Section 20. Definitions

The following words and terms when used in this chapter shall have the following meanings unless the context indicates otherwise:

"Aerial device" means any one of the following types of vehicle-mounted apparatus used to elevate personnel to jobsites above ground:

1. Extensible boom platform.

2. Aerial ladder.

3. Articulating boom platform.

4. Vertical tower.

5. A combination of any of the above, as defined in ANSI A92.2.

"Anti-two block device" means a device consisting of a hollow weight suspended from the boom nose or jib of log loaders, cranes, or related hoists by a chain. The weight hangs with hoist cable running through its center. An electromechanical switch mounted on the boom nose or jib is connected to the chain via a retractable steel cable. When contact is made with the suspended weight by the hook block or any other lifting device nearing the nose or jib, the anti-two block switch circuit is deactivated, and hoist up or telescope out is prevented.

"Apex" means the point at which two saw cuts meet to form a notch.

"Applicator" means a qualified person engaged in the application of materials such as, but not limited to, pesticides, growth regulators, and fertilizers.

"Approved" means acceptable to the federal, state, or local jurisdiction having enforcement authority.

"Arboriculture" means the art, science, technology, and business of utility, commercial, and municipal tree care.

"Arborist" means an individual engaged in the profession of arboriculture.

"Arborist climbing line" means a line designated to support the climber while aloft in a tree or attached to a crane, constructed according to specifications outlined in 16VAC25-73-90 A 8.

"Arborist saddle" means an arrangement of straps, fittings, and buckles or other elements in the form of a waist belt with a low attachment element or elements and connecting support encircling the legs, suitably arranged to support the body in a sitting position.

"Ascender" means a mechanical device used for climbing rope.

"Authorized" means designated by the entity that has care, custody, and control of the unit.

"Back cut" means the cut made in a tree limb or trunk on the side opposite the intended direction of fall.

"Belay" means roping technique, managed by the ground person, to safeguard the arborist while climbing.

"Brush hog" means a heavy-duty rotary mower, normally pulled by a farm-type tractor, used for cutting and mulching brush.

"Bucket" means a basket-type platform approximately four feet (1.22 m) high, which is attached to the end of the upper boom on an aerial device, providing a work platform for working aloft.

"Bucking" means the act of sawing trees, limbs, or both, into smaller sections once they are on the ground.

"Cant hook" means a long-handled lever fixed with a blunt metal end to handle logs; includes a swinging, metal hook opposing the blunt end to create leverage.

"Carabiner" means a connector generally composed of a trapezoidal or oval-shaped body with a closed gate or similar arrangement that may be opened to receive an object and, when released, automatically closes to retain the object.

"Chopping tool" means a wooden, fiberglass, or steel-handled tool with a sharp, single- or double-edged steel head or blade mounted to it that is used to cut or split wood (for example, an ax or machete).

"Climbing/friction hitch" means a hitch used for securing a tree climber to the climbing line, permitting controlled ascent, descent, and work positioning. Examples of climbing hitches include, but are not limited to, the tautline hitch, Blake's hitch, and the Prusik hitch/knot.

"Climbing system" means the various pieces of gear, or components that the arborist relies upon to secure himself while aloft in the tree, such as, but not limited to: an arborist saddle, one or more arborist climbing lines, and one or more lanyards as well as carabiners and/or snap hooks approved by their manufacturer for climbing.

"Conventional notch" means a directional felling cut into the side of a tree, facing the intended direction of fall and consisting of a horizontal face cut and an angle cut above it, creating a notch of approximately 45 degrees.

"Crew leader" means the qualified arborist designated as the individual in charge of a specific job or group of workers.

"Crotch" (n.) means branch union; the angle formed by two branches in the tree. "Crotch" (v.) means to place a line through a branch union.

"Damaged" means a defect, impairment or injury to machinery, vehicle, tool, material or equipment that would meet the manufacturer's criteria for removal from service, or in the absence of such criteria, would materially effect the safe operation or safe use of the item during tree trimming operations.

"DBH" means acronym for diameter at breast height; diameter of a tree measured at 4.5 feet (1.3 m) above ground.

"Deadman control" means a safety switch, electrical or mechanical, that deactivates the equipment's function when released by the operator.

