Technical Rescue: The Importance of 15:1

Subsequent to this incident, in 1981 the IAFF published a white paper entitled Line to Safety. It is within this widely distributed opinion paper that the groundwork for the first edition of NFPA 1983 would be laid. In the opening, it is stated that a 7:1 or 10:1 safety factor is adequate for a safe working load in industry, but is “inadequate for critical rescue use.” It is here that a two-person load is stated to be 600 lbs and a 15:1 safety factor should be applied to the rope, necessitating an MBS of at least 9,000 lbs. It should be noted, at the time, ropes had to be larger than ½-inch in order to meet this requirement. The paper mentions 5/8 inch–¾ inch in diameter rope examples. A final bit of trivia about Line to Safety is that in the references, it endorsed two then-unknown-to-rescue manufacturers—Pigeon Mountain Industries (PMI) and Bluewater. This thrust these two caving/climbing rope companies into the professional rescue scene in a big way.

The major tenets of Line to Safety would be echoed in the first version of NFPA 1983 that became available in June of 1985. This document would define one and two-person loads as 300 and 600 lbs, respectively. It also designated rope and equipment as one-person and two-person. Maximum working loads were expressed in pounds by dividing the MBS of a new rope by a factor of not less than 15. Finally, one last fan favorite in the first edition of 1983 was that life-safety rescue equipment was one-time-only use and had to be retired after use in an actual rescue.

At this point, you should be asking yourself “Why?” If you think about it, it really makes sense. At the time, there was very little in the way of research or empirical testing in rescue rope, equipment and methods. There were few subject matter experts who actually carried credibility in fire-rescue circles. Most were from the climbing and caving communities and their respective rescue circles. The techniques and equipment being used by fire departments for vertical rescue came directly from cavers and climbers. This included caving kernmantle rope, the Cole Rack and the Anderson figure-of-eight descender. As it were, the founders of two prolific rescue rope and equipment companies that remain today lobbied hard in the early days to lower the strength requirements and strict language.

In the eyes of the fire service, the IAFF and 1983 committee members of the time, the rope and equipment should be over-engineered to mitigate both the unknown and the foreseeable abuse and misuse of rescuers. Little was known about the effects shock loading, the degradation of nylon and polyester over time, and an infinite number of “what if ... ?” in rope and rescue. Contrast that to present day, there is an endless library of testing and data if you know who to ask and where to look. This is largely thanks to the International Technical Rescue Symposium, formerly NATRS. The first symposium took place in 1985 and served as a venue for rescuers to present on anything from laboratory to “backyard testing” in rescue. This included slow-pull testing, drop testing, the infamous belay tests, and even what really happens to your rope when it is urinated upon. Much of this data can be accessed online and has been published in other academic and periodical venues.

The events of June 27, 1980 and subsequent papers and standards effectively “professionalized” rescue in North America. Over the next decade, at NATRS, in texts, articles, fire halls, and even bars, the best tools and techniques for rescue would be tested, argued over and scratched out on napkins, as an informal body of knowledge of best practices would be baptized under fire. Ultimately, this would result in inventors and manufacturers responding to rescuer needs and bringing equipment to market designed specifically for professional technical rescue. Kirk Mauthner and Traverse Rescue would bring the 540 Belay to market in the mid 1990s and by the turn of the millennium, Petzl would introduce the Industrial Descender (I’D). In present day, the market and demand for this gear is insatiable. Groundbreaking advances that once were years apart are now occurring every few months.

Postmodern era in technical rescue

The current trend is a great advancement of technology and equipment. Much more than the 1980s and 1990s, the rescue community is seen as a market to make profits. Everywhere you turn is another rope rescue instructor with an upstart training company. Twenty years ago, there were less than a dozen pieces of specialized rescue equipment specifically engineered for our needs. Today there are over a dozen devices from different manufacturers that are analogous to the Petzl I’D.

Incredible innovations are made by international companies just as often as they are by intrepid engineers in garages with 3D printers. One of the problems as a trainer that I do not relish tackling is really having to pick the best device or platform to teach rescuers across an entire state. What brands or devices do I bring into my personal rescue philosophy? In the 1990s a rack was like air and water—had to have it. In the 2000s it may have been the I’D. In the 2010s it could arguably be the CMC MPD. The field is more blurred as the years pass. I hate the idea of wholly aligning a curriculum with one product.

