Monthly Archives: April 2014

Emerald Ash Borer – Symptoms and Treatment

Emerald Ash Borer

(Courtesy of  USDA Animal & Plant Health Inspection Services) 

 Symptoms and Treatment: 

Adult EAB

Although you can’t always spot it, the beetle may live in cut wood such as firewood. You can help stop the beetle by not moving firewood. Moving firewood can spread the beetle, its larvae and its eggs to healthy trees. Burn your firewood where you buy it.


Adult beetles are most active during the summer and early fall. If you see the beetle or any signs of infestation, you need to report it immediately. (Contact your local U.S. Department of Agriculture Office.) During the late summer, fall and winter months, the beetle’s larvae tunnel deep into the trees they infest.

The Signs:
 Since the beetle is difficult to spot, you can look for signs of infestation.


Canopy Dieback
Canopy Dieback

Canopy dieback begins at the top of the tree and progresses throughout the year until the tree is bare.



Epicormic Shoots:


Sprouts grow from roots and trunk.

Bark Splitting:

 Vertical bark splits expose S-shaped galleries beneath the bark.


 S-shaped Galleries and D-shaped Exit Holes:

 Galleries under the bark reveal the back and forth feeding pattern of the EAB larvae.  Adults emerge from D-shaped exit holes.



 The following insecticides for professional use have been shown to be effective against the Emerald Ash-Borer either as a soil drench or as a tree injectible. (Read the full report of insecticide treatment and their rate of effectiveness by following the link below.)


1. Merit® (75WP, 75WSP, 2F) (Imidacloprid) – Use as soil injection or drench. Mid-fall and/or mid-to late spring.  Merit® also is available as a trunk injectible.


 2. XytectTM (2F, 75WSP) (Imidacloprid) – Soil injection or drench Mid-fall and/or mid-to late spring.


3. IMA-jet® (Imidacloprid) – Trunk injection Early May to mid-June.


4. Imicide® (Imidacloprid) –  Trunk injection Early May to mid-June.


5. TREE-ägeTM (Emamectin benzoate) –  Trunk injection Early May to mid-June. While relatively expensive, this product has shown to be the most effective chemical  treatment to combat the Emerald Ash Borer according to studies by the Michigan State University and others.

6. Inject-A-Cide B® (Bidrin®) –  Trunk injection Early May to mid-June.


*Homeowner Use – Bayer Advanced Tree & Shrub Insect Control -(Imidacloprid) Soil drench – Mid-fall or mid-to late spring.

Rigging Pulleys and Blocks-Part I

Tools & Techniques:
Pulleys and Blocks

When Friction is Not a Friend

By Michael Tain

CMI Rescue Pulley

(A CMI rescue pulley in support of a static load. Note the lack of a bushing for sling attachment, thus requiring the use of a connecting link, and the thin side plates with sharp edges. Photos by Michael Tain.)

Pulleys and blocks play a major role in the modern tree climber’s bag of tricks, often performing vital functions in the most basic of tasks, such as hitch advancement, or the most complex, as in a multiple system rigging required tree removal. Regardless of application, the primary function of a pulley or block is to reduce friction as much as is possible within the given situation.

With the various types of pulleys and blocks available to tree crews today there’s one for almost every application, but along with the benefit of choice comes the burden of knowledge. The wrong block or pulley used in the wrong situation can be catastrophic for the pulley, the line, the tree and even the crew members in the path of destruction. A basic knowledge of some of the applications, suitability and safety concerns of these useful tools will go a long way towards ensuring that crews not only use them most efficiently, but also as safely as possible.


Pulleys and blocks perform the same basic function: providing a sheave or surface of some sort that reduces friction as much as possible on a running rope. In many industries the terms “block” or “pulley” mean the same piece of gear, this is not the case in tree care applications. While both perform the same basic function – and can even work interchangeably in the short term – the wrong choice can have disastrous results, especially when large woody debris at a height is involved.

Blocks, but not for the alphabet

The term arborist block is used to refer to a block/pulley designed to deal with the heavy loads and extreme forces of dynamic rigging situations. While there are a variety of designs and styles available, they will have several basic components in common: a bushing, a sheave and cheek plates.

