived from this test can be compared against other dynamic ropes if needed.
• Must hold a minimum of 5 falls @ FF1.7 with 80kg – The test is repeated until the rope breaks. The higher the number of falls a rope can survive, the stronger the rope is and the better it might perform in the long run. As we would want to replace cowstails that have taken a significant fall, this number is not as important as with climbing where repeated falls during a route are possible during one outing. It is another good way of comparing different ropes you are trying to choose between.
• Sheath percentage – Typically between 30-40%, the thicker the sheath the tougher the rope will likely be. A heavier rope (given as weight per metre) is also an indicator of how dense the rope is, which can mean tougher and longer lasting in the harsh cave environment.
• Diameter – The range in diameter is not specific to the type of Dynamic rope, but is another factor to consider. Smaller (<10mm) diameter ropes are skinnier and have less material to cut or abrade through before they become damaged or break. Fatter ropes (10-11mm) have a bigger safety margin for damage occurring during use, but are bulkier when knotted. If you are prepared to replace your cowstails more regularly then thinner ropes are fine, but for most of us a diameter of around 10mm is ideal. Any thickness of rope can be catastrophically damaged or cut in an extreme event like a bad fall over an edge.

There are possibly no totally perfect Dynamic ropes out there for use as cowstails, as not all of the ideal properties are compatible. For instance, a really tough outdoor centre top-rope with a fat sheath and thick diameter probably won’t be super stretchy as you don’t want a lot of stretch for top-roping. A mega stretchy lead rope for ice climbing will reduce the Impact Forces on your iffy ice screw placements but might be so supple that it is prone to premature wear from the gritty cave environment. With all these numbers to look at you might be a bit overwhelmed, so what do I do? Well I usually just look at the caving retailers to see what rope they are selling for cowstail lengths, or pop along to somewhere like Go Outdoors during a sale and buy a middle ground 20-30m long 10mm Single rope to chop up as and when I need it. Running a caving business means I can get through cowstails for me and my clients quite fast, but individual cavers probably won’t want more than one or two sets at a time, so you are limited in choice by which retailers sell Dynamic rope by the metre. Starless River and Inglesport do sell Dynamic rope in 1 metre increments and are trusted sources for caving kit. You’ll need between 2.5m and 3m of rope to tie a set of asymmetrical cowstails depending on choice of knots and how tall you are. You can always use a hot-knife to remove excess after a few caving trips have confirmed that you have your legs lengths right for you, so go for 3m if it is your first time or ‘try before you buy’ in store.

The current rope reel I am working through is a Beal Karma 9.8mm Dynamic Single Rope. This is not me saying you should go out and buy this specific rope, it is just an example of a suitable choice for cowstails. This rope is nice and bouncy with 38% dynamic elongation, but only has 8% static elongation. It has a relatively low Impact Force of 7.5kN due to the stretch. The sheath makes up 33%, which is on the more supple end instead of the tougher end of the spectrum, but I replace my cowstails regularly, so I’m not concerned too much by longevity so long as it doesn’t disintegrate on the first use.

Here are a few other things you’ll possibly see on the labels for Dynamic climbing ropes:

• ‘Dry Treated’ ropes. These ropes have a chemical treatment to reduce the amount of water that they absorb. Wet ropes are weaker ropes believe it or not, but don’t panic, it’s not a killer! Dry treatments are probably great for climbing in the rainy UK, but the treatment breaks down and wears off the rope over time. For caving cowstails exposed to grit, mud and water on every use, the dry treatment probably lasts a handful of uses, so I don’t specifically seek out a rope with this option.
• ‘Unicore’ ropes. This is a construction process that glues the inner sheath to the core of the rope. This means that if the sheath of the rope is cut, it won’t slide down and expose the core completely. This means the core stays protected that little bit longer and you can potentially still ascend or descend the rope to get off it. There is no functional benefit to this for cowstails, as sheaths tend to be worn through in localised areas instead of the sheath being cut or damaged in a line as might happen during a climbing fall when a rope is dragged over an edge. That’s not to say that this might not occur to cowstails, but any extra cost for this feature is not really balanced against the benefit for this use. For SRT Low Stretch ropes though, that is another matter and perhaps something I’ll come back to talk about in a future post.
• Multi-rated ropes. Some Dynamic ropes meet the testing requirements to be classed as more than just a Single, Twin or Half rope, or possibly all 3. We are only interested in the Single Rope certification, and a rope holding the other certifications as well does not make it any better for use in cowstails. They are also likely to be thinner and more expensive than normal Single Ropes, and probably not available in 3m lengths!

