Abstract: Belay testing with rescue loads has been happening for over 30 years. One thing that is common to research and testing is the need for consistency, control of variables and repeatability. Much of the testing on belay devices and techniques has been done without human operators. Presumably the small number of tests with human operators in device testing is because human factors add a host of variables like reaction time and grip strength, which give varying results. In 2017, Petzl released a technical supplement on the ASAP and ASAP Lock mobile fall arrestors for use at the anchor to belay up to 550 pound loads. This device actuates and arrests by means of an inertia lock and does not require human operator reaction to the situation and a subsequent action with the device. We know that Petzl tested the device exhaustively but we wanted to do a test with real world conditions as a typical rescue team would set up a belay and how a typical rescuer would operate a belay with a Petzl ASAP Lock at the anchor. This presentation takes a look at the results of our test conducted August 16-17 2018 with the Phoenix Fire Department. Bio: Tom Pendley served as Deputy Chief of Operations, Training and Special Operations for the Peoria Arizona Fire Department, before retiring in 2016 after 26 years of Service. He taught technical rescue for the Phoenix Fire Department for 15 years and was a technical rescue instructor trainer for the Arizona State Fire Marshals Office for 10 years. Tom served 14 years as a volunteer with the Maricopa County Sheriff’s Mountain Rescue Team including 5 years as team commander. Tom now works full time at the helm of Desert Rescue Research, which specializes in developing high quality technical rescue training resources. He currently lives with his family in Port Townsend, Washington. ITRS 2018

Belay performance testing with a Petzl ASAP Lock at the anchor.

By Tom Pendley

A rescue belay has become a core component of any rescue activity with risk of falling. Much time and effort has been devoted to finding the best device or technique that gives rescuers a competent, reliable and efficient belay or backup. The Phoenix Regional Technical Rescue Teams began conducting belay performance testing with rescue loads in 2010 with all regional rescue team members. This effort was in response to a rescuer injury while on rappel in 2009. In this incident, the rescuer was belayed with a separate rescue rope with a tandem prusik belay (TPB). The rescuer lost control of the brake end of the rope while negotiating a secondary edge about 150 feet from the belayer. The rescuer grabbed the rappel line with gloved hands and effectively slid about 40 feet down the fixed line and

hit the ground. The resulting injuries included severe burns to both hands and various muscle sprains and contusions. After the incident occurred, team members questioned the belayer and found that the belayer had no idea that and incident had occurred. The belayer just assumed that it was a fast rappel. After investigating this incident, it was felt that many factors (including human factors) contributed to this incident.

• It was a partially controlled fall (gloved hands on rope) and did not reach free fall speed. There was enough friction that the belayer was able to quickly pull rope through the TPB

• Over 150 feet of rope was in play including typical slack and rope stretch. • The rappeler was out of sight of the belayer. • The region had not been practicing arresting falls with any type of belay and the

only muscle memory the belayer has was to pay rope out or bring rope in

Since that time, every rescue team member gets experience catching falls with the TPB during initial training and periodically during CE training. Over this 10 year period, countless belay arrest exercises were conducted and even with rescuers knowing that the drop was coming, results were extremely variable. The TPB certainly works but operator technique, reaction time, skill, chance and other human factors affect the performance of the belay. In many cases belays were observed to be excellent and in a small but significant number of cases, belays were observed to result in over 10 feet of rope movement before the TPB arrested the fall or the load hit the deck. The Phoenix region recently decided to transition to the Petzl ASAP Lock as their primary belay device for rope rescue. The phase in period began with conducting basic training with the device and having the rescuer catch falls of a rescue load with the rescuer belaying the load and as it was lowered, release the main line and measure the arrest distance. This group of rescuers is slated to be the instructors for the roll out of the program. On August 16th and 17th 2018, we conducted an informal backyard drop test session from the top of the Phoenix fire department training tower with 300 pound loads and 540 pound loads. The belay station was set back from the edge approximately 12 feet. Approximately 19 feet of rope was in play between the test mass and the belay device. The belay changed direction over the edge on a canvas edge pad low directional for about half of the tests and in a steel carabiner high directional for the other half of the tests. We felt that this test setup was very typical real world conditions. The rope used was PMI easy bend 12.5mm and was about 3 years old. An Enforcer load cell was placed at the anchor and at the load.

