Ascending Multi-System

Updated: 2018-11-06

The Ascending Multi-System allows you to reuse components and easily switch among all major ascending systems: Frog, Rope Walker, Mitchell, and Texas.

Introduction

Most cavers only use a Frog System for vertical caving. However, there are numerous other systems with their own advantages, and these systems share many of the same components. I have developed what I call the Ascending Multi-System, which allows cavers to easily switch among:

  • Frog System
  • Rope Walker
  • Mitchell System
  • Texas System

If you have a vertical system, then you already have most (or all) of what you need for these other systems. With a few tweaks, you’ll be able to easily switch to any of these systems, even in the field at the base of a climb!

This article is not a complete discourse on any single system. For detailed information on vertical systems and techniques, I highly recommend the book On Rope by Bruce Smith and Allen Padgett, ISBN 1-879961-05-9.

What is an Ascending Multi-System?

An Ascending Multi-System is a set of vertical gear that easily switches among multiple vertical systems. I coined the term because I don’t know anyone specifically optimizing a set of vertical systems for fast and easy switching.

The multi-system presented here can easily convert to Frog, Rope Walker, Mitchell, or Texas. Since most components for the individual systems overlap, there are very few extra components to carry. Upgrading from a single-purpose Rope Walker or Mitchell adds virtually nothing in terms of weight and bulk, while upgrading from a Frog adds about 50% more weight but can build four different ascending systems, as well as have redundancy in case components fail.

Which Ascending System is Best?

The “best” system depends on the specific ascent. What is best for one ascent might not be best for another. This is why the Ascending Multi-System is so beneficial.

Frog and Mitchell are both great all-purpose systems, but Mitchell is bulkier. Frog is inefficient if done improperly, while Mitchell and Rope Walker are easier for beginners (or tired cavers) to do correctly. For many short climbs where you wear your gear between ascents, Frog and Texas are good choices. Texas is small and simple but horribly inefficient. If you have a long ascent, Rope Walker is undoubtedly the best choice—it is by far the most efficient.

Table 1: Best (and worst) ascending systems by task.

Task Frog Rope Walker Mitchell Texas
Efficiency Good Best Good Poor
Heavy loads Best Good Good Poor
Size/weight Good Poor Poor Best
Fast on/off Good Poor Poor Best
Ease of fit Poor Good Good Best
Crossing lips Good Best Poor Poor
Crossing knot/rebelay Best Poor Good Good
Downclimbing Good Poor Best Poor
Versatility Good Good Best Poor
Changeover Good Poor Best Good

Weight Comparison

Since all the systems use overlapping components, upgrading to an Ascending Multi-System has only a minor impact on size, weight, and additional components. I won’t go in the details here, but I do have a complete breakdown of weight and components in my Ascending Multi-System manual, including a list of individual components. (The component list makes a handy shopping guide.)

These weights are based on my personal system. They are only the ascending systems and do not include the descending components (e.g., rack or bobbin). Although your ascending systems may vary slightly, these serve as a good basis for our weight comparison.

As you can see from the table, a complete Ascending Multi-System adds about 50% more weight than a typical Frog, and virtually no noticeable difference to the Rope Walker and Mitchell. However, the advantage to the Ascending Multi-System is that you can build all four systems with it instead of being stuck with just one, plus have redundancy in case of component failure.

Table 2: Weight comparison. For more detail, see the Ascending Multi-System manual.

Weight Frog Rope Walker Mitchell Texas Multi-System
Minimum 2.00 kg (4.4 lb) 2.39 kg (5.3 lb) 2.57 kg (5.7 lb) 1.76 kg (3.9 lb) 3.05 kg (6.7 lb)
Maximum* 2.00 kg (4.4 lb) 2.85 kg (6.3 lb) 2.96 kg (6.5 lb) 1.96 kg (4.3 lb) 3.05 kg (6.7 lb)

* Maximum includes all optional functionality, such as a safety ascender for Rope Walker and Mitchell System or a second foot loop for Texas System.

Changes to Standard Systems

To accomplish all this reuse and quick field conversions among systems, we do need to tweak a few systems.