Bushing, not bush league

The bushing in an arborist block is intended for sling attachment and will have some form of locking mechanism to ensure it does not release mid-load. Available mechanisms include spring locks and captured bushings with screw locks. Arborists in the market would be best served to purchase captured bushings regardless of locking mechanisms, as attempting to find a bushing dropped from 90 feet into a pile of pin oak brush can be a bit challenging. Whichever type of locking mechanism the bushing has, the user should be certain it’s correctly locked and secured after every load, or catastrophe may rear its ugly head.

As mentioned previously, the bushing – typically the smaller diameter of the two block ends – is intended for sling attachment, with the sling then attached to the tree with an appropriate hitch such as the cow hitch with a better half. The use of connecting links, even large heavy-duty rigging carabiners, from the sling around the bushing is a poor idea, as the possibility of side or cross loading is highly likely in dynamic rigging situations, and the metal-on-metal contact between connecting link and bushing quickly degrades the strength of both.

ISC Block

(An ISC spring-lock aluminum arborist block. Note the spring-lock captured bushing for sling attachment and the thick side plates with rounded edges, making it appropriate for more dynamic loading.)

(Article courtesy of Tree Services Magazine:

Rigging Pulleys and Blocks-Part II

Tools & Techniques:
Pulleys and Blocks

When Friction is Not a Friend

By Michael Tain

Sheave, not sleeve

The surface of an arborist block that the line is intended to run over is called a sheave, and it’s typically the larger diameter of the two block ends. This sheave should turn freely, minimizing the amount of friction the rope experiences when running over/around it.

Bend radius is a concept that must be understood when matching arborist blocks with rigging lines. In short, the sharper the bend in a rope passing over or around any object, the more strength the rope will lose. A bend radius of 8 to 1 is the most advantageous for minimizing strength loss, though a radius of 4 to 1 is acceptable in arborist rigging situations with lines of braided construction. As an example, a .5-inch rigging line should be used with a block with a 4-inch-diameter sheave for optimal strength retention, though a sheave diameter of 2 inches would be minimally acceptable.

Cheeks like a chipmunk

The cheek plates of a well-designed quality arborist block are thick and extend beyond the bushing/sheave with somewhat rounded edges. This thickness helps provide the strength required for enduring the loads and forces involved multiple times in tree removal rigging.

In addition, the extension of the cheek plates helps ensure that the sling remains in proper contact with the bushing, and the rigging line in proper contact with the sheave, while rounded edges help minimize rope damage should the line get trapped or run between the edge and the tree.

Pulleys aren’t bullies

Pulleys, as mentioned previously, are not the same piece of gear as a block in the tree industry. They should, perhaps, be thought of as the slender, more sensitive, but still quite useful, cousin of the big, burly arborist block.

While they do have the sheave of an arborist block, they lack the bushing for sling attachment, typically having an opening of some sort for the attachment of a connecting link. This particular lack is what prevents the safe use of pulleys in rigging applications involving dynamic loads and forces. The use of a connecting link through the opening provided can lead to cross or side loading in these situations. Given enough force or large enough load, the connecting link can tear entirely through the pulley’s thin, non-chipmunk like cheek plates, sending the load and pulley on a high-speed one-way trip to the unsuspecting branch manager.

Arborist Block

(An arborist block-note the bushing-being used as the traveler in a balance slide line rigging system.)

An attempt to avoid the use of a connecting link by girth hitching the sling through the pulley’s provided opening is also problematic and unsafe, and can lead to bent and mangled cheek plates or slings severed by the sharp edges present in most pulleys.

There are a wide variety of pulleys available to modern arborists, and far too many configurations to all be discussed here. The few listed below give a good introduction to some of their appropriate applications.

Fixed, no not that way, sides – Pulleys with fixed sides or cheek plates typically, though not always, have a distance between the two sides equal to the thickness of the sheave. This allows their effective use in a number of applications, but common uses include as a fair lead for climbing hitches and as the traveler in a slide line system.

Multiple sheaves – Pulleys with more than one sheave are readily available and are particularly useful in the construction of mechanical advantage systems to provide lifting or pulling force greater than the input force.

Prusik minding – These pulleys are shaped in such a way that the cheek plates of the pulley, when properly used and configured, actually “mind,” or advance, a prusik or other hitch when it reaches the pulley. This feature is exceptionally useful when moving or advancing a load when it cannot be allowed to slip or travel backwards, or when attempting to apply gradual, constant force in a mechanical advantage system.

