Mod 5: Technical Skills I Rope Rescue Level I Mod 5: Technical Skills I
Definitions Knot – an intersection of interlaced cord – to entwine the rope to cause friction upon itself Hitch – Knot that wraps around an object in such a way that if the object is removed, knot falls apart Bend – class of knots that join ropes together Loop – a turn of rope that crosses itself Bight – A turn of rope that does not cross itself Standing line – rope not fastened at rigging point Working line – end of rope used to rig or tie
Knots, Bends, Hitches These Elements should possess the following: Relatively easy to tie Identifiable Maintain configuration Minimal effect on rope strength Knots diminish strength of rope through bends % of strength lost – 2:1 Rule Relatively easy to untie after loading Elements selected for use should not be so complex that they cannot be tied, identified, or untied with speed and proficiency Elements selected should maintain configuration when loaded 4:1 rule / 2:1 rule Rope does not significantly lose strength until it has a bend less than 4 X its diameter (this rule applies to natural fiber rope more than synthetic which realistically uses a margin of 2:1). The 4:1 rule also applies to safety and efficiency margin for pulleys. The diameter of a pulley should be at least 4 X the diameter of the rope to insure safety and efficiency.
Knots Steps for Tying Knots Select proper knot Dress the knot Properly align and straighten all of the knot parts removing extra twists and crosses Set the knot Tighten all parts of the tie so that rope parts touch and grab to cause friction Back up knot (safety) Not all knots require overhand safeties or back up knots but it is NEVER wrong to do so. Openings or bites and tails of knots should be appropriately sized Tying knots just large enough to accommodate the application is a good fundamental to keep elements as condensed as possible
Knots Overhand Square Knot Bowline Clove Hitch Simple Figure 8 Knot Figure 8 On A Bight Figure 8 Follow Through Figure 8 Bend Double Figure 8 On A Bight Butterfly Knot Double Fisherman’s (Grapevine) Bend Prusik Hitch Munter Hitch Practical Session: Provide each student with a section of rope and systematically demonstrate each knot, bend, hitch Instruct students to watch methodology first and then have them duplicate the process Explain the application of each knot, bend, hitch while demonstrating
Anchoring Techniques for securing the rope and other elements of the high angle system to something solid Two basic categories for anchors Single Point Anchors - Single secure connection for an anchor Multi Point Anchor System - One or more anchor points rigged to provide a structurally significant connection for elements of a rope rescue system Selection based on strength and location Two basic categories Single anchor points Multiple anchor points used to create anchor systems Deciding factors for selection of single point vs. system Strength “Bombproof” Location
Anchoring Anchor Assessment Strength – “Bombproof” or “Not” Design Stability Location Avoid Tunnel Vision Strength Sufficient or not to support load and forces that will be applied Design Cylindrical, Open or Close ended, I beam, Angle – These designs affect the surface contact between the anchor and the mechanism of attachment will be determining factors in application selection Sharp edges, burrs, smooth or rough also affect edge protection and positional control of the anchor point (discuss use of duck tape to keep anchors in place) Stability Is the anchor kinetic or moveable – Large rocks, vehicles, etc.. Connections – root systems, welds, bolts, etc… - must be assessed as part of the strength or overall capability of the anchor Location Does the location of the anchor provide optimal design and function of the rope system or will directionals be required Inferior anchors may be selected if the superior anchor would result in inefficient rescue operations Anchor selection requires broad thinking at times
Anchor Points Natural Anchors Trees Rocks Structural Anchors Size Root Systems Soil Types Live or Dead Rocks Marginal Structural Anchors Structural columns Projections from beams Supports for large machinery Stairwell support beams Brickwork with bulk Engineered anchors for window washers Trees with solid foundations and viability and appropriate diameter Rocks are marginal due to their instability and the difficulty to maintain the position of the attachment point Structural elements must also be considered for composition Cast Iron, Mortar, Rust / Decay, etc… Engineered anchors will typically be labeled with load design
Anchoring Single Point Applications Rope: High Strength Tie Off / Tensionless Hitch Characteristics: Strongest anchor point Tension is assumed through friction between the coils and the anchor Number of coils / wraps is dependant on the diameter of the anchor Not always the most advantageous use of rope Edge protection should be utilized Clove Hitch, Bowline, and Figure 8 Follow Through Strongest application: Strength of the rope itself is not lost through knots because the attachment figure 8 and carabiner are not loaded when the hitch is done correctly The smaller the anchor = the more wraps and conversely for the larger the anchor Tensionless hitch requires the end of the rope to be utilized and the rest of the rope to be deployed over the edge unless the rope bag is being passed around the anchor during construction (difficult to manage). The midpoint of the rope cannot be utilized to maximize usage if the rope length accommodates such an application. Exposing the rope to potential abrading or cutting elements on the surface of the anchor require edge protection Clove, Figure 8, and bowline can be utilized as anchor attachments in certain applications – predominantly victim packaging.