"Dielectric" means nonconductive of electrical current.

"Direct contact" means a direct contact is made when any part of the body touches or contacts an energized electrical conductor.

"Direct supervision" means direct supervision occurs when a qualified arborist or a qualified arborist supervisor is physically present on the jobsite.

"Drop-starting" means the act of starting a chain saw by pushing the saw away from the body with one hand while simultaneously pulling on the starter cord handle with the other.

"Electrical conductor" means any overhead or underground electrical device capable of carrying an electric current, including communications wires and cables, power lines, and other such fixtures or apparatus.

"Electrical hazard" means an object or situation that poses risk of injury or death due to direct or indirect contact with an electrical conductor. Where unguarded, energized electrical conductors are present, specific minimum approach distances based on the arborist's or worker's level of training, as set forth in this regulation, shall be followed.

"Electrical system owner/operator" means an organization that operates or controls the transmission and/or distribution of electric power through electrical conductors.

"Electric supply" means conductors used to transmit electric energy and their necessary supporting or containing structures. Signal lines of more than 400 volts are always supply lines, and those of less than 400 volts are considered as supply lines if so run and operated throughout.

"Energy (shock) absorber" means a component of a climbing system whose primary function is to dissipate energy and limit deceleration forces that the system imposes on the body during fall arrest.

"Fall-arrest lanyard" means a rope or strap designed to be used with a full-body harness to limit maximum arresting force on a climber to 1,800 pounds (8 kN) in a fall.

"False crotch" means a device installed in a tree to set ropes during climbing or rigging because there is not a suitable natural crotch available, or to protect an available crotch, and/or to reduce wear on ropes.

"False crotch for rigging" means a pulley, block, sling, lashing, or metal ring affixed to a tree's leader or limb, through which a load line is passed, to lower or raise limbs or equipment.

"False crotch redirect" means the use of a false crotch in conjunction with either a natural crotch or a second false crotch in instances where the arborist is working away from the trunk of the tree and could otherwise be subject to an uncontrolled pendulum swing in the event of a slip.

"Footlock" means to climb up a suspended rope by pulling with the hands and arms and pushing upward with the feet. The loose end of the rope is wrapped under the middle and over the top of one foot and is locked in place with pressure from the other foot.

"Friction point" means the point at which the rope surface of the climber's hitch rubs against the climbing line.

"Good working condition" means a term describing a piece of equipment that has no mechanical defects, has all guards in place, and is operated as intended by the manufacturer.

"Ground fault" means any undesirable current path from a current-carrying conductor to ground.

"Guarded" means covered, fenced, enclosed, or otherwise protected by suitable covers or casings, barrier rails or screens, mats, or platforms that have been designed by the electrical system owner/operator to minimize the possibility of dangerous approach or accidental contact by persons or objects under normal conditions. Also see unguarded.

"Handline" means a length of rope designated as a tool to leverage, lift, and hold tools, equipment, wood, or other objects; the proper rope strength is specified for each particular use.

"High-pressure excavation" means the removal or displacement of soil using pressurized air or water.

"Humboldt notch" means a directional felling cut into the side of a tree, facing the intended direction of fall and consisting of a horizontal face cut and an angled cut below it, creating a notch of approximately 45 degrees. A Humboldt cut is usually reserved for larger trees on steep slopes.

"Indirect contact" means indirect contact is made when any part of the body touches any conductive object, including tools, tree branches, trucks, equipment, or other objects, that is in contact with an energized electrical conductor. Such contact can also be made as the result of communication wires and cables, fences, or guy wires being accidentally energized.

"Job briefing" means the communication [ before work begins ] of at least the following subjects for arboricultural operations: hazards associated with the job, work procedures involved, special precautions, electrical hazards, job assignments, and personal protective equipment.

"Kilovolt, kV ( [ Table 1 )" means the term for 1,000 volts, abbreviated as kV. Higher voltages are generally given as kilovolts. Example: 12.5 kV (12,500 volts) and 19.9 kV (19,900 volts).

"Kilonewton, kN" means the measurement of force, abbreviated as kN. Equal to 224.8 pounds. Example: 24.02 kilonewtons equals 5,400 pounds.

