J-_5_tree-climbing-field-guide-2005-edition.pdf

National Tree Climbing Guide 2005 Edition

National Tree Climbing Guide 2005 Edition

United States Department of Agriculture

Forest Service

Technology & Development Program

6700 Safety & Health March 2005

0567–2819–MTDC

United States Department of Agriculture

Forest Service

Technology & Development Program

6700 Safety & Health March 2005

0567–2819–MTDC

The Forest Service, United States Department of Agriculture (USDA), has developed this information for the guidance of its employees, its contrac-tors, and its cooperating Federal and State agencies, and is not responsible for the interpretation or use of this information by anyone except its own employees. The use of trade, firm, or corporation names in this document is for the information and convenience of the reader, and does not constitute an endorsement by the Department of any product or service to the exclusion of others that may be suitable.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, sexual orientation, or marital or family status. (Not all prohibited bases apply to all programs.) Persons with dis-abilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720-2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, Room 326-W, Whitten Building, 1400 Independence Avenue, SW, Washington, D.C. 20250–9410, or call (202) 720-5964 (voice and TDD). USDA is an equal opportunity provider and employer.

Dennis Davis Project Leader

USDA Forest Service Technology and Development Program Missoula, MT

TE02H23—Technical Services

March 2005

National Tree Climbing Guide 2005 Edition

National Tree Climbing Guide 2005 Edition ii

Acknowledgments

We would like to acknowledge the Forest Service employees whose work has helped us produce the National Tree Climbing Field Guide. Specifically, we would like to acknowledge:

Jerry Berdeen, Dorena Genetic Resource Center, Umpqua National Forest

Burnham Chamberlainø, Clackamas River Ranger District, Mt. Hood National Forest

Tyler Groo, Paulina Ranger District, Ochoco National Forest

Dale Kane, USDA Forest Service, retired

Chuck McDonnell, Quinault Ranger District, Olympic National Forest

Dennis Ringnes, USDA Forest Service, Genetic Resource Center, Camino, CA

Donna Stubbs, Supervisor’s Office, Fremont National Forest

Robert Walkowiak, Barlow Ranger District, Mt. Hood National Forest (writer and editor of the 1996 edition) iii

Contents

Acknowledgments ............................................................................ ii

About the Project Leader ................................................................ iv

1. Introduction

1.1 Training

1.2 Physical and Mental Fitness

1.3 Hazardous Duty Pay

1.4 Obtaining Climbing Equipment

1.5 Terms and Definitions

2. Preparing for a Climb

2.1 Basic Tree Climbing Equipment

2.2 Working as a Team

2.3 Checking for Hazards

3. Ropes, Knots, Splicing, and Webbing

3.1 Ropes

3.2 Knots

3.3 Whipping

3.4 Splices

3.5 Webbing

4. Climbing Safety—Equipment, Systems, and Procedures

4.1 Safety Equipment

4.2 Safety Systems

4.3 Safety Procedures

4.4 Using Explosives in Trees

4.5 Using Chain Saws in Trees

5. Climbing Equipment—Use and Care

5.1 Climbing Spurs

5.2 Ladders

5.3 Pole Steps

5.4 Swiss Tree Grippers

5.5 Ascenders

5.6 Tree Steps

6. Rappel Systems—Use and Care

6.1 Rigging and Rappelling

6.2 Sky Genie

6.3 Figure-8 Descenders

6.4 Rappel Rack

6.5 Prusik System

7. Rescue

7.1 Rescue Equipment

7.2 Rescue Procedures

8. Equipment Specifications

8.1 Carabiners and Screw Links

8.2 Climbing Belts and Safety Harnesses

8.3 Climbing Helmets

iv

Contents

About the Project Leader Dennis Davis is the specifications engineer for firefighting equipment with the Missoula Technology and Development Center in Missoula, MT. He is a volunteer firefighter/emergency medical technician and a battalion chief for the Frenchtown Rural Fire Department in Frenchtown, MT.

8.4 Ropes

8.5 Webbing

8.6 Miscellaneous Hardware

9. Handling Materials and Tools While in Trees

9.1 Pruning Branches

9.2 Harvesting Seed

9.3 Harvesting Scion Material for Grafting

10. References

1. Introduction

CClimbing and working in trees demands specialized equipment and skills. The potential for a serious injury or fatal fall is always present, so employees shall be trained and certified before they engage in tree climbing operations and activities. The Forest Service Health and Safety Code Handbook and applicable State and Federal safety codes shall be followed.

This guide has been produced and edited primarily by tree climbers working in the Northwest coniferous forests. Every attempt has been made to include comments from climbers in other parts of the United States as well as climbing techniques for different types of trees. Some procedures and techniques cited in this guide do not apply to some types of tree climbing done by Forest Service employees. Each job assignment must begin with a job hazard analysis that addresses the climbing dangers associated with the job, any unusual circumstances, and the employees’ plan for completing the task safely.

1.1 Training

Written materials, like this guide, play an important role in acquiring knowledge of tree climbing techniques. But no amount of reading can make a person a safe, efficient tree climber. That takes practice—practice under the guidance of an experienced and competent instructor or certified climber.

Study can prepare new climbers for their initial hands-on training or provide experienced climbers with a handy review.

