UNIT INSTALL AN ANCHOR SYSTEM VER 2.4 01/09/2004 Copyright PACI UNIT DESCRIPTION: This unit refers to the knowledge and skills required to install an anchor system suited for supporting persons working at height. This unit can apply to any situation where a load bearing system is required since the physics and fundamental mathematical principles do not change. The principle change is the underlying surfaces to which the anchors are attached or inserted (eg natural rock, snow & ice, structural beams etc). A knot is a knot regardless of environment. Elements 1. Identify and select solid and reliable anchor points Performance criteria 1.1 A systematic search is conducted and possible anchor points within chosen area are identified and assessed for suitability. 1.2 Underlying structural integrity of area surrounding chosen anchor point is assessed. 1.3 The condition of the anchor is checked to ensure it is solid and reliable. 2.1 A range of possible knots are evaluated and the most appropriate knot is selected to achieve the task. 2.2 Method of tying is within established parameters for type of knot. 2. Select and apply appropriate knots to suit the situation 2.3. Knots are recognisable in form and shape as the particular type intended to be tied. 2.4 Knot symmetry is adjusted to optimise strength and behaviour under anticipated load. 2.5 Tail ends protruding from primary/critical knots are of sufficient minimum length to prevent failure due to slippage under load. 3.1 Anchor system is installed to meet the requirements for the particular type of work task. 3.2 Anchor system is accurately positioned to enable work task to be completed. 3. Establish the anchor system to suit the job/task requirements 3.3 Anchor system is installed in a way that reduces the risk of total collapse on account of the failure of a single component and/or anchor point that is structurally weak or susceptible to failure in the manner used. 3.4 Diversion systems are used where necessary to re-direct the trajectory of force from the primary anchor system to align ropes in a more advantageous position or to avoid sharp edges. 3.5 Angles within the anchor system are within stipulated parameters to reduce excessive transmission of tensional forces to individual anchor points under load. RANGE OF VARIABLES Variable statement 3.6 Anchor system is capable of withstanding maximum predicted operational load. Categories Anchor points may be natural or artificial and may also be permanent or temporary: A. Natural (regarded as permanent but condition may deteriorate over time) a1. boulders a2. rock features (bollards, flakes, threads, spikes) 1. Anchor points a3. trees B. Artificial [Permanent]: b1. Structural fittings and features on top of buildings Page 1 of 9
b2. Structural members/support beams/columns b3. Bolts (drive-in, expansion or glue-in) b4. Chains [Temporary]: b5. Portable clamping devices b6. Screw-in anchors (roofs) b7. Removable protection devices (eg wired nuts, hex s, cams used in climbing) b8. Counter-weights and proprietary frames (eg vehicles, tripods, booms, free-standing tripods etc) b9. Pitons (drive-in including all shapes and sizes used in climbing) b10. Hooks Current condition of anchors may be affected by: a. age b. deformity c. structural cracking 2. Condition of anchors d. wear e. corrosion f. decay (eg exposure to UV radiation\weather) g. stress and strain h. insect damage i. chemicals/corrosive substances Categories include: a. End-line knots -figure 8 family of knots (eg figure 8 on-the-bight, adjustable double figure 8 on-the-bight, rethreaded figure 8) 3. Knots b. Mid-line knots -alpine butterfly -clove hitch c. Sliding friction knots -traditional prusik and french prusik variant Page 2 of 9
-bachman -klemheist (tied using tape) d. Joining knots -double fishermans (very secure but difficult to untie after loading) -square fishermans (easier to untie after loading) -re threaded figure 8 (can also be used to join ropes end to end) In industrial roping contexts, the anchor system may be: a. A single web sling (1 ton WLL) wrapped around an obviously solid structural beam b. Independently anchored twin ropes (work rope and safety rope) to meet requirement of AS 4488 for industrial rope access work (eg high-rise window cleaning) c. Two or more linked anchor points that share a load d. A combination of purpose installed (eg bolts), portable and existing structural anchor points e. Part of a fall protection system f. Part of a belay system g. Part of a mobile anchorage (horizontal static lines, type 2/3 fall-arresters) h. Incorporated as part of a vertical rescue procedure (eg lowering, hauling) i. Temporary (eg Fibre rope horizontal static line) j. A portable proprietary frame that is assembled in-situ (eg tripod) 4. Anchor system In recreational contexts, the anchor system may be: a. A combination of natural and/or artificial anchor points b. Configured and used for abseiling activities c. Configured and used for top rope