"Ladder" means a two-, three-, or four-legged structure that utilizes vertical side legs with cross sections uniformly placed between the side legs to be used as steps; available in wood, aluminum, or fiberglass; used to ascend to and descend from a height. Also see tripod/orchard ladder.

"Lanyard" means a component of a climbing system consisting of a flexible line of rope, wire rope, or a strap that generally has a connector at each end for connecting the body support to a fall arrester, energy absorber, anchorage connector, or anchorage.

"Leg protection" means personal protective equipment constructed with cut-resistant material, such as ballistic nylon, intended to reduce the risk of injury to the legs during chain-saw operations.

"Line-clearance tree trimming" means the pruning, trimming, repairing, maintaining, removing, or clearing of trees or the cutting of brush (vegetation management) that is within 10 feet (3.05 m) of electric supply lines and equipment . Line-clearance tree trimming activities are performed by the employees of the owner or operator of the electrical or communication systems, or independent contractors engaged on behalf of the owner or operator of the system to perform the work.

"Load binder" means a synthetic strap with a ratchet mechanism or a properly secured rope or chain to encircle a tree trunk or limb as a means of preventing splitting.

"Manual land clearing" means the removal of trees, shrubs, and vines using chain saws or other cutting tools where there are no structures or objects that need to be avoided and pull lines are not used to pull or drop a tree and/or trunk to the ground.

"Maul" means a heavy-handled hammer, sometimes made with a single edge; used to drive wedges or split wood.

"Minimum approach distance" means safe working distances from overhead electrical conductors as defined in Table 1 of 16VAC25-73-50.

"Open-face notch" means a directional felling cut into the side of the tree, facing the intended direction of fall and consisting of two cuts creating a notch greater than 70 degrees.

"Outrigger" means built-in device used to stabilize cranes, aerial devices, and similar equipment.

"Phase" means any current-carrying conductor that has an electric potential other than ground (ground is assumed to be 0 volts).

"Phase to ground ( Table 1 )" means the electric potential (voltage) between a conductor and ground.

"Phase to phase" means the electrical potential (voltage) between two conductors, each having its own electric potential relative to ground.

"Primary conductor" means any conductor, including aluminum, copper, or aluminum conductor steel reinforced (ACSR), that is bare, covered, or insulated, with a nominal voltage above 750 volts.

"Proximity" means an area within 10 feet (3.05 m) of energized overhead electrical conductors rated 50 kV phase to phase or less. For overhead electrical conductors rated more than 50 kV phase to phase, the distance is increased 4/10 inch (10 mm) for each additional kV.

"Prusik knot" means a sliding friction knot, as in a work-positioning lanyard.

"Prusik loop" means an endless loop of rope used to fashion a Prusik knot. The endless loop may be spliced or knotted with, at minimum, a double fisherman's knot.

"Qualified arborist" means an individual who, through related training and on-the-job experience, is familiar with the equipment and hazards involved in arboricultural operations and who has demonstrated ability in the performance of the special techniques involved.

"Qualified arborist trainee" means an individual undergoing on-the-job training under the direct supervision of a qualified arborist. In the course of such training, the trainee becomes familiar with the hazards and equipment involved in arboricultural operations and demonstrates ability in the performance of the special techniques involved.

"Qualified crane operator" means an individual who, by reason of a recognized credential or professional standing, or through related training and on-the-job experience, is familiar with the equipment and hazards involved with arboriculture crane operations and who has demonstrated competence in operating a crane and performing the special techniques involved.

"Qualified line-clearance arborist" means an individual who, through related training and on-the-job experience, is familiar with the equipment and hazards in line clearance and has demonstrated the ability to perform the special techniques involved. This individual may or may not currently be employed by a line-clearance contractor.

"Qualified line-clearance arborist trainee" means an individual undergoing line-clearance training under the direct supervision of a qualified line-clearance arborist. In the course of such training, the trainee becomes familiar with the equipment and hazards in line clearance and demonstrates ability in the performance of the special techniques involved.

"Qualified personnel" means an individual who, by reason of training and experience, has demonstrated the ability to safely perform assigned duties and, where required, is properly licensed in accordance with federal, state, or local laws and regulations.

"Quick-acting connector" means hose connectors in a hydraulic or pneumatic system designed to allow rapid connection or disconnection without leakage when the system is pressurized.

