Setting up a “Frog” Ascending System Warning! Do not attempt to use any ascending system for first-time climbing without expert guidance. You may be hurt or killed. Don’t do it! The rope ascending system that American cavers dub the “Frog” is unquestionably the most universal rope ascending system in the world of caving. Although several other ascending systems are considerably more efficient for climbing unobstructed ropes, the Frog combines light weight and minimum bulk to create a system that is particularly effective for expedition caving and for crossing mid-rope obstacles such as rebelays. It is the first ascending system that cavers should master. The Frog is a sit-stand system requiring two ascenders: A specifically designed “chest” ascender attached directly to the seat harness and a handled ascender connected to both feet via a long foot loop. A safety tether always connects the upper ascender to the sitharness. A sit/stand motion similar to doing deep knee bends is used to ascend. A materials list for constructing a Frog System can be found at the end of this article. Links in the chain Considerable effort has gone into testing and refinement of the Frog. Although simple in terms of equipment, the Frog is a very complex ascending system in terms of effective implementation. A full understanding of the system is vital before variations are attempted. Due to ignorance, there are probably more poorly implemented Frogs than any other ascending system per capita. Any “weak link” in the chain of setup and adjustment of a Frog System has a dramatic, negative consequence. Link #1 – The climber

Fig. 1: Body type dramatically affects Frog System efficiency. The climber on the left is taller and his fingertip-to-Croll distance is also a greater proportion to his total height. This means he inevitably makes more vertical progress with each sit/stand cycle than the climber on the right.

More than other common rope ascending system, different body types affect the effectiveness of the Frog. Tests have shown that stature (height), torso-to fingertip distance, chest breadth and body weight distribution can radically alter climbing efficiency. Specific results are dependent upon the individual, but in general, short individuals, climbers with barrel chests or short torso/arm combinations are at a disadvantage compared to tall, slender climbers with long torsos and arms. This aspect alone however, is not sufficient reason to substitute another ascending system without first learning and mastering the Frog. For the majority of climbers, the Frog offers a good overall combination of efficiency and versatility.

Link #2 - The sit-harness A sit harness designed specifically for “Frogging” is integral to the entire system and its basic design must be considered as seriously as the hardware. Because the Frog is a sitstand system, the climber uses the harness at every cycle. It is essential that a Frog harness have a low “tie-in” to place the lower ascender as low as is practical. The potential distance between the two Frog ascenders is critical to efficient climbing. Rock climbing harnesses are designed to prevent inversion during a fall and have a much higher tie-in point than Frog harnesses. This makes them generally less effective for the Frog System. The most common mistake for beginners is to purchase the wrong type of sit harness for Frogging.

Fig. 2: Left: The Petzl “Fractio” caving harness designed for the Frog System. Right: A Petzl “Sama” rock-climbing harness. The red arrows show the position of the tie-in points of each harness. Note the distinctly different designs.

Adjusting a sit-harness improperly can affect climbing efficiency. Most Frog harnesses use specialized hardware at their tie-in point. The interplay of the hardware and harness affects the ways the harness loads and consequently, the entire Frog system. Specifics vary with each harness, but general recommendations can be made (see next section). Link #3 – The harness connector Most Frog sit-harnesses are designed to use 10mm screw links of specific design. They are variously called “half-rounds, “half-moons” and “semi-circular screw links.” One Petzl variation is constructed with a carabiner-style gate and given the proprietary name “Omni” (See figures 3 A&B). The link may be made of aluminum, steel or stainless steel. Using the proper screw-link is vital because the rest of the Frog system attaches to it. Carabiners are designed to be loaded in one direction and are NOT acceptable for the multi-directional loading that Frog harnesses experience.

Semi-circular screw links are designed in combination with Frog harnesses to load the link from side to side and downward (See figures 4A& B). This prevents the link Fig. 3A: 10 mm half-round, screw Fig. 3B: 10 mm Petzl “Omni” from rotating or rising during link harness connector. carabiner-style half-round. climbing. The rounded upper portion of the link allows the various Frog components to articulate freely without hanging up on a gate. A general recommendation for proper sit-harness adjustment is to first adjust the waist strap tight enough to load the screw link from side to side without unnecessary discomfort. Only afterwards should the leg loops be tightened to prevent upward movement of the link.