This guide will give you a basic understanding of the equipment and the tree climbing techniques you must master to become a competent climber. The reference list in chapter 10 provides additional sources for increasing your tree climbing knowledge.

Climbers should review the equipment manufacturers’ specifications and instructions for equipment care and use.

Tree climbing assignments are accepted solely at the discretion of the climber. He or she alone is responsible for determining the advisability of climbing a particular tree, in a particular set of circumstances, on a particular day.

Work supervisors should promptly withdraw a climber’s certification or remove the climber from climbing duties when the climber

• is physically or mentally unable to climb safely,

• has an unsound safety attitude, or

• has exhibited unsafe climbing habits.

1.2 Physical and Mental

Fitness Tree climbing is arduous, demanding work that requires upper body strength and overall flexibility. Besides being physically fit, you must be able to identify and compensate for any physical or mental condition that might temporarily impact your climbing ability. Compensating may mean not climbing until the condition is no longer a problem.

1.3 Hazardous Duty Pay

Tree climbing work can be hazardous and hazardous duty pay is appropriate as outlined in the Forest Service Manual.

1.4 Obtaining Climbing

Equipment With a variety of commercial equipment available, it should not be necessary to fabricate your own. Before buying any equipment, check with your regional tree climbing coordinator. Make sure equipment meets safety standards and is suitable for the intended use. Buy only from reputable dealers familiar with the equipment and its construction, materials, and breaking strengths. Several such dealers are on Government contract. Chapter 10 of this guide contains a list of some equipment manufacturers and distributors.

1.5 Terms and Definitions

Nomenclature associated with tree climbing and tree climbing equipment includes a number of commonly used terms. Sometimes, one term has several different meanings.

To avoid confusion and possible climbing accidents, key terms are defined:

Field Guide Terms Definitions (Other Terms in Use)

Anchor Point A secure point, usually another tree, used to secure the ropes used for climbing or belay.

Ascenders Any climbing device used to ascend a (Jumars, Gibbs) vertically fixed rope. The term ascenders usually refers to mechanical devices.

Belay A method of protecting a climber in case of an accidental fall. A safety rope tied to a climber is paid out or taken in as the climber moves by a second person (the belayer) or by the climber in a self-belay (using the 4-inch tie-in). By controlling the safety rope, the belayer can stop the climber from falling.

Carabiner An oblong metal ring with a spring- (Biners, Locking loaded gate on one side used for Carabiners) various purposes in climbing, such as attaching equipment to the climber or securing the climber to a rappel system. Carabiners are normally produced from bar stock that is formed into the desired shape.

Carabiners used in life-support applications shall be the self-closing, positive-locking type of carabiner.

Chest Harness Straps placed around the chest and shoulders only to secure the proper positioning for a chest attachment point.

Chicken Loops Sewn, tied, or buckled bands of webbing or rope that fit around the ankle to prevent the ascender slings from slipping off the climber’s foot.

Climber A person certified to climb a tree; the person climbing.

Climbers Belt A wide padded belt made of synthetic (Linemans Belt, material usually having two large Body Belt, metal D-ring attachment points on the Safety Belt) sides. A climbing belt does not have an attached chest harness.

Climbing Harness A type of harness that provides both (Safety Harness, pelvic and upper body support and Sky Genie Harness, can be adjusted to fit individual Full Body Harness) climbers. Climbing harnesses may be a one-piece design (full body harness) or any two-piece design that meets UIAA (Union International des Associations d’Alpinisme) or NFPA (National Fire Protection Association) standards. Climbing harnesses normally have separate leg loops. Climbing harnesses should be suitable for rescue applications. Tree climbing harnesses will usually have all of the above plus two large D-ring attachment points on the sides.

Climbing Helmet Designed specifically for climbing, this helmet has a three-point chinstrap and is designed to remain in place during a fall. It is rated for the helmet’s ability to protect against side and top impacts. A hardhat is not an acceptable substitute.

Climbing Line A rope used in tree climbing that may be used for ascending into a tree, descending from a tree, and/or working aloft in a tree.

Climbing Spurs L-shaped metal shanks that attach to (Climbers, Tree the foot and lower leg and are used to Climbers, Gaffs, ascend or descend a tree bole by Pole Gaffs, Spurs, means of a sharp spike (gaff) that Tree Spurs, penetrates the tree bark and sticks Linemans Climbers, into the wood of the tree.

Spikes)

Climbing Team The basic team required for all tree climbing assignments, which is made up of two or more certified tree climbers, each capable of performing the same assignment as the other.

The team consists of (at a minimum) a climber and a ground person who switch roles periodically to reduce fatigue.

Descenders Any rappelling device used to descend a vertically fixed rope.

Etrier A webbing ladder or aid sling used to (Step-Up Sling, span distances of up to 6 feet where Aider) tree branches are missing. Usually constructed of flat or tubular webbing in a step fashion. Manufactured etriers are usually sewn to create the steps;

however, knots may be used to create the steps from a length of webbing.

Fall Factor Divide the length of the fall by the length of the rope in actual use. Fall factors greater than 1.0 can cause injury from the force of the sudden stop.

Foot Lock A method of safely ascending a free- (Secure Foot Lock) hanging rope without mechanical assistance by wrapping the rope around the feet.

Four-Inch Tie-In A self-belay system usually consisting of a rope, webbing, and carabiners. It is used as a safety line to secure the climber to the tree below the 4-inch bole diameter and at 3-foot intervals along the bole when climbing above the 4-inch bole diameter.