climbing activities: c1. in a top belay procedure where the belay person is positioned at the top of the route c2. in a bottom belay procedure where the focal point of the anchor system hangs over the cliff edge and the belay person is positioned at the bottom of the route d. Configured and used as a belay system for lead climbing at the top of a pitch or the top of the route d1. the anchor system is constructed using removable protection devices such as wired nuts, hex s and cams e. Incorporated as part of a system for lowering/hauling procedures f. Permanent (eg bolts and chains) or temporary In emergency contexts, the anchor system may be: a. Any combination of natural, and/or artificial and/or structural anchor points b. Configured to permit the most efficient retrieval and/or evacuation of a patient Page 3 of 9
Page 4 of 9 c. A single web sling (eg 1 ton WLL) wrapped around an obviously solid structural beam
Work tasks requiring the use of anchor systems could include: a. Industrial: a1. tree lopping/surgery a2. cleaning (eg window cleaning, gutters, water blasting etc) a3. refurbishing surfaces (eg painting) a4. installations (eg satellite dish, solar hot water, roof sheeting) a5. routine maintenance of exterior equipment and/or fittings a6. testing/measuring a7. photography/cinematography a8. inspections (eg cracks, corrosion, leaks) a9. pest control/removal a10. site rehabilitation (eg disused mining sites, open pit mines, steep embankments) 5. Work task a11. cutting, grinding and other hot work a12. tree lopping / tree canopy access a13. climbing buildings & structures (eg tower climbing or tactical climbing to access a position on a building) b. Recreational: b1. abseiling b2. climbing (top rope, lead, artificial wall, natural rock, big wall/aid, snow & ice, high alt) b3. canyoning b4. caving b5. tyrolean / rope traverse / flying fox c. Emergency situation: c1. Preparing to access the patient from above using a roping procedure c2. Installing and then operating a mechanical advantage system to retrieve a patient c3. Installing and then operating a lowering system to evacuate a patient Page 5 of 9
EVIDENCE GUIDE Assessment must confirm: a1. ability to distinguish between the operational requirements of an emergency roping procedure against the deliberate action of a routine work task. A professional or occupational vertical rescue team will have need of urgency in its selection and installation of an anchor system. Where the provision of pre-hospital care is the primary objective, the team leader may elect to place reliance on a single anchor point provided it has been assessed as absolute quality. Routine work tasks are not emergency procedures and thus reliance on a single anchor point should be avoided. In industrial rope suspension contexts, AS 4488 specifically require the installation of twin independently anchored ropes. Assessment must confirm that the trainee can form a judgement about the nature and context of the requirements of the anchor system and construct it accordingly. This can be accomplished through careful setting of the assessment scenario and confirming that the trainee possesses knowledge and understanding of the requirements to achieve a result of competent in contrast to what constitutes a result of not yet competent. a2. ability to identify solid and reliable anchor points a3. ability to select and apply a range of knots best suited for the intended application a4. ability to work alone and unaided (ie can be relied upon to comply with standards and to exercise due care and diligence so as not to endanger the lives of others) 1. Critical aspects of evidence to be considered a5. ability to tie knots and rig an anchor system within a reasonable time frame. For example, it may be unacceptable if the learner takes three (3) hours to rig one anchor system. A realistic time frame should be determined and then agreed upon based on the operational requirements for the job/task. The following benchmarks may be useful: -in a recreational situation involving friends (no legal relationship owed) 20 minutes may be a nominal assessment timeframe -in a situation where a leader/guide is establishing an anchor system for an organised activity, 10 minutes may be a nominal assessment timeframe -in an emergency situation where a seriously injured person is in need of urgent prehospital care, every minute counts. A nominal assessment timeframe must be carefully considered in the light of the complexity of the situation. a6. sufficient knowledge of forces created by angles within an anchor system a7. ability to establish the anchor system to suit the intended application (eg top-rope climbing, abseiling, hanging belay on a pitch, roof work etc) In recreational contexts: -the ability to identify and use available natural anchors (eg trees, boulders, rock features such as threads ) -the ability to select and use removable protection devices (eg wired nuts, hex s, cams) in lead climbing applications In industrial rope access contexts: -the ability to identify and use solid and reliable anchor systems using the available structural fittings/beams/work surface -in the absence of solid and reliable structural fittings, the ability to use portable clamps and/or counter-weights, and/or screw-in bolts/anchor plates as suited to the situation. -knowledge and application of relevant Australian Standards for industrial applications eg: Page 6 of 9
