This pamphlet is based on the experiences of the Scouts and Scouters of Boy Scout Troop 940 and several books which are listed in the reference section. The equipment, procedures and skills presented are not the only ones available. However, we have found them to be safe and provide a great experience for our Scouts.
WARNING VERTICAL ROPE WORK IS DANGEROUS AND REQUIRES SPECIALIZED KNOWLEDGE, TRAINING AND PERSONAL EXPERIENCE. SERIOUS INJURY OR DEATH COULD RESULT FROM THE USE OF THE TECHNIQUES AND EQUIPMENT DESCRIBED IN THIS GUIDE. THE BOY SCOUTS OF AMERICA AND TROOP 940 TAKE NO RESPONSIBILITY FOR USE OF THESE TECHNIQUES.
Safety is our primary priority in all rope events. Before every session,
the Rope Captains should point out that safety is everyoneís job.
We should look out for each other. This includes students watching out for
our Rope Captains.
REMEMBER: SAFETY IS NO ACCIDENT
Be sure to touch each part with your hand to insure that is locked, hooked or attached. Belayers use the command "Show me" and the rappeller will touch each component checking that they are locked.
The Margin of Safety is the strength of your rope system divided by the load, and it is your buffer against disaster when things go wrong. For example, let us say a rescuer weighs 170 pounds. Then let us say that the rappel rope, anchor, harness and other parts of the system will hold 170 pounds. The Margin of Safety is 170 divided by 170 or 1:1. There is no margin for any increase in the load. If the weakest link in the system is 1700 pounds, 1700 divided by 170 equals a Margin of Safety of 10:1. The National Fire Protection Association Standard 1983 recommends a 15:1 Margin of Safety. If you have a 200 pound person, you want to have a system capable of 3000 pounds.
The rope skills that we teach are based on systems that are backed up by another system. Each anchor point is backed up by another system. However, there are limitations on how far you can carry this approach. You can get so carried away with a backup for everything that the system becomes so cumbersome or take so long that you are no longer functional. You must have the right balance of the likelihood of failure, the ways to minimize the possibility of failure, and other ways to back up the system. Make sure that the back up does not defeat the function of the original piece of equipment. For example, backing up a healthy tree that is more than 12 inches in diameter may not be effective.
Helmets should be lightweight and comfortable. Best construction materials are plastic or fiberglass. They should be adjustable and have chin straps. Everyone in the rappelling areas must wear a helmet.
Gloves must be worn during a rappel or a belay to keep from getting a
rope burn from the friction generated by the ropeís passing through
the hands. Leather gloves are the best. Nylon gloves will melt and cloth
gloves tend to wear out quickly.
Brake hand must be gloved.
Loose clothing can become caught in the carabiner, resulting in your being hung-up midway down the cliff.
Carry a 6 ft length of prusik rope encase you do get hung-up. You can set a prusik knot with a foot loop, step up to relieve the tension on the system and clear the problem.
When selecting a rope on which your life is going to depend, strength
must be the first and foremost consideration. Types of physical construction:
Laid rope is constructed from 3 separate bunches of continuous nylon filaments
that are twisted together. Laid rope has a tendency to untwist and stretch
as weight is placed on it. Goldline is the most popular and a 7/16 Goldline
has a tensile strength of 4500-5500 pounds.
In braided ropes the yarns are plaited and braided around an inner core,
forming an outerwoven jacket or sheath. This rope is called "Kernmantle"
rope and consists of a core or "kern" of many small laid cords.
Each cord is made up of twisted nylon filaments. Every filament runs the
length full length of the rope. The cords are held together by a tightly
plaited sheath called a "mantle" which protects the rope from
cuts and abrasion. 11 mm Bluewater II strength is 6,000 lbs.
Dynamic Rope: All ropes used for lead climbing are dynamic - they are designed
to stretch when fallen on, absorbing and dissipating the energy generated
by the fall (like a rubber band). Dynamic ropes are multicolored and may
stretch as much as 10%. (a 100 ft rope will stretch to 110 feet)
Static Rope are designed with minimal stretch and are used for rappelling
and caving. Normally static ropes are a solid color or one color with a
dark strip. Static rope will stretch about 1-2%.
Ropes are certified by UIAA (Union Internationale des Associations díAlpinisme)
We highly recommend investing in 11 mm kernmantle rope for rappelling/ascending.
The following table illustrates the pounds of pressure created by a sudden
drop. Long fast descents with quick breaking action can create these types
of stress on the rope.
Static Weight 100 pounds dropped 5 feet equals 500 foot pounds 100 pounds
dropped 10 feet equals 1000 foot pounds 100 pounds dropped 15 feet equals
1500 foot pounds 100 pounds dropped 20 feet equals 2000 foot pounds 100
pounds dropped 25 feet equals 2500 foot pounds
200 pounds dropped 5 feet equals 1000 foot pounds 200 pounds dropped 10
feet equals 2000 foot pounds 200 pounds dropped 15 feet equals 3000 foot
pounds 200 pounds dropped 20 feet equals 4000 foot pounds 200 pounds dropped
25 feet equals 5000 foot pounds
Wear and knots can seriously reduce these figures.
