Appendix 2: Detail of installation on two ropes with two ascenders
Warnings
- Carefully read the Instructions for Use used in this technical advice before consulting the advice itself. You must have already read and understood the information in the Instructions for Use to be able to understand this supplementary information.
- Mastering these techniques requires specific training. Work with a professional to confirm your ability to perform these techniques safely and independently before attempting them unsupervised.
- We provide examples of techniques related to your activity. There may be others that we do not describe here.
1. Descender : + backup ascender + footloop.
2. Climber who is focused and conscious that he/she is alone.
3. Primary rope: Ø > 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.
Installing the secondary ascender: RESCUCENDER only!
If primary ascender fails, there is a possibility of a factor 2 fall onto the backup ascender (twice the length of the extension). This type of fall is prohibited with a frame-loaded ascender, used without an energy absorber (ASCENSION, BASIC, MINI TRAXION...), because the rope's sheath will be damaged or torn by the cam's teeth. Petzl therefore recommends using a cam-loaded ascender: the RESCUCENDER.
Note: attention, in case of a fall, do not try to grab the RESCUCENDER. There is a risk of poor locking if the user grabs the RESCUCENDER frame (normal locking if the user grabs the sling or connector).
Fall tests (height = twice the length of the extension), close to the knot, 80 kg dummy
| Backup ascender | Extension | Impact force | Effect on the rope |
| RESCUCENDER | GO + EXPRESS 17 cm + OK | 4.8 kN | |
| ASCENSION | GO + NITRO absorber + OK | 4 kN | |
| ASCENSION | GO + EXPRESS 17 cm + OK | 4.7 kN | 185 cm of sheath torn |
Notes:
- Always carry a descender (GRIGRI) and a footloop/ascender combo (TIBLOC + ANNEAU) to ascend the rope in case of failure to complete the climb.
- The two ascenders must not be connected to the same point on the harness: they can collide and be damaged during a fall.
- Roofs and traverses complicate the system: they require numerous directional points and additional precautions. Do another risk analysis for these particular cases.
