306.003 - Basic Rope Rescue Equipment PDF - Training Manual

TRAINING AND EQUIPMENT MANUAL 306 RESCUE EQUIPMENT 306.003 BASIC ROPE RESCUE EQUIPMENT EFFECTIVE: DECEMBER 2008 The purpose of this section is to provide a guide for members in the use and care of rescue ropes and related rescue equipment. The procedures in this section are recommended to be used w...

TRAINING AND EQUIPMENT MANUAL 306 RESCUE EQUIPMENT 306.003 BASIC ROPE RESCUE EQUIPMENT EFFECTIVE: DECEMBER 2008 The purpose of this section is to provide a guide for members in the use and care of rescue ropes and related rescue equipment. The procedures in this section are recommended to be used when appropriate. It is understood each rescue emergency has its own special circumstances, but the major factor in any incident should always be safety. Basic rescue equipment is carried on all truck companies. This equipment includes life ropes, webbing, lifting harness, signal rope, and carabiners. Roof ropes are carried on all engine and truck companies. The Urban Search and Rescue team companies carry an assortment of additional equipment for specific rescue situations. Rope rescue equipment is divided into two general categories--software and hardware. Software includes rope, webbing, prusik loops, pick-off strap, and commercial harnesses. Hardware includes carabiners, pulleys, anchor plates, and ascending and descending devices. RESCUE SOFTWARE Rescue Rope Rescue rope is used for a variety of purposes in technical rescue. It is the primary tool for raising and lowering rescuers, equipment, and victims. It is used to protect rescuers and victims as they move and work in elevated positions where a fall could cause injury or death. It is used to create pulley systems. Rescue Rope Construction There are many types of rope on the market, but only a few specially manufactured ropes meet the stringent requirements for rescue or life-safety rope. Synthetic ropes have replaced natural-fiber ropes in the past several years. Naturalfiber ropes such as manila, hemp, and sisal come from plant fiber. The fiber is woven together; and, since the entire rope is made of many short fibers, the strength is uncertain and inconsistent. Natural-fiber ropes do not have sufficient strength in manageable sizes to safely hold live loads. Section 306.003 Page 1 of 63 Synthetic rope is lighter, stronger, and more resistant to decay and rot than natural fiber rope. Nylon synthetic rope is the preferred material for rescue rope. There are several different kinds of nylon ropes manufactured for rescue use. Some ropes have a high stretch factor and are designed for mountain climbing. These ropes, called high stretch (dynamic) ropes, stretch at least 10 percent at 450 lbf. (lbf. force) (2kN) and may stretch as much as 60 percent of their length before breaking. This is to absorb the shock of a falling load and reduce the impact on the falling climber and on his/her anchors and equipment. High-stretch (dynamic) rope is used when long falls may be anticipated; it is not practical for rescue work. High-stretch rope acts like a rubber band when loaded, which is a definite hazard and disadvantage when trying to raise or lower a heavy load. Low-stretch (static) ropes are the preferred types of rope for rescue work. They stretch very little when loaded, less than 5 percent at 450 lbf. (2kN) with a minimum elongation of not less than 15 percent @ 75 percent of breaking strength, and a maximum elongation of not more than 45 percent @ 75 percent of breaking strength (NFPA 1983, 1995 edition). They should not be used where the stretch of a highstretch (dynamic) rope may be needed to absorb the shock of a long fall. Low stretch (static) rescue rope is constructed using a kernmantle design. Kernmantle is a German word meaning core and sheath. The kern, or core, is made up of continuous parallel fibers running the length of the rope. This is known as block creel construction. The core carries the majority of the load, or about 75-90 percent of the rope's strength, and is protected by the mantle or sheath. The sheath is a tight weave of nylon, which carries the remainder of the load. By its design, low stretch (static) rope has a thicker sheath that protects it from abrasion damage. The sheath also protects the core from abrasion, dirt, and the effects of sunlight, which can weaken nylon with prolonged exposure. (Figure 1) Pique Kernmantle Rope Courtesy of CMC Rescue, Inc. F Figure 1 Most rescue rope used in the fire service today is 1/2-inch (12.7mm) diameter, lowstretch kernmantle rope. Most rescue hardware in use today is not compatible with ropes larger than 1/2-inch (12.7mm). There really is no need to use a rope larger than 1/2-inch (12.7mm); by today's manufacturing standards 1/2-inch (12.7mm) rescue rope meets or exceeds the minimum safe working and breaking strengths. NFPA 1983 is the standard for life safety rope. Minimum breaking strength for rope used in one-person systems shall not be less than 4,500 lbf. (20kN). Minimum breaking strength for rope used in two-person systems shall not be less than 9,000 lbf. (40kN). There will be a 15:1 safety margin. Section 306.003 Page 2 of 63 This means a single-rope system can be used and still meet the safety standard. All Rescue Systems 1 require two 1/2-inch (12.7mm) NFPA-certified ropes. An extreme rescue load is given as 600 lbf. (~3kN), about the weight of two fully equipped rescuers. A 9,000 lbf. breaking strength rope with a 600 lbf. (~3kN) load provides a 15:1 safety margin. NFPA 1500 (1997) 5-9.3 states, life safety rope may be reused if inspected before and after each use, and no impact load, damage, or exposure to any chemical material known to deteriorate rope has occurred. Refer to the full NFPA 1983 (1995 ed.) and NFPA 1500 (1997 ed.) 5-8 on fire service life safety rope, harnesses, and hardware for the specific requirements. Inspection Visually inspect the rope for: 1. 2. 3. 4. 5. Unusual wear. Cuts. Exposed core material. Excess wear and abrasion of the sheath material. Discoloration that could be from chemical contamination. Feel the rope as it is being stuffed into the rope bag for: 1. 2. 3. 4. 5. 