1. Descender : + backup ascender + footloop.

2. Climber who is focused and conscious that he/she is alone.

3. Primary rope: ? > 10 mm dynamic (EN 892) or low stretch kernmantel (EN 1891).

4. Two point anchor, in the route's fall line, positioned to minimize rub points.

5. Solid anchor.

6. Beware of rockfall during access.

7. Access rope with intermediate anchor.

8. Clear space in front of the climber: no clothing hiding the ascender, no pack cord or strap that can interfere with the system's operation.

9. Self-belay system with two ascenders.

10. A light suspended weight to help the ascenders slide.

Example of premature wear on a fixed rope:

Notes:

• The quickdraw helps avoid collisions between the devices, but should not reduce comfort: adjust its length so the straps do not pull on the neck during a rest or fall.

• The two ascenders must not be connected to the same point on the harness: they can collide and be damaged during a fall.

• Respect the recommended ascender position: BASIC above and ASCENSION below. The reverse position turns out to be tricky when changing systems from ascending to descending.

• Always carry a descender (GRIGRI) and a footloop/ascender combo (TIBLOC + ANNEAU) to ascend the rope in case of failure to complete the climb.

• Roofs and traverses complicate the system: they require numerous directional points and additional precautions. Do another risk analysis for these particular cases.

  
  

【轉自：https://www.petzl.com/US/en/Sport/Appendix-3--Detail-of-installation-on-one-rope-with-two-ascenders?ActivityName=rock-climbing】