So, bearing in mind that I’ve just written around 1000 words on why we need to use Dynamic Single Ropes, I’m going to circle back and talk about Low Stretch (Semi-Static) ropes quickly.

Lanyards made of stitched Low Stretch ropes conforming to EN354 or EN358 are designed solely for limiting movement (Work Restraint) or as positioning devices (Work Positioning), and are totally unsuitable for use as cowstails where a FF1 is possible. But what about if we tied knotted cowstails from Low Stretch rope? The main reason I generally advocate using knotted cowstails over stitched ones, is that the knot itself acts as a small shock absorber if you slip and land on your cowstails. How much this absorbs will be unpredictable and depends on many factors, but testing has shown the tightening of the knots reduces impact forces when compared to similar length stitched cowstails. Cowstails which are tied in Low Stretch rope will certainly have the same knot tightening effect the first time they are hung on or fallen onto, but the peak Impact Force will still be higher than with Dynamic rope. Dynamic rope with tight knots or stitched terminations will have higher stretch than Low Stretch rope when catching a fall, even if you are only falling onto a 1 metre length of it. A Low Stretch cowstail with tight knots will be very static and give almost no stretch, just like the EN354 and EN358 lanyards mentioned above. There is some good drop testing data available on the How Not 2 website comparing Dynamic, Low Stretch and Webbing cowstails. Check that site out if you’ve not visited before, there is loads of cool information and they do a really good job of testing real use cases for climbing and caving kit. I’d also highly recommend their YouTube channel as well.

The last thing to talk about quickly here is the lifetime of the Dynamic rope you are using for your cowstails. Manufacturers will give the rope a working life, usually between 5-10 years. We should stay within that of course, but I doubt I’ve ever retired a cowstail due to age. They go in the bin because they wear out or go very stiff. The cave and mine environment is tough on kit, and you are better off replacing your cowstails more frequently than the lifespan of the rope. How frequently depends on your level of use. As a caving instructor I tend to get through mine in a year or so. Over time your Dynamic rope will become less stretchy as it fattens up from abrasion and the ingress of dirt. When they become stiff or fluffy, or you just don’t feel the rope handles the same as it did when it was newer, then it is probably time to replace them. The number of cavers I’ve seen with ancient cowstails is crazy. Yes they don’t get exposed to UV light much and they still look okayish, but if you’ve not been able to undo the knots since 1998 or can’t recall which mate gave you them from his retired climbing rope then are you really sure you want to risk a big fall onto them? £6 or £7 is all you need to spend every year or two for fresh cowstails, that’s only two pints of beer! Replace them as often as you feel you need to, and after any damage or fall. A cavers kit check workshop is a great way to spend a couple of hours if you want to know more about how to check your own gear.

Choice of Knots

Different knots were invented for different purposes. Some have beneficial properties for use in cowstails, others do not. Any knot will reduce the overall strength of the rope that it is tied in, but none so much that we have to worry about the rope breaking during normal SRT use. With a properly certified Dynamic climbing rope, the lost strength still leaves us with a rope that is more than strong enough. With the choice of knots for our cowstails not determined by a bun-fight about a few % points of strength lost compared to another knot, we can then concentrate on the more important aspect of the choice – does the knot have suitable properties for what we want to do with it?