Ground Person The person on the ground supporting the climber. The ground person is a certified climber who is qualified and able to perform the same climbing assignment as the person climbing.

The ground person remains on the ground and must be properly equipped and ready to perform a rescue at any time.

Haul Line A small rope or cord used for raising (Equipment Line, and lowering equipment and Tag Line, Work Line) materials to and from the climber.

Hip Thrust A method for ascending a free- (Body Thrust) hanging rope without mechanical assistance.

Lanyard A short piece of rope or webbing that (Safety Lanyard, secures the climber to the tree. It Adjustable Lanyard, usually consists of an adjustable Prusik Lanyard, length of rope or webbing with a snap Flip Line) catch on each end for attaching to a climbing belt or climbing harness.

Pole Steps Metal steps screwed into the tree bole to make the climb easier. Steps should only be placed in trees that must be climbed often.

Rappel Rope A rope used to rappel or descend (Main Line, Prusik from a tree.

Rope, Descent Rope)

Saddle A type of work harness that is (Sit Harness) designed specifically to support the climber for long periods in a sitting position. A saddle differs from a safety harness by not having a chest component and may have either two separate leg loops or a single wide strap that encircles the climber below the buttocks.

Safety Line A rope that is either attached to a (Safety Rope, climber and used for belaying by a

Belay Rope) ground person or is attached to a firm anchor point and adjusted by the climber (such as with the 4-inch tie-in).

Safety Strap A length of rope or webbing used as a (Sling) protection point in a belayed ascent by either the ground person or the climber in a self-belay (as in the 4-inch tie-in). These straps are placed around the tree bole and secured by either a knot or carabiner, then secured to the belay rope with a carabiner.

Sectional Ladder A specially designed ladder for tree (Swedish Ladder, climbing that interlocks and Tree Ladder) individually secures to the tree. This ladder comes in 10-foot sections that can be stacked to provide a continuous ladder.

Secured A climbing system that is attached to the climber and connected to the tree that protects the climber from unintended movement. Climbers are secured when they are tied in, using a lanyard, on belay, or when they are ascending a climbing line with the footlock technique while using a Prusik loop or ascenders.

Sky Genie A system consisting of a special rope, (Genie) a rappel device, and a tree-crotch lanyard developed for descent from a tree, either in a climbing or rescue situation.

Snap Catch A metal device with a ring on one end (Rope Snap, that usually attaches permanently to a Snap Link, rope or cable. The other end has Snap Hook) a spring-loaded, locking gate. Unlike the gate on a carabiner, the gate on a snap link does not lock into the body of the snap link and does not offer any additional strength when closed.

Snap catches shall be the self-closing, locking type.

Steel Cable A lanyard composed of steel cable Lanyard and used with the Swiss Tree

Grippers.

Steel-Core A manila or nylon rope with a steel Lanyard cable core in which a snap has been (Flip Rope, Spur spliced at one end. This rope is used Rope, Cable-Core as a lanyard when spur climbing and Lanyard) when cutting, trimming, or pruning in a tree.

Swiss Tree Specially designed tree climbing Grippers equipment used for ascending to and (Swiss Tree descending from the live crown of a Climbers, Bicycles) tree. The set consists of two grippers

(foot attachments) and a specially designed climbing belt. Each gripper consists of a foot platform and a band that wraps around the tree and grips the bole. This equipment cannot pass limbs, limb stubs, or other tree bole obstructions, so the tree must be completely pruned to either the working level or to the live crown, where the grippers can be safely removed to continue the climb in the live crown.

Tree Bole The main vertical part of a tree.

(Bole, Tree Stem, Tree Trunk)

Tree Climbing Any task performed in or on a tree Work where access is accomplished by means of free climbing, friction knots or mechanical ascenders, climbing spurs, bole gripping systems, permanently or temporarily mounted steps, or stacked sectional ladders.

Tree-Crotch A piece of rope or webbing designed Lanyard specifically for rigging a rappel rope in (Cambium Saver a tree to reduce abrasion to the Lanyard, rappel rope and the tree. The Friction Saver) lanyard is designed with an O-ring at one end and a snap catch or small-diameter ring at the other end. A double-rope rappel can be rigged so that the rappel rope does not contact the tree bole, and the rappel rope and tree-crotch lanyard can be retrieved from the ground. (see Rappel Rope).

Tree Steps A metal, L-shaped step that attaches to the tree with a chain that is wrapped around the bole and secured to one end of the step.

Additional terms are defined and discussed throughout the guide. Become familiar with all terms associated with tree climbing work to improve communication with fellow climbers.

2. Preparing for a Climb

Your preparations shall include obtaining any special training the assignment might require, discussing with your other team member the best way to accomplish the job, and preparing a job hazard analysis for each assignment. The job hazard analysis shall include the following:

1. Analyze the assignment, then obtain the equipment needed.

2. Inspect the equipment.

3. Establish radio contact with the local forest/district office or central dispatch from the climbing site. If direct radio contact is not possible from the climbing site, an alternative method for summoning emergency help shall be established before climbing.