Anchoring Single Point Applications Anchor Straps Characteristics: Strong and rapid to deploy Variables exist through different configurations and adjustability Labeling requirements per NFPA 1983 make their strength capabilities easily identifiable Create fixed anchor points where multiple components can be fixed Edge protection should be utilized Can be configured as choker, basket or straight depending on space and load Can be wrapped around an anchor multiple times if needed to condense rigging space Some anchor straps have adjustable lengths – typically not as strong Rigging plates can be attached to anchor straps for multiple attachment points and the ability to change those attachment points without altering the anchor Rope sleeves or fire hose can be pre rigged to anchor straps for edge protection
Anchoring Single Point Applications Webbing / Pre sewn Slings Should be duplicated for strength and redundancy Wrap 3 pull 2 is strongest configuration Time intensive Requires edge protection Use of webbing for anchors has been replaced by anchor straps Too slow to configure Difficulty in equally loading both segments.
Anchoring Multi Point Anchor Systems Utilized when single bombproof anchors are not accessible or present Tension Back Tie LDA (Load Distributing Anchor) An anchor system that maintains and redistributes (if one anchor point fails) near equal loading on multiple anchor points despite direction of pull LSA (Load Sharing Anchor) An anchor system that distributes the load between multiple anchor points but does not adjust to direction changes in pull. Describe Tension Back Tie, LDA, LSA Tension Back Tie requires a support or back up anchor that is in line with direction of pull or multiple anchors that can be collected with a centering point at the primary anchor LDA results in pendulum and elongation if failure occurs of one of the anchors LSA results in pendulum if failure occurs of one of the anchors
Anchoring Picket Systems Comprised of pickets that are 4’ – 5’ in length of at least 1” diameter. (steel) Drive pickets at least half depth at 15 degree angles Lash pickets together utilizing clove hitches and at least 3 wraps Tension lashings by twisting ½” steel 4 – 6 times and drive it into the ground Standard picket systems are 3 pickets by 3 pickets spaced approximately the length of the picket Can only be established in solid soil bases.
Critical Angles Understanding of Forces Physics of Force Amplification from Critical Angles - Anchor Tension Rigging Precautions Don’t compromise directional anchors Use multi point anchor systems only as a last resort keep inside angles 90° or less, never more than 120° Systems should always be constructed with appropriate critical angles in mind Explain Anchor Tension and lateral forces Directionals and Multi point anchors can be compromised when angles exceed 120 degrees. High Lines are examples of systems that exceed critical angle requirements and they require very specialized rigging and redundancies.
Critical Angles Less than 45 Degrees = load distribution that is equal to or less than the load itself at each anchor point Greater than 45 Degrees (NEVER more than 120) = Amplification of the load and its distribution to each anchor
Critical Angles 100+ lbs 100+ lbs 71 lbs 71 lbs 100 lbs 120 71 lbs 71 lbs 100 lbs Any angle greater than 120 degrees applies more than the load to each anchor 90 100 lbs
Anchor Points Discuss Back Tie Technique, Anchor Usage, Vehicle Safety Steps
Anchor Points Tensionless Hitches / High strength Tie Offs with Back Ties
Anchor Points Establishing a high directional
Anchor Points Use of Natural Anchors
Anchoring Anchors should be created for two primary components Mainline: Primary line of movement for rescuers and victims Directionals: Used to bring the mainline into a more favorable position or angle Belay: Safety line designed to provide protection against a fall or system failure. Belay lines should avoid the use of directionals and should take the shortest direct path to the load The primary anchor that should be established is the belay anchor because it requires a direct route to the load The same anchor can be utilized for both the belay anchor point and the mainline anchor point if it is engineered to sustain all load possibilities without compromise.
Belay Operations Components Belay Device or Hitch Belayer Anchor Point Belay Line (Rope) Attached to Rescuer / Victim Attachment Points on Harness Speed and Functionality – Attach to the midline rigging component on the harness Attachment Points on Harness The Belay should be attached midline and contained so that if loaded it will not result in the rescuer hanging from their side or back Redundancy – Tying the belay around multiple midline fabric components of the harness afford a high degree of safety but are slow and cumbersome to rig and un rig and are not recommended by most manufacturers. Speed and Functionality – Attaching the belay to the rigging component of the harness is within the manufacturer’s design configurations and is much faster and easier to rig and unrig.
