White Paper on Harnesses in the Challenge Course Industry

Transcription

1 White Paper on Harnesses in the Challenge Course Industry Introduction The regulation of the challenge course field including ziplines is a recent phenomenon. The myriad of aerial adventure environments that currently exist are unlike typical amusement rides with regard to participant engagement. Challenge courses attempt to bring the outcomes and experiences of rock climbing and mountaineering to built environments. Much of the equipment and many of the techniques have been adopted from those recreational activities. These particular recreational activity standards have been referenced in the ACCT standard as they are consistent with the types of harnesses which are commonly used in the challenge course industry. Despite the quality assurance criteria such as performance and testing that are achieved by requiring adherence to widely recognized harness standards, there exists a great deal of confusion about the varying requirements for harnesses used aerial adventure environments. Harnesses A harness is an arrangement of straps and fittings designed to connect a body to another object. The primary benefit of a harness is its ability to distribute forces across larger sections of the body than is possible with a direct connection point. Harnesses for humans differ considerably based on their style (full body, seat, chest) and connection points (dorsal, sternal, waist, shoulder). This diversity reflects the variety of activities in which harnesses are used. For example, a parachute harness is a full body with shoulder connections. In contrast, most cavers wear a seat harness with a waist connection. As this brief example demonstrates, there are significant differences among harnesses no single best harness exists. Instead, a suitable harness reflects the particular circumstances of the activity. ANSI Z359.1 outlines the safety requirements for Personal Fall Arrest Systems, Subsystems and Components including harnesses. Fall Arrest describes a specific situation whereby a worker on an elevated platform may be subject to a fall. Under the standard, a maximum fall distance of 6 ft. free fall with an additional 3.5 ft. stopping distance is allowable. There is no expectation of the worker recovering or engaging in self-rescue in fact, the worker is not to come into contact with any objects during or after the fall. The requirements of this standard specifically exclude the construction industry, window cleaning belts, and sports related activities.

2 While there is currently no performance standard that specifically mentions challenge courses, zip lines, or other aerial adventure parks in its scope of purpose, the ACCT standards require adherence to other widely recognized harness standards including ANSI Z , ASTM F , EN , and NFPA to verify compliance with quality assurance criteria such as performance and testing. The key characteristics of these harness standards are summarized in the appendices. The ANSI Z359.1 standard does not envision the harness being used either suspension or positioning outside the circumstances of an unintentional fall. This is in direct contrast to the manner in which harnesses are used in aerial adventure environments where the harness is intended to support the participant s body during climbing, resting, or falling (ASTM 1773). This fundamental difference of intent and the requirements that flow from it makes ANSI Z359.1 an inappropriate standard for the zip line industry where the key criteria include: their design for climbing and suspension; their ability to fit a range of participant sizes, specifically individuals who are outside the limited weight range; their capacity for the expected load; their compatibility with facility design; and proven track record in aerial adventure environments. Designed for climbing & suspension ANSI Z359.1 does not include a waist connection and has only allowed a sternal connection since the 2007 edition. The lack of a frontal waist connection is problematic since this connection point is what allows individuals to maintain a comfortable sitting position, climb, or take other positive action to regain their position on the structure (Seddon, 2002). In addition, with a waist connection point patrons are able to reach their connection point, transfer between safety systems as necessary, and adjust the length of their lanyards to an optimal length -- tasks which are not possible with a dorsal connection. Rescuers using sit harnesses are able to more easily reach their subject and maintain the subject in a position of comfort and support. The ability to perform these climbing-related tasks explains why a sit harness with a waist connection (worn with or without a chest harness) is the predominant type of harness used in challenge courses, zip lines, and canopy tours. Both ASTM F which covers rescue, safety, and sport activities and EN which covers harnesses used in mountaineering and climbing include frontal waist connections. Ability to fit a range of participant sizes ANSI Z359.1 standards cover users in the range of lb ( kg). This limited range needlessly eliminates large numbers of participants (and workers) whose weights put them outside this range. In contrast, EN has standards for full body with waist connection, child s full body (for individuals under 40 kg or 90 lb), sit, or sit/chest combination. Similarly, ASTM 1772 standards also cover full body with waist connection, sit, or sit/chest combinations. The variety of harness styles offered in these two