6. Soft spots. Kinks. Unusual bulges. Inconsistent texture and flexibility. Unequal diameter or thickness. Excess contamination from dirt and debris. Any of these could indicate damage to the core of the rope and may require taking a rope out of service. If in doubt, take the rope out of service. Cleaning Keep ropes clean of mud and dirt, which can act as a sharp abrasive if allowed to work its way into the core of the rope. 1. Wash rope in a standard front-loading washing machine or in an open tub by hand. 2. Wash in cold water. Section 306.003 Page 3 of 63 3. Do not use strong detergents, as they may cause damage to the rope. 4. To avoid mildew and mold, ensure the rope is completely air dried before storing in a rope bag. 5. Do not dry rope in direct sunlight. Storage One of the most convenient methods of storing and carrying rope is in rope bags. It is easier and quicker to stuff a rope into a bag than it is to coil it. Rope bags protect the rope from damage, making deployment quick and easy. Bagged rope can be carried to remote rescue sites more easily than coiled ropes. Nylon rope can be damaged by many substances, materials, and by poor storage habits. Prolonged exposure to sunlight will degrade nylon rope. Moisture will cause mold and mildew to grow, which may weaken a rope. Rope should be stored in a dry area. Acids, chemicals, and strong detergents will damage nylon. Storing a rope with knots left in it will eventually cause that portion of the rope to weaken. Storing rope on concrete can cause damage from the caustics found in some concrete mixes. If stored on a vehicle, rope should be kept away from fuel, oil, and exhaust fumes, as these will cause rope to degrade in strength. Damage When working around any software, caution shall be taken to avoid serious damage. There are many ways to damage a rope while in use. Objects falling and striking rope can cut or crush the fibers, but the number one cause of rope failure is abrasion and cutting as the rope runs over sharp edges. This can be avoided by using edge protection, wherever possible. There are many forms of edge or abrasion protection that can be used, including turnout coats, packs, and heavy clothing. Fire hose sections split down the middle, carpet, and salvage covers are all potentially good abrasion protection. There are also commercial devices such as edge rollers. Stepping on a rope forces dirt and debris into the rope's core, which accelerates wear from abrasion. Nylon has a low melting point and is easily damaged by excessive heat. The minimum melting temperature of low stretch nylon rope is 400° F. When two pieces of nylon come in contact, with one stationary and the other in motion, the heat buildup caused by the friction will cut right through the stationary piece of nylon. There are many situations in technical rescue where this could occur, and care must be taken to avoid this problem at all times. Fast rappels will also cause severe overheating of metal components, which can damage the rope. Properly controlled rappels will prevent this hazard. Section 306.003 Page 4 of 63 Strength Bending rope fiber reduces the strength of a rope. Any knot will reduce the strength of a rope. Whenever a rope is placed under a load with a sharp bend in it, there is a strength loss. The bigger the diameter of the bend, the less strength loss. Tests have shown there is not a significant loss of strength until nylon rope is bent to less than four times the diameter of the rope. For a 1/2-inch (12.7mm) rope, the minimum bend should be 2 inches to maintain the maximum strength. Marking Rescue rope should be marked or tagged so that the history of each individual rope can be maintained. Each rope should have an identifying mark or number on both of its ends. A middle mark is sometimes helpful and saves time when setting up some rescue systems. The US&R station has the material to mark new ropes. Rope Log A rope log for recording the usage of each rope must be maintained. Information to be recorded includes: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Purchase date. Manufacturer. Size. Length. Whether it is high stretch (dynamic) or low stretch (static). Whether it is lifeline or utility grade rope (how the rope was used). Any unusual loading. Whether a fall was caught. Whether any object fell onto the rope. What materials (sand, glass, etc.) the rope was in contact with. Washings. Every time a rope is used, the usage should be recorded in the rope log. Information about how it was used will help to decide when to retire a rope from service. When to retire a training rope will be determined by reviewing the rope log, inspecting the rope for damage, and by using common sense and good judgment. Section 306.003 Page 5 of 63 Life rescue ropes placed out of service and routed to the US&R station if any of the following conditions are found. A replacement rope should be immediately requested from the US&R station. 1. There is excessive sheath wear. 2. More than half of the outer sheath yarns are broken in one pique. 3. Severe shock force from a fall or stressed with a load beyond what it was designed to hold. 4. Contaminated by chemicals. 5. Worn out from use or age. 6. An inspection exposes an obvious fault or damage. 7. Usage cannot be accounted for. SAMPLE ROPE LOG SERIAL NUMBER ID MARKING DATE OF MANUFACTURE FIBER LENGTH ISSUE DATE COLOR DIAMETER DATE IN SERVICE CONSTRUCTION MANUFACTURER LOT # INSPECT THE ROPE FOR DAMAGE OR EXCESSIVE WEAR EACH TIME IT IS DEPLOYED AND AGAIN AFTER EACH USE. IMMEDIATELY RETIRE ALL SUSPECT ROPES DATE USED PURCHASED FROM: REMARKS: INCIDENT LOCATION TYPE OF USE ROPE EXPOSURE DATE INSPECTED INSPECTOR INITIALS ROPE CONDITION AND COMMENTS PURCHASE DATE: Rescue rope and software should be purchased only from a reputable dealer or manufacturer of rescue equipment. Quality lifeline rope normally is not available from marine or hardware stores. Section 306.003 Page 6 of 63 Prusik Cord Prusik cord is 8mm in diameter. It is the same low stretch, nylon Kernmantle construction as rescue rope. Prusik cord is used primarily to make Prusik loops. Prusik Loops Prusik loops perform three important functions in rescue systems. 