Belay Operations Two Load Design Applications 300# Design Load Auxiliary Equipment with “L” design loads. 600# Design Load Tandem Prusik Belay (TPB) LRH, PMP, Paired Prusiks Auxiliary Equipment with “G” design loads. Briefly describe belay components and their load designs.
Belay Operations Belay systems will be utilized at all times during this course and should be utilized during rescue events. Rare situations that might exclude the use of a separate belay system would be: An experienced rescuer that feels a belay will be a hindrance to rescue efforts Multiple lines risking entanglement Free drops where spinning may cause entanglements Limited access requiring a bottom belay Separate belay systems afford safety and redundancy Bottom belays do not work with all descent control devices Belayer can only exert as much pressure as body weight or rope can slip out of grip of belayer Belayer is in danger of being hit by objects Does not provide back up for failure of main line anchor, or rappel devices The elimination of a belay line requires significant risk benefit analysis and should require consensus from operational command and the safety officer.
Belay Operations Maintain proper amount of slack When lowering or descending, pull “Z”,s and maintain slack at top side so that rescuer has a relatively taught line from their perspective When hauling or ascending, keep taught. Ensure Fall / Failure protection capacity is present Utilize standard communications and safety checks Rescuer – “On Belay” (Prompt) Belayer – “Belay On” (Response) Proper Slack Pulling “Z”,s affords enough slack to stay ahead of the load movement safely without hindering load movement or loading the belay device. Fall / Failure protection Different devices utilize different mechanisms to seize the load if fall or failure occurs Ensure that the mechanism is properly set or in operating order by applying a pull test prior to deploying the rescuer Communications / Safety Safety checks should be conducted of the system and the rescuer Communication sequence should be systematic
Belay Operations Edge Tender Individual who maintains communication and oversight of operation between the rescuer and the top side Belay Commands: Too much slack = “Tension the Belay” Not enough slack = “Slack the Belay Edge Tender ideally has visual and verbal contact with both parties Should have a safety line attached due to proximity of edge Discuss Edge Tender Responsibilities: Safety Line Management Communications
Main Line Operations Two Categories of Application Rescuer Based Rescuer Based – Descending (Rappelling) and Ascending (Climbing) Team Based – Lowering and Hauling Systems Rescuer Based Predominantly used to gain initial access to victim for assessment / packaging Team Based Predominantly used for victim movement
Rescuer Based Operations Rappelling requires proper manipulation of the Descent Control Device (BBR) Signs of effective manipulation are: Controlled descent with minimum physical effort Controlled descent with appropriate and consistent speed so that the rope is not damaged by heat and anchors are not damaged by shock loads Ability to stop descent at anytime Ability to tie off securely and operate hands free of the rope Ability to operate in any body position including inversion BBR’s are engineered to control the rope through friction – A skilled rescuer manipulates the rack to “do the work for him”. Rope should not be fed through the rack and speed of travel should be consistent – this is all managed through correct manipulation of the rack Rescuers must possess the skill sets to stop, tie of, and perform rescue actions whether self rescue or pick offs which may require inversion. Specific skills will be taught in hands on session.
Rappelling Rappelling – Note Body Position and hand placements
Rescuer Based Operations Ascending / Climbing Ascending - a further development of competency in the vertical environment Change Over - a transition from a rappel to ascent and back to a rappel Types of Ascenders Friction hitches (the most common is the Prusik Hitch) Mechanical ascenders Typically performed in self rescue applications In rescue applications, ascending is typically only performed for self rescue in which a personal component (gear, clothing, physical element) have become caught in the BBR and the load must be taken off of the rack to correct the problem. May also be utilized perform rigging and anchoring at elevated objectives. Specific skills will be taught in hands on session.
Rescuer Based Operations Pick Off Rescue Techniques (Level II KSA) Single rescuer has direct contact with rescue subject Generally performed when rescue subject is uninjured or slightly injured Completed by rescuer being lowered or on rappel Involves attaching rescue subject directly to rescuer’s rappel system Pick Off Rescues are a Level II Skill Set per NFPA 1006 but are an imperative component in a rescuers skill sets to be effective as part of a rescue team. The Victim is typically trapped at an elevated level and unable to climb up or down due to injury or environment.
Rescuer Based Operations Pick Off Rescue Techniques Will require line transfer if victim is on rope If victim is not on rope, a hasty harness will be required Victim’s injuries may require c spine precautions to be taken Line transfer rescues may be situation in which Belay system might not be used due to propensity for entanglement Specifics of pick off Rescue Techniques will be taught in hands on session
Pick Off Rescues Line Transfer Pick Off Rescues - Inversion
Pick Off Rescues Pick Off Rescues