Fig. 4A: The Petzl “Fractio” Frog harness loads the half round steel screw link sideways to prevent it from rotating. It uses the leg loop tension to prevent the link from moving upward.

Fig 5: As the climber ascends, the motion of the climbing rope can rotate the gate open if the Maillon is improperly oriented. The Petzl “Omni” will not unscrew accidentally.

Fig. 4B: The On Rope “Goliath” Frog harness uses a slightly different configuration to keep the half round connector in place. A Petzl 10 mm Omni carabiner-style connector is shown.

Safety note: Even the orientation of the half-round screw link is vital to safety. Screw links depend upon closed gates for much of their strength. During the ascent, the rope can rub against the screw link gate in a downward direction. If the gate is oriented to close to the climber’s left, this motion will tend to screw the gate closed. Oriented the other direction (closing to the climber’s right), the rope can unscrew the gate and open the Maillon. Traditional threaded screw links must be oriented so they screw closed to the climber’s left. The Petzl “Omni” may unlock, but does not lose strength and cannot open due to a different design.

Link #4 – The lower ascender

Fig. 6: The Petzl Croll ascender attaches directly to the half round. It uses half-twist connector holes to keep it flat against the climber’s stomach or chest.

A special mechanical ascender is attached directly to the semi-circular screw link (Figure 6). It is designed with a half-twist to allow it to sit flat against the body. The most common ascender of this type is the Petzl “Croll” and that name will be used in this article to represent the basic design. Other manufacturers also make similar “half twist” ascenders designed for the Frog. Handled or nonhandled ascenders without the half twist will still work, but since they will not lie flat, they throw the climber’s weight away from the rope and greatly reduce efficiency and comfort. A chest strap is attached to the top of the ascender to allow “hand’s free” operation (See next section).

Link #5 – The chest “harness” (strap) A chest harness or strap is attached to the top of the “Croll” ascender and worn over the shoulders. It serves two purposes: It raises the Croll automatically when the climber stands up and it helps keep the caver upright when resting on rope. There are many variations, but a common chest “harness” is actually a simple strap of 1-inch (25mm) flat webbing with a quick-adjusting buckle. The strap is threaded in a specific manner to pull only at the front of the harness. Many climbers use a small quick link to prevent the buckle from moving. Although tempting, do NOT run the strap from the top of the Croll and over the shoulders to the rear of the sit-harness. This will pull the sit-harness waist loop up onto the climber’s kidneys with each sit/stand cycle. It is very uncomfortable and not recommended (see figure 7).

Fig. 7: Three common Frog chest harnesses. A simple strap with steel buckle (left) is preferred for most expedition caving. The “H” harness (center) is more comfortable, but bulkier and more complicated. Both the strap and the “H” harness pull only on the front of the harness. The third type (right) passes over the shoulders and attaches to the rear of the sit-harness. This is not recommended because it pulls the sit-harness up over the kidneys when climbing.

Proprietary Frog chest harnesses (The “H” harness in Figure 7) work reasonably well. Unfortunately, they do not fit all climbers and are more complex and bulkier that the simple chest strap. Many climbers claim they are more comfortable. Be sure to try one on before purchase to be sure it will allow sufficient adjustment, particularly for larger climbers. The plastic buckles also tend to break after only moderate use. Important notes: The climber must be on rope with the Croll (lower ascender) loaded with full body weight while adjusting the chest harness. Even if the harness is pulled tight when standing, there may be as much as 1 foot (300mm) of slack in the harness after the Croll is loaded. The climber should not hunch over when tightening the Frog chest harness. Hunching will prevent the climber from sitting upright during the climb. Proper procedure is to keep your back straight, pull yourself as close to the climbing rope as possible and then tighten the chest strap/harness until it is snug. This approach applies to all three types of harnesses shown above. Link #6 – The Cowstails A safety tether is always attached from the upper ascender to the sit harness. Some climbers prefer a dedicated tether (used only for the Frog system), while others use one of two general purpose, load-bearing tethers called “Cowstails.” A set of two cowstails are not specifically a part of the Frog ascending system, but when used as a Frog safety tether, they must be considered within the context of the entire system. Cowstails are used to secure the climber in a variety of situations. This author considers Cowstails standard equipment for all vertical caving with ALL ascending systems.