More attachment points – Pulleys, typically of a smaller size, are readily available with multiple attachment points that provide uses in both rigging and climbing situations that are only limited by the imagination of the user and the strength of the chosen pulley.

General rigging – While a pulley’s lack of bushings and more slender construction preclude their use in dynamic rigging situations, they are highly applicable and safe in non-dynamic applications, such as lifting, pulling or redirecting, as long as their safe working load is not exceeded.

Spider leg balancing a load

A spider leg used to balance a load, one of the rigging applications that is much easier to control readily through the use of blocks and pulleys.

Loads, briefly

Terms such as breaking strength, safe working load and working load limit are a discussion all to themselves, but prospective block and pulley users should be aware of the strengths of their chosen devices and how they will function within the chosen application.

In short, a listed breaking strength is just that, the one-time load the pulley or block should take before breaking. Multiple uses will incrementally reduce that breaking strength, and multiple uses near the maximum strength of the block or pulley will reduce its strength even more severely, thus care and caution must be used when employing rigging systems and the blocks/pulleys within them.

Prusik mindng pulleys

(Multiple sheaves prusik minding pulleys being used in a mechanical advantage system.)

Pulleys and blocks can increase the safety and efficiency of both individual climbers and entire tree crews, but only if they are being used appropriately and correctly. The basic knowledge, descriptions and limitations discussed here are a good first step towards helping tree care professionals use blocks and pulleys to battle friction in the pursuit of safe, efficient tree care.

(Michael (House) Tain is a contract climber, splicer, educator and writer associated with North American Training Solutions/Arbor Canada Training and Education, currently located in Lancaster, Ky.)

(Article courtesy of Tree Services Magazine:

Maintaining Your Climbing Equipment

Maintenance Matters

Maintaining your climbing equipment is imperative to staying safe aloft
By Anthony Tresselt

(All life support carabiners should be marked with their ratings and the markings should be legible.)
(Photos courtesy of Anthony Tresselt unless otherwise noted.)

As with any type of skilled labor, high-quality tools and equipment are necessary for safe production tree climbing. As important as knowing how to use these tools and equipment can be, keeping them functioning properly, inspected for signs of wear, and knowing when to retire them is equally important. Tools can only perform as designed if they work and are used as intended. Just as a chain saw must be tuned, fueled and sharpened for effective cutting, climbing gear must be properly maintained. While a malfunctioning saw could be  a safety concern, it is more likely to be a frustrating nuisance. However, when it comes to life support equipment,  the results of poor maintenance are guaranteed to be much more severe.

Through knowledge, regular inspection and maintenance, climbing gear can be kept in tip-top shape, performing safely and as designed for many jobs today, tomorrow and many days to come.

Instruction manuals

Realistically, we can only discuss general guidelines. The vast amount of gear available to the modern tree climber coupled with the multifaceted way it can and is deployed would lead to a tome of epic proportions in trying to cover every detail. However, there are similarities and processes that can be applied universally across the range of climbing equipment.

Furthermore, there are instructions! Equipment manufacturers provide detailed instructions for the use and upkeep of all gear. These may come with the equipment or tool or can be obtained online in a digital format. Keeping a file of these for reference is a great first step in proper maintenance. Use these as the guidelines and training tools for which purpose they were developed.


Much like the high-tech industry, climbing hardware refers to the infrastructure items on which we build our systems. These are the ascenders, connecting links, adjusters and anchor points we use to get up, go to work and get down safely. Start by checking for ratings and markings. Most life support equipment is constructed of metal. As such, it will have ratings etched, stamped or molded into it. Find these and be sure they are still legible. Even properly rated equipment with unreadable marking can be a bone of contention for insurance and/or OSHA inspectors. More importantly for the working arborist, it is a good indicator of wear and use.

For instance, a carabiner with a laser-etched rating that is worn off may be a good field guide as to the amount of metal that has been worn away. This is not to say that the carabiner has an immediate chance of failure. However, if you have properly used a carabiner to the point that the ratings, whether etched or molded into it, have worn off, then you have used that tool for a while and you should consider replacing it.

Also note how distributed the wear is over the entire body of the tool. Back to our carabiner example: If the center of the spine is worn or nicked up but the rest of the carabiner looks relatively new, there may be a gear interface issue.