3 standards makes it easy for operators to properly equip participants in a wide range of shapes and sizes. Capacity for the expected load ANSI Z359.1 allows workers to take an 8 kn force into their dorsal attachment and a 4 kn force into their sternal attachment. These allowable maximums produce a dorsal safety factor of 2.75 and a sternal safety factor of 4. Given that aerial adventure environments including zip lines limit participants potential fall distance, the corresponding forces on participants are low. As such, it is highly likely that a safety factor between 2.75 and 4 would achieved using harnesses meeting ASTM 1772 and EN with the added benefit that a waist attachment (with or without a chest harness) directs this force into a suitable location on the body. Seddon (2002) indicates that a frontal attachment is both acceptable when the potential fall distance is short (2 ft or less) and might be preferable in situations where the harness is used for suspension. In the event of a slip or short fall, sit harnesses with a waist connection distribute the impact force across individuals thighs and buttocks and exert less pressure on the area of the inner thighs and groin than full body harnesses with dorsal connection. A chest harness that is worn in conjunction with a seat harness provides the participant with additional upright stability. It is clear to us that the ASTM 1772 and EN harness standards provide an equivalent level of safety in aerial adventure environments as in the applications for which they were originally written. Compatible with facility design Managing the height of falls and enabling participants to safely and effectively interact with the aerial adventure environment depends on the location of connection points. Since waist connections (with or without a chest harness) predominate in the challenge course industry, most aerial adventure environments have been designed and built assuming the use of a primary waist attachment point. Given that ANSI Z359.1 does not allow for a waist attachment, a number of perverse operating and design issues will be created by limiting harnesses to those that meet ANSI Z For example, lanyard lengths will need to be altered connecting the same length lanyards to a sternal location rather than a waist connection will likely position participants below the objects they are meant to climb or land on. It may also put the top connections out of the reach of participants and staff creating transfer problems. Shortening the lanyards, however, may put participants in close proximity of connections, such as carabiners or snaps, which were designed to be further away. In eliminating harness standards such as ASTM 1772 and EN with a waist connection, hazards may, in fact, increase.

4 Proven track record in aerial adventure environments The test methods outlined in the various standards are designed to produce reproducible results in a laboratory setting and provide a basis for comparing products. They are not able to simulation real-life settings and as a result, caution should be taken when choosing a standard on the basis of its testing. For example, all of the harness standards use a rigid test torso when humans are essentially pliable. How well a harness stays on a rigid test torso may not be indicative of well that same harness will stay on a moving, squishy human wearing clothing. In their statistical analysis of the severity of injuries to rock climbers based on harness type, Hohlrieder, Lutz, Schubert, and Eschertzhuber (2007) found that rock climbers using a sit harness were afforded an equivalent level of safety to rock climbers using a full body harness or combination of seat and chest harness. Harnesses certified to EN and ASTM 1772 have a proven track record in the challenge course environment. Conclusion The dependence on equipment for managing the risks of engaging in activities at height has understandably led to a concern about its strength, performance, and durability. Manufacturers, professional associations, and government bodies devote much effort to testing and approving equipment meant to protect people at height. The myriad of standards in existence reflects the disparate tasks that are performed at height. As the appendices indicate, the variance among harness standards is primarily one of scope, not the degree of safety afforded to the user. Section of ANSI Z359.1 acknowledges that the standard does not address sportsrelated activities. In contrast, EN and ASTM F1772 specifically address climbing and sport activities. The waist connection outlined in these standards has proven track record in aerial adventure environments and has been recognized by regulators in other jurisdictions (for example TSSA 2009). The UK has recognized the uniqueness of aerial adventure environments when the UK Health and Safety Executive (HSE) created the Work at Height Amendment for persons instructing climbing and caving. This approach recognized the unique nature of the environment in which these professionals work, and the role of professional organizations in developing standards that promote safety. With regard to injuries, the HSE established that the use of long-established recreational climbing techniques provides an equivalent level of safety to that of industrial rope access. We are encouraged by many aspects of the proposed Cal OSHA regulations and voice our support for regulations that enable operators to provide an equivalent level of safety based on applicable performance criteria. For the reasons stated above, we contend that the ASTM 1772 and EN harness standards are preferable to ANSI

