CATS - Certified Arborist Tree Service of Albuquerque Arborist Safety and ANSI Questions and Answers 1 — Questions and Answers
Question 1: An arborist crew is performing pruning work near a secondary distribution line with a voltage of 7.2 kV (7,200 volts). A homeowner, who is an unqualified person according to ANSI Z133, walks into the work zone. What is the minimum approach distance (MAD) that must be maintained between the homeowner and the energized conductor?
- 5 feet
- 10 feet (Correct answer)
- 15 feet
- 2 feet
Correct answer: 10 feet
ANSI Z133 establishes specific Minimum Approach Distances (MAD) to protect individuals from electrical hazards. For unqualified persons, such as the general public or ground workers without specific electrical hazard training, the MAD for energized conductors with a phase-to-phase voltage up to 50 kV is 10 feet.
Question 2: According to ANSI Z133 safety standards, which of the following is NOT considered mandatory personal protective equipment (PPE) for an arborist operating a chainsaw on the ground?
- Hard hat meeting ANSI Z89.1 standards
- Hearing protection
- Wire-core lanyard (Correct answer)
- Leg protection (chainsaw chaps or pants)
Correct answer: Wire-core lanyard
ANSI Z133 mandates specific PPE for chainsaw operators to mitigate common injuries. This includes head protection, eye protection, hearing protection, and cut-resistant leg protection for ground operations. A wire-core lanyard is a component of a climbing or work-positioning system and is not required for ground-based chainsaw work.
Question 3: A certified arborist is setting up a work site for a tree removal adjacent to a public sidewalk. According to ANSI Z133 standards for work-site safety, what is the primary purpose of establishing a clearly marked drop zone?
- To provide a designated area for the wood chipper.
- To keep tools and equipment organized.
- To prevent pedestrians and unauthorized personnel from entering the area where overhead hazards exist. (Correct answer)
- To provide a designated rest area for crew members.
Correct answer: To prevent pedestrians and unauthorized personnel from entering the area where overhead hazards exist.
ANSI Z133 requires that the work area, and specifically the drop zone, be secured to protect people and property from the hazards of falling limbs and debris. This involves using cones, signs, or barriers to control the area directly beneath the work being performed and prevent unauthorized entry.
Question 4: ANSI Z133 mandates that a job briefing be conducted before any tree care operation begins. In addition to discussing the work plan and potential hazards, what critical safety component must be confirmed as available on-site?
- A detailed schematic of the tree's root system.
- A working means of communication and emergency contact numbers. (Correct answer)
- A certified mechanic to service equipment.
- At least three ground workers per climber.
Correct answer: A working means of communication and emergency contact numbers.
Before any job begins, ANSI Z133 requires a job briefing that includes establishing emergency procedures. A fundamental part of this is ensuring there is a reliable way to contact emergency services and that relevant phone numbers are readily available for all crew members.
Question 5: Which of the following actions is a direct violation of ANSI Z133 safety standards for operating a brush chipper?
- Standing to the side of the infeed chute while feeding material.
- Wearing loose-fitting clothing or gloves with cuffs. (Correct answer)
- Inspecting the chipper for defects before starting it.
- Feeding short, brushy material into the chipper using a longer branch.
Correct answer: Wearing loose-fitting clothing or gloves with cuffs.
The ANSI Z133 standard explicitly prohibits wearing loose-fitting clothing, jewelry, or cuffed gloves when operating a brush chipper. These items can become entangled in the material being fed into the machine, creating a severe caught-in hazard that can pull the operator toward the infeed rollers.
Question 6: An arborist is rigging a large limb with a calculated weight of 800 pounds. They are using a block and a rope that each have a Working Load Limit (WLL) of 1,000 pounds. According to ANSI Z133 principles, why is this setup potentially unsafe?
- The WLL of the block and rope must be added together.
- The forces generated during rigging can easily exceed the static weight of the limb. (Correct answer)
- The tree itself is not rated with a Working Load Limit.
- The setup is safe because the limb's weight is under the WLL of each component.
Correct answer: The forces generated during rigging can easily exceed the static weight of the limb.
A core principle in rigging, emphasized by ANSI Z133, is accounting for dynamic loading. The force exerted on the system can be much greater than the static weight of the piece being moved. A limb falling even a short distance before the rope catches it can generate forces two to three times its weight. In this scenario, the 800-pound limb could easily generate forces exceeding the 1,000-pound WLL, leading to catastrophic failure.
CATS - Certified Arborist Tree Service of Albuquerque Arborist Safety and ANSI Questions and Answers 1
An arborist crew is performing pruning work near a secondary distribution line with a voltage of 7.2 kV (7,200 volts).
A homeowner, who is an unqualified person according to ANSI Z133, walks into the work zone.
What is the minimum approach distance (MAD) that must be maintained between the homeowner and the energized conductor?