1. Hauling prusiks 2. Braking prusiks 3. Ratchet prusiks In a raising system, the hauling prusik grabs the rope and pulls it into motion as part of a mechanical advantage system. The ratchet prusik holds the rope while the mechanical advantage system is reset. In a belay system, the tandem braking prusiks grab the belay line to prevent it from moving if there were a mainline failure, providing safety for the rescuer/victim. When working with 1/2-inch (12.7 mm) rescue rope, the prusiks should be 8mm in diameter. Prusik cord must be compatible with the particular rescue rope, which is being used. Some ropes have a special coating that reduces friction and reduces the effectiveness of prusik hitches, which are attached to them. Special care must be taken in selecting compatible rescue rope components. Soft, pliable rope is preferred for prusik material. The cord used for prusik loops should be pinch tested to determine if it is pliable enough to adequately grab onto the rescue rope. (Figure 2) This is done by bending the cord into a bight with two fingers. If the distance between the cords on either side of the bight is greater than the diameter of the cord, the cord is too stiff and the prusik hitch will not grab the rope. Conversely, if the Prusik Cord Pinch Test accessory cord is too supple and the bight Figure 2 has almost no gap at the bend, the cord will grab too quickly and absorb very little shock. The goal here, especially with a braking prusik, is to allow the prusik to slip before setting on the rope, thereby absorbing some of the shock as the prusik arrests the moving rope. The 8mm prusik cord used for prusiks on 1/2-inch (12.7 mm) rope are cut to 70 inches (1.79 m) in length to create long prusiks and 57 inches (1.46 m) in length to create short prusiks. (These lengths are compatible with 2-inch prusik minding Section 306.003 Page 7 of 63 pulleys.) Several of each size are needed in most rescue systems. Each length of 8 mm cord is tied into a continuous loop using a double overhand bend. Once tied, prusiks should remain tied. A single prusik attached to the 1/2-inch (12.7 mm) mainline with a three-wrap prusik hitch is used for a hauling and ratchet prusik. A set of tandem prusiks, one long and one short, attached to the 1/2-inch (12.7 mm) belay line with three-wrap prusik hitches, is used for a braking prusik. Tests by several different groups from different areas have shown the tandem prusik belay system to be the most effective means of protecting a rescue load. It was the only system tested that was consistently able to stop and hold rescue loads dropped from nominal heights without serious damage to the belay line. The tandem prusik belay is easy to set up, versatile, secure, and reliable. It also requires training and practice on the part of the rescuer to operate properly. Some rescuers are concerned about supporting a load with 8mm rope, thinking it is a weak link in the system. In fact, 8 mm prusiks are stronger than the main line with a knot in it, attached, and bent around a carabiner. In all the testing done, prusiks have never failed at the bend of a carabiner. Care and Maintenance Same as for rope. Webbing Webbing is used extensively in rescue work to build anchor systems, create harnesses, package and secure victims; and to lash rescue components together. Because of its very small diameter, webbing is a better material to use when snapping into carabiners because it is more efficient in maintaining its strength. 4,000-pound webbing loses very little of its strength when bent around a carabiner. Webbing is relatively inexpensive and can be cut into short lengths for many uses. It is lightweight and easy to tie. Section 306.003 Page 8 of 63 Construction of Webbing Nylon tubular webbing should be used in rescue applications. There are different methods of manufacture. Until 2000, the preferred method of construction was spiral weave/shuttle loom. Although this type of construction is still safe to use, it is being replaced with needle loom construction, which is flat webbing that is folded and stitched together on one side. (Figure 3) Folded Edge 1 Needle Loom Construction Tubular Webbing Stitched Edge Figure 3 Webbing comes in several sizes. The one-inch size is most widely used and has a 4,000 pound breaking strength. Two-inch webbing has a breaking strength of 7,000 pounds. Webbing is available in a variety of colors. A system of color-coding webbing to determine length greatly aids in setting up rescue systems. If known, for example, all pieces of orange webbing are 20 feet in length, it is easy to select the proper piece of webbing to construct a specific anchor sling or to lash a victim into a litter. The Rescue Systems 1 course uses the following color-coding for all webbing: Green Yellow Blue Orange 5 Feet 12 Feet 15 Feet 20 Feet These lengths have proven to be the most useful for rescue applications. Care and Maintenance Same as for rope. Section 306.003 Page 9 of 63 Pick-Off Strap The pick-off strap is a section of 1-3/4inch webbing used to connect the rescuer and victim together during a rescue to "pick-off" a victim who is stranded on the side of a building, rock face, or other slope. This strap is about 48 inches in length and has a "D" ring sewn on to one end. In the middle, a sliding buckle allows the rescuer to adjust the distance between him/herself and the victim. The other end is folded over and sewn to ensure the buckle does not come off during adjustment. (Figure 4) Figure 4 Care and Maintenance Same as rope for the webbing portion plus inspection of "D" ring and buckle. Rescue Harnesses Many commercial harnesses on the market are made specifically for rescue work. Adjustable harnesses are preferable for rescue team equipment caches. They can be worn by various persons or adjusted over layers of clothing, depending on the weather. The Department utilizes a one-piece, class-three harness and a two-piece that consists of a waist and chest harness. Harnesses should be adjusted as tightly as possible and still allow agile movement. Care and Maintenance Same as for pick-off strap. Section 306.003 Page 10 of 63 RESCUE HARDWARE Carabiners Carabiners are metal connectors that link the different components of a rescue system together. There are four basic parts of a carabiner: (Figure 5) 1. 2. 3. 4. Gate Spine Lock Spine Lock Gate Hinge Carabiners for rescue work should be the locking type to prevent unwanted gate openings and come in a variety of shapes and sizes. Hinge Figure 5 Carabiner Construction Carabiners are made of aluminum or steel. Aluminum carabiners have a breaking strength from 6,070 to 6,745, depending on the size. Steel carabiner’s breaking strength is 16,187. All mechanical advantage systems shall be built utilizing steel carabiners. Aluminum Carabiners 1. 2. 3. 4. 5. 6. Lighter. Do not rust. Usually less expensive. Wear out faster. Not as strong. May be damaged by dropping and shock loading. Steel Carabiners 1. 2. 3. 4. 5. 6. 