2. Interdependent assessment of units AS 1891 series AS 4488 series (for twin rope suspension work on surfaces or environments where suspension is deemed to be continuous ie no opportunity to stand and remove tension from the suspension rope) In emergency services contexts: -the ability to identify the optimum configuration so that a medic can access the patient in the shortest possible time frame. Elaborate or overly complex anchor systems will result in loss of crucial minutes that could have been spent in reaching & treating the patient. The risks posed by reducing the number of redundant systems needs to be balanced with the advantages in reaching the patient in a shorter time frame and hence delivering important prehospital care that may actually save lives. -In some cases, the team commander (ie team captain) may locate and use a single anchor point which has been assessed to be absolute (eg an obviously solid structural beam or tree or boulder). a. For the purposes of integrated assessment, this unit must be assessed in conjunction with; Select, use and maintain equipment; and then contextualised with a unit relevant to the workplace eg Approach the work position using abseiling techniques; or Install and operate a single rope belay system to safeguard a person; or Install and operate a hauling system. a. Underpinning knowledge a1. In industrial contexts, the ability to ensure that anchors can withstand the minimum forces specified by the AS 1891 series and AS 4488 when used in a life supporting role at a workplace. 3. Required knowledge and skills A2. In emergency situations (such as those experienced by professional/occupational vertical rescue teams), the ability to identify an anchor point of such strength and quality as to constitute acceptability for use as a sole point of anchorage. Such an anchor must be stronger than the rope and in fact the rope will fail before the anchor itself will begin to yield (such an anchor is known as an Absolute anchor ). A3. Equipment and their design limitations a4. Knowledge of knots and their application b. Underpinning skills b1. Problem solving 4. Resource implications 5. Consistency in performance b2. Ability to select an appropriate knot and tie it correctly within a short time frame tail ends protruding from the knot must be at least 200mm for 10-13mm diameter ropes. a. Assessment of this unit requires access to a site suited to the context of the students work situation (eg for industrial contexts = buildings and/or structures; for outdoor recreation contexts = natural cliffs). b. Assessment of this unit will require human resources consistent with the Assessor and Workplace Trainer competency standards. a. Competency in this unit must be assessed on more than one occasion over different surfaces/structures in order to ensure consistency of performance over the range of variables and workplace contexts that are relevant or applicable. The anchor system is an integral component of all roping activities and opportunities therefore exist to have students build and rebuild anchors at various stages during a course of instruction. b. If the student can successfully install an anchor system on one occasion but not the next, competency cannot be inferred. The student MUST prove, through a series of relevant and contextualised activities that s/he can perform consistently. For the purposes of inferring competency, observations made over at least three (3) separate instances with error free performance over the course of the activity. This requirement is best accomplished over the course of a normal training program spanning one or more days. The assessor must distinguish Page 7 of 9
between what constitutes a counselling point (eg reducing anchor complexity or choosing one knot instead of another) in contrast to what would have led to a catastrophic anchor failure. Assessment context will be either recreational, industrial or emergency services oriented. A distinction must be made between what is work and what is emergency. For example, an unconscious patient suspended in a harness is in a life threatening situation. The effects of suspension trauma will trigger rapid onset of shock and eventually death. Medical opinion is divided on an exact time frame for survival but estimates are that chances for recovery are slim beyond twenty (20) minutes suspension. This means that a team that takes thirty (30) minutes to reach the patient will be ineffective. However, the risks posed by using single point anchors must be balanced with the