The role of the knots in cowstails is to create secure and stable loops that we can use to attach the rope to carabiners at one end, and our harness at the other. When we load the cowstail leg by hanging or falling onto it, the force is in line with the rope and loops, end to end. As both the carabiner and harness end of the cowstail leg are effectively the ends of the rope (even if the tail of the harness end is used to create the second leg of the cowstail), we should use loop knots that are stable as end of rope knots. By this I mean a knot that is stable when loaded on the eye (loop) and the working end, and the spare ‘tail’ of the rope is not at risk of coming undone. A mid-rope loop knot is a type of knot that is most stable when loaded on both the strands that emerge from it. I’m not going to cover exactly how to tie or use each knot in this article, but will provide links to details about the knot elsewhere on the website.

Two common end-rope loop knots used for caving are the Overhand on the Bight and Figure of Eight on the Bight. They are called ‘on the bight’ because they are tied using a bight (a doubled over section of rope like a loop with no twist) to create an eye. Both of these knots are suitable for cowstail ends.

The Overhand on the Bight – The Overhand is a more compact knot that uses less rope than a Figure of Eight, but because there is less rope-to-rope contact inside it, it will produce less stretch in the cowstails when tightened during a fall. It has sharper bends than the Figure of Eight, meaning it is a slightly weaker knot, but is still more that strong enough. More importantly for us, those tighter bends means that it is harder to untie than a knot with gentler bends. An Overhand that is hung on a lot or fallen on will be be more difficult to periodically untie and inspect or slacken off, which really is something we should be doing with our cowstails. The Overhand knot with a 5cm loop uses around 50cm of rope, plus a 10cm tail is needed.
A well dressed Overhand on the Bight knot with at least 10cm of tail is a suitable stable loop knot for cowstails.

The Figure of Eight on the Bight – The Figure of Eight (or Fig8) is longer than the Overhand, so is slightly more bulky. There is an extra turn of rope in the knot beyond the Overhand, giving more rope to tighten and produce extension during a fall. The bends within the knot are more gentle than the Overhand, meaning it is both marginally stronger, and is easier to untie than the Overhand after heavy or repeated loading. The Figure of Eight on the Bight with a 5cm loop uses between 60-70cm of rope, plus a 10cm tail is needed.
Like the Overhand Knot, a well dressed Fig8 on the Bight with at least 10cm of tail is a suitable stable loop knot for cowstails.

One other knot that pops up now and again in the middle of the cowstails is the Alpine Butterfly, probably because it is known to be a good mid-rope loop knot, so is occasionally used as the centre knot of the cowstails where it attaches to the harness D-ring. Although there is nothing fundamentally unsafe about using an Alpine Butterfly as the centre knot of the cowstails, it is not truly being used as a mid-rope knot in this role and is not likely to be loaded on both sides during normal use. There are no benefits for choosing this knot in this position over the Figure of Eight or Overhand Knots. It would not be safe to use on the carabiner end of the cowstails though, as it is not a stable end rope knot and is at more risk of deforming or coming undone if one of the strands is left as a short and unloaded tail.

One thing of note with the loop knots that are described above is that the loop is open during use. Carabiners attached to the loop are able to freely rotate and reposition. While this might be an advantage in rigging, it can be a disadvantage for the carabiner end of the cowstails. If we reach for the carabiner during a strenuous move, we might find that it was rotated into an awkward position to operate, or even to be loaded over the carabiner gate and not down the spine as it should be. Cavers who use loop knots in the carabiner end of their cowstails will often use rubber ‘keepers’, or carabiners with eyes or securing pins to maintain the correct axis of the carabiner in the loose knot eye. I’ve seen electrical tape used to wrap the knots and hold carabiners in place. This is a bad idea for many reasons, including potential damage to rope from the glue’s solvent, and the inability to untie or inspect the knots. Simply tightening the loop down to hold the carabiner in place is usually not successful, as the loop will always extend and draw out from the knot a bit when loaded. So while this free movement of the carabiner in the loop is not a deal breaker, there are better knot options for this end loop of the cowstail. For the centre knot of the cowstail though, where a loop that can move freely on the D-ring of the harness is beneficial, the use of either the Overhand on the Bight or Figure of Eight on the Bight would be fine. The Figure of Eight on the Bight is probably the most ideal knot for the centre knot, but if I’m a bit limited on available rope I’d happily use the Overhand on the Bight.