7. Stronger. Less susceptible to abrasion and wear. Heavier. More expensive. May rust. Require more maintenance. May also be damaged by dropping and shock load. Section 306.003 Page 11 of 63 Refer to the NFPA 1983 standard for minimum breaking strengths. Carabiners come in different sizes, but the standard locking "D" will fit most rescue applications. Large locking "D" carabiners are available and will fit over most rescue litter rails. Standard locking rescue carabiners, which meet the NFPA 1983 standard are strong enough to stand alone. Some rescue systems advocate doubling up carabiners and turning them so the gates are opposite and opposed. This is to prevent accidental opening of a gate during a rescue and the loss of the connection. With locking carabiners, this is unnecessary; and, in fact, has led to side loading of carabiners and damage to carabiner gates and locking mechanisms. Locking carabiners are at full strength when the gate is closed and locked. A locking carabiner should not be unlocked and opened when under load. There are some circumstances when a locking carabiner has come unlocked on its own while in a system. This can happen if the locking mechanism is rolled across a face of a cliff or a building. It can be overcome by making sure the gate is turned away from the face. Vibration can also cause gates to open, which can cause the lock to unscrew. To overcome this, turn the gate down so gravity is working against the gate to keep it closed. Care and Maintenance Carabiners must be kept clean of dirt and oil. Wipe them down with a clean rag and keep them off the ground to prevent dirt from being forced into the gate and locking mechanisms. Use a ground cloth, coat, or other object to lay out hardware when setting up systems. This will not only keep everything clean but will help to prevent loss of equipment. Sharp burrs and nicks in carabiners and other hardware are damaging to software. If they are small, they can be gently filed or sanded off. Carabiners with gates that stick or will not close should be discarded if they cannot be fixed by blowing out the lock and hinge with compressed air. Do not use oil or grease to lubricate because it collects dirt and dust and acts as an abrasive compound, which wears out the mechanism or jams it. Section 306.003 Page 12 of 63 Cautions Carabiners are designed to be loaded end to end. They should never be side loaded. Opening a loaded carabiner can cause serious damage to the carabiner, or even complete system failure. A common mistake is locking a carabiner while it is loaded. When the weight is taken off the system, the locking mechanism should not come undone. Therefore, carabiner locks should be tightened before loading only. Rescue Pulleys In technical rope rescue, rescue pulleys are used to: 1. Change direction of force on a running rope. 2. Reduce rope friction. 3. Create mechanical advantage for hauling systems. Rescue pulleys are all metal for maximum strength. The sheave, or the area the rope runs on, should be metal and should be the proper width for the diameter of rope being used. Not only should it be wide enough, but also its diameter should be four times the diameter of the rope for minimum loss of rope strength as the rope bends around the sheave. The side plates must be moveable so they can be placed on the rope anywhere in the system. The axle should be firmly attached with rounded bolt heads to prevent damage to other rescue system components. The bearing should be the sealed ball-bearing type so it turns freely and will not be contaminated with dirt and debris. (Figure 6) Parts of a Pulley Figure 6 Section 306.003 Page 13 of 63 There are special pulleys manufactured to meet technical rope rescue requirements. Prusik minding pulleys are designed to work with prusiks to make a self-tending brake system for belay lines and ratchets for mechanical advantage pulley systems. (Figure 7) Prusik Minding Pulley Figure 7 Double sheave pulleys are valuable for setting up parallel systems and for increasing mechanical advantage. Refer to the NFPA 1983 standard for minimum breaking strengths. Care and Maintenance Pulleys need to be kept clean and free of any sharp edges, nicks, or burrs. These can be lightly filed or sanded off. Ensure the bolts holding the pulley together are tight and the sheave and side plates rotate freely. The attachment point should be checked for wear and elongation. This can indicate excessive loading, and the pulley should be discarded if any such defects are found. Do not lubricate the bushings or bearings with grease or oil; this will attract dirt and other debris, which will create excessive wear. Figure 8 Descenders Figure 8 descenders were designed as descending or rappelling devices. They work by creating friction when the rope is wrapped around them. The original Figure 8 plate looked like a numeral eight, but with unequal rings. The larger ring is the location where the rope passes through to create friction, and the smaller ring is for attaching to a harness or anchor. Rescue-8 descenders have an added feature called ears. These were added to prevent the rescue rope from accidentally forming a girth hitch and causing a jam, which is difficult to fix. Rescue-8 descenders are Section 306.003 Page 14 of 63 easier to lock off and accept larger ropes. They are stronger and, because they are larger, they dissipate heat more quickly. (Figure 8) There are several problems associated with the use of Figure 8 descenders. 1. They twist any rope, which goes through them. 2. They are one-person devices with limited ability to hold heavier loads. 3. Once attached to a system, friction cannot be increased to any great degree. Figure-Eight Plate Figure 8 For many years, Figure 8 descenders were used for breaking devices on lines belaying rescue (two-person) loads. Drop tests have shown Figure 8 descenders are inadequate for stopping a rescue load with as little as a one-meter drop. Figure 8 descenders should only be used for one-person rappels of limited distance and for lowering one-person loads. Refer to the NFPA 1983 standard for minimum breaking strengths. Care and Maintenance Sharp edges and burrs will destroy software very quickly and should be filed off. Dirty rope will wear hardware more quickly than clean rope. Wear greater than 15 percent of the original thickness is excessive, and the Figure 8 descender should be discarded. Brake-Bar Rack Brake-bar racks are friction devices designed for use on the mainline, in lowering systems, or for rappelling. Friction is created by reeving the rope over and under the bars; the more bars used, the greater the friction. Adjusting the distance between the reeved bars along the rack, with maximum friction obtained by pushing the bars close together, can also control friction. Four bars should be used when a single-person load is on the line. The rope should also pass under the last bar used when rappelling to simplify tying off the rack, in mid rappel, without losing friction. (Figure 9) Brake-Bar Rack Figure 9 Section 306.003 Page 15 of 63 Parts of the brake-bar rack include: 1. 