4. Establish a check-out and check-in procedure.

5. Assess the environment for potential hazards.

6. Assess the tree and immediate area for potential hazards.

2.1 Basic Tree Climbing

Equipment The tree climbing team must have basic equipment to accomplish any climbing assignment. Specialized equipment may also be needed depending on the nature of the assignment. The following equipment should be taken on all tree climbing assignments:

1. Team tree climbing equipment

A. A haul line.

B. A rappel rope.

C. A mechanical rappel device or system and compatible rappel rope (see chapter 6). A rappel system is included as basic equipment to allow a rescuer to remove an immobilized climber from the tree. The system must be capable of lowering the combined weight of a disabled climber and the rescuer. The Prusik rappel system is an alternative to a mechanical rappel system.

D. A rescue pack (see section 7.1 for recommended contents).

2. Individual tree climbing equipment (each person on team)

A. A climbing harness (climbing or saddle harness with a chest harness, or full body harness)

B. A climbing helmet

C. Two lanyards

D. Four locking carabiners (minimum)

E. A pruning saw

F. Eye protection

The red fire pack, available from the General Services Administration (National Stock No. 8465-01-141-2321), helps organize tree climbing gear. When carrying gear long distances, packs with more support may be more suitable.

Gear should be packed the same way each time so climbers become familiar with everything and can retrieve what they need quickly. The teeth of saws and the points of gaffs should be covered. In addition, these sharp items should be stored in compartments separate from harnesses, webbing, and ropes.

3. Clothing and personal gear

A. Wear a long-sleeved shirt and sturdy pants or coveralls while performing tree climbing work.

Clothing tends to become torn and pitchy during climbing assignments. Clothing should be loose enough to permit the extreme range of movement required for tree work.

B. Never wear jewelry while climbing or place anything around your neck, including cameras or extra climbing equipment.

C. Eye protection shall be worn.

D. Gloves are recommended, but not required for general climbing. Sturdy gloves, such as heavy-duty leather gloves, are a must for any rappelling.

E. Soft-soled footwear is recommended to reduce damage to the tree from repeated climbing. Soft-soled hiking boots, high-top tennis shoes, and crepe-soled work boots are appropriate for most tree climbing work. Logger-style boots with Vibram-type soles may be used. When working with climbing spurs, wear boots that have suitable heels to keep the spurs in place and rigid arch supports to reduce fatigue and discomfort.

Y

2.2 Working as a Team

A climber and a ground person make up the basic climbing team. One ground person can serve several climbers, but must be able to maintain visual and voice communication with all climbers at all times. Roles are interchangeable, so all team members shall be certified climbers who are qualified to perform every aspect of the climbing assignment.

All team members shall have current medical training equivalent to at least an American Red Cross basic first-aid course. The team shall establish radio communications with the forest or district office or central dispatch from the climbing site before climbing. An established sign-out system shall also be in effect with the local forest/district office or central dispatch.

All team members shall be completely equipped to climb and shall thoroughly rehearse the climbing methods and techniques they will use. Working as a team includes the following:

1. All team members shall perform an equipment check on each team member’s equipment before climbing.

2. The ground person and the climber should switch roles, as necessary, to prevent undue fatigue. Alternating roles from tree to tree gives the climber an opportunity to rest.

The ground person shall NOT sleep, but shall remain alert while climbers are aloft.

3. Both climber and ground person should remain alert to hazards in the tree and the environment, discussing potential problems as they arise.

4. The ground person should carefully watch the climber and communicate any problems; it is often easier for the ground person to identify hazards and recognize unsafe climbing practices than it is for the climber to do so.

5. The ground person should assist the climber by helping with harness adjustments, inspecting equipment, and attaching or removing items from the haul line.

6. The ground person should maintain verbal and visual contact with the climber. When the climber is collecting cones, the ground person should assist by pointing out areas where cones can be collected.

7. The ground person shall be prepared to perform a rescue or render first aid at all times.

8. The ground person shall not be directly underneath the climber at any time unless first cleared by the climber to be there. Whenever a ground person is underneath a climber, the climber remains in an “at rest” position until the ground person is no longer there.

2.3 Checking for Hazards

Any number of hazards may prevent a tree from being climbed. The climbing team must perform a thorough tree hazard assessment before any tree is climbed. Remember, no tree is worth a human life.

Hazards are generally grouped into two categories:

environmental hazards and tree hazards. The following lists of potential hazards represent a starting point for the focus of a hazard tree assessment. In special situations where hazards cannot be mitigated, consider seeking additional help from specialists or receiving additional training before performing any work.

2.3.1 Environmental Hazards

The climbing team must assess the environmental hazards at each tree and monitor the weather throughout the day for changes that could make climbing more hazardous. Never climb a tree under any of the following conditions.

• The wind speed exceeds 25 mph or the wind is blowing in gusts. In light winds, try to keep your back to the wind.

Do treetop work first, when conditions permit. If winds increase later, it may still be safe to work lower in the tree.

• It is not fully daylight. Visibility is especially important late in the day when fatigue is a factor. Do not start a tree climb that cannot be completed in full daylight.

• Air temperature is low enough to create an unsafe condition in your judgment. Be particularly aware of cold temperatures. Cold impairs dexterity, especially in the fingers, which can jeopardize your ability to accomplish tasks safely.

• A lightning storm is close. If you are in a tree when a lighting storm appears imminent, descend as quickly and safely as possible.