Clean equipment is happy equipment! Clean hardware/equipment also functions as designed. In general, soap and water will suffice for cleaning climbing hardware. You can use compressed air, but be careful not to force dirt or tiny debris further into moving parts and mechanisms. Dry lubricants, such as graphite or Teflon, will keep dust from clinging to moving parts. However, the solvent abilities of other oil-based lubricants may also be helpful.


In tree climbing, nothing takes abuse quite like ropes and other cordage items. If they get wet, dry thoroughly as soon as possible. Protect them from excessive wear by using friction-management devices. Inspect ropes regularly and retire if any doubt exists as to the strength or integrity. Missing or frayed lockstitching on splices can be repaired. Chafe guards, by design, will wear and should be rotated or replaced as necessary.

Slings affixed to metal objects without the ability to rotate freely (i.e. girth hitched) should be rotated regularly to check for wear to both items. This also allows for faster, more thorough drying. Slings, hitch cordage, climbing lines and other cordage-based equipment can be washed.

Specialized rope washers are available and may be a great alternative. However, in many cases no specialized equipment is necessary. Disassemble gear and/or systems as appropriate. Longer lengths should be chain knotted or placed in a mesh bag. Use a machine without a central spindle. The front-loading industrial machines at your local Laundromat work well. Use warm to cold water with a mild detergent absent of fabric softener and your ropes will have a new lease on life. Wash as often as necessary.

(A series of slipknots on a four-parted rope make it ready for the front-loading washer and a new lease on life.)


Keep leather climbing saddle components supple and oiled with an appropriate leather treatment. This helps keep leather from cracking and makes drying it out easier, not to mention providing a more comfortable fit.

Lubricate buckles for smooth, proper function. Check shackles for tightness and apply thread- locking liquids as the manufacturer recommends. A small dab of fingernail polish applied to the screw head and the body of the shackle will allow you to detect movement in the field. Reapply the thread locker and marking as necessary.

Check your bridge and replace on a regular basis. Use materials recommended or provided by the harness maker. Not all cordages and webbing are created equal, and some are downright poor choices for a harness bridge. Customizability and ease of replacement are key features of rope and webbing bridge harnesses. Use these features to your benefit, and maintain the bridge with inspection, cleaning and regular replacement.

(Using fingernail polish on the head of shackles allows the climber to easily determine if they have become loose in the field.)


We’ve looked at a few maintenance issues and procedures for climbing equipment. Like all tools, from your chain saw to your brush chipper to your truck, climbing equipment is subject to wear and tear even through proper use. Keep all your climbing tools in good working order through cleaning, inspecting, lubricating and replacing when necessary. Follow the manufacturer’s recommendations and inquire if you are unclear. Keep manuals and literature provided with all equipment in an organized file and refer to it as necessary. This is also an excellent place to document your inspection process in a timely manner as determined by your usage patterns.

Take care of your equipment with proper maintenance and it will take care of you through a lifetime of reliable function.

(Tony Tresselt is a climber, trainer, writer and student of arboriculture associated with North American Training Solutions, Arboriculture Canada Training and Education and Arborist Enterprises. Follow his exploits or get in touch at his blog or his website Gravitational

(Article courtesy of Tree Services Magazine:

Tree Health: Winter Weather Woes

Keeping customers happy while dealing with snow and ice damage

By John C. Fech

(Rabbit browsing is common in winters with extended snow cover.
Photos by John C. Fech, UNL)

There are many ways to perceive or view winter damage to trees. One is to deny it, to say to yourself or others “Oh, it’s not really that bad,” and find ways to deflect attention to the injury. Another is to accept it, to realize that it is what it is, or aquí es en Español. A third is to fight it, to dig right in and think of ways to recover from it, or prevent it in the future.

Which of these works best? While this question can be difficult to answer, it’s helpful to understand the thought processes behind the feelings associated with the damage. In most scenarios, a combination of the latter two is usually most reasonable. After all, tree care providers are not in control of all the factors that affect trees, and as such it’s illogical to assume that as a result of your efforts nothing bad will ever happen again.

Consequences of damage

There are basic rules, or tenets, that are part of our culture and hard to argue with. The first two: There are only two things certain in life, death and taxes; and supply and demand drives our economy. The third: cause and effect. In the context of winter damage, the cause is usually unknown, at least in the short run, and the effects can be varied.

