RRC Rope Systems & Throw Bag Techniques 2 — Questions and Answers
Question 1: In a Z-drag mechanical advantage system used in river rescue, what is the approximate pulling advantage it provides?
- 1:1
- 2:1
- 3:1 (Correct answer)
- 5:1
Correct answer: 3:1
A Z-drag creates a 3:1 mechanical advantage, meaning three units of rope movement at the hauling end moves the load one unit.
Question 2: What is the most common knot used to form a fixed loop at the end of a rescue rope when attaching to a victim or anchor?
- Bowline
- Figure-eight on a bight (Correct answer)
- Clove hitch
- Sheet bend
Correct answer: Figure-eight on a bight
The figure-eight on a bight is preferred in rescue because it is strong, easy to inspect visually, and does not jam under heavy load.
Question 3: What is a Munter hitch (Italian hitch) primarily used for in rope-based river rescue systems?
- Joining two ropes of different diameters
- Creating a belay or rappel without a descender device (Correct answer)
- Forming a self-tightening anchor loop
- Attaching a carabiner to a victim's PFD
Correct answer: Creating a belay or rappel without a descender device
The Munter hitch creates friction on a carabiner to control descent or provide a belay without needing a mechanical device.
Question 4: What is the minimum recommended tensile (breaking) strength for a rescue rope used in swiftwater operations according to NFPA 1983 technical use standards?
- 4.5 kN (1,000 lbf)
- 9 kN (2,000 lbf)
- 20 kN (4,500 lbf) (Correct answer)
- 40 kN (9,000 lbf)
Correct answer: 20 kN (4,500 lbf)
NFPA 1983 requires a minimum 20 kN breaking strength for technical-use rescue rope to ensure an adequate safety margin under dynamic loads.
Question 5: A 'load-releasing hitch' (such as a Mardsen or Radium release) is incorporated into a tensioned rescue rope system for what critical reason?
- To increase the mechanical advantage ratio
- To allow the tensioned rope to be safely eased after the load is on it (Correct answer)
- To prevent the rope from sliding through anchor rings
- To color-code rope segments for easy identification
Correct answer: To allow the tensioned rope to be safely eased after the load is on it
A load-releasing hitch allows rescuers to slowly release tension from a highly loaded rope system without dangerous shock loads or the need to cut the line.
Question 6: When establishing a high-line (Tyrolean) rope system across a river for patient transport, what is the most critical factor in anchor selection?
- Anchors must be at equal height on both banks
- Anchors must each be able to withstand the full system load independently (Correct answer)
- Anchors must be natural features only (trees/boulders)
- Anchors must be placed exactly perpendicular to the current
Correct answer: Anchors must each be able to withstand the full system load independently
Each anchor must be independently rated for the full system load because catastrophic failure of one anchor would transfer all force to the other.
Question 7: When inspecting a rescue rope before use, which defect is considered a mandatory retirement criterion under NFPA 1983?
- Slight discoloration from UV exposure
- Visible core damage or cut through the sheath (Correct answer)
- Minor stiffness from cold temperatures
- Surface dirt that has not been washed off
Correct answer: Visible core damage or cut through the sheath
Any damage to the rope core or sheath breach that exposes the core compromises structural integrity and requires the rope to be removed from service immediately.
RRC Rope Systems & Throw Bag Techniques 2
In a Z-drag mechanical advantage system used in river rescue, what is the approximate pulling advantage it provides?