Fig 8: A Cowstail set made of 11mm climbing rope. The butterfly knot connects directly to the sit-harness maillon.

Cowstails are usually tied using a single 10 foot (3 meter) piece of 10-11mm climbing rope. Dynamic rope is slightly preferable. Several different knots can be used and the knots described here are only recommendations. The longer tail is fitted with a locking carabiner and the shorter tail with a non-locking carabiner. Cowstails are designed to be a quick attachment system and quick links should NOT be used. A ½ Fisherman’s (Grapevine) knot is excellent for tying the carabiners to the tails because it cinches around the carabiner to hold it in proper orientation. Other knots may require the use of a rubber band or tape to hold the carabiner properly. A butterfly or figure-8 on a bight knot is usually used at the sitharness attachment (see figure 8).

*Be sure to secure the tails on all cowtail knots with duct tape. Unsecured tails can jam into ascenders and cause severe problems. (See figures 8 & 9)* The cowstails MUST be adjusted to accommodate each individual. This is the single-most critical adjustment of the Frog system and pre-made cowstails are seldom the correct length. Improper lengths can cause many problems, particularly during complex rope work. Generic methods for determining cowtail length have been published and most are notoriously unreliable. Recommendations such as: “When the cowstails are attached to the sit harness, they should touch the chin or reach the tip of your nose,” do not address the real issues. Specific body proportions of the individual must be paramount. The “chin” or “tip of the Fig 9A: The short tail Fig. 9B: The long tail must nose” lengths may work on average, should measure allow easy access to the upper approximately from the ascender when loaded. The but will cause great difficulties for elbow to the center of the length is good when the finger climbers whose body proportions are palm. Fingers should curl tips can just touch the top of unique. Often these climbers simply over top of carabiner. the ascender when loaded. accept the problems as “that’s the way it is” when in fact, the cowstails are not adjusted to fit the climber’s real needs. Better to base cowstails length on specific individual needs and the practical use of the cowstails: 1. The length of the climber’s arms compared to the rest of the body is the primary determining factor for cowstail length. “Croll to Chin or nose” distance is irrelevant and in my opinion, a foolish basis for determining tail length. 2. The actual use of the cowstails. The climber must be able to perform the necessary functions on rope. Can the climber reach the equipment? Will it do the job? The cowstails should be adjusted with the sit-harness on and the climber and the cowtails attached directly to the harness Maillon via a butterfly knot. The short tail is less critical than the long one, but still important. After loading the knots, the short tail should be approximately the same as the distance from the elbow to the middle of the palm of the hand. This takes the individual’s arm length into account and consequently their ability to actually reach the gear! If the fingertips can close over the top of the carabiner when the cowtail is pulled taut, it is usually sufficient (see figures 9 A&B).

The long tail is often used as the safety to the upper ascender and its length is more critical than the short tail. Its length should be guided by a basic premise: When attached to your upper ascender, it can not allow your ascender to be out of practical reach. It makes no sense to have a safety tether that is longer than you can reach. Just being able to reach the handle of the ascender is NOT sufficient. Here’s the test: When hanging from your long cowtail attached to the upper ascender, you must be able to reach the cam of the ascender to release it. If the tail is too short, it will restrict your maximum Frog stroke. If too long, you can be stranded on rope if the ascender is out of reach. It usually takes several attempts to adjust the cowstails. Be sure to load the tails with full body weight and set the knots each time when adjusting them. Don’t shortcut this adjustment or you will regret it. Remember that the tails will lengthen slightly with use. Link #7 – The proper gear positioning This is the subject of considerable debate. Froggers agree that proper gear positioning prevents many problems, but they don’t agree about which problems are important. Rather than just saying “Do this because it’s done this way,” I present my preferences with explanations based upon my own and other caver’s practical experience. For both right and left-handed climbers, the cowstail set should be attached to the screw link on the LEFT side of the Croll (the closed side of the Croll and to the climber’s extreme left). When a left-handed Croll is manufactured, you can put the tails on the other side! Placing the cowstails on the open (right) side of the Croll allows them to jam up against the Croll cam and safety catch when the tails are loaded. This often makes it very difficult to open the Croll. If the Croll is left open, it is also possible for the cowstails to enter the Croll through the open gate and foul the system.