The most obvious effect is the injury to a woody plant. Many trees are quite valuable to clients in terms of aesthetics, temperature modification and property value; their demise is usually problematic.

If the damage is severe, one consequence may be the loss of a customer, even though the tree care company had nothing to do with the injury. Clients can be fickle and use the damage as a reason to switch to another company or discontinue tree care altogether.

Winter construction projects can cause damage that is difficult for trees to recover from. The loss of a good reputation is also a possibility. Losing a positive reputation amongst the customer base, other tree care providers, city officials and suppliers can have long-term negative effects on a company, especially if it’s a small company and word-of-mouth is the primary advertising method.

Regardless of which of the three may be encountered, none are desirable. On the other hand, dealing with damage in a sound and responsive manner may increase your standing with the customer and positively reinforce the business relationship. Therefore, proceeding in a logical and straightforward manner is a worthy endeavor.

(Corrugated PVC collars are effective in preventing damage from mice and other critter)

Seven steps

As with any of the problems that we encounter in life, a certain level of acceptance is healthy. It matters not whether you’re considering which eldercare facility is best for your parents or how to invest for retirement, a step-by-step process is a good course of action. The following seven steps, courtesy of Steven Rodie, ASLA, University of Nebraska-Lincoln, are an effective guiding procedure in terms of diagnosing winter damage and devising a healthy response for the customer.

1 Accept the situation

2 Analyze facts and feelings

3 Define goals and objectives

4 Generate ideas to achieve goals and objectives

5 Select best ideas or combination of ideas

6 Implement

7 Evaluate; start over; never finished

Accept the situation. This requires work by both the tree care provider and the customer. Sure, it’s different work for each party in that the worker/owner/arborist usually sees the tree as a valuable part of nature and possible work for hire, while the owner will be thinking more locally and property specific. In the end, it is what it is; it happened.

Analyze facts and feelings. The fact may be that a large limb has fallen to the ground or is hanging on the house, or the entire tree has turned brown and needs to be dealt with. The owner often sees these facts, but combines the actual occurrence with the hurt or loss of a valuable asset and needs to process the feeling in their own mind. It’s best to keep this in mind when talking with the customer and give them some time to work through their feelings, especially if it is a memorial or historical tree.

Define goals and objectives. Depending on the severity of the injury, it is helpful to revisit the importance and purpose of the damaged tree. If the tree in question was an undesirable volunteer that sprouted 2 feet from the foundation, then this may be a blessing rather than a problem. Damage often provides an opportunity to rethink why each tree is in place on a given property in terms of the benefits it provides and the effort that is required for its care.

(Warming and cooling of the bark in winter can cause damage to the cambium)

Generate ideas to achieve goals and objectives. Recovering from winter injury is usually easier if several ideas to move forward in a responsible manner are generated. These should be directly related to the goals and objectives for each tree as well as the property as a whole. As a tree care provider, it’s wise to generate some ideas based on your experience with other clients and share them with the customer, keeping in mind that they will likely have some ideas of their own.

Select best ideas or combination of ideas.Selection of “best” ideas is a highly subjective process. After the ideas are presented to the customer, unless their choice is a poor arboricultural practice such as topping a winter damaged tree or removing most of the lower limbs (lions-tailing), deferring to their choice is probably the best course of action. Once you have presented several reasonable and sound options, remember that it’s their tree and they have the right to choose their preferred course of action.

Once the choice has been made it’s time to implement the action. Some actions should be implemented immediately; for example removing a fallen limb. For some damage the required actions may be part of a longer-term plan. If this is the case, devise a simple project plan or punch list detailing the work and the time frame to get it done, and present it to the customer in a walk and talk around the property.

Evaluate; start over; never finished. After the implementation of the plan, it’s wise to evaluate how well the action accomplished the goals and objectives for the trees on the property. Did the removal leave an unacceptably large gap in the tree line? Does dead wood remain in the tree that needs to be removed? Would application of mulch around the remaining specimens improve their function and appearance? Have defects such as cracks, codominant leaders or decay developed since the implementation? All of these are important questions to ask and discuss with the customer. Following the discussion, it may be necessary to start over, or implement additional actions. In terms of good tree care, the use of best management practices is never finished, at least as long as the tree is in the ground on the property.