benefits to be obtained without recklessly endangering lives (the effects of gravity cannot be isolated!). Therefore, context and relevancy is important when assessing trainees in their ability to install solid and reliable anchor systems. The student will install the anchor system to suit a realistic situation that is relevant to his/her workplace needs. Regardless of the context, common principles prevail which include, but are not limited to: -application of angles and how this affects transmission of force within the system -selection and use of knots (knots used are common to all forms of work at height) -use of synthetic fibre ropes -protection from sharp edges and/or abrasive surfaces -the underlying strength and integrity of the anchor points that are chosen The following conditions of assessment must be met: a. Assessment of this unit must occur in a real situation or another situation that can accurately simulate the conditions expected in a real workplace. 6. Context for assessment b. Assessment will be designed to determine the students ability to apply knowledge and skills to suit either a site/job-specific situation or a range of work situations in a multi-site context. Where site-specific assessment takes place, this should be indicated on the statement of attainment since the person s knowledge & skills will be limited. Multi-site training means the student can transfer his/her knowledge and skills outside of the immediate workplace and in a range of situations. c. Competency must be demonstrated in the context relevant to the learners workplace (eg natural cliff environment, buildings, structures, confined space access, roofs, etc) d. The student will be given access to equipment resources that are typical of and relevant to the workplace. In recreational contexts, equipment used to rig anchors may include climbing protection devices (eg cams, wired nuts etc). The type of anchor points available may include trees, boulders and natural rock features. In outdoor recreation contexts, activities are carried out for fun and adventure. Equipment used to rig anchors may include removable protection devices (eg wired nuts, hex s, cams), tape slings, a variety of rope diameters and constructions, and include a combination of naturally occurring anchor points (eg trees, boulders, rock features etc). Abseiling & top rope climbing applications: -assessment must confirm ability to identify and use naturally occurring anchor points Lead climbing / Big wall / Aid climbing applications: -assessment must confirm ability to select and use a range of removable protection devices (eg wired nuts, hex s and cams) In industrial contexts, activities are carried out under a contract for work where the intention is to make a profit. There is no apparent emergency. Equipment used to rig anchors may include proprietary frames, portable clamping devices, counter-weights, bolts, vehicles, structural beams/members, and other in-situ structural fittings. The requirements of Australian Standards Page 8 of 9
will apply eg AS 1891.4. When assessing student competency, assessors must consider the time frame in which the student completes the assigned task. Assessment should capture the ability of the student to tie knots and establish anchors in a time frame that is realistic to the learners workplace. Time taken is a measure of student efficiency. e. Assessment of this unit will include a combination of techniques including: -direct observation of performance -oral questioning -written examination In emergency situations (ie public safety), the critical distinguishing feature is that a seriously injured person must be accessed and stabilised in the shortest possible time. Procedures are not carried out for profit but rather to save lives. Equipment therefore will typically be highly portable, able to be backpacked in to the incident site or be air transportable (eg helicopter). Assessment must closely simulate the circumstances that the team might be deployed in. It is pointless training with equipment that the team would never use or simply cannot obtain or worse still, not relevant. For example, some emergency services teams use proprietary frames to give them an advantage when no overhead anchorage is available. The frame particularly facilitates manoeuvring a stretcher over a cliff edge or in an underground situation or perhaps over a manhole entrance. However, not all teams will have need for a frame. This is particularly true in situations where a team has to walk long distances or scramble over rough terrain frames are heavy and bulky. In a natural cliff environment, trees, boulders and bolts (where they exist) may be used to build the anchor system. In some cases, a team may even install their own bolts using a cordless drill. In a building/structural environment, web slings are typically wrapped around obvious hard points and diversions are used to re-direct the trajectory of ropes so obstacles can be avoided. Page 9 of 9