Figs 10 A & B: A common gear placement for a right handed climber is shown in Figure 10A (left). Be sure that the Croll is closed before placing descender on the climber’s right. Figure 10B (right) illustrates the danger of placing the descender on the climber’s right with the Croll gate open. The descender carabiner has entered the Croll gate and closed the cam on itself. This can seriously damage the Croll and/or the carabiner. Cowstails can also jam into the Croll if placed on the right side.

Any descender may be used with the Frog System, but some are better suited than others for complex rope maneuvers with the system. In general, the type of caving that will be done is the best determining factor in selecting a descending device. Descenders can either be directly connected to the half round or connected via a locking carabiner. The descender may be attached to either the right or left side of the Croll. Although righthanded climbers usually prefer to attach the descender to the right side of the Croll, the practice warrants this warning: With the descender on the right side of the Croll (open side of the Croll and the climber’s extreme right), there is the possibility that the descender or the attachment carabiner may jam itself into the open Croll (see figures 10 A&B). This is very annoying and sometimes difficult to rectify. ALWAYS be sure that the Croll cam is closed before placing a descender on the right. The order: For right-handed climbers when looking down at their own gear, the preferred positioning on the Maillon screw link is: Cowstails on your extreme left, Croll in the center and descender on the extreme right. Left handed-climbers can place the descender on either side although the same warning applies if placed on the right side of the Croll. Link #8 - The top ascender/foot loop

Fig 11A The foot loops are often connected to the upper ascender with a quick link. This allows easy attachment and detachment of the safety tether (cowstail).

Fig. 11B A common foot loop configuration: a single line to a double loop. Some climbers prefer a single large foot loop for both feet. Others use separate lines to each foot.

The upper ascender is usually a handled ascender although a non-handled ascender may be used. Foot loops run from the top ascender down to both feet. Foot loops may be made of either small diameter rope (8 mm is common), 5.5 mm spectra cord or webbing. Many climbers attach the foot loop cord to the ascender with a 6-8 mm oval Maillon Rapide link (see figure 11A). Maillon makes attaching and removing the safety tether carabiner easier than clipping it into the holes of the ascender or a knot loop. It also increases ascender versatility since the foot loops may be easily removed if necessary.

Foot loop configuration is a matter of personal preference. Some climbers use a single line with one large loop for both feet and some prefer a separate line for each foot. The most common setup is a single foot line ending in a double loop knot such as a double figure 8 (see figure 11B). Many climbers place plastic tubing inside the foot loops to

make the loops easier to get the feet in and out of and to reduce wear. Both foot loops are the same size, usually just big enough to get on your feet without using your hands. The length of the foot loops should generally be as short as possible without allowing the two ascenders to hit each other when the legs are fully extended. A starting length recommendation is: When the legs are fully extended during climbing, the two ascenders should be close to each other, but should not touch. With experience, this length can be modified to suit the individual climber’s needs.

Fig. 12 With legs fully extended on rope, the upper and lower ascenders should be very close to each other.

Proper foot line adjustment is critical and VERY personal. If too short, the lower ascender will hit the upper ascender before the legs are fully extended during the standing part of the cycle. Short foot lines also throw the climber away from the rope if too large a step is attempted. Just because you can take a bigger step does not mean that you should.