(Winter storms, especially storms in late winter, can be responsible for damage)

Diagnosing damage

For maladies that occur in winter, a good starting point is to attempt to distinguish between winter damage and other causes. This may be easier for existing clients than for new ones, in that notes and comments made in the records for each day’s work or routine inspection can provide a basis for comparison. As each are considered, the “cause and recovery” approach should be utilized.

The most common causes of winter damage are mice and other critters, winter construction projects, sunscald, desiccation, winter storms and miscellaneous forces. Depending on the area of the country and the length of time trees are covered with ice and snow and the soil is frozen, lots of damage can happen over the winter, most of which neither the tree care worker/arborist or the property owner has any control over. In certain instances it may be coincidental and could have just as easily occurred in the summer.

Miscellaneous causes can also be classified as “additive” causes, where slope, inadequate room for shoots and roots to grow, impervious soils, cold temperature stress from fluctuating winter temperatures, or any combination thereof can cause trees to fail.

(John C. Fech is an ISA Certified Arborist, PNW ISA Certified Tree Risk Assessor at the University of Nebraska-Lincoln and a frequent contributor.)

(Article courtesy of Tree Services Magazine-

Arborist Ropes: Care and Maintenance

Care and Maintenance

 By Kate Leifheit

(Pick a color, any color.  Rope manufacturers often use bright colors so arborists can quickly and easily distinguish the ropes used for various arboricultural operations. Ropes are manufactured using a multitude of construction methods and materials, resulting in different tensile strengths and stretch.  It cannot be overstated how important it is for arborists to research and learn which rope is most compatible with their climbing or rigging system.  Proper rope selection and care is vital for performing safe and effective tree care. 
Photo courtesy of ISA.)

Ropes may be considered an arborist’s most important tools. They can be used to support limbs, tools or a person. Their adequacy as a tool is based on material, construction, tensile strength, elasticity and working-load limit. Manufacturing techniques, including the way rope strands and yarns are twisted and braided, also affect the characteristics and durability of various types of rope. Because of its role in supporting tree climbers or heavy limbs in rigging operations, it is of utmost importance to purchase ropes that are approved for tree work. Arborists shall maintain their ropes in proper working order and retire them once they show signs of excessive wear.

Common factors that weaken rope

Shock loading – This is a dynamic, sudden force placed on a rope or rigging apparatus when a moving load or piece is stopped. Shock loading can occur during rigging operations when a piece of wood falls and is then caught suddenly by a rigging system. The farther a piece falls before being caught by the system the greater the amount of force generated and experienced by the rope, rigging point and rigging system. Letting a piece run and bringing it to a stop more slowly will put less force on the rigging system and rope.

Sharp edges – Sharp edges can cut or cause heavy abrasion to a rope. These edges may appear naturally on a tree and affect a rope when you are using a natural branch union. Be aware of any sharp metal pieces embedded in trees that might cut a rope under tension. Sharp edges may also be present on climbing hardware or other equipment, meaning that proper inspection before each use is critical.

Stretch – Any time a load is placed on a rope stretch can occur. The rope may bend or get caught when a portion bears the majority of the load unevenly. This is due to forces resulting from the load not being able to flow or travel well beyond a bend in the rope. Depending on the bend, the part of the rope from the bend to the load may bear almost all of the force, and the part of the rope from the bend and away from the load may bear almost none of the force. This is considered an unequal load.

Friction – Friction occurs when a rope rubs against itself, another rope, hardware or a part of the tree. The rubbing causes wear on the rope, which decreases its strength over time. Using devices like blocks, pulleys, and ring friction savers correctly can help protect a rope from wear and extend its service life. Ropes that have a mantle sheath with larger strands generally have a higher resistance to abrasion.

(ANSI Z133 Safety Requirements for Arboriculture Operations section 8.1.4 states: “Arborists shall inspect climbing lines, worklines, lanyards and other climbing equipment for damage, cuts, abrasion and/or deterioration before each use and shall remove them from service if signs of excessive wear or damage are found.” 
Photo courtesy of ISA.)

Heat – Excessive heat is a natural enemy of most materials, and rope is no exception. Arborist ropes are subjected to a lot of heat. Friction causes heat when rope rubs against blocks, equipment, rigging points, tree limbs and other objects. Rope rubbing against rope also causes hot spots. Heat is a factor in reducing a rope’s service life. It’s important to take measures to avoid excessive friction or conditions that may produce excessive heat on your rope.