• A rainstorm is imminent. Wet branches are slippery. A wet rope may not be as strong as a dry one.

• A powerline is close enough to the tree that you, your equipment, or the tree branches could come in contact with the powerline. Consider any tree suspect if a powerline is anywhere in the vicinity. DO NOT climb any tree that is closer than 10 feet from energized electrical conductors.

2.3.2 Tree Hazards

Check every tree thoroughly before the climb. Both team members should walk around the tree and assess it for potential hazards. Many hazards can be compensated for easily, allowing the tree to be climbed safely. Other trees have severe hazards that preclude them from being climbed unless a special need exists, the climber is properly trained and equipped, and any hazards are mitigated. When climbing any tree, if you encounter a hazard that cannot be mitigated, descend immediately.

The following hazards may prevent a tree from being climbed, if it is not possible to compensate for them.

Rain-, ice-, or snow-covered branches. These branches pose slipping hazards that may affect climbing performance. Climbers may need to use a safety line or lanyard for added safety.

Moss and lichen. Moss and lichen create a slippery climbing surface. This hazard is especially prevalent in the Northwest. Climbers may need to use a safety line or lanyard for added safety.

Brittle limbs caused by low temperatures. Use the same precautions you would use with any brittle limbs. If the temperature is too low to climb safely, then you should not be climbing.

Tree species with brittle limbs. Test limbs for soundness before using them for support. Climbers may need to use a safety line or lanyard for added safety.

Small-diameter boles and limbs. Keep hands and feet as close to the bole as possible. When climbing above the 4-inch diameter point in conifers, a safety line shall be used. A safety line may be used earlier in the climb for added safety.

Steeply sloping limbs. Always keep your hands and feet as close to the bole as possible. Wedge them close to the bole when you are using sloping limbs for support.

If your hands or feet continually slip, consider climbing with your lanyard attached at all times or use a safety line for a belayed ascent. Exercise caution on trees with branches that slope upward. To avoid getting your feet stuck, do not use them for support. If these branches cannot be avoided, consider using tree steps or using webbing slings for steps.

Damaged limbs. Never use damaged limbs to support your weight.

Branch stubs or dead branches. Never use branch stubs or dead branches for support. Remove dead branches while ascending the tree if there is a chance they might be used inadvertently while descending.

Abnormally large amounts of branch mortality.

These conditions may indicate unsafe limbs and hidden rot. This is mainly a problem in conifers.

Weak branch unions. Weak branch unions are places where branches are not strongly attached to the tree.

A weak union occurs when two or more branches of similar size grow so closely together that bark grows between the branches, inside the union. This is usually a problem with branches that are growing upright.

The ingrown bark does not have the strength of wood.

The union is much weaker than one that has more wood. The included bark may also act as a wedge and force the branch union to separate. Elm and maple, which have a tendency to form upright branches, often produce weak branch unions. Weak branch unions also form after a tree or branch is tipped or topped (when the main stem or a large branch is cut at a right angle to the direction of growth, leaving a large branch stub). The stub inevitably decays, providing very poor support for new epicormic branches that usually develop along the cut branch.

Poor tree architecture. Poor architecture is a growth pattern that indicates weakness or structural imbalance.

Trees with strange shapes are interesting to look at, but may be structurally defective. Poor architecture often arises after many years of damage from storms, unusual growing conditions, improper pruning, topping, and other damage. A leaning tree may or may not be a hazard. An arborist knowledgeable about that tree species should examine leaning trees that might be a hazard.

Forked boles and spiked top. Unless the tree species naturally forks, do not climb above a forked bole. Treat any fork with suspicion, because the fork is potentially a weak point. Never climb into a dead or spiked top. Forks sometimes indicate an old, broken top. Frequently, they are associated with wood decay, which further weakens the area, making it unsafe for climbing. Most hardwood trees fork naturally, so a forked hardwood tree would not cause as much concern as a forked conifer.

Cankers. A canker is a localized area on the stem or branch of a tree, where the bark is sunken or missing.

Wounding or disease causes cankers. Stems are more likely to break near the canker. A tree with a canker that encompasses more than half of the tree’s circumference may be hazardous even if exposed wood appears sound.

Cracks. Deep splits through the bark that extend into the wood of the tree are primarily a problem in deciduous trees. Cracks are extremely hazardous, because they indicate that the tree is failing. These trees should be evaluated by a person familiar with the species and climbed by certified climbers who are properly trained and equipped for the hazards associated with the job.

Decay. A decaying tree can be prone to failure. Decay is primarily a problem in deciduous trees. The presence of decay by itself does not indicate that the tree is hazardous. Advanced decay (wood that is soft, punky, or crumbly, or a cavity where wood is missing) can create a serious hazard. Signs of fungal activity, including mushrooms, conks, and brackets growing on root flares, stems, or branches indicate advanced decay. A tree usually decays from the inside out, eventually forming a cavity. Sound wood is added to the outside of the tree as it grows. Trees with sound outer wood shells may be relatively safe, but this depends on the ratio of sound to decayed wood and other defects that might be present.

If decay is evident and you have doubts about the tree, avoid it. Arborists are best qualified to evaluate the safety of a decaying tree.