Each test was recorded for later analysis but the at the time the method used to record arrest distance was for a rescuer to watch a tape mark on the rope and establish visually where the release of the main line occurred. After the arrest, a measurement was taken of the rope travel distance from the time of release and the energy absorber extension was measured. Because we had a limited number of Absorbers, we reused absorbers for several tests. Once the absorber began to extend, we did not allow more than about 6 inches of extension before replacing it. ASAP test August 16, 2018

Test# Device MassRope

movementforce@anchorlbs

TagDamagedYes/No

Extensionofabsorber

1 ASAPLockLD 296 N/A* 0 no no

2 ASAPLockLD 296 31” 1008 yes 2”

3 ASAPLockLD 290 22” 918 Yes/same Same/2”

4 ASAPLockLD 296 18” 972 Yes/same 2”

5 ASAPLockLD 296 24” 914 No/new 0

6 ASAPLockLD 540 18” 820 No/same 0

7 ASAPLockLD 540 11” 1072 No/same 0

8 ASAPLockLD 540 18” 1216 Yes/same 4”

9 ASAPLockLD 540 28” 904 Yes/New 8”

10 ASAPLockLD 540 21” 962 Yes/same 3”

ASAP test August 17, 2018

Test# Device MassRope

movementforce@anchor

TagDamagedYes/No

Extensionofabsorber

1 ASAPLockHD 296 11” 658 No 0”

2 ASAPLockHD 296 8” 648 No/same 0”

3 ASAPLockHD 290 10” 668 No/same 0”

4 ASAPLockHD 296 12” 688 No/same 0”

5 ASAPLockHD 296 9” 648 No/same 0”

6 ASAPLockHD 540 5” 862 No/same 0”

7 ASAPLockHD 540 12” 862? No/same 0”

8 ASAPLockHD 540 11” 1132 No/same 0”

9 ASAPLockLD 540 11” 878 No/same 0”

10 ASAPLockLD 540 12” 1046 No/same 0”

11 ASAPLockLD 540 6” 1270 No/same 0”

12 ASAPLockLD 540 8” 1280 No/same 0”

13 ASAPLockLD 540 11” 1282 Yes/same 2”

14 ASAPLockLD 540 11” 1090 No/New 0”

15 ASAPLockLD 540 10” 1096 No/same 0”

Observations:

1. On day 2 of testing, tests began in a steel carabiner high directional and overall arrest distance was lower than day 1 and there was very little extension of the absorber. I initially assumed that increased friction from the high directional carabiner was the cause. While that may have contributed to the lower movement, I believe there were two other factors. First, the redirect carabiner at the anchor was rigged in the swivel of the enforcer load cell with the carabiner for the absorber. On the first day the redirect carabiner was offset back at the anchor strap. In the video analysis, it looks like there is contact between the two carabiners at the time of arrest. This is compounded by a rescuer holding tension on the brake end of the rope, possibly resulting in increased friction. Second, while the ASAP appeared undamaged and in good condition at the end of Day 1, by the 25th drop on day 2, there was clear deformation of the pivoting action of the wheel and that ASAP may have become slightly more sensitive with each successive drop. The ASAP arrested every fall and never damaged the rope.

2. Even though I demonstrated the technique I wanted each rescuer to use,

there was clearly significant variation in the amount of grip and back tension on the brake going to the redirect carabiner. Some held tight and in the video, you can see others holding the brake end of the rope quite loosely. I think this increased variation in force and distance.

3. On day 1 on the 540 pound drops on a low directional, the average rope movement was 19.5 inches and average 1038 pound arrest force at the anchor. There was extension of the absorber on three of the four drops with an average of 5 inches of extension of the absorber. On day 2, the 540 pound drops in the high directional averaged 11.8 inches of movement and average of 956 pound force arresting the load. An additional 5 drops with 540 pounds were made on day 2 with the belay configured to change direction at the edge on a canvas pad like day 1. The average overall rope movement was 9.2 inches and the average arrest force was 1203 pounds force at the anchor.

As mentioned in observation 1, the redirect carabiner was configured different on day two. I do not know if this accounted for the rope movement / arrest distance being an average of 10 inches less on day two. Also, on day two, the average arrest force on the low directional was on average about 200 pounds force greater than on day one. There was the most minimal extension of the absorber on day two resulting only in the damage indicating tag being torn.

4. On day two, the belay rope was configured high in a steel carabiner

change of direction at the edge for the first 10 drops. Average arrest force was somewhat lower at the anchor with the high carabiner change of direction as opposed to the low canvas pad.

5. It is obvious that either a canvas pad or high directional carabiner absorb

significant energy. We did not get consistent readings from the load cell at the test mass and were not able to compare force at the load vs. force at the anchor. Much historical drop testing has been done on a drop tower with no change of direction. A change of direction is real world and a drop tower is not.

6. * The first drop had a miss-rigging of the haul system used to raise the

load up and then lower the load at a consistent speed allowing a release mechanism to drop the load for the belay to catch. On the first drop, slack was not preset into the system and the load was caught partially by the raising system. This resulted in a partially controlled speed situation which was below the designed actuation threshold of the ASAP. The ASAP did not arrest the first drop because it was not a free fall and was partially controlled.

Conclusions and recommendations This was an informal backyard test. It was not noticed that the redirect carabiner was a configured a bit different on day two. The way that it was rigged on day two added the force generated at the redirect to the load cell for measurement. That did not happen on day 1 so measurement of the arrest force was skewed between the two days. I do not think that the configuration on either day affected the performance of the ASAP. I believe that the Petzl ASAP Lock demonstrated very consistent and minimal arrest distance on 24 drops. The arrests occurred without the need for reaction time from a human operator or an action by a human operator.

As noted on observation #6, the ASAP is designed to arrest at a certain speed of rope movement (about 2.5 m/s) if the load is descending with partial control, say 2 m/s, the ASAP will not actuate. This is a precaution that must be discussed during initial training with operators when using the ASAP lock at the anchor to belay one person or two person loads. Perhaps a drill to manually actuate the ASAP in a partial control situation would give good muscle memory. The incidence of a partial control or out of control situation on the main line descent control device could be more common than a catastrophic mainline failure. Reporting of these types of incidents is virtually non-existent. An effective way to deal with these types of situations is important for all teams. At least discuss the possibility. Remember human factors affect how we integrate into the rescue system in many ways. A lot happens in the split seconds of a fall or incident. We all have instinctive reactions, which can be unpredictable. Training purposefully to give muscle memory for a particular desired reaction is optimal. The Petzl ASAP is one effective and useful tool but it is my feeling that the most important factor for safe rescue systems and a safe and effective rescue belay is regular team training with your tools, good leadership and communication and a culture that values proficiency and a high degree of competency in individual skills. Recommendations for future research It is my intent to do additional testing in 2019. I would like to see what effect the rescuer back tension has on arrest distance and extension of the absorber. Some comparative testing with and without back tension on both low and high directionals would be interesting. Testing is a lot of work and this test, which I deem successful, underscores the importance of attention to detail and carefully thought out rigging, safety and documentation. Thanks to: Petzl for generous support with ASAPs and Absorbers Dale Stewart and AHS Rescue Bobby Dubnow The Phoenix Fire Department The members of the Phoenix Regional Technical Rescue Teams

Foreachdrop,therescuertookastancefacingtheanchorandheldbacktensiononthebelaytominimizeslackandstretch.Therescuerhadnotaskotherthantoholdbacktensiononthebelay.NooperatoractionorreactionisrequiredwiththeASAP

10ofthedropsonday2hadthebelaychangedirectioninacarabineratastructuralhighdirectional.

15ofthedropschangeddirectionlowwithadoublelayercanvasspad.