Moisture – This can cause strength loss in ropes depending on the material they’re constructed from. While nylon has some absorption properties and can lose strength when wet, a material like polyester does not experience strength loss due to moisture. This is one reason why most arborist ropes are constructed from polyester. It’s recommended that you store all of your ropes in a rope bag to keep them clean and dry. Do not use excessive heat to dry your ropes, and do not store them on the ground.

Knots – Each time a knot is tied in a rope it loses a percentage of its original strength.

Signs of a weak rope

Regular rope inspection shall be performed before each use to determine if the rope is still in proper working condition. During inspection, look for the following characteristics of a weak rope:

Discoloration – This may be an indication of chemical damage.

Variance in diameter – Variance in diameter may indicate core damage.

Hard spots and contamination – These usually signify a rope is excessively worn or weakened by overloading and shock loading.

Gloss, glaze and streaks – These indicate signs of heat or friction damage.

Frays, pulls and broken strands – If more than half of the outer sheath is frayed, then you should retire the rope immediately. Broken strands may indicate the rope was torn by friction, cut by a sharp edge, or the working-load limit was exceeded. Retire the rope immediately if two or more strands are broken.

Heavy abrasion – Usually caused by friction and extreme wear.

Milking – This is the shifting of the sheath leaving a rope end without a core.

Rope care

  • Here are some simple things you can do to increase the service life of a rope and limit damage:
  • Hang your rope off the ground or keep it in a rope bag. A rope can absorb chemicals from concrete or other porous surfaces when kept on the ground.
  • Use a rope washer or wash your rope in a washing machine on a delicate cycle to clean off dirt and grit. Do not use detergents or fabric softeners, and do not put the rope in a dryer. Ropes should be hung to dry.
  • Try to use the rope on smooth, natural branch union points or use a friction-reducing device to help maintain the rope’s original strength and lessen abrasion.
  • Keep the rope away from temperatures that can cause rope damage.
  • Cut off damaged portions of the rope and rotate the use of climbing line ends if not using a spliced eye.

(Tree care operations can be hard on ropes. Dynamic loads can cause shock loading, heavy loads can exceed the rope’s working-load limit, and natural branch union rigging can cause excessive friction. For these reasons, selecting a rope that is designed for the type of work that will be performed and inspecting ropes before each use is vital. 
Photo courtesy of Baltimore City Parks;

Monitor rope use

Monitoring the use of a rope will help you assess its condition and strength during daily inspections. Avoid using a rope that has been loaded above the working-load limit. Remember that the tensile strength decreases after each use of the rope. After purchasing a rope, write down:

  • the date the rope is put into service;
  • rope tensile strength;
  • the working-load limit;
  • its type of use; and
  • the approximate latest date the rope should be retired.

Once a rope is ready to be retired from climbing or rigging applications, it can still be used as a tag line. When disposing of an old rope, it’s best to cut the rope into short lengths to prevent someone else from using it.

(Don’t store your rope near sharp objects, and make sure blades in the work zone are covered/ sheathed when not in use
Photo courtesy of ISA.)

Remember these key points about rope safety:

  • Always visually and manually inspect ropes before each use and remove from service ropes that show signs of excessive wear or damage.
  • Always keep loads under the working-load limit.
  • All climbing gear, including lanyards, hardware, saddles and splices, must be in good working condition and not be altered in a way that would compromise the integrity of the equipment.
  • Rope should be clearly marked for specific use (i.e., which ropes are for climbing and which ropes are for rigging).
  • Never leave a rope unattended in a tree.
  • Review rope regulations and standards governing your region (in the U.S., refer to ANSI Z 133-2012 Safety Requirements for Arboricultural Operations section 8.1).

Carefully monitoring rope use, selecting the right ropes for the specific purpose, adhering to safety standards, and properly maintaining and storing your ropes and other equipment will help ensure a safe and efficient worksite.

To learn more about rope construction, maintenance and selection – and earn CEUs – visit ISA’s Online Learning Center ( to take the new course, Arborist Ropes. Kate Leifheit is ISA’s former educational products coordinator.

(Article courtesy of Tree Services Magazine-