TTRS vs. STM/UTB

Another aspect that must be addressed is single tensioned mainline (STM) and un-tensioned belay (UTB) versus two tensioned rope systems (TTRS). Researchers like Mauthner and myself almost definitively proved the efficacy of TTRS versus UTB. In short, the benefits include the integrity of the rope and sheath from edge damage.

Additionally, fall distances and impact forces are greatly reduced. The problem with TTRS is that most descent control device configurations in a lowering setup rely too heavily on human reaction time. When lowering with a TTRS using I’Ds, MPDs, and similar, when one line is cut away, the operator of the surviving line often demonstrates a momentary delayed reaction. This results in an unacceptable fall distance or even ground impact.

Mauthner’s solution involves additional rescuers “tailing” the ropes. This requires throwing extra staffing at the problem. I see this more as an engineering problem. Manufacturers should give us a device that is sized like an I’D, works like an MPD, and has auto-stop properties of the Petzl ASAP.

Despite the obvious advantages, the jury is still out in other areas of TTRS. There are competing schools of thought on how they are managed in Artificial High Directional (AHDs). Both high have problems. One high, one low has its own problems. Some theses only work if the assumption can be made that the AHD is bomb-proof. Most believe the edge transition to be the most precarious time, but it is often difficult to maintain dual tension during many edge transition scenarios. As a community, we know we want to live in a world of TTRS, but there are pieces to the puzzle that have not been definitively addressed.

Force-limiting systems and devices

One of the greatest paradigm shifts that directly relates back to safety factors is the concept of force limiting. This concept was proliferated largely by Mauthner, Lt. DJ Walker and myself during the International Technical Rescue Symposium in 2014. Basically, the market has brought rescuers all manner of devices that will slip at reasonably predictable values without damaging the rope. This means many systems can be rigged with a device that can be likened to a fuse, pressure relief valve or shock pack. Prusiks were erroneously portrayed as force limiting through the 1980s and 1990s, but were anything but predictable. The MPD, I’D, Gri Gri, D4 and similar devices are all capable of this force limiting behavior. So why does that matter? It means things will not break or explode as believed in the 15:1 days. Rather, they will slip when over-tensioned or strained. Thus, the death moans of the old Kootenay Highline and all the Prusik bypasses and load release hitches to boot! Now that is exciting. Highline recipe: 1. Far side—tensionless anchor or knotted termination. 2. Nearside—MPD or I’D Z-Rig. First trackline done. Need more support or elevation? Repeat steps one and two until satisfied.

Where we’ve been and where we’re going

The last 10 years of “sexy” rope training in niche schools has been highlighted by rigging and AHD work that takes hours before the first line is loaded. Photos of such courses flood social media. I love this stuff and enjoy it with the best of them. But rigging for art’s sake does not the best rescuer make. Recent and future years have, and should have, a renewed emphasis on personal on-rope skills. This means true rope ascending, changeovers, controlled descent and negotiating obstacles. Rope access techniques and technical rescue in the fire service will continue to merge. It should not require a $400 piece of kit to perform a standard pick-off. With typical climbing system, carabiners and a soft link, most rescuers should be able to facilitate most one-on-one rescues.

Additionally, the proliferation of automatic back-up devices will replace the need for a dedicated belay operator. This will save a unit of staffing. This enables faster patient access, faster rescues and better empowers rescuers to maneuver and self-rescue. In every discipline, a return to original roots happens periodically. It gives me great satisfaction to conclude that 15:1 is not really very important anymore. It is real and part of our rescue history—our early foundations and identity. As a rescue community, it is important to remember who we are and where we came from. Now is the time for our community to look forward and solve more difficult problems. The cliché arguments about absolute breaking strength and two-person loads is so 1995. The present-day is one of force-limiting systems rather than absolute catastrophic failure, advancing our personal on-rope rescue craft, selecting the right tools from many options and troubleshooting new paradigms like TTRS.