Look Out Below!

Giving the All Clear for Drop Zone Safety

Heads up! Are you paying attention? Beneath every tree canopy lies the possibility that a broken branch, a sudden equipment malfunction, or a simple miscommunication can turn routine work into a serious accident.

Drop zone safety remains one of the most overlooked but important lessons for any arborist to learn today — but don’t learn this lesson the hard way. Keep your eyes to the skies and your boots on the ground to ensure you, your crew, and the public stay safe while working in the drop zone.

Laying Down the Ground Rules

The number one priority in drop zone safety is proper planning and set up. Without this critical first step, falling debris such as branches or trunk sections could cause irreparable harm to people and property. Given that struck-by accidents are one of the most common causes of fatalities in the industry, the need for a visibly delineated area beneath the tree canopy is paramount.

When setting up the drop zone, remember the acronym DiRFT — Do it Right the First Time. Before starting any tree work, plan ahead by knowing the location and size of the designated drop zone in relation to the tree’s height and spread, followed by careful placement of high-visibility markers such as signs, cones, tape, or ground workers.

While visible demarcation is key to setting the boundary of what’s safe and what’s not, it’s not the only thing that factors into drop zone safety. Buffer zones, hazard identification, escape routes, communication methods, and emergency response plans are also vital plays from the drop zone safety handbook.

“A safe drop zone comes from good planning, visible barriers, clear communication, and the discipline to stop and reset if those controls break down,” Korey Conry, trainer & safety supervisor at Mountain F. Enterprises said.

As professionals, arborists have standards. This is true in both the quality of the work they perform and the standards they hold themselves to, including the American National Standards Institute (ANSI) ANSI Z133: Arboricultural Operations — Safety Requirements. Often considered the gold standard of safety guidelines in the arboriculture industry, the ANSI Z133 sets the precedence of safe tree work operations in many disciplines:

Section 3 — General Safety Requirements, Section 6 — Portable Power Hand Tools, and Section 8 — Work Procedures cover many aspects of drop zone safety, with 3.4 — Job Briefing and Worksite Setup, 3.5 — Traffic Control, 6.1 — General, 8.1 — Climbing Procedures, 8.2 — Ropes and Arborist Equipment, 8.3 — Pruning and Trimming, and 8.5 — Rigging being the most pertinent.

“It’s important that we always use ANSI Z133 procedures to keep everyone safe and consistent,” Conry reminded.

To reduce the risk of injuries and fatalities, tree care companies should implement clear and consistent drop zone safety policies using ANSI Z133 guidelines:

• Define a 360° perimeter around the tree using marker colors that are visually distinct from work zone markers;
• Ensure 3-way communication is established before any personnel are allowed to enter the drop zone;
• For tree pruning, cones must be placed at least 10 feet beyond the drip line;
• For tree removals, targets must maintain a minimum distance of 20 feet away from the drip line;
• For tree felling, the drop zone must be set at a distance of at least twice the height of the tree; and
• Rope handlers must remain at a distance no less than 1.5 times the tree’s height.

Danger From Above

Unexpected mishaps in the drop zone can literally come out of the blue, so remain vigilant of these common hazards when working in or around the drop zone:

• Primary Hazards: Falling branches, limbs, trunk sections, tools, equipment, and rigging gear.
• Secondary Hazards: Ricocheting/swinging/bouncing/rolling limbs, slipping or tripping over fallen debris, sharp points/edges from branches and tools, pinch points in climbing and rigging gear, snagged/tangled climbing lines, eye or lung irritation from sawdust, and electrocution from powerlines.
• Tertiary Hazards: People entering the drop zone unexpectedly, falling from a height, poor spatial awareness, poor communication, complacency, and weather conditions like wind, rain, or smoke.

Conry stressed the importance of not underestimating hazards with complacent mistakes or assumptions.

“Tree workers underestimate just how far debris will travel, especially when limbs swing, bounce, or roll after hitting the ground in the drop zone,” he stated. “ANSI Z133 reminds us that the drop zone isn’t just straight down — it extends outward, at least twice the length of the material being cut, and often more depending on the situation.”

Lisa Tadewaldt, owner of Urban Forest Pro, added that there’s more than meets the eye when it comes to identifying hazards, and necessary precautions should be taken to protect the crew at every stage.

“Lots of things can look different once you are in the tree,” she noted. “For example, hangers you could not see from the ground, proximity of power lines to tree parts, or additional defects such as cracks. Let the ground crew know when the hazards have changed from what was discussed on the ground.”

The Hierarchy of Controls by the National Institute for Occupational Safety and Health (NIOSH) can help mitigate these hazards by using a combination of engineering, administrative, and personal protective equipment (PPE) protocols for drop zone safety:

• High-visibility markers or physical barriers
• Traffic control procedures
• Job briefings and site hazard assessments
• Three-way communication systems
• Adjustments to rope angles and speeds
• Safety training and education programs
• Safety gear

Tim Spence, business owner of Arborist Halifax, advised staying ahead of the game by creating a step-by-step action plan of where and how tree work will be performed before it starts.