2. 3. 4. 5. A steel rack, with an eyelet and retaining nut. Aluminum or steel bars, six bars minimum. One 1-inch top bar with a training groove. One 3/4-inch bar with a straight slot. Four 3/4-inch bars with angled slots. When reeving a brake-bar rack, the rope should first contact the large (1 inch) bar passing over the training groove. The rope should then pass under the next bar (with the straight slot), forcing the bar against the rack. The rope then passes over and under the rest of the bars. The training groove in the large bar and the straight slot in the second bar are provided to ensure the rack is reeved properly. Care and Maintenance A small file or emery cloth can be used to round any burrs or sharp edges. The brake-bar rack should be inspected for worn bars, cracks, secure nut, or bent rack. It should be removed from service if the rack is deformed or cracked, or when a bar is worn to less than one-third of its original diameter. Mechanical Ascender The mechanical ascender is a common ascender used in the fire service. (Figure 10) All ascenders are designed for use in ascending a fixed rope. They may be used in rope-rescue pulley systems as a ratchet cam or hauling cam. The potential force of the rope-rescue system must not exceed the manufacturer's rated strength of the device. Refer to the NFPA 1983 standard for minimum breaking strengths. Components of the ascender may include: 1. Shell. 2. Cam (may be free running or spring loaded). 3. Pin. Ascender Figure 10 Section 306.003 Page 16 of 63 Care and Maintenance A small file or emery cloth can be used to round any burrs or sharp edges. The ascender should be inspected for worn cam teeth, egg-shaped or cracked pinholes, and worn cord or chain-holding pin and cam to sleeve. It should be removed from service if the sleeve or cam are cracked, when the sleeve is deformed, if the pinhole is worn enough to allow the pin to slip out, or if it has been dropped from waist height. Cautions Ensure the pin is through both sides of the sleeve and locked before use. Do not use as a brake cam. Some tests have shown when an ascender is used as a braking cam and is subjected to a significant shock load, the rope it is connected to has occasionally parted. Edge Protection Edge protection is used to protect rope and webbing from abrasion and sharp edges. There are several types of edge protection on the market such as edge rollers, roof rollers, and edge guards. Edge Roller Edge rollers are constructed of an aluminum frame and rollers. The frames may be connected together in series to provide protection on multiple sides. (Figure 11) Care and Maintenance A small file or emery cloth can be used to Edge Rollers round any burrs or sharp edges. The Figure 11 edge roller should be inspected for wear on the rope contact points, tightness of any nuts and/or bolts, and moving parts should move smoothly. It should be removed from service if the rollers are stuck or damaged, or if the frame is damaged. Section 306.003 Page 17 of 63 Edge Guard Edge guards may be constructed of canvas, rigid plastic, or fire hose. (Figure 12) Care and Maintenance They must be kept clean by wiping or rinsing with water, and they should be inspected for excessive wear. Edge Guard Figure 12 Anchor Plates Anchor plates are used to gather equipment. They are stamped from sheet aluminum (not cast) or stainless steel. (Figure 13) Care and Maintenance Clean with a damp cloth. Do not drop. Inspect for cracks, deformation, and burrs. Remove from service if cracked, deformed, or dropped from a significant height (waist high). Burrs can be removed with emery cloth of file. Anchor Plate Figure 13 RESCUE KNOTS Rescue knots are a key link in all rope rescue systems. Members must continually practice and develop knot-tying skills until they can tie knots properly in the dark, when cold or tired. An improperly tied knot or the incorrect knot could result in system failure. Knots should be standardized so everyone on the team can readily identify and safety check a system. Qualities of a Good Rescue Knot There are many knots, but only a few are necessary to perform rope rescue. To be a good knot for rescue, knots should meet certain criteria. 1. 2. 3. 4. 5. Easy to tie. Easy to identify to determine if they are tied correctly. Will not work loose on their own. Minimally reduce rope strength. Relatively easy to untie after loading. Section 306.003 Page 18 of 63 Knots should be untied before storing. Knots left tied will decrease a rope's strength over time. Knot Terminology There are many different names for knots and there is confusion as to what is and is not a knot. In an effort to standardize terminology, this unit will attempt to use the current names for each knot but will list other names by which they are known. (Figure 14) Working End Standing Part The running end of a rope is the part used for work such as hoisting, pulling, or belaying. The working end of a rope (also known as the loose end or bitter end) is used in forming a knot. The standing part of a rope is between the working end and the running end. Running End Parts of a Rope Figure 14 A knot is a rope or webbing, which is intertwined. A bend is two rope or webbing ends connected together. Bight A hitch is a rope or webbing around an object (if the object is removed, the hitch will fall apart). A bight is formed by simply bending the rope back on itself, while keeping the sides parallel. Loop A loop is made by crossing one side of a bight over the standing part so the rope crosses itself. A round turn is made by continuing to cross one side of a loop all the way around to form a circle with the ends of the rope parallel as in a bight. (Figure 15) Round Turn Bight, Loop, Round Turn Figure 15 Section 306.003 Page 19 of 63 Family of Eight Knots The family of eight knots meets most of the criteria for a good rescue knot. These knots are popular in the rescue community because they are: 1. Secure when tied correctly and unlikely to come apart with flexing and bending. 2. Easy to identify and to see if they are tied correctly. 