Webbing (sometimes called tape) is essentially flat rope. It most common
usage is for slings, harnesses (Swiss seats) and rigging. The size are most
often used is I inch and has a breaking strength of 4,500 lbs.
Webbing is made in two forms: flat and tubular. Both appear flat, but tubular
is hollow. Tubular is usually stronger and more flexible than flat. Tubular
is constructed in two very different ways: spiral structure (shuttle loom
construction) which is very strong and chain structure (needle loom construction),
which is weaker and has a lengthwise seam.
Melt ends to prevent unraveling. Mark ends with identification and length.
Store the same way as rope. Create a chain to store easily.
Check stitching for looseness.
Home sewn webbing is only 10% or the strength of commercially sewn web.
When you buy a harness, try it on. Make sure it fits comfortably and
has a good quality buckle. Look for padding, equipment hooks, belay loops,
adjustable fit.
ALWAYS DOUBLE WEBBING BACK TROUGH THE BUCKLE.
Carabiners (sometimes called biners or snap links) undergo more research,
engineering and testing than any other product used for climbing. All this
attention is warranted because few products are subjected to the stress
and abuse carabiners endure. Carabiners can hold 4000 to 6000 pounds, making
them strong enough to handle the loads found in normal climbing situations.
Carabiners are designed to be loaded along their major axis (end to end)
with the gate closed. Loading in any other way will reduce its strength
by 50% to the point of failure.
Biners are used for a multiple of functions that basically replace knots:
rigging anchors, rope attachment, belaying, rappelling (Army style - not
recommended)
There are many different types of decenders on the market today. The
most common are the "Figure 8" and "Rack". The Figure
8 with ears or "Rescue 8" is the best for rappelling up to 200
feet. after that the rope becomes a self belaying and is cumbersome to "feed".
The Rack can be adjusted to different friction settings.
Decenders must be inspected before and after each rappel. Retire if worn
or dropped higher than waist high onto a hard surface. Wear can be caused
by rappelling with a dirty rope.
Just like decenders, there are many different manufactured and types. Gibbs ascenders use a cam which does not damage rope and can be used as self belays in rescue systems. Petzel and CMI both make ascenders which are easier to install/remove but the cam "fuzzes" the rope more than a Gibbs. They all need a chest harness to keep you in a vertical position.
There are three types of knots used in vertical rope work: End-Line, Mid-Line and End-to-End.
In addition the Prusik Knot is a friction knot for ascending or belaying in rescue operations.
The following tests were done by Mr. Jerry Smith of the California Mountain
Company using Wellingtonís 1/2 inch Rhino Rescue Rope pulled end
to end. Results will be different on other sizes and brands.
Knot Strength in Lb. Percent Lost Control Rope 10,705 - Bends Figure
Eight Bend 8,640 19% Double Fishermanís 8,440 21% Loops Bowline
7,180 33% Inline Figure 8 6,280 41% Double Figure 8 8,820 18%
Dressing a knot involves the orientation of all the knot parts so that they are all properly aligned, straightened or bundled, and so the rope parts of the knot look like the picture books. Neglecting this activity may result in an additional 50% reduction in knot strength.
Setting a knot involves tightening all the parts of the knot so that all of the rope parts touch, grab, and cause friction upon other parts of the knot so as to render it operational. A loosely tied knot can easily deform under strain and change in character. For instance, an effectively set bowline required tension in three directions at the same time.
Vertical ropework demands a skilled rigger. The rigger selects the site and ties off the ropes and pads. Securing the rope is a critical skill that should be mastered by all climbers and rappellers.
1. The rigging should provide for ease as well as safe access to the top of the drop. 2. The rigging should be strong enough to withstand a shock load as strong as the rope. 3. The rigging should allow the rope to hang free to avoid any unnecessary abrasion 4. The rigging should avoid hazards such as waterfalls, loose or unstable rocks, sharp edges, mud or curved breakovers. 5. After rigging, rope should be long enough to reach the bottom. 6. Whenever possible, use a natural rig point to preserve the ecology.
1. Select the site. The site should be sought and designated for climbing and rappelling - not just any rock that looks good. Rock should not be unduly fractured, brittle, loose, slippery or crumbly. Soft sandstone should be avoided. 2. Select anchors, Primary and backup. Set up two ropes 3. Tether Lines: Many accidents result from a lackadaisical attitude at the edge. It is never smart to hand-over-hand down a tether line to the edge. Secure tether lines and anyone near the edge must be hooked in. 4. Carpet or padding used to protect the rope from the edge of the rock. 5. Wrap trees with cloth to protect bark and ropes. 6. Lower first rope to the bottom. Always allow an extra 10 feet for belaying. 7. Always use a tensionless anchor. 8. Use a figure 8 or double figure 8 and biner to tie off main rope on anchor. 9. Mark off "landing zone" and keep it clear of all non essential personnel.
NEVER buy used equipment. You have no guarantee of how it was used. NEVER buy surplus military equipment. It is designed for different functions.