“Having a safety briefing in the morning or before commencing a job ensures all crew members are on the same page,” he said.

Lines of Communication

Effective drop zone safety relies on clear, simple, and consistent communication between climbing arborists and ground crews. A formal command-and-response system using three-way communication is necessary to ensure every command is heard, received, and acknowledged.

“The crew should rely on short, standardized verbal commands such as ‘slack,’ ‘hold,’ ‘lower,’ or ‘stop,’ with the ground worker repeating the command back to confirm it was heard correctly,” Conry explained.

ANSI Z133 3.4.4 — 3.4.5 offers other examples of acceptable three-way communication such as eye contact, hand signals, whistles, and radio transceivers. Ultimately, arborists should rely on a combination of verbal and non-verbal techniques to increase the success rate of communication and reduce the risk of confusion and injury.

For example, when the climbing arborist is ready to drop a branch, they will look below and shout a command like “stand clear.” The ground crew will respond in kind by repeating back “clear” and making eye contact with a hand signal to verify the command was received and acknowledged. In situations where distance or background noise reduce verbal acuity, headsets and non-verbal communication methods like hand signals, eye contact, body positioning, and rope tugs become an arborist’s most valuable tool.

Being shown the ropes is equally as important when working in the drop zone. Knowing how to control the direction and speed of tie-offs makes for safe and efficient rigging operations:

• Configure the rigging system to your advantage by selecting a strong rigging point above the work being performed;
• Make pieces easier to handle and guide them in the right direction by using redirects and pruning techniques like step cuts, snap cuts, sectioning, and open-face notching;
• Equipment like blocks, pulleys, plates, and friction devices like port-a-wraps help guide tie-offs with smooth, easy descents;
• Pre-tension ropes prior to making cuts to reduce unexpected dynamic forces; and
• Use speed lines to quickly move limbs to the drop zone, if necessary.

“There are many different techniques, equipment, and nuances involved in rigging,” Spence noted, “so it requires adequate training and experience to assess each tree or scenario on a case-by-case basis.”

Stand Your Ground

Even properly established drop zones will fail if the boundaries and rules aren’t respected or enforced. Drop zone safety guidelines between the crew and the public are slightly different, but the general principle is the same. “Nobody should be in that area unless it’s absolutely necessary and communication is maintained,” Conry urged.

Ground crew members often assume that they are permitted in the drop zone at any time because of their job responsibilities, but this mindset misses the mark on industry standards. ANSI Z133 8.5.12 states that “workers shall stay out of the drop zone until it has been communicated by a qualified arborist, a qualified arborist trainee, or the worker aloft directly involved in the rigging operation that it is safe to enter.” This is important to remember because even though it may be tempting to walk into the drop zone and grab branches, the climbing arborist may still be in the process of dropping another limb overhead.

“The groundsman should make it a habit to stand outside the drop zone where the climber has a good visual on them and notify the climber when entering the drop zone,” Spence advised. This principle applies to climbing arborists, as well.

“If the arborist in the tree has not received confirmation [from the ground crew], they must assume that workers are in the drop zone,” Tadewaldt added.

Curious bystanders may also be interested in watching tree work up close, but traffic controllers need to stand their ground and enforce the rules for everyone’s sake.

“For jobs in public spaces, one crew member may need to act as a traffic or pedestrian control spotter to prevent bystanders from walking into danger. Enforcing the rules means stopping work immediately if someone enters the drop zone, establishing boundaries, and reminding both the crew and the public that only trained workers are allowed inside,” Conry concluded.

Up in the Air

Time is money, but safety is priceless. In arboriculture, cutting corners can cost far more than just a few minutes — it can cost lives. Adopting drop zone safety protocols is not only smart, but also a sign of forward thinking and a healthy respect for industry standards and best practices.

“We enforce these practices in several ways, including a general culture of professionalism, regular safety meetings where these procedures are discussed, and job site checks where safety procedures are perfected through on-site coaching,” Tadewaldt said.

Professionals who promote this safety-first mindset and exercise a proactive approach to their work can better protect themselves, their fellow workers, and the public from hazardous work near trees. So, whether you are an arborist, a grounds person, or a member of the public, bringing safety to the forefront of your life instills a sense of professionalism, integrity, and reliability that defines what it truly means to be a cut above the rest.

About the Author

TJ Yurko is an ISA Certified Arborist^® (PR-5403A), ISA TRAQ Arborist, and Certified Landscape Horticulturist Technician at his company, Tree J Consulting, where he advises clients on urban forestry and arboriculture best management practices and strategies for tree care operations.