3. Easy to learn. As with any knot, the family of eight knots needs to be dressed and set, which means all the strands should run parallel and lie flat against each strand. This makes the knot stronger and easier to check for safety. "A knot that looks bad probably is bad." Figure 8 Stopper The Figure 8 stopper, also known as the Figure 8 knot, is used as the foundation knot for other knots in the family of eight knots. It is called a stopper because it is used in the end of a rappel line to prevent someone from rappelling off the end of the line. It is also used to keep rope ends from accidentally running through hardware in a system. The foundation for the family of eight knots (Figure 16), the Figure 8 stopper knot. It should look like a number eight when held up by either end. Figure 8 Stopper Figure 16 Section 306.003 Page 20 of 63 Figure 8 on a Bight A Figure 8 on a bight is tied in the same manner as the stopper, but is tied with a bight in the rope to form a loop of rope at one end. This is a secure loop for attaching the rope to anchors, equipment, or rescuers. A tail at least 6 inches in length must be left at the end of the rope. (Figure 17) Figure 8 on a Bight (1) Figure 8 on a Bight (2) Figure 17 Figure 8 Follow Through This knot is used in place of the Figure 8 on a bight when it is not possible to slip the loop over the intended object or clip it in with a carabiner. The Figure 8 follow through allows tying directly into or around an object. A Figure 8 stopper is tied and then the working end of the rope is passed around the object and follows the path made in forming the stopper back through the knot. The key to this knot is to leave enough length on the working end of the rope to pass around the object and complete the knot, leaving a 6-inch tail. The result is the same as the Figure 8 on a bight. (Figure 18) Section 306.003 Page 21 of 63 Figure Eight Follow Through (1) Figure Eight Follow Through (2) Figure 18 Figure 8 Bend The Figure 8 bend is used to join the ends of one rope or the ends of two ropes of the same diameter together. A Figure 8 stopper knot is tied in the working end of the rope and left loose. The other end of the same rope or the working end of the other rope is passed through the Figure 8 stopper following the path used to form the stopper. Six-inch tails are left on the ends of the rope coming out of the knot. (Figure 19) Figure Eight Bend (1) Figure Eight Bend (2) Figure 19 Section 306.003 Page 22 of 63 In-Line Figure 8 The in-line Figure 8 is a directional knot, which can be tied in the middle of a rope for attaching loads or for creating a trucker’s hitch, which is useful for tensioning guy lines when building ladder gins and "A" frames. (Figure 20) In-Line Figure Eight (1) In-Line Figure Eight (2) In-Line Figure Eight (3) Double Overhand Bend The double overhand bend is used to tie two equal diameter rope ends toether. It is the preferred knot for tying prusik loops. It must be tied leaving at least 2-inch tails when tied using prusik cord and 6-inch tails when using webbing. The double overhand bend is also known as a grapevine knot or a double fisherman’s knot. (Figure 21) Double Overhand Bend (1) Double Overhand Bend (2) Double Overhand Bend (3) Figure 21 Section 306.003 Page 23 of 63 Overhand Bend The overhand bend, also known as the water knot, is used for tying the ends of webbing together or to form a continuous loop of webbing. This bend must be tied leaving at least 2-inch tails. After any twists are removed, all four legs are set by pulling on each one to remove any slack. (Figure 22) Overhand Bend (1) Overhand Bend (2) Figure 22 Three-Wrap Prusik Hitch This is the method of attaching prusik loops to rope for hauling prusiks, ratchet prusiks, and braking prusiks. A two-wrap prusik hitch is often used in mountaineering but does not have sufficient holding power for rescue applications. (Figure 23) Three-Wrap Prusik Hitch (1) Three-Wrap Prusik Hitch (2) Three-Wrap Prusik Hitch (3) Figure 23 Section 306.003 Page 24 of 63 Clove Hitch The clove hitch is used to secure the working end of a rope or webbing around an object. Slack is removed from the standing part of the rope by pulling on the working end to cinch up the knot. (Figure 24) Clove Hitch (1) Clove Hitch (2) Figure 24 Two Half Hitches Two half hitches are used to secure the working end of a rope or webbing. They usually follow a knot or round turn around an object. Two half hitches can be formed using the end of the rope or a bight may be formed in the rope to simulate the end. (Figure 25) Figure 25 Section 306.003 Page 25 of 63 Round Turn and Two Half Hitches The round turn and two half hitches are used to secure the end of a length of webbing to an anchor point such as a ladder rung or the frame on a rescue litter. (Figure 26) Round Turn & Two Half Hitches Figure 26 Bowline The bowline is no longer used as a rescue knot because the knot reduces rope strength by a larger degree than the figure of eight family of knots. The bowline is still a very useful knot for lifting tools aloft and attaching tag lines and signal lines to objects. ANCHOR SYSTEMS An anchor (also called an anchor point) is a stationary object capable of supporting the load attached to it. An anchor system is the rope, slings, and hardware used to attach a load to the anchor, including the anchor. Section 306.003 Page 26 of 63 Types of Anchors An anchor can be natural or fabricated. Natural anchors, such as large living trees, large rocks, and root systems, are common in the wilderness environment. When an anchor's stability is questionable, multiple anchors may be needed to create a solid anchor system. When natural anchors do not exist, as is often the case in the urban environment, fabricated anchors need to be created with vehicles or established on or in buildings. They can be built with pickets or can be made by drilling holes and inserting expansion bolts and other devices. Vehicles make good anchors, as long as these strict rules are followed: 1. The vehicle must have solid points to connect to (frames and axles are the most reliable). 2. The engine must be turned off and the key removed from the ignition. 3. The brake must be set and the wheels chocked. 4. Everyone must clearly understand the vehicle cannot be moved during the rescue. Buildings have many potential solid anchors, but care must be taken. Rust, corrosion, or weathered and deteriorating mortar and brickwork may weaken anchor points that look solid. Try to select structural components of the building, such as: 1. 2. 3. 4. Structural beams and columns. Well-established anchors for large machinery and equipment. Solid large-mass portions of the structure. Spanning window and door openings with furniture, timber, or other strong material can create anchors. When buildings are structurally unstable as the result of collapse, it may be necessary to establish ground anchors with pickets. Pickets will be discussed in detail later in this section. Considerations when Selecting Anchors When selecting anchors the following factors must be considered: 1. The purpose of the system that will be attached to the anchor. 