There is a type of loop creating knot that can be tied around a carabiner to tightly hold it in place. These constricting ‘noose’ knots are related the Stopper Knot, and are probably the most common cowstail end knots in use by cavers. Usually known by cavers as a Barrel Knot, the two common variants of these knots are actually called either a Poachers Knot or Scaffold Knot.

The Poachers or Scaffold Knot – The Poachers Knot is a constricting knot that can be tied around a carabiner to hold it in place. The difference in the two is the number of turns that the rope makes around the working line, two for the Poachers and three for the Scaffold. You can keep adding more turns but then the knot becomes bulky and uses a tonne of rope, also you start to look like a trainee hangman! 45cm to 55cm of rope is needed for these, plus a 10cm tail, so they are no more rope hungry than the other options discussed above. When these knots are tightened down on the carabiner, they prevent it rotating so that it always remains orientated in the best way for clipping. The three-turn Scaffold is marginally stronger than the Poachers, but either are acceptable for use as cowstail end knots. I’d use either depending on how much rope I have available.

It is important to highlight that in all of the cowstail testing data that I have seen, cowstails tied using a hand-tightened Poachers Knot produced the lowest impact forces when compared to Overhand or Figure of Eights on the Bight.

Dressing Knots

A well dressed (neat) knot is better than an untidy one with crossing strands. There might only be few percentage points of strength gained with a neat knot, but that is not the main factor we are concerned about. A well dressed knot is stable, easier to inspect, and easier to untie after heavy or repeated loading. Poorly dressed knots can deform in use or hide errors that we made during tying. I’m a bit OTT on this I’m afraid. If you’re going to tie a knot, tie it right; dress and set it properly. Anything else is poor workmanship.

Setting Knots

So that a knot remains stable in use, we should also ‘set it’. This means that once it is tied and dressed we should pull it as tight as we can by hand. This does not remove its ability to tighten up if we fall onto it (much more force involved than pulling by hand) but does mean that the strands of rope in the knot are gripping one another firmly, increasing the friction and reducing the chance that the knot will work loose or deform into something less stable or undo entirely. Loose knots will also tighten a lot during use, and if you’ve measured up your cowstail legs to how you want them, you might then find the length increases dramatically when you first hang on them. Typically we will need to tie cowstails (and other rigging) slightly shorter than the final result needs to be, so as we set and tighten the knot the first time it is loaded it will extend to the length we want it. This takes a bit of practice and it is not unusual to have to retie cowstails a few times to get them just how you want them.

Choice of Carabiners

The carabiner is the business end of the cowstails. You’ll be using these a lot and so consideration needs to be given to the shape, size and mechanism of the carabiners you choose to use on your cowstails. I’ll break down the broad choices below and leave you to decide what you prefer and select a specific model, but I will state here that my personal preference and recommendation for those starting out with SRT is to use a ‘D’ shaped screw gate carabiner on both of the cowstail legs.

Snap Gates

Snap gates are single action hinged gates that are commonly used on climbing gear like quickdraws and trad protection. They are fast to open and close with one hand, making them ideal for quick clipping during strenuous moves. They don’t have a locking mechanism to potentially jam up with mud, and can be operated easily with gloved hands. You can get solid gate and wire gate variations. The wires are more resistant to being knocked open by vibrations and impacts, but are more at risk of being damaged while caving than the solid gates. Snap gates are very easy to accidentally unclip in the right circumstances and offer no defence from levering open if the gate is pressed against something like a rock or part of the knot. Some cavers who use snap gates will defend them to the death, but I’m not sure if the benefit of the speed of use offsets the greater relative risk of accidental unclipping. They are however probably the second most common carabiner I’ve observed in use on one or both cowstail ends.

