SR Official Stance on 6mm Purcell Prusiks – CLICK HERE

The UIAA has just released their latest research and approval for braking devices.
This research falls in the wake of our 2005 research entitled, Hang Em’ High , that was reported to the UIAA about our findings.
We are proud to make a difference in the safety and understanding of the climbing and rescue communities.

We produce some of the best practical research available. You’ll hear about this research from any other rescue or climbing instructor/training institution, but you’ll get the first hand information here. Our research on multi-point anchors, ice screw and Abalakov anchors, belay device testing, and other applications of using equipment in real-world configurations is what the rescue field is based on.

Click photo below for a short video of some of our re-bored ice screw testing

Drop Testing Ice Screws Ouray Beverly

“Another Day at the Office.” Marc Beverly performing real-world drop testing on ice screws in Ouray, Colorado.

Please read these articles.


Present Course of Study for Marc Beverly, PhD, MPAS, IFMGA

The following papers are non-published pilot research studies that give a look into important present topics in climbing and rescue work.

– “Tracklines, what are the actual forces and implications ?”

– “Physiological Effect of Suspension Stress” University of New Mexico Exercise Science Lab 2010-2016. This work was Beverly’s dissertation work, but was rejected by the Wilderness Medical Society for publication because “it was not of interest to their readership.” The WMS did publish and present this abstract at their Telluride Conference in 2016. The preliminary pilot research paper can be found by clicking here. It is Beverly’s contention that “there should be a complete re-evaluation of harness construction,” based on his findings.

– Resting Metabolic Rate, the Red Bull Effect.pdf

– Acute High Altitude Exposure and Intense Burpee Exercise Performance.pdf


Purcell Prusiks

Strike Rescue’s official stance on the use, and misuse, of 6mm Purcell Prusiks:

J. Marc Beverly was contracted in 2006 to provide the instrumentation and data collection for the group performing the original research on Purcell Prusiks. Marc had done some preliminary testing on the use of 6mm material while working at the Pararescue School at Kirtland AFB, Abq., NM.

Strike Rescue does not recommend the use of 6mm PPs based on actual research that has shown catastrophic failure and impact forces exceeding standard recommendations with unacceptably high frequency (2 out of 3 on FF2). Yes, they are convenient since they are indeed smaller. However, in a rescue or big wall situation, 6mm PPs have no place as a tie in point to an anchor if there is a possibility that the load could rise above that anchor. This would be considered dangerous and improper application of materials.

6mm PPs can be used for ascending on rope or integrated into a system where substantial impact forces may be absorbed by other components in a system, but that system should be tested before use of 6mm PPs. An inappropriate rope to use might beHTP since the stretch is <1%, rendering it an effectual sold anchor point.

Furthermore, work hardening of knotted perlon will contribute to more frequent failures as the modulus of the material increases dramatically after the first loading event. Sewn PPs have not been tested by independent sources outside of manufacturer origin or in real world application. Use at your own risk. Failures of PPs during testing have been noted at variable locations that include, but are not limited to, the figure 8 knot or the girth hitch attachment point.

In general, it is a good device for static loading such as hanging on or rope ascension progress capture.

One cannot make assumptions in rigging. Using 8mm perlon does not necessarily make things better since the perlon is too stiff and offers no give.

Perhaps the worst enemy is not knowing what you don’t know…and testing your hypothesis on yourself or others anyway