Books and magazine articles can discuss the physics of falling until the cows come home, but until a belayer feels the actual forces of a leader fall, they will never fully comprehend how difficult it can be to stop a climber from hitting the deck. Thanks to the new Petzl Assur'Tec system, imagination and guesswork is removed as the device effectively and easily provides climbers with tangible feedback during safe belay practice.
The North American debut of the Assur'Tec system took place April 12-14 at the Boulder Rock Club as part of the Climbing Wall Summit (click here to read the April 17, 2007, SNEWS® story, "Climbing Wall Summit soars to success"). Roody Rasmussen, president of Petzl America, told SNEWS®, "We developed this belay simulator as a hands-on educational tool for climbers." Although the company already has a nice online fall simulator (click here to check out), there is simply no substitute for the real thing.
The Assur'Tec consists of an electric winch that hoists a heavy mass (in this case, 180 pounds of steel) about 30 feet up in the air. When the weight is released, a dynometer measures how much force the top anchor sustained. A technician at the top operates the system: checking the area for safety, running the winch, releasing the weight, and reading the forces. A second technician works with climbers to ensure they are properly positioned and rigged for the belay (helmet required and gloves recommended), keeps the drop zone clear, and reattaches the weight to the winch cable.
The fall is about 7 feet and held by about 30 feet of dynamic rope. This translates into roughly a fall factor 0.23, which is relatively mild and quite common. But it's enough to give a good range of forces, depending upon the belayer and their set up.
Belayers are encouraged to make several catches. First, they are anchored to the ground so that the belay device does nearly all the work of stopping the fall. Then, they can belay unanchored (as is the typical case in sport climbs), where they are pulled up into the air by the force of the fall. They can also try belaying with a semi-static automatic device, such as a Petzl Gri-gri, or a more dynamic belay device, such as a Black Diamond ATC.
Our SNEWS® editor assigned to attend the Petzl workshop has been climbing for 30 years and caught countless falls, and he told us he was thoroughly impressed. When anchored and using a semi-static device, the force on the top carabiner registered about 8.5 kN (6,270 pounds of force). When unanchored with the same device, the fall generated about 6.7 kN (4,940 pounds of force) and he was lifted 5 feet in the air. Using a tube-style device, he was also lifted off the ground, but about a foot of rope slippage (enough to cause rope burn without gloves) limited the force to about 4.2 kN (3,100 pounds of force). Feeling a bit cheeky, our editor also skillfully demonstrated how easy it is to completely defeat an automatic belay device by (intentionally) belaying improperly -- the weight hit the floor mats at full velocity (creating much noise and some wide-eyed looks) and the top anchor was only subjected to 0.5 kN.
Petzl has taken the Assur'Tec workshop to several rock gyms in France, and it is now ready to tour in the United States and Canada. The company is still working out the logistics of moving equipment and personnel around (it requires use of a 30-foot overhanging climbing wall), so dates and venues are pending.
SNEWS® View: The new Petzl Assur'Tec workshop is the most significant advance in climbing safety in recent years. This technology has been around for decades (load cell and a winch), but, until now, it was never available to the masses.
Anyone who has been paying attention to the climbing world has heard numerous stories of climbers decking from inattentive belayers or improper use of belay devices. Indeed, belay failure (for whatever reason) is likely the leading cause of serious climber injury (followed by breaking carabiners, but that's another story).
Far too many climbers get complacent when belaying because they haven't experienced significant falls -- either as the one falling or the one belaying. While schools and rock gyms generally do a commendable job at belay technique instruction, the lessons are all too easily forgotten in part because climbers do not get real time feedback. The Assur'Tec system is a superb educational tool that needs to reach as many climbers as possible.
Stores that sell climbing gear shouldn't just consider this system as something they can't use or sell either. Scheduling an Assur'Tec workshop, perhaps in conjunction with a rock shoe demo, and working with a local rock gym is a great opportunity for specialty climbing retailers. It creates goodwill and reminds climbers of why you're different from the chain and Internet stores. Be sure to stock up on belay gloves since many climbers will be seeking them out following this fall simulation.