Frog Chest Harness

I replace the troublesome Frog chest harness with a bungee. The Frog chest harness is typically a tangled mess, must be tightened to the point that the user is hunched over, and then tightened more once on rope. In contrast, a bungee takes only a second to slip on and off and doesn’t need to be readjusted.

If you need the Frog chest harness to keep your body upright, know that the typical Frog chest harness is not designed to be load bearing. Instead, try a Rope Walker or a Mitchell.

Frog Cow's Tail

By default, this Ascending Multi-System only has the short cow’s tail available because the long cow’s tail is used to connect the handled ascender to the seat harness. Thus, the short cow’s tail is available for approaching climbs and for the rare ascending-to-descending changeover.

However, the Ascending Multi-System includes a second complete cow’s tail that you can attach to your half-round. This isn’t shown in the diagrams but is an option. I recommend always attaching it so the longer tails can be used for approaching drops or hanging your pack as you ascend.

Frog Foot Loop

Instead of the typical Frog foot loop, by necessity this Frog system uses a rope connected to two foot straps with chicken loops. You do not have to use the chicken loops while using the Frog, but they are required for all the other systems.

So Many Rope Walkers…

There are numerous Rope Walker systems, identified by their bungee configuration: Double Bungee, Single Bungee, Bungee and a Half, or No Bungee. The Rope Walker that best fits our goal of reusability is the Double Bungee using a Petzl Croll as the foot ascender and a Petzl Basic as the knee ascender.

Additionally, instead of the typical single roller chest harness, you will need a double roller variety to reuse for the Mitchell. In North America we’re forced into a double roller anyway because currently the only commercial chest roller you can buy is the PMI double chest roller.

Build Your Own

Ascending Multi-System

Know Your Knots!

All vertical cavers should be competent in knots. You are trusting your life to a knot, so you should be able to identify the knot and know that it is tied correctly. And you need to know how to tie the knots yourself because you might need to retie or adjust something when you’re on your own, like in the middle of an ascent.

At the bare minimum, I think all cavers should know:

  • Figure 8 on a Bight
  • Alpine Butterfly
  • Grapevine (Double Fisherman)
  • Barrel (Triple Fisherman)
  • Prusik
  • Bowline
  • Water knot

If you don’t know how to identify and tie all of these, study my Knots article before continuing any further and before getting on rope. Your life literally depends on it.

Custom Fit Your Components

Buy three 10 ft (3 m) sections of 9 mm dynamic rope and one 6 ft (2 m) section of 3/16 in (5 mm) bungee. We are building two cow’s tails, a long line for the Mitchell, and a bungee for the Rope Walker and Frog. You will need to partially assemble the ascending systems to check sizes. If you are not familiar with the assembly, see the respective systems below.

Note that cow’s tails typically have two sides with one side twice as long as the other. However, for the Rope Walker knee ascender, I find a ratio of 1:1 works best. To differentiate, I will refer to the cow’s tails as 2:1 and 1:1 respectively.

Your lengths and cow’s tail ratios may vary from mine. However, for reference, I am 6 ft tall and my final ropes are 8 ft long. My long line is 4.5 ft tied. One cow’s tail has 2 ft and 1 ft sides (2:1). My other has 1.5 ft sides (1:1). My bungee is 5 ft long and 3.5 ft tied.

Do Not Use Half-Barrel Knots

A common method for attaching vertical gear is to tie a half-barrel knot. One of the advantages is that it cinches down on your gear. This is a fine practice but is not suitable for the Ascending Multi-System because we regularly switch components. The cinching makes switching extremely difficult, so we need something with a fixed loop.

Instead, I recommend a figure 8 on a bight or a bowline (preferably with a Yosemite tie off) for your end loops. You can use a half-barrel, but only if you add an overhand knot inside the loop to serve a stopper and prevent it from cinching down fully.

Measure Your Mitchell Long Line

The long line has figure 8 loops on both ends and extends from your foot strap to just above your chest harness.