Root problems. Trees with root problems may fall without warning for any number or reasons, especially when the tree’s leaves grow in summer, increasing the weight the tree must support. Besides decay, roots may have a number of other problems. They may have been severed; they may have been paved over; they may have been harmed when the soil grade was raised or lowered; or a car may have driven over or parked on top of them. Mounded soil near the base of the tree, twigs that have died back, deadwood in the crown, and leaves that are offcolor or smaller than normal often are symptoms associated with root problems. Because most defective roots are underground and out of sight, aboveground symptoms may serve as the best warning.

Indications of root, butt, or bole rot. In conifers, the soundness of any tree with rot cannot be trusted.

Indicators of rot include fruiting bodies of decay fungi, exposed wood that is decaying, and other indicators of internal wood decay. Wood is generally a strong material, but its strength is greatly reduced by decay.

Some decay is obvious (for example, rotten wood in an exposed scar), but other decay may be hidden (for example, internal wood decay in a forked top).

Loose bark. Loose bark may peel off when grabbed for support or when spurs are used. In dead conifers, large sections of bark may break loose and fall, injuring a climber or damaging equipment. Certified climbers who are properly trained and equipped for the hazards associated with the job should do critical work in such trees.

Dead wood. Dead trees and large, dead branches are unpredictable and may fall at any time. Dead wood is often dry and brittle and cannot bend as a living tree or branch does. Dead branches or treetops that are already broken off (“hangers” or “widowmakers”) are especially hazardous. Certified climbers who are properly trained and equipped for the hazards associated with the job should do critical work in such trees.

Multiple defects. Recognizing multiple defects in a tree is critical when evaluating the tree’s potential to fail. Multiple defects that are touching or close to one another should be examined carefully. The combined potential of multiple defects can far exceed the sum of the individual hazards considered separately. If more than one defect occurs on a main stem, you should assume that the tree is potentially hazardous.

Large portions of other trees or snags lodged in the crown. Trees or snags lodged in the crown of another tree may move or fall, striking the climber or pinning the climber in a tree. Tree climbing to remove these hazards, or to perform critical work in the tree, should be done by certified climbers who are properly trained and equipped for the hazards associated with the job.

Bee, hornet, or wasp colonies. Insect colonies may be in trees adjacent to the one to be climbed. Climbing may disturb the colony. Often colonies cannot be seen from the ground. When you are climbing, always let your ground person know when you spot a colony. If you cannot descend immediately and you are being attacked, secure yourself to the tree, cover your face, and don a bee hood if one is available. A can of bee and wasp spray that will stun bees, wasps, and hornets should be carried during high-risk seasons. Climbers allergic to insect stings should have the appropriate medication with them. The climbing team’s first-aid kit should include an insect-sting kit, which may have to be purchased separately.

Climbing to monitor or remove insect colonies should be performed only by certified climbers who are properly trained and equipped for the hazards associated with the job.

Animals in the tree. Even small chipmunks can cause enough commotion to startle a climber and create a hazardous situation. It is best to return to the tree at a later date and climb it when the animal is not present or to designate the tree as unsafe to climb without special training and precautions. Tree climbing to monitor animals, or for other animal-related activities, should be done by certified climbers who are familiar with the behavior of the animals being monitored, are properly equipped for the job, and are properly trained in the methods necessary to minimize and mitigate the associated hazards.

Large birds nesting in the tree. Be cautious of birds nesting in the tree that is being climbed or in nearby trees. Even small nesting birds can create hazardous situations when they are threatened. If you encounter a large bird’s nest, cancel the planned climbing activities for that tree and the surrounding trees. Climbing to monitor birds or their nests should be performed only by certified climbers who are properly equipped for the job and are properly trained in the methods necessary to minimize and mitigate the associated hazards.

Hazardous situations should be avoided as much as possible, unless a specific need for climbing exists. A thorough tree hazard assessment is crucial for determining the extent of the hazard and the climber’s ability to deal with

it. Although trainee climbers can successfully compensate for many hazards, as the severity of the hazard increases so does the level of experience required. The type or severity of a hazard may warrant additional training, specialized equipment, or outside expertise.

When climbing, if you discover a hazard that was not spotted from the ground, or that appears to be more hazardous than you originally thought, descend immediately unless the hazard can be mitigated.

2. Preparing for a Climb - Notes

3. Ropes, Knots, Splices, and Webbing

Tree climbers use different types of ropes, knots, splices, and webbing to perform their work. Each has a specific use or purpose, and you must know when, where, why, and how to use each of them appropriately. See chapter 8 for minimum rope and webbing requirements.

3.1 Ropes

The working characteristics of a rope depend on the materials used to construct it and the construction method.

Not all ropes are suitable for tree climbing work. When selecting rope, consider these points:

1. How will the rope be used—haul line, rappel line, lanyards, or 4-inch tie-in?

2. What rope properties are required for the intended use—static compared with dynamic breaking strength?

3. What type of material is best for the intended use— nylon, Kevlar, manila, polyester, or polyolefin?

4. What type of construction is best for the intended use— laid, kernmantle, or braided?

Because most tree climbing ropes are used for life support, it is critical that you be thoroughly familiar with all aspects of the rope from the time it is purchased until it is retired from service. If you are not personally familiar with the history of the rope you are going to rely on, do not use it. Purchase ropes only from reputable dealers knowledgeable about materials, construction, and breaking strengths. Never purchase used ropes.