5 Z359.1 and should be recognized as providing for a superior level of safety and application in aerial adventure environments, including zip lines. Background on the Association for Challenge Course Technology The Association for Challenge Course Technology (ACCT) grew out of a series of symposia held by challenge course builders and was incorporated in The first Standards were published in The ACCT has grown to become the world s largest American National Standards Institute (ANSI) Accredited Standards Developer focused specifically and solely on the Challenge Course and Canopy/Zip Line Tour Industry. The ACCT is comprised of more than 2600 members and continues to bring together key stakeholders to address, update and improve challenge course and canopy/zip line tour standards and practices. The Annual ACCT Conference educates hundreds of industry professionals through more than 100 workshops and interactive sessions. Background on the Zip Line Industry In the past several years, zip lines have become the most visible component of the wider challenge course industry. A zip line consists of a pulley riding on an inclined cable. Once a person steps off an elevated platform, gravity takes over and transports him or her to the end. In addition to being a standalone structure, a zip line may be used to dismount from a high ropes course or adventure park facility, may be arranged in a series so that patrons can progress from zip line to zip line without returning to the ground (i.e. a zip line tour), or may be part of a canopy tour that includes bridges, rappels, and climbs. A zip line is one of many types of aerial adventure environments.

6 References ANSI/ASSE Z Safety requirements for Personal Fall Arrest Systems, Subsystems, and Components. American National Standards Institute. Des Plaines, IL: Author. Association for Challenge Course (2012). ACCT Challenge Course Standards (8th ed.). Deerfield, IL: Author. ASTM Standard F (2013). Standard Specification for harnesses for rescue, safety, and sport activities. West Conshohocken, PA: Author. ASTM Standard F (2004). Standard Terminology related to Climbing and Mountaineering Equipment and Practices. West Conshohocken, PA: Author. BS EN12277:2007 (2007). Mountaineering equipment- harnesses- safety requirements and test methods. European Committee for Standardization. Brussels, Belgium: Author. Health and Safety Executive. (2007). Falls from height: Guidance on the application of the work at height amendment regulations 2005 to persons instructing climbing and caving. Norwich, UK: Author. Hohlrieder, M., Lutz, M., Schubert, H, Eschertzhuber, S. (2007). Pattern of injury after rock-climbing falls is not determined by harness type. Journal of Wilderness and Emergency Medicine, 18, NFPA (2012) Standard on life safety rope and equipment for emergency services. National Fire Protection Association. Quincy, MA: Author Seddon, P. (2002). Harness suspension: Review and evaluation of existing information. Contract research report 451/2002. Norwich, UK: Health and Safety Executive. Technical Standards & Safety Authority. (2009). Amusement devices code adoption document amendment -- zip lines (Reference number AD-530/09). Toronto, ON: Queen s Printer for Ontario.

7 APPENDICES Table A: Harness Classifications Chart Standard Full Body Full Body Small Sit Harness Chest Harness Harness ANSI Z Yes N/A NO NO For users between lbs ( kg) ASTM Yes No Yes Yes EN Type A Type B Type C Type D For users up to 40 kg (90 lbs) NFPA Class III N/A/ Class II N/A

8 Table B: Testing Requirements Standard ANSI Z ASTM F1772 EN NFPA Harness Type Full Body Full Body Connection Location Upright Static Tests Head Down Belt Test Dorsal 22.2kN n/a 25 mm Sternal only 16 kn?? 25 mm Frontal (waist or sternal) 16 kn 10 kn 10 kn 20mm Drop Test 100 kg 1 meter drop Drop 1 meter drop Sit Harness Waist 16 kn 10 kn Chest with Sit harness Full Body Waist & chest 20 mm Frontal (waist or sternal) 15 kn 10 kn 20 mm Small Body Sternal 10 kn 7 kn 20 mm Sit Harness Frontal 15 kn 10 kn 20 mm Chest with Sit Harness Waist & chest n/a 10kN 20 mm Sit Harness Waist 16 kn Not 11 kn 25mm 136 kg 1 meter drop Full Body Harness Frontal (waist or sternal) 16 kn 10 kn 11 kn 25mm 136 kg 1 meter drop