  1. Tie a figure 8 loop in one end and attach it to your foot strap.
  2. Put the rope through a roller in your chest harness.
  3. Tie another figure 8 loop about 2 in (5 cm) above your chest harness when standing. Do not cut off the excess rope!

Measure Your Cow's Tails

Our cow’s tail has figure 8 loops on both ends and a butterfly knot offset from the middle. Do not use half-barrel knots for the ends. These cinch down, making it difficult to reconfigure.
  1. Tie a figure 8 loop in one end of a rope.
  2. Tie a butterfly knot in the middle of the rope so the figure 8 in step 1 is about level with your chin when the butterfly knot is attached to your seat harness.
  3. Tie another figure 8 loop in the other end of the rope so that side is half the length of the side you just tied (2:1).
  4. Test the cow’s tail on rope with both a Frog and a Mitchell. You want to balance these opposing factors:
    1. Priority: Long side must keep the top of the Frog handled ascender within reach of your fingertips.
      Secondary: Long side should allow you to reach the top of knee ascender. If not possible, use a small tether.
    2. Short side should be short enough to perform a Frog changeover but long enough to allow you to stand with the knee ascender for the Mitchell or Texas.
  5. Tie a second cow’s tail with both sides the same length (1:1). Attach this to your Rope Walker knee ascender.
    1. The side to your foot strap must be long enough to prevent your ascenders from hitting during steps but still keep the knee ascender below your half-round.
    2. The side to your half-round should be long enough to allow you to stand.

Make Your Rope Walker Bungee

  1. Put on your Rope Walker system without the bungee.
  2. Tie a figure 8 loop in one end of the bungee and attach it to your Croll with a 3.5 mm screwlink.
  3. Feed the other end of the bungee through the pulley and to your knee ascender. Note: pulley always remains on bungee. When not in use (e.g., using bungee to replace Frog chest harness), move it to rear above your seat harness.
  4. Raise your knee ascender as you step up and tie a figure 8 loop in the bungee 4–6 in (10–15 cm) above the ascender.
  5. Attach the bungee to the ascender with a 3.5 mm screwlink.
  6. Take several test steps up, alternating feet. The bungee should be slightly tight, keeping both ascenders upright.
  7. Cut off any excess bungee and heat seal.

Note that over time the bungee will stretch. You can either retie your end loops, or you can simply tie a few overhand knots near the ends to shorten it. (Don’t tie them near the middle because that will interfere with the pulley.)

Cut and Retie Your Ropes

  1. Mark the potential ends of both cow’s tails and the long line. Untie all knots and find the longest mark.
  2. Cut all ropes to the longest mark (making all the same max size adds redundancy). Be sure to properly seal the ends.
  3. Retie your long line and both cow’s tails. To fit, you may need to adjust the loop diameter or tail length of the knots. You can also use different knots: the bowline uses the least amount of rope, the figure 8 uses more, and the half-barrel with stopper uses the most.

Recheck Sizing

  1. Load all knots on rope (crucial to final sizing).
  2. Recheck the sizing of all your systems.
  3. If necessary, adjust the knots then repeat these three sizing steps.
Ascending Multi-System: Frog

Frog System

Most popular. Good general purpose. Small and lightweight. Proper sizing and technique is critical to efficiency.

Requires

  • Frog seat harness
  • Petzl Croll
  • Handled ascender
  • Cow’s tail 2:1
  • Long line
  • L/R foot straps
  • Bungee
  • Carabiner
  • Two 5–6 mm oval screwlinks
  • Two 4 mm delta screwlinks
  • Two 3.5 mm oval screwlinks

Optional 2nd Cow's Tail

  • Cow’s tail 1:1
  • Two carabiners

Frog Assembly

  1. Croll on half-round to the right of all other gear.
  2. Bungee on top of Croll with 3.5 mm screwlink, over right shoulder, to back or left side of seat harness with 3.5 mm screwlink or carabiner.
  3. Handled ascender on long line with 5–6 mm screwlink to both deltas on foot straps (chicken loops optional).
  4. Cow’s tail mid on half-round, left of Croll; handled ascender on long side with 5–6 mm screwlink; carabiner on short.
  5. Optional second cow’s tail: Cow’s tail mid on half-round, far left. Carabiners on each tail.