"Saddle, arborist": see arborist saddle.

"Secured (object)" means made firm or tight; fastened. Example: The load is secured to the truck.

"Secured (person)" means when an arborist is safeguarded from unintended movement by utilizing a climbing system that is attached to the arborist and connected to a tree or other stable support. Examples of being secured include, but are not limited to, (i) being tied in, (ii) using a work-positioning lanyard, (iii) being on belay, and (iv) ascending the arborist climbing line using the footlock technique while utilizing a Prusik loop or ascenders.

"Shall," as used in this regulation, denotes a mandatory requirement.

"Should," as used in this regulation, denotes an advisory recommendation.

"Snap hook" means a self-locking or double-locking rope snap. The locking type (required by this regulation for climbing) has a self-closing, self-locking gate that remains closed and locked until intentionally opened by the user for connection or disconnection. A captive eye is an integral part of a snap hook but is independent of the hook and gate portion.

"Split tail system and split tail" refers to a system in which the climbing line is tied to the saddle, preferably indirectly with an ANSI-compliant carabiner or locking rope snap, without leaving a tail beyond the termination. The climbing/friction hitch is then tied onto the climbing line with a separate short section of climbing line called a split tail. The split tail is separately connected to a designated anchor point on the saddle.

"Spotter" means a person within voice and visual communication of the driver and located in a position to view the area in which the vehicle (unit) is backing to help ensure that the backing operation is, and will remain, safe.

"Step potential" means the voltage between the feet of a person standing near an energized grounded object. It is equal to the difference in voltage, given by the voltage distribution curve, between two points at different distances from the electrode. A person could be at risk of injury during a fault simply by standing near the grounding point.

"Tackle blocks and pulleys" means equipment used in most tree situations to take a strain rather than move a load. Critical components of the system are the appropriate ropes, blocks, and, especially, the lock or connecting link.

"Termination knot" means any knot suitable for rope termination, including, but not limited to, double fisherman's loop (scaffold hitch), anchor hitch, and buntline hitch.

"Tied in" means the term that describes an arborist whose climbing line has been run through a natural or false crotch attached to an arborist's saddle and completed with a climbing hitch or mechanical device, permitting controlled movement and work positioning.

"Tool lanyard" means short line or strap used to secure a tool while working aloft.

"Tripod/orchard ladder" means a three-legged ladder that utilizes the third leg to form a tripod to stabilize itself among orchard trees and/or shrubs. It is recommended for use on turf for better stability and to avoid slippage of the legs. Not recommended for use on hard surfaces.

"Unguarded" means not guarded from approach or contact with electrical conductors.

"Volt" means a unit of electric potential difference between two points. Lower-voltage systems are generally expressed in terms of volts, for example, 120 volts or 240 volts.

"Wedge" means a piece of material with two sides meeting at an angle; used to raise or split objects by applying a driving force, such as with a hammer.

"Wheel chock" means wedge-shaped block manufactured or employer approved to prevent unintentional movement of vehicle. Wheel chocks are placed in front of or in back of a vehicle's tires or tracks. If necessary, the chocks can be placed both in front and in back of the tires or tracks.

"Worker" means an individual involved in an arboricultural operation, such as ground operations, equipment operations, and removal operations.

"Working load" means limiting load values derived from the minimum breaking strength of a cord or rope divided by the design factor. For example, given a minimum breaking strength of 10,000 pounds (44.48 kN) and a design factor of 10: 10,000/10 = 1,000 (working load, in pounds) or given a minimum breaking strength of 10,000 pounds (44.48 kN) and a design factor of 5:10,000/5 = 2,000 (working load, in pounds).

"Working-load limit" means the working load that must not be exceeded for a particular application as established by a regulatory or standards-setting agency.

"Workline" means rope used for lifting, lowering, or guiding limbs or equipment, or both, into or out of the tree.

"Work-positioning system" means an arborist climbing system designed to be used under tension to support the arborist or other worker on an elevated vertical surface, such as a tree limb, and allow him to work with both hands free.

Historical Notes

Derived from Volume 27, Issue 15, eff. April 27, 2011.

Statutory Authority

§ 40.1-22 of the Code of Virginia.