Trees and Construction Flashcards
11 cards from real Certified Arborist Test practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 11 Trees and Construction flashcards as text
To stop a cable that is attached to anchoring hardware from wearing out too quickly, which of the following devices should be used?
Answer: Thimble
A thimble is a protective fitting used to prevent a rope or cable from wearing out too quickly where it forms a loop (eye) around anchoring hardware. It provides a smooth, rounded surface that prevents sharp bends and friction, which would otherwise abrade and weaken the cable over time. This extends the lifespan and maintains the strength of the cable.
Which part of a tip-tied branch will come off the cut?
Answer: Butt end
When a branch is 'tip-tied,' the rigging line is attached near its tip. Upon making the cut, the heavier butt end of the branch, which is closer to the trunk, will be the part that comes off the cut first. The rigging system then controls the descent of this butt end, allowing for a controlled and safe removal.
Which of these tools should be reserved for connectors that are rarely required to be opened?
Answer: Screw links
Screw links, also known as quick links, are best reserved for connectors that are rarely required to be opened. They provide a very strong and secure connection but typically require a wrench or tool to fully tighten and loosen. This makes them less convenient for frequent use compared to carabiners or shackles, which are designed for quicker attachment and detachment.
If the pulley's diameter is three times larger than the rope's diameter, what would be the bend ratio of a block-based rigging system?
Answer: 3:1
The bend ratio in a rigging system is calculated by dividing the diameter of the pulley (or block sheave) by the diameter of the rope. If the pulley's diameter is three times larger than the rope's diameter, the ratio is 3 divided by 1, resulting in a 3:1 bend ratio. A higher bend ratio is generally preferred as it reduces stress on the rope and extends its lifespan.
The process of removing limbs or bringing down an entire tree with the use of ropes and other tools is called:
Answer: Rigging
Rigging is the specialized process in arboriculture that involves using ropes, blocks, pulleys, and other equipment to safely remove limbs or entire trees in a controlled manner. This technique is essential in confined spaces or near structures, allowing arborists to lower sections of a tree without causing damage to property below.
Which of the following branches is propping the best for?
Answer: A large branch that is expanding parallel to the ground.
Propping is a support technique best suited for large, heavy branches that are expanding parallel to the ground or at a low angle. These branches are particularly susceptible to breaking under their own weight or from external loads like snow. Propping provides physical support from below, preventing failure and extending the branch's life.
One cycle for a rigging line in terms of rope is defined as:
Answer: Just one lift and one drop
In rigging, one cycle for a rigging line is defined as just one lift and one drop of a load. This definition is crucial for tracking the rope's usage and wear. Each cycle subjects the rope to stress, friction, and potential shock loads, which contribute to its overall fatigue and determine its safe working life.
How deep should the first notch be when felling a tree?
Answer: Not to exceed one-third of the tree's diameter
When felling a tree, the first notch (or face cut) should not exceed one-third of the tree's diameter. This specific depth is critical for creating a strong hinge that effectively guides the tree's fall direction. A deeper notch can weaken the hinge too much, leading to premature splitting or an uncontrolled fall, increasing safety risks.
What kind of knot should be used to attach the block to the tree when installing a false crotch?
Answer: Cow hitch
The cow hitch (also known as a girth hitch) is the most appropriate knot for attaching a block to a tree when installing a false crotch. It is simple, strong, and provides a secure, non-slip attachment by wrapping around the tree and through the block's attachment point. This effectively distributes the load and ensures stability.
Which of the following trees would a lag-threaded rod be appropriate to use?
Answer: A small tree
Lag-threaded rods are generally appropriate for cabling or bracing in smaller trees where the wood is sound and the anticipated loads are relatively light. For larger trees or those with decay, through-rods with nuts and washers are preferred. Through-rods provide greater strength and stability by distributing forces more effectively across the wood.
Which of the following is typically the weakest component in a rigging system?
Answer: Rigging line
In most rigging systems, the rigging line (rope) is typically the weakest component due to its susceptibility to wear, abrasion, knots, and dynamic loading. While other components like blocks and carabiners are designed with high strength ratings, the rope itself is often the first point of failure if not properly managed, inspected, and used within its working load limits.