2. The direction the pull comes from. A non-directional anchor is one that will withstand a pull from any direction. Section 306.003 Page 27 of 63 A directional anchor is one that will withstand a pull in only one direction. Pay attention to the anchor location in relation to the load and the activity. Methods of Attaching Webbing Slings to an Anchor Girth Hitch A girth hitch or Lark's foot is the least acceptable method of attachment and shall not be used for mainline connection to anchors. A potentially dangerous condition of over stressing the webbing where it crosses itself and bends back can damage the webbing. (Figure 27) The girth hitch should only be utilized in a vertical/horizontal fall arrest, one-person system, (also known as lead climbing) as part of the belay protection. Figure 27 Single-Loop Anchor Single loop is acceptable for single-person loads in special applications, such as ladder slings as long as the material selected is long enough to allow for a shallow angle between the legs. (Figure 28) Figure 28 Section 306.003 Page 28 of 63 Three Bight A three bight is the second best choice of connection if a prettied or presewn sling is used. To avoid serious side loading of carabiners, the critical angle at the point of attachment must be kept well under the 90-degree maximum. (These critical angles will be discussed later.) Some side loading will occur regardless of the angle. (Figure 29) Figure 29 Multi-Loop Anchor (Wrap Three, Pull Two) Multi-loop is the preferred way to attach webbing to any anchor because additional strength is gained with the additional strands of webbing. In the wrap three, pull two multi-loop, a length of webbing is wrapped around the anchor three times and tied with an overhand bend. By grabbing two strands and pulling them tight, one strand cinches down on the anchor to prevent slipping up or down. The overhand bend should be located against a 3-inch or wider anchor on the load side to reduce the force on the knot. This will allow the knot to be untied more easily after loading. (Figure 30) Figure 30 The length of webbing selected needs to be long enough to form an angle no greater than 90 degrees between the two legs to prevent over stressing each individual leg. Tensionless Anchor The tensionless anchor is a quick and easy anchor requiring a minimum amount of equipment. It is also the strongest method of anchoring a rescue line. The tensionless anchor is designed to wrap around a round or oval-shaped anchor. The anchor must be at least four times the diameter of the rope to maintain full strength of the rope. The running end of the rope is wrapped at least four times around an anchor point, such as a tree, in a neat series of wraps. As with all anchor systems, the tensionless anchor should be applied as low on the anchor point as possible. A Figure 8 on a bight is tied in the running end, and a carabiner is snapped into it. The carabiner is then snapped onto the standing part of the rope. Section 306.003 Page 29 of 63 Multi-Point Anchor Systems Two and Three-Point, Load-Sharing Anchors. (Figure 31) 2 Point Load Sharing/Load Shift 105 lbs. 105 lbs. 210 lbs. Directional Shift 210 lbs. 70 lbs. 70 lbs. 70 lbs. 210 lbs. 0 lbs. 0 lbs. 210 lbs. 210 lbs. 3 Point Load Sharing/Load Shift Load Sharing Anchors Figure 31 A system that employs load sharing between multiple anchor points is only desirable in certain situations. As long as each anchor leg is stressed equally, the anchors are sharing some of the load. However, any shift in the direction of the load shifts the entire load onto one anchor. If the reason for using multiple anchors is because one is inadequate, then failure of the anchor system may result if the load shifts to that anchor point. Section 306.003 Page 30 of 63 Self-Adjusting Anchor Systems The self-adjusting anchor system, also known as self-equalizing anchor system, centers the system between two or more anchor points. It allows the load to be distributed to each anchor point by permitting the point of attachment to shift within the anchor as the system is loaded. Caution: Once the full load is on the system, the friction is too great to allow further equal distribution during a load shift. The inability for the system to provide equal distribution on the anchor points could cause an anchor to fail. If one of the anchor points fails, the shift to the remaining anchor points will cause a drop in the system toward the load. If the anchor legs are long, this drop can create a shock load on the remaining anchor points, which may result in their failure. Keeping the adjusting anchor sling legs short (12 inches maximum) reduces this problem. When the anchor points are not close together, tag lines are used to extend them to a collection point where the self-adjusting anchor is attached. This allows the adjusting legs of the system to remain short. (Figure 32) 12” max Two Point Self-Adjusting Anchor 12” max Three Point Self-Adjusting Anchor Figure 32 Section 306.003 Page 31 of 63 Back-Tied Anchor System Pre-tensioned back tying is another method of creating a secure anchor system from a single questionable anchor (similar concept to picket systems). (Figure 33) Wrap 3, Pull 2. Slings are interwoven, tying them together. Wrap 3, Pull 2 3:1 Tensioning system is Tied off with two half hitches. Back Tied Anchor System Back Tied Anchor System Figure 33 Back-tied anchors are the preferred method of creating a secure, multi-point, and directional anchor system. By using this method, a weak anchor point located close to the rescue site can be made solid. The only limitations are the length of the material being used to back tie. Use webbing or rescue rope to connect the anchor to the back-tied anchor with a simple 3:1 mechanical advantage system. (Use carabiners without pulleys to save equipment.) Intertwine the back-tied system with the forward anchor webbing to create an integral system. Tension the 3:1 system and pull the center portion of the back-tied system while under tension to remove remaining slack. Tie off with a couple of half hitches or use a prusik to hold the 3:1 system. Check the back tie(s) a while later for additional stretch, known as creep. This is accomplished by retightening the 3:1 and retying them. Section 306.003 Page 32 of 63 The back-tied anchor should be located directly behind the first anchor, in line with the load; but, if it is not possible, use two back ties in order to balance