What minimum tensile strength is designed for ropes with a 20 kN T rating?

When determining the minimum tensile strength for ropes rated with a 20 kN T rating, it's essential to understand the conversion between kilonewtons (kN) and pounds-force (lbf). One kilonewton is approximately equal to 224.81 pounds-force. Therefore, to convert the 20 kN rating into pounds-force, you multiply by this conversion factor:

20 kN × 224.81 lbf/kN ≈ 4485 lbf.

This value typically rounds to approximately 4496 lbf, reinforcing the robust strength required for ropes used in rescue operations, ensuring they can handle substantial loads and provide safety for rescue personnel.

The other options present tensile strength values lower than the calculated typical strength for a rope rated at 20 kN, thus failing to meet or exceed the necessary safety standards required for rope rescue operations.