3.1.1 Characteristics of Rope

Consider the following when selecting a rope for tree climbing work:

1. Elasticity. This refers to how much a rope can stretch before it reaches its breaking strength. The elongation is measured as the percentage of increase in the rope length under a given load. The amount of elongation at the breaking strength determines whether a rope is considered static or dynamic.

A. A static rope has less than 20-percent elongation at the breaking strength and less than 2-percent elongation at a working load of 200 pounds. As a rule, these ropes are stiffer than dynamic ropes, which can make knot tying more difficult. Generally, static ropes are more resistant to abrasion and dirt penetration. Principal uses for static ropes include haul lines, lanyards, safety straps or slings, ascender ropes, and rappel ropes. Never use static ropes in situations where a fall could occur, such as with the 4-inch tie-in system, or as a safety line for a belayed ascent.

B. A dynamic rope has an elongation of 40 to 60 percent at the breaking strength and less than 8-percent elongation at a working load of 200 pounds.

A dynamic rope absorbs the shock of a fall, giving the climber added protection. Principal uses for dynamic ropes include safety lines and 4-inch tie-in systems. Because of their versatility, dynamic ropes are suitable for lanyards and rappelling. They are NOT recommended for haul lines or ascender ropes because of their tendency to stretch.

C. Stretch at working loads in nylon rope:

• A 7/16 -inch (11-millimeter) static kernmantle rope stretches 1.5 to 2 percent of its unweighted rope length.

• A 7/16-inch (11-millimeter) dynamic kernmantle rope stretches 5.5 to 7.5 percent of its unweighted rope length.

• A 7/16-inch (11-millimeter) dynamic laid rope stretches 9 percent of its unweighted rope length.

Remember, these estimates refer to the stretch of the length of rope being loaded, so while a 150-foot static kernmantle rope may stretch 21/4 to 3 feet if its entire length is loaded, you may only be loading 50 feet of the rope with the remainder coiled on the ground, so the actual stretch will only be 3/4 of a foot to 1 foot.

2. Abrasion resistance. Stiffer ropes generally resist abrasion better than more flexible ropes. All ropes may be abraded from within by dirt particles rubbing against the fibers or from the outside by contact with rough or sharp surfaces.

3. Tensile strength. Tensile strength is the resistance of a rope to a force tending to tear it apart. Tensile strength is determined by steadily applying an increasing load on a rope until it breaks.

4. Breaking strength. Breaking strength refers to the value at which a rope breaks when subjected to a sudden force from a known weight over a specified distance.

5. Resistance to sunlight. All synthetic and natural fiber ropes will deteriorate with continued exposure to sunlight. Ultraviolet degradation of synthetic rope and webbing is the most significant factor affecting the aging of rope, especially when the cordage is in storage longer than in actual use (assuming it has not been damaged).

Rope made from Kevlar is especially sensitive to

T ultraviolet degradation and should be stored according to manufacturer’s instructions. It is impossible to assess the strength of a rope or webbing that has been stored for long periods in direct sunlight. The cordage may be unsafe to use long before it shows any signs of wear. Rope life is easy to assess by visual and tactile inspection when it has been protected from damage and stored in a cool, dark place.

6. Heat resistance. Heat resistance is the ability of a rope to withstand overheating and melting due to normal or rapid (6 feet per second or more) rappelling or other friction caused by a rope rubbing against or over a surface. When heated, a rope will soften. Softening always permanently weakens the rope and may result in rope failure.

7. Water absorption. The more water repellent a rope the better. A rope that is wet is usually not as strong as when it is dry. A rope’s abrasion resistance and tensile strength may be reduced significantly when it is wet.

8. Chemical resistance. Chemicals such as gasoline, bleach, acids, oils, spirits, lacquer, battery acid (including any residual acid that may be found on jumper cables), and lacquer thinner can damage ropes.

Any vapors these chemicals give off may also damage ropes. Any rope that has been exposed to, or even stored near, fuels such as gasoline, diesel, or kerosene should be immediately retired from safety use in situations where the rope’s failure could create a safety hazard.

9. Aging. Ropes have a finite service life, even if they are not used. A rope’s strength decreases over time.

3.1.2 Types of Rope Materials

The type of material a rope is made of determines how it can be used in tree climbing applications. Types of rope material include:

1. Manila. Manila is a natural fiber that is treated with oily compounds when manufactured into rope. These oily compounds are lost as the rope ages, reducing its strength over time. Never use a plain manila rope for life-supporting lines or other important uses. Quality control is difficult because natural fibers tend to rot and degrade. Degradation occurs not only during use, but also in storage and often isn’t evident on inspection.

Manila rope is not as strong as nylon rope of the same diameter, and breaking strengths may vary widely depending on the manufacturer. Water absorption is high compared to synthetic fibers. Manila ropes are only suitable for utility purposes, except when combined with steel cable such as steel-core rope lanyards that are acceptable for life-safety use. Manila ropes are considered static ropes.

2. Polyolefin. Ropes of polypropylene and polyethylene melt at 310 °F, but may begin to soften and weaken at 100 °F. These temperatures can be easily reached or exceeded when the ropes are subjected to abrasion and friction. Use ropes made exclusively of these materials only for haul lines or other uses that do not include life support.

