Gasworks method
The gasworks method is a method of securely spending rope when belaying with the Grigri . It is named after the Gaswerk climbing hall in Zurich , where it was introduced by Matthias Bühler and Roland Seiz based on the 3-legged logic of Walter Britschgi .
Problem
The Grigri is a semi-automatic belay device from the manufacturer Petzl that locks automatically when there is a strong pull. This mechanism, which is intended in the event of a fall, can, however, interfere with the rapid release of the rope. Especially with older, thick ropes, the device tends to block earlier. In this situation, many inexperienced belayers behave incorrectly by letting go of the brake cable, deactivating the brake with one hand in order to release the guide cable with the other. This means that two principles of the 3-leg logic have already been violated: the braking hand principle and the braking mechanism of the device.
If exactly then a fall occurs, the belayer's natural reflex is to hold on to everything. This causes the violation of the third principle, as this reflex counteracts the braking mechanism of the device. The hand on the load rope reduces a jerky impulse that the device needs to brake and burns itself in the process. Even if the impulse is sufficient, the other hand grips the device more tightly and continues to deactivate the brake.
In practice, this has often caused accidents in which a climber falls while paying out the rope. The gasworks method offers the possibility of quick and safe payout of the rope while adhering to all principles of the 3-leg logic.
application
With the gasworks method, the belayer presses the brake mechanism with his thumb when dispensing. The remaining fingers still loosely encircle the brake cable. This allows the guide hand to pull out the rope quickly without blocking the device. The index finger rests under the metal fold of the grigris.
In the event of a fall in this situation, the pressure that can be exerted on the braking mechanism with the thumb will usually not be sufficient to disable the braking mechanism. If this is the case, however, the remaining four fingers on the brake cable provide sufficient braking power to be able to absorb the fall.
This technique makes belaying with the Grigri safer, but like any other belaying method it requires intensive training under expert guidance.
Individual evidence
- ↑ a b Chris Semmel, Florian Hellberg: Manual work or automation? Secure properly Part 1. In: DAV Panorama . No. 3 , 2010, p. 66–69 ( PDF [accessed November 20, 2015]).
- ↑ Walter Britschgi: Understandable . Manual on belay devices in climbing. 2004, p. 71 .
- ↑ Back up with Grigri. (Video) Retrieved November 20, 2015 (gas works method at 1:31).