Screw Gates

Screw gates are the most common type of carabiner to see on cowstail ends. The locking screw on the gate can be opened with a few turns in a couple of seconds, and secured again just as fast. They can be used with gloves on and when passing over simple terrain can be left unscrewed and used as snap gates for faster progress if desired. When you want the security you simply screw them up. The closed screw sleeve prevents the gate being pushed open if pressed against a surface or knot, although they can be broken or bent if larger forces are applied. Some models can jam if you screw them up tighter whilst hanging from them. The carabiner body stretches slightly under load and the nose jams on the screw barrel. This can be remedied by hanging on it again before trying to unscrew it. Lots of screw gate carabiners are made in way that prevents this occurring though, with a washer or other type of stopper on the thread that prevents the screw barrel being done up too tight and jamming on the nose. Budget carabiners will possibly still use the cheaper nose-lock construction. Occasionally a screw gate might do itself up partially while the gate is open, and then not be able to close fully. This can usually be spotted and remedied quickly with a small twist of the screw to open it fully and allow the gate to shut properly. With the screw gate carabiner there does come a risk of mud and grit entering and affecting the operation of the screw thread, but I have yet to have any major problems with this when carabiners are regularly cleaned after use.

Twist Locks (2 action)

Twist locks, or roll locks, are like an auto closing version of a screwgate. You twist the gate sleeve until a notch in the gate allows it to be hinged open. When releasing the gate it swings shut and the spring-loaded sleeve rotates back into the locked position. These are usually very easy to use, and with a good design of knurled gate sleeve, can still be used with gloves on. They are fast to open and immediately secure when closed. Similar to snap gates, if they are pressed or moved against a surface just right then they can be accidentally opened, so care is needed to position these so the gate is not rubbing on the rock or rigging. This ‘roll-out’ is not common but is something that you need to be aware of. The gate sleeve mechanism is a bit more liable to jamming when filled with mud and grit than a screw gate, but regular cleaning should prevent most issues.

Triple Locks (3 action)

Triple locks operate on a similar principle to the twist lock, but with one extra movement stage needed. Typically you lift the locking sleeve slightly before it will rotate like the twist lock and allow you to hinge the gate open. When closing, the lock reapplies itself automatically. These are a bit slower to operate, and small hands or lefties might struggle a bit with larger carabiners, but practice makes them quicker to use. The roll out risk is minimal, although you can always make something fail if you try hard enough, and they are similarly prone to issues from grit and mud as twistlocks are. These might be a bit slow for normal cowstail use, but are good for connections on the SRT kit that are not opening and closing frequently. That said, if you want the most secure of the ‘normal’ carabiner options, these are the ones to go for.

Other Gate Mechanisms

You can get all sorts of fancy 2 and 3 action gate mechanisms. From lever locks (Petzl Eashook) to magnetic gates (Black Diamond Magnetron) and twin gates (Grivel Twingate) to wire or sleeve pull down locks (Petzl Vertego WL). All of these can be considered for use on cowstails if they suit you and the environment that you use them in. There is always a balance of speed and ease of use verses security, so some research and trying out in the shop is advised before making any purchases.

Shape and Size and Other Considerations

Carabiners usually come in either ‘D’, oval or HMS wedge shapes. Within those broad categories you also get variations in size and gate opening. D and HMS carabiners tend to have the largest gate openings, which can make it easier to clip into big knots. Small hands might struggle with large HMS carabiners, but there are some good compact ones on the market currently. The larger D style of carabiners seem to offer the best compromise between size, gate opening and ease of use. Ovals are also fine, but due the symmetrical shape they don’t always fall into the hand as perfectly as a D shaped does for clipping. If you’re still keen on snap gates, it is worth considering a bent gate version, as these have good sized gate openings and the curved gate makes clipping very easy.

Using the same type of carabiner on either cowstail leg is the most common thing to do, but there are many cavers who use different carabiners on their long and short cowstail legs. An example of this is having a snap gate on the shorter positioning cowstail to make it easer and faster to clip in and out during some strenuous moves, and a locking gate carabiner on the long cowstail for security when needed. This choice is fundamentally down to personal preference and is one for you to decide on when you are experienced enough to know why it might make a difference for you. As stated above, I’d recommend starting off by using 2 screw gates if this is your first set of cowstails.