Conversely, if the foot loops are too long, vertical progress is limited on every stroke. Overly long foot loops also make rope maneuvers such as changeovers and rebelays very difficult. Do not dogmatically attempt to get the two ascenders close to each other by over-lengthening the foot lines. This hinders the ability to unload cowstails during changeovers and when unclipping from rebelays, particularly if the climber’s arms are short. Arm length (specifically: the Croll-to-fingertip distance) affects the potential length of the long cowstail/safety tether, which is the limiting factor of the Frog system. The practical length of the foot loops will vary depending upon the proportion of the climber’s leg length to their Croll-to-fingertip distance. With experience, foot line lengths will be modified depending upon personal preferences and body type. Materials list 1. A sit-harness with a low tie-in point designed for the Frog system. Do not use a rock climbing harness. 2. A 10mm half round (semi-circular) screw link or the equivalent designed for human loads for the sit-harness. Do not use screw links purchased at a hardware store! Buy the screw link from a reliable caving/climbing dealer. Do not use carabiners on harnesses designed for a semi-circular screw link.

3. A “Croll” type chest ascender. 4. A 10 foot long (3 meter) chest strap of 1 inch (25mm) flat webbing with buckle OR a pre-made Frog chest harness. Avoid designs that connect to the rear of the sit-harness. 5. A handled mechanical rope ascender. It is not essential to use a handled ascender as the top ascender in the system, but most climbers prefer it. 6. At least 15 feet (4.5 meters) of 8mm climbing rope for the foot loops. Spectra cord or the equivalent is also acceptable. 2 feet (.75 meters) plastic tubing for inside of foot loops is optional 7. At least 10 feet (3 meters) of 10-11mm climbing rope for cowstails. Dynamic rope is preferred, but not mandatory. Factory made cowstails are not recommended. They are usually the wrong length and NOT adjustable. 8. Two (2) “D” shaped carabiners: One (1) wide-mouth, non-locking, “D” shaped, carabiner for the short cowtail. One (1) wide-mouth, locking, “D” shaped, carabiner for the long cowtail. 9. One (1) 6-7mm oval screw link to attach foot loops to upper ascender. Do not use screw links purchased at a hardware store! Buy the screw link from a reliable caving/climbing dealer. The Good, the Bad and the Ugly The Good: 1. The Frog System is virtually universal. It is unquestionably the world-wide standard. This means that training and methods are relatively consistent around the world. Most expedition rigging is designed with the Frog system in mind. It is the first ascending system a caver should master. 2. The Frog System is simple, light and very compact. It is slightly faster than the Mitchell System (my opinion AFTER testing) for crossing mid-rope obstacles such as rebelays. It is well-suited for multiple pitch caves where the pitches are relatively close together or relatively short (less than 40 meters). 3. “Gearing up” and “gearing down” (travel readiness) times are minimal with the Frog. No other system approaches the Frog in this regard. 4. Initial tests indicate that the Frog system may be one of the best overall ascending systems for carrying heavy (expedition size) cave packs.