3. Nylon. Nylon is a durable, strong, synthetic fiber with widely varying physical properties. Of the many types of nylon yarn manufactured, the two most common in rope construction are nylon 6, also known as Perlon, and nylon 6,6. Nylon 6,6 has a slightly higher melting point (500 °F) than nylon 6 (419 °F) and also a higher breaking strength; these differences, however, are not always apparent because other factors, such as rope design, contribute to the overall properties of a rope.

Nylon ropes have a high breaking strength relative to their size and a high abrasion resistance when dry.

Untreated, they readily absorb water, which reduces their tensile strength by up to 10 percent. Nylon ropes that have a minimum breaking strength of 5,400 pounds are suitable for climbing when they are new. Ropes of nylon may be either static or dynamic, depending on their construction.

4. Polyester. Dacron and Terylene are trade names for polyester fibers. This material melts at 480 °F and is not affected by water. Breaking strength is about 75 percent of similarly designed nylon 6,6 static ropes. Elasticity is about the same as manila rope. Polyester ropes are considered static ropes.

5. Kevlar. Kevlar is an extremely strong, high-temperature-resistant fiber. However, it has a very low elasticity and breaks if bent too tightly, such as in a knot. This type of rope is often used by rescue teams for high-angle rescues when several lives may depend on only one rope. Because of the high cost and limited life of this type of rope, it is not recommended for tree climbing applications.

3.1.3 Types of Rope Construction

The most common construction methods for rope are kernmantle, laid, and braided.

1. Kernmantle construction. Kernmantle rope consists of a central core (kern) of fibers that support most of the load on the rope (about 80 percent). A woven sheath (mantle) covers this core and supports less of the load (about 20 percent). The sheath’s tight weave protects the core fibers from abrasion, dirt, and sunlight. The resulting rope is strong and resists damage, yet is easy to handle.

2. Laid construction. In laid construction, small fiber bundles are twisted together and combined into larger bundles that are twisted around one another. The “lay” of the rope is the direction in which the strands are twisted. Most ropes are right-laid (strands spiral upward to the right when the rope is held vertically). The lay may be either hard or soft. Hard-lay construction creates a stiff rope in which knots are difficult to set and hard to untie after use. When under a load, these ropes resist abrasion and hold their shape better than soft-laid ropes. Soft-lay construction results in a flexible, easy-to-use rope, but one that unwinds easily and is not recommended for rappelling. All ropes of laid construction tend to untwist when loaded, causing spin and rope kinking. The amount laid ropes untwist when loaded depends on the strength of the lay. Because each fiber may appear at the rope’s surface in several places along its length, the load-bearing fibers are more susceptible to abrasion damage.

3. Braided construction. Many types of braided rope are available. These ropes are gaining popularity among tree climbers because of their excellent knot holding and handling characteristics. Generally, braided ropes are softer and more flexible than kernmantle or laid ropes. However, the external fibers are susceptible to snagging, and the rope usually has a lower breaking strength compared to kernmantle or laid ropes of similar diameter.

3.1.4 Care, Cleaning, and Storage

1. A rope should never be stepped on, driven over, or have other equipment piled on it. This can grind abrasive dirt into the fibers or abrade or cut the outside surface.

Sharp or heavy objects can cause unseen damage that may cause unexpected failure.

2. New rope should never be washed, rinsed, or soaked before initial use because of the naturally slippery quality that makes it soft and supple. The fibers adjust favorably, depending on use. Washing a new rope tends to remove the natural slipperiness, causing it to become dry and brittle, thereby shortening its life.

3. Rope should only be washed when very dirty. Wash ropes to keep dirt from working its way inside, where it can abrade and weaken internal fibers.

4. When a rope must be washed, check the manufacturer’s instructions. If acceptable, first soak pitchy areas with hand cleaner, then wash by hand or in a front-loading machine with mild detergent in warm water. Drip dry out of direct sunlight; never machine dry.

5. Proper storage maximizes a rope’s useful life. Store rope in a cool, dark, dry place. Exposure to direct sunlight rapidly deteriorates rope fibers. Untie all knots before storage and never hang a rope over a nail, small diameter peg, or hook. Ideally, rope should be coiled and stored in a rope bag that can be closed tightly.

3.1.5 Hazards

Even normal wear and tear can, over time, seriously reduce any rope’s strength. That’s why it is important to purchase only high-quality ropes and implement a documented monitoring system with frequent inspections, proper storage, and strict rope retirement standards as a way to minimize hazards. Even when using high-quality ropes, potentially hazardous situations exist in tree climbing work, including:

1. Using the wrong rope for the job.

2. Using inappropriate knots or tying knots improperly.

3. Hauling equipment up a tree or using sharp tools aloft.

4. Using a knife close to a rope under tension. A rope under tension cuts quite easily. Whenever rappelling or ascending on a rope, a knife or other sharp tool should not be used, except in an emergency when no other tool is available.

5. Bending ropes through knots or over carabiners.

Bending reduces a rope’s overall strength. A rope bent in an arc that is less than four times its diameter will reduce its strength at that point by as much as 25 percent.

6. Using wet ropes.

7. Climbing or rappelling with a rope that has been driven over, used for towing, or otherwise severely damaged.

8. Using a stored rope that was damaged by animals, particularly mice.

9. Climbing with spurs—gaffs can cut rope.

10. Failing to retire stressed or seriously damaged rope.

11. Using a fixed…