It is worth me noting here that the British Caving Association’s Qualification Management Committee requires the use of at least one locking carabiner on cowstails for those leading or taking part in LCMLA or CIC instructed caving activities.

Assembling Your Knotted Cowstails

Well done for making it down this far. Time to start putting our cowstails together. The equipment I’m using is as follows…

• 2 screw gate D shape karabiners
• 2.5m of Dynamic Single rope
• SRT harness with a D ring

You might opt for different carabiners or slightly longer section of rope if needed, but the process is the same. The lengths I’m setting the cowstails up at will be a good starting point for you to begin with, but you can always make some tweaks to suit you once you start using them. If you are doing this for the first time, or just to make it easier to get it right first time, put your SRT harness on so that you can measure the leg lengths from your D ring.

Here’s a short video I have over on my YouTube Channel showing the process that I use to set up a new set of cowstails. There is a step by step write up of the process below if that is easier for you to follow.

Step 1

First you want to tie one of the carabiners into the end of the Dynamic rope with a Scaffold Knot. Tie the knot around the hinge end of the carabiner, so the opening end is away from the knot. Make sure you have at least 10cm of tail on the knot, but you don’t want a huge amount of wasted rope flapping around there. Once you are happy with the dressing of the knot, don’t forget to pull it tight by hand or by clipping it to a solid structure and giving it a good pull to set it and grip the carabiner tightly.

Step 2

Next you want to hold the carabiner just under your chin and let the remaining rope hang down in front of you. Take hold of the rope where it crosses your harness D ring. Before you tie the knot here, add around 25cm more rope (approximately a hand span) to the length of this first leg. Where you are holding the rope now wants to be the centre of the loop you are about to tie.

Step 3

Tie a Figure of Eight on the Bight knot where you are holding the rope. The loop you form wants to be no more than around 5cm in length ideally. Once you have dressed the knot, pull it tight to set it. Next, you can either attach the Figure of Eight on the Bight to your harness D ring, or just hold it front, but we need to see if the cowstail leg is the correct length. With the carabiner under your chin, the end of the Fig 8 should be sat right at the top of your D ring. If it is too long or too short, either untie and start again, or adjust the leg length by feeding a single strand of rope through the knot.

Step 4

Take the end of the remaining rope and tie it to your other carabiner using a Scaffold Knot. Again, dress and set this, ensuring there is a 10cm tail.

Step 5

With the Fig 8 still attached or held at the harness D ring, hold the long leg of the cowstail up vertically. What we want is for the top of the carabiner to be level with the top of our forehead. If that is the case then great, you are done and ready to go try them out. Your short one will sit at chin/shoulder height, which is the height a traverse rope is ideally rigged to. And your long one will give you a bit more reach for passing knots or as a safety backup during manoeuvres, but not be so long that if you ended up hanging on it you’d struggle to reach the rope you clipped it to.

Fine Tuning

If the long side of the cowstails is too long, then you have a couple of options. You might end up doing one or both.
A. Untie the Scaffold Knot and retie it again, starting with the leg a little shorter than you did the first time. Do this with a bit of trial and error until you have managed to get the long cowstail to the correct length. If you have done this and there is a lot of spare rope left in the tail of the knot, move on to the next option.
B. If after working through these steps you have successfully fine tuned the leg lengths to be chin and forehead height respectively, but still have a lot of spare rope in the tail, then there is one last step. Tie the tail loosely around the cowstail leg with something like a normal Overhand Knot or Stopper Knot, and then go and do some caving. It’s a bit bulky on that side, but when you are sure you won’t need the extra rope after you’ve tried the cowstails on a few SRT trips, then you can cut the spare off. Use a rope cutter or old knife heated on a gas hob to melt the rope through, ensuring you still leave 10cm of tail on the knot. Only cut the excess from the rope when you are sure you won’t need it!