Frog Sizing

  • Long line should place upper ascender slightly above the Croll when standing upright.
  • Cow’s tail to ascender should allow full squat but keep top of ascender within reach. Short side is generally half of long.
  • Bungee should be tight enough to keep Croll upright when squatting and very tight when standing.
  • To quickly shorten long line or bungee, tie overhand knots.

Emergency Repair

  • Bungee: (1) use one hand to hold Croll upright during sit-stand, (2) make a carabiner chest harness, or (3) replace bungee with rope or webbing. Warning: do not loop around only neck because of the choking hazard during falls. Instead, go over shoulder to seat harness.
  • Cow’s tail: use without. Warning: dangerous if Croll fails. Use chicken loops!
  • Long line: (1) retie cow’s tail as long line, (2) add cow’s tail and convert to Texas, or (3) add chest harness and convert to Rope Walker.
  • Foot strap: (1) use one foot, (2) retie large loop at end of long line for both feet, or (3) make a cinch strap.
  • Seat harness: (1) make a diaper harness and resize system, or (2) switch to a Mitchell or Rope Walker without a seat harness.
  • Ascender: Use Basic or Prusik. To replace Croll, either use Basic on far left of half-round or use short-handled Prusik and manually advance.
Ascending Multi-System: Rope Walker

Rope Walker

Most energy efficient but bulky. Excellent crossing lips. Chest harness helps maintain upright position. Safety can be used while ascending for three points of contact.

Requires

  • Seat harness
  • Chest harness
  • Petzl Croll
  • Petzl Basic
  • Cow’s tail 1:1
  • L/R foot straps
  • Bungee
  • 5–6 mm oval screwlink
  • Two 4 mm delta screwlinks
  • Two 3.5 mm oval screwlinks
  • 1/8″ steel swivel pulley
  • 2″ (50mm) spring clip

Optional Safety

  • Cow’s tail 2:1
  • Handled ascender
  • 5–6 mm oval screwlink
  • Carabiner

Rope Walker Assembly

  1. Croll on delta of right foot strap.
  2. Petzl Basic on cow’s tail 1:1 mid with 5–6 mm screwlink; one side to delta on left foot strap; other on half-round.
  3. Bungee to tops of Croll and Basic with 3.5 mm screwlinks.
  4. Pulley attaches to bottom of chest roller with spring clip.
  5. Optional safety: cow’s tail 2:1 mid on half-round; handled ascender on long with 5–6 mm screwlink; carabiner on short.

Rope path: (1) optional safety to (2) chest roller to (3) knee ascender to (4) foot ascender.

Rope Walker Sizing

  • Knee ascender should be high enough to step without ascenders touching but remain below the seat harness.
  • Bungee should be tight at full step, very tight when standing.
  • Top of safety ascender should be within reach when loaded.

Emergency Repair

  • Chest harness: (1) make a carabiner chest harness, (2) attach bungee through safety ascender and use without chest harness, (3) retie cow’s tail or add long line and convert to Frog, or (4) convert to Texas.
  • Seat harness: (1) make a diaper harness or (2) use without seat harness but note upside-down foot hang can occur if chest harness fails.
  • Bungee: (1) convert to Texas, (2) if short, connect bungee from Croll to seat harness and manually raise Basic, (3) add long line and convert to Mitchell, (4) attach rope or webbing to ascenders and manually raise each ascender, or (5) reach down and manually raise each ascender.
  • Pulley: (1) use a carabiner or screwlink, or (2) use second roller.
  • Cow’s tail: (1) retie long line as safety, or (2) use without safety.
  • Foot strap: (1) convert to Texas, or (2) make a cinch strap.
  • Ascender: (1) convert to Texas, (2) replace with handled ascender, or (3) move Basic to foot and use Prusik for knee ascender.
Ascending Multi-System: Mitchell

Mitchell System

Good general purpose but bulky. Chest harness helps maintain upright position and increases efficiency.

