Cabling Bracing and Support Systems Flashcards
6 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 6 Cabling Bracing and Support Systems flashcards as text
What is a propping system in arboricultural support, and when is it used instead of cabling?
Answer: A vertical or angled support post or beam placed beneath a heavy limb to support it from below — used when cables cannot be installed above (no suitable upper anchors) or as a supplement to cabling for very heavy limbs
Propping involves placing physical supports (typically adjustable steel props or treated timber posts) beneath overextended or heavy limbs when cable installation above is impractical. Props support the limb's weight from below rather than suspending it from above.
What is the purpose of a 'guy wire' support system for transplanted trees, and when should it be removed?
Answer: Guy wires provide temporary support to newly transplanted trees to prevent wind toppling during establishment, and should be removed after 1-2 growing seasons once the root system has established adequate anchorage
Post-transplant guying provides temporary stability during the critical establishment period when the root system is too limited to provide adequate anchorage. ANSI A300 Part 4 (Lightning Protection) and ISA guidelines recommend removing guys after 1-2 growing seasons — leaving them longer inhibits trunk development and can cause girdling damage.
How does an arborist calculate cable tension requirements for a cabling system, and what safety factor is applied?
Answer: Calculations consider the weight of the failure part, the angle and geometry of the cable relative to the defect, the distance from the defect to the anchor, and the dynamic loading factor — resulting in a required cable WLL typically with a safety factor of at least 2:1 applied to the calculated peak load
Cable system design requires estimating the mass of the failure part, calculating the dynamic loads from wind and swing geometry, determining the cable tension required to resist those loads at the installed cable height, and selecting cable and hardware with WLL that meets or exceeds the calculated peak load with a safety factor margin.
What distinguishes a 'supplemental support system' from a 'life support system' in ANSI A300 Part 3 terminology, and why does this distinction matter?
Answer: A supplemental support system augments the tree's own structural capacity but the tree could potentially remain standing without it; a life support system is the only thing keeping a critically compromised tree from failing — creating different management implications and ethical obligations
ANSI A300 distinguishes whether a cabling system enhances an otherwise functional tree's structural margins versus whether the system is the only barrier preventing imminent failure. Life support situations carry significant ethical and liability obligations — the arborist must clearly communicate to the owner that the tree depends entirely on the system and what consequences system failure or tree removal would involve.
What is the proper documentation protocol after installing a cabling or bracing system, and why is documentation important?
Answer: Written documentation must record the system design rationale, hardware specifications (size, type, manufacturer), installation heights and positions, the defect being addressed, work performed, recommendations for follow-up inspection, and any limitations or conditions that could affect the system's adequacy
Comprehensive written documentation after cabling installation creates the record needed for future inspections, establishes the design basis for evaluating system adequacy over time, communicates owner responsibilities, and provides legal protection for the arborist by demonstrating professional diligence and informed consent.
What is the 'load path' concept in evaluating a tree's structural integrity, and how does it apply to cabling system placement?
Answer: Load path is the route through which forces (gravity, wind) are transferred from where they are applied through the tree's structure to the ground — identifying interruptions or weaknesses in this path directs cabling placement to support the compromised structural element
Load path analysis traces how forces travel through a tree's structural system — from canopy loading through branches, trunk, root flare, and into the root system. Structural defects that interrupt this path (decay at critical points, included bark unions, cracks) are the weak links that cabling addresses, placed to bypass or supplement the compromised element.