If the long cowstail is too short, then you’ll need to generate some more rope to use.
A. Untie the Scaffold Knot in the long cowstail and this time use the Poachers Knots. The extra rope freed up using the smaller Poachers Knot should lengthen the leg by around 10cm. If this results in the long cowstail being the correct length for you now then great. If not, go to the next option.
B. Start over again but this time use Poachers Knots for both carabiners. You’ll get about 20cm more rope verses the Scaffold Knots.
C. You can add yet more rope into the cowstail legs by replacing the Figure of Eight on the Bight with an Overhand on the Bight. Go back to Step 2 and this time pull through only around 15cm of extra rope before tying the Overhand. Check you still have the short cowstail length correct (D ring to chin) and then you should have more rope when you retie the Poachers on the long side. Don’t be tempted to tie the carabiner end knots with shorter tails than 10cm, they do get sucked in a bit and you don’t want to risk a knot undoing. If you still think your cowstails are a bit short, don’t worry because too short is better than too long, and you’ll still get some elongation during their first use. Of course you might have cut your rope too short to begin with though.

Settling In

When you have tied your cowstails according the instructions above and got them all to the correct dimensions, you might think that they look a little short compared to other people. The first time you hang on them properly they are going to grow a bit. If you have a tree or other solid place to gently hang available when you tie the cowstails then you can complete this step at the same time, but don’t worry as it’ll naturally happen during the first few uses anyway. Despite setting the knots hand tight, you will still get tightening occurring when your full body weight is applied. When this has happened we can check our lengths again. The final working lengths of the SRT cowstails after first use should have the short side carabiner between chin and nose, and the long side comfortably within reach when you are hanging from it, so just above head height.

You might well decide that you preferred the cowstails at their original shorter lengths before they settled. You can always untie one or both legs and start again. Now you have seen how much that particular rope tightens up during use, you can start from Step 1 again but reduce the leg length accordingly. You could put a small wrap of masking tape on the rope before you untie the knots so you can see where to tie the new knot to be shorter this time around. Just take the tape off when you’re done so the glue doesn’t do anything odd to the rope sheath.

A quick note for really tall folks – your short tail might be as long as my long one! This will need to factored in for rigging rebelay loops, so you might want to start off with cowstails that are shorter for your body proportions than the description above.

A quick note for really short folks – if taller cavers rig traverses you might find you are on tip toes or jumping to use your short cowstail. Either have a word with them or consider adding a touch more to your short so it a similar length to theirs, that way you should still be able to use the rigging of taller people without effecting the efficiency of your kit for passing rebelays or hanging traverses.

Conclusion

Remember that these recommended lengths and components are just a starting point and can be adjusted to suit you as you use your kit more and learn what you prefer. If you’ve got your cowstails set up as I’ve described, you should have no problem using them for any of the SRT manoeuvres after a little practice, but if you feel you would prefer a shorter short tail, or want really secure triple locking carabiner, then do it! If you can safely do everything that you need to do using your cowstails set up how you want them then that’s all you need to worry about. Untie, clean and inspect them often, and don’t hesitate to replace them if you feel uneasy about any wear or stiffness.

These individual variations to make cowstails work best for you are one of the main reasons I’d advocate using knotted rope cowstails over any of the stitched alternatives. If you can try the stitched ones by borrowing a set from someone and they work fine for you then there is nothing wrong with going down that road, but once you know how to make a set of knotted tails, you’ll always have the cheapest, bespoke and most efficient setup for you.

And finally, to end with the traditional disclaimer – don’t learn something from the internet and then go off underground expecting to be an expert. Practice somewhere safe and easy to get back to the floor, or under the supervision of someone experienced who can solve any problems that you might get into. Borrow kit from you caving club or mates and try it before committing your own money where you can. My top tip is to invest in skills before shiny things. Whatever you do, be safe and make good decisions.

Thanks for reading. Check out the other articles and videos in the back catalogue, and keep checking back for more in future. If you’ve liked these resources then consider dropping me a message if you are ever looking to hire someone for SRT training in future.

Further Reading and Information Sources