What is the diameter range for the Rescue line in TRT inventories?

• A. 3-11mm
• B. 1-13mm
• C. 8-11mm
• D. 11-13mm

Answer: (C)

Rescue line size is chosen to balance strength with handling and equipment compatibility. For TRT gear, the standard rescue line diameter is in the 8–11 mm range. This size provides enough breaking strength to support a person or arrest a fall during belay and lowering operations, while remaining light and flexible enough to pass through anchors, carabiners, and pulleys and to tie secure knots. A rope within this range also tends to wear more evenly, resist abrasion, and work well with common rescue hardware.

Ranges outside this window aren’t as practical. A much smaller rope would risk insufficient strength for human loads and gear safety. A much thicker rope, while stronger, is heavier, stiffer, harder to handle, and can cause more friction or incompatibility with equipment. So 8–11 mm hits the right balance for typical TRT scenarios.