Requires

  • Seat harness
  • Chest harness
  • Handled ascender
  • Petzl Basic
  • Long line
  • Cow’s tail 2:1
  • L/R foot straps
  • Two 5–6 mm oval screwlinks
  • Two 4 mm delta screwlinks

Optional Safety

  • Cow’s tail 1:1
  • Petzl Croll
  • Carabiner
  • 5–6 mm oval screwlink

Mitchell Assembly

  1. Handled ascender on long line with 5–6 mm screwlink, through right chest roller, to delta on right foot strap.
  2. Petzl Basic on cow’s tail 2:1 mid with 5–6 mm screwlink; long side to delta on left foot strap; short on half-round.
    Optional: switch feet and use Croll instead.
  3. Optional safety: cow’s tail 1:1 mid on half-round; Croll on one side with 5–6 mm screwlink; carabiner on other.

Rope path: (1) handled ascender to (2) left chest roller to (3) knee ascender. Also, (4) handled ascender long line through right chest roller to right foot.

Mitchell Sizing

  • Upper ascender should be just above chest harness when standing upright.
  • Knee ascender should be within reach of hand.
  • Top of safety ascender should be within reach when loaded.

Emergency Repair

  • Chest harness: (1) convert to Texas, (2) add bungee and convert to Frog, or (3) make a carabiner chest harness.
  • Seat harness: (1) make a diaper harness or (2) use without seat harness but note upside-down foot hang can occur if chest harness fails.
  • Long line: (1) convert to Texas, (2) retie safety as long line, or (3) add bungee and convert to Rope Walker.
  • Cow’s tail: (1) use with no safety, or (2) add bungee and convert to Frog or Rope Walker.
  • Foot strap: (1) convert to Texas, (2) add bungee and convert to single foot Frog, or (3) make a cinch strap.
  • Ascender: (1) use Croll or Prusik, or (2) add Croll and bungee and convert to either Rope Walker or Frog.
Ascending Multi-System: Texas

Texas System

Small and lightweight. Fast to put on and take off. Inefficient on rope. Best suited for short climbs (less than 30 ft or 10 m).

Requires

  • Seat harness
  • Cow’s tail 2:1
  • Cow’s tail 1:1
  • Petzl Basic
  • Handled ascender
  • Left foot strap
  • Carabiner
  • Two 5–6 mm oval screwlinks
  • 4 mm delta screwlink

Optional

  • Right foot strap
  • 4 mm delta screwlink

Texas Assembly

  1. Cow’s tail 1:1 mid on half-round; handled ascender on one side with 5–6 mm screwlink; carabiner on other.
  2. Petzl Basic on cow’s tail 2:1 mid with 5–6 mm screwlink; long side to delta on left foot strap; short on half-round.
    Optional: switch feet and use Croll instead.
  3. Optional: attach right foot strap with delta next to left for increased efficiency.

Texas Sizing

  • Top of upper ascender should be within reach when loaded.
  • Knee ascender should be within reach of hand.

Emergency Repair

  • Cow’s tail: (1) add long line and retie as cow’s tail, (2) add long line and convert to Frog, (3) add chest harness and long line and convert to Mitchell, (4) add chest harness and bungee and convert to Rope Walker, or (5) retie remaining cow’s tail to long line and convert to Frog without tether to handled ascender. Use chicken loops as backup!
  • Seat harness: (1) make a diaper harness, (2) add chest harness and foot strap and convert to either Mitchell or Rope Walker, which are both functional without a seat harness.
  • Foot strap: make a cinch strap.
  • Ascender: use Croll or Prusik.

I have compiled this article into a printable PDF. In addition to the steps, diagrams and sizing, it includes the complete weight analysis and bonus emergency components section.

You can print the manual normally, but it is specifically designed to be printed as a center-bound booklet on regular 8.5×11 inch paper as a handy field manual. Keep a copy in your vertical bag!

Ascending
Multi-System
Manual

Updated 2018-11-06

This article has also been partially published in:

  •  “Ascending Multi-System.” Texas Caver, Volume 59, Issue 4, December 2013, pp. 22–25. (Note: actual journal inaccurately self-documents itself as Volume 60 on the cover.)
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