the direction of pull on the forward anchor. Critical Angle A concern when rigging any anchor system is to avoid creating too wide an angle between the legs of the system. Try to select anchors relatively close together, and use lengths of webbing and rope long enough to avoid creating wide angles. (Figure 34) How Angles Affect Forces on Anchors and Lines 103 lbs. 103 200 lbs. 185 lbs. 90 185 lb. 200 lbs. 140 lbs. 200 lbs. o 120 200 lbs. 140 lbs. 160 60 750 lbs. 750 lbs. Figure 2 Critical Angle Figure 34 The angle between anchor points, known as field angle should never exceed 90 degrees. Angles greater than this critical 90 degrees begin to exert forces on the anchors, which will be greater than the load itself. Anchors and material used to build anchors can easily be over stressed and fail under these forces. A 90-degree angle distributes 92.5 percent of the load to each anchor. A 120-degree angle distributes 100 percent of the load to each anchor. This defeats the entire purpose of constructing multiple point anchors. Section 306.003 Page 33 of 63 Picket Anchor Systems When other anchors are not available, anchors can be constructed using pickets. Picket systems take time to set up and are limited by the stability of the soil they are being driven into. The ideal material to use for pickets is 1-inch diameter rolled steel, which is 4 feet long, pointed at one end, and squared off at the other. It is difficult to find adequate material to use for pickets; therefore, it is recommended rescue teams carry a supply of at least six pickets. (Figure 35) 15 Degrees From Vertical Single Picket Figure 35 Section 306.003 Page 34 of 63 Picket Construction A picket should be driven 2 feet to 15 degree angle 3 feet into the soil (2 feet in stable from vertical soil, up to 3 feet in unstable soil) at a 15-degree angle from vertical away from the intended load. Load Driving additional pickets behind it, 3 feet apart, in line with the intended load and tying them together with lashing material will 36“ reinforce a single picket. Connect the pickets together with a 20-foot length of 1-inch nylon webbing or 1/2-inch (12.7 mm) utility rope between each picket. The lashing between pickets is known as Spanish Windlass. It is connected to the base of the rear picket with a One, One, Picket with Spanish Windlass clove hitch or round turn and two half hitches. Starting at the base of the rear picket, wrap the lashing material to the top of the forward picket with three to six wraps, and tie off with another clove hitch or round turn and two half hitches. Use a picket, wooden stick, or other piece of debris inserted One, One, One, Picket with Spanish Windlass between the wraps to twist the Picket Systems windlass in order to tension the lashing between pickets. Tension Figure 36 only until the forward picket starts to move, then back off one-half turn and secure the device used to twist the windlass by driving one end into the ground. Proper tensioning results in the load being shared by each picket. The load should be connected to the base of the forward picket. (Figure 36) Section 306.003 Page 35 of 63 Picket Capacities The load capacity of a picket is determined using loamy soil of average compactness. Many variables affect the load capacity of pickets. 1. The type of soil is most important. Clay and gravel mixtures have only about 90 percent of the holding power of ordinary soils. The holding power of river clay and sand is only about 50 percent of ordinary soils. 2. The soil's moisture content and compactness. 3. The material used for pickets, the dimensions, and how they are placed. Pickets hold longer under a gradual pull than if they are exposed to a sudden shock force. A single picket can hold up to 700 lbf. A 1-1-1 combination picket or three pickets in line and lashed together will hold about 1,800 lbf. A 3-2-1 combination can hold as much as 4,000 lbf. The latter is built by driving three pickets and securing them together as a bundle. This becomes the primary anchor point. Two pickets are driven together and tied into a bundle behind the three. One picket is driven behind those, and all are lashed together with a Spanish Windlass system. (Figure 37) Three, Two, One, Picket with Spanish Windlass Figure 37 RESCUE HARNESSES To perform as a professional rescuer, a commercial rescue harness is necessary. The Class II rescue harness provides the rescuer/victim with adequate support while being suspended from a rope rescue system for extended periods. Some seat harnesses formed from 1-inch webbing have been known to cause injury to rescuers when suspended for extended periods. Section 306.003 Page 36 of 63 Chest Harness The chest harness is made from a 12-foot or 15-foot length of webbing, depending on the size of the rescue victim who is wearing the harness. The chest harness is necessary for all rescuers and victims who are raised or lowered on a rope rescue system. The chest harness is not designed to be used alone; it is to be used with a seat harness. The harness will keep the rescuer/victim from inverting while being suspended from a rope rescue system. The harness will also distribute the force over a greater portion of the body during a fall when the belay catches the load. In a low-angle rescue situation, the chest harness is not necessary since the rescuers do not leave the ground. Instructions 1. Fold webbing in half and tie an overhand in it. 2. Place webbing over left shoulder so the overhand (bight) rests on the left side of chest. (Figure 38) Figure 38 Section 306.003 Page 37 of 63 3. Take the end of webbing in front of you and wrap it around body from the left to right (under left arm) so it crosses over the webbing running down the back (Figure 39) and ends up back in front at the bight made in step one and tie two overhand safety knots. (Figure 40) Figure 39 Figure 40 4. Grasp the webbing that is behind you and bring it up over right shoulder (Figure 39) and through the original bight made in step one, tie two over hand safety knots. (Figure 41) To connect the harness, capture both sides of the original bight with carabiner, not just through one side. Figure 41 Section 306.003 Page 38 of 63 Hasty Harness The hasty harness is a pelvic harness made from a 12-foot or 15-foot length of webbing. The hasty harness is only to be used as a quick method of attaching a victim or rescuer to a rope rescue system for a rapid rescue. It should not be used as a primary method of packaging a rescuer/victim because of its limited means of security. Instructions 1. Take the selected length of webbing and tