Technical Bulletin #2
Patroller Self Evacuation
Welcome to our new series of Technical Bulletins for the working patroller. We at the Association of Professional Patrollers strive to provide outstanding educational opportunities to patrollers and a certification program for the ski patrol professional.
Patroller self evacuation is a skill that is part of the Association of Professional Patrollers test for Certified patrollers. This test requires the patroller to have a good foundation of knowledge in rope rescue and rappelling skills.
In risk management and the fire service we call events that have high consequences and occur infrequently- "High Risk/ Low Frequency events". Self-Evacuation from a lift meets this criteria. Risk can be mitigated by having policy and procedures in place and having patrollers well rehearsed in the skills required for self-evacuation. Self-evacuation can happen in severe environmental conditions and the patroller probably won't have a buddy to perform a safety check before he/she leaves the chair on rappel. In other words, this skill may not be for all your patrollers and you can screw this up! The following link from OSHA reviews fatalities and serious injuries that are the result of rappelling accidents.
The 2012 edition of "Accidents in North American Mountaineering" focused on rappelling accidents with an article "Know the Ropes: Rappelling Fundamentals to Save Your Life". The article reviews rappelling accidents from 2000 to 2012. The causes of rappelling accidents were listed as-
Uneven ropes- largely due to rappelling off the end of the rope- 29% (Rappelling from two strands to one)
Inadequate anchor systems- 25.8%
Inadequate rappel backup - 19.4%
Poor technique - 11.3%
Inadequate equipment-- 9.7%
A self-evacuation program should have a yearly sign off. The program should have standards for the OSHA "Lock out, Tag out" procedure, and patrol-approved equipment, such as size and type of rope, harness and descent rappel device to be used. The policy should include an auto block or GRB (guide rappel back up) if this is required by your patrol or mountain risk manager. Patrols are using one rope doubled for rappelling or single rope technique with a block such as the carbineer block. Single rope with carbineer or other blocks adds another dimension and can cause catastrophic failure if not performed correctly. Zion National Park discourages blocks because of the number of canyoneering rappelling accidents that have occurred in the park.
Presently the only standard for emergency rappelling is the National Fire Protection Association (NFPA) standard 1983 (2012) which is designed for firefighters for emergency bailout from a burning building. This standard has a minimum rope diameter of 7.5mm. The NFPA 1983 standard has a fire escape webbing standard for emergency rappelling. The advantage of webbing is that it is very compact to carry. These bailout systems have special descender devices and hooks. Rope manufactures have developed stronger and thinner ropes for firefighter bailout applications such as Technora rope. Some patrollers are using these ropes and there is a warning on them about the small diameter. The warning from Sterling Rope is, "Due to the small nature of this cord, Sterling Rope does not recommend the 6mm TRC for vertical egress without first being professionally trained on rappelling with small diameter cords".
The NFPA rope standards can be found at this link.
The self-evacuation procedure can be broken down to the following elements with potential hazards listed during the procedure:
Lock out/Tag out complete and confirmed.
Discard your skis or secure your skis.
Pick a high anchor point for your anchor. Deploy your rope with a stopper knot for single rope technique. If you are using a block, make sure you are on the right line for rappelling and blocked correctly. If you are using a double- rope technique, knot both rope ends together to avoid the leading cause of rappelling accidents, that being rappelling from two ropes onto one, as shown in the above statistics. Get in your harness and check that it is doubled back and free of the lift. Now is the time to apply the auto block or GRB. Failure to apply a rappel backup is the third leading cause of rappelling accidents. Test your auto block to see if it is working. The following link provides information on applying, testing and using the auto block:
Apply your descender device to the line. If you are using the Munter knot make sure it is rigged correctly. Rigging this knot incorrectly will cause a fall with no restraint. Ask your partner for a safety check, or if you are alone check everything again. While still in the chair, load and test your rappel system for cross- loaded carabineers and that the Munter knot is rigged properly. Your locking carbineer should be in and down and locked. Transition the edge, if there is one on the chair, and start your descent. The following video from the American Mountain Guide Association reviews rappelling on an extension. Patrollers usually do not use extensions because of the edge transition.https://www.youtube.com/watch?v=07xUFZRQdng
A recent survey of ski patrol management and members of the APP board found the following elements in place for patroller self-evacuation programs in the Western United States:
A Survey Monkey survey was sent to the Association of Professional Patrollers Board members and 11 patrol managers in the Western United States. Of these, 21 Board members and patrol mangers responded.
Question 1- Does your ski patrol have a patroller rappelling self-evacuation program? (Note not public evacuation)
Yes- 85.7% No- 14.2%
Question 2- Does your ski patrol have a written policy for its patroller rappelling self-evacuation program?
Yes- 84.2% No- 15.7%
Question 3- Do your patrollers rappel on single or double lines?
Single- 21% Double- 68.4%
Question 4- Are you aware of any governmental rules and procedures for patroller rappelling self- evacuation programs?
Yes- 31.5% No- 68.4%
Question 5- Are you aware of any accidents that have occurred in patroller rappelling self-evacuation programs?
Yes- 11.1% No- 55.5%
Question 6- What size rope do you use for patroller rappelling self-evacuation?
6mm- 21% 7mm- 42.1% 8mm- 31.5%
Question 7- What kind of rappel device does your patrol use?
Figure 8- 57.8% ATC or Similar- 21% Munter- 10.5%
Question 8- Does your patrol require an autoblock or Guide Rappel Backup for patroller rappelling self- evacuation?
Yes- 21% No- 78.9%
Question 9- Does your patrol use a commercial or patroller-made webbing harness?
Commercial- 36.8% Webbing- 63.1%
Question 10- Does your ski patrol require an annual skills check off for its patroller rappelling self- evacuation program ?
Yes- 78.9% No- 5.26% Is the skills test a rappel?- 15.7%
Of the surveyed ski patrols and APP Board members most have patroller rappelling self-evacuation programs. In general most patrols have a written policy, rappel on 7 or 8 mm doubled lines and use a harness made of webbing with a figure 8 rappel device. Almost all patrols require an annual skills check off. Only 21% of patrols in this survey used an autoblock or Guide Rappel Backup. Even though there is no policy in place, 31.5% of survey responders thought there were governmental regulations on patroller rappelling self-evacuation.
Patroller rappelling self-evacuation is a high risk/low frequency event which may be required under severe environmental conditions. In survey response, 11.1% of patrollers reported being aware of accidents in rappelling self-evacuation programs. The root causes of these accidents were all human factors and not equipment failures. Increased rappel safety may occur with application of an autoblock or GRB. The use of the Munter knot for rappelling was used by 10.5% of patrols. Switching to a dedicated rappel device and autoblock or GRB could increase the safety factor in patrols rappelling on Munter knots.
Author's note: The vast majority of rappelling accidents are caused by operator error, not by equipment failure. In personal experience of four known accidents or near misses, causes were carbineer rollout on wall transition, rappelling off the end of the rope (100ft rope in 200ft bag), failure to maintain control of rappel with brake hand because of pendulum and improper technique used for rappelling. These are all human factors.
Next Technical Bulletin— Stranded Skier pick offs
Robert Walters is on the APP Board and holds degrees in Education, Fire Service Administration and Fire Science. He presently is the Team Coordinator for the Technical Rope Team and Ski Response Team at Jackson County Search and Rescue and is a Technical Rescue Instructor. In addition, he responds with a Fire Department Technical Rescue Team and practices paramedicine with a community ambulance service. He can be reached at firstname.lastname@example.org.
All views are the opinion of the author and do not represent the Association of Professional Patrollers or its sponsors.