The Bad: 1. The Frog requires more energy and/or more time to climb an unobstructed rope when compared to many other systems. The longer the pitch, the less effective the Frog becomes. 2. The Frog is extremely equipment specific and is somewhat difficult to adjust properly. Once it is done however, it need not be redone until it is time to replace equipment such as cowtails. The Ugly: 1. Extensive testing indicates that certain body types are significantly less effective with the Frog system than others. If you fall into that category, you will be able to use the Frog, but it will require more energy than more efficient body types. 2. Good Frogging technique requires lots of practice and constant attention to maintain a vertical position. Fatigue can hamper proper technique, forcing the arms to take more of the load. References “The Frog Ascending System – A Detailed Description” by Matt Oliphant. NSS News, May 1996. On line publication: October 14, 2000, with revised discussion of pick-offs at: http://technology.darkfrontier.us/Vertical/Frog/ Author’s note: Oliphant’s article is authoritative and based on extensive practical experience. It does however, omit some of the small details that are addressed in this article. It contains more than Oliphant’s personal recommendations for constructing a Frog system. He has also included procedures for negotiating many of the rope maneuvers common to expedition-style caving. This is good, solid information from an authoritative source. On Rope: North American Vertical Rope Techniques for Caving by Bruce Smith and Allen Padgett. National Speleological Society Vertical Section. Second edition, Jan. 1997. Author’s note: The section of On Rope discussing the Frog system has a definite American bias toward the setup and use of the Frog system. This differs in some ways from the International style, but is worth reading for another point of view. The approach is somewhat superficial and lacks practical insight on the details of the Frog system. It occasionally takes unnecessary “pot shots” at European techniques. Notes on Alpine-style SRT. This is an on line publication at: http://wasg.iinet.net.au/srt/srt.html Author’s note: This is an Australian-based web site. It approaches the Frog System as the ONLY way to ascend a rope and dismisses other systems without intelligent cause. It is somewhat superficial in its descriptions and illustrations, but does carry the disclaimer that these are “notes” on the topic. Some of the recommendations are directly at odds with notions that both European and American authorities agree upon. It briefly outlines procedures for negotiating a number of common rope obstacles and situations. Vertical - A Technical Manual for Cavers by Alan Warild. Fourth Edition, 2008. A pdf version can be downloaded at: http://www.cavediggers.com/vertical/ Author’s note: Another Aussie approach to general vertical caving. Comprehensive regarding the Frog. However, the descriptions and conclusions about the effectiveness of other ascending systems are inaccurate to varying degrees, obviously due to lack of actual experience with them. Detailed information about harnesses and the Frog system. This is a good, in-depth resource.

Life on a Line – The Underground Rope Rescue Manual by Dr. David Merchant. Second Edition, June 2007. Downloadable for a price at: http://www.lifeonaline.com/ Author’s note: “Life on a Line” is more about cave rescue than the Frog system. However, valuable information about the Frog’s good and bad points can be inferred by examining the rescue tactics targeted at both the Frog method and the gear. It is interesting that Merchant’s rescue methods as described in print seem somewhat at odds with practical rescue experience. This is particularly true of some of Merchant’s equipment recommendations. Merchant informed me that he was limited by British publishing restrictions related to an “official” rescue publication. A comprehensive work, but unfortunately somewhat suppressed. Alpine Caving Techniques by Georges Marbach and Bernard Tourte. English Edition, Translated and adapted by Melanie Alspaugh. 2002. Author’s note: Truly authoritative, but extremely biased toward French methods. There are arrogant and unnecessary swipes at anyone other than the “true believers.” One gets the idea that all other ascending systems are worthless under all conditions. A diligent reader can separate mindless dogma from fact and it is well worth reading this book carefully. In many ways, this is the best overall text on the topic of Alpine SRT. "Typecasting the Vertical Caver" by John Woods. Nylon Highway #53, Dec. 2008. National Speleological Society Press. On line at: http://www.caves.org/section/vertical/nh/53/Typecasting.pdf Author’s note: This is an ergonomic study of the Frog ascending system. Specifically addresses the topic of different body types and their potential effectiveness with the Frog System. It reveals surprising test results for many Frog system devotees. "Comparisons of the Frog and Mitchell ascending systems for crossing common mid-rope obstacles" by John Woods. Nylon Highway #53, Dec. 2008. National Speleological Society Press. On line at: http://www.caves.org/section/vertical/nh/53/MitchvsFrogPart2.pdf Author’s note: Real-world comparisons of the Frog and Mitchell ascending systems. It discusses the both system’s effectiveness in negotiating rebelays, crossing knots, deviations, for changeovers and for overall vertical effectiveness. Contains comparative information on relative system sizes, weights, and bulks. Dispels many common myths. “Converting the Mitchell System to a Frog System" by John Woods. Nylon Highway #53, Dec. 2008. National Speleological Society Press. On line at: http://www.caves.org/section/vertical/nh/53/ConvertMtoF.pdf Author’s note: A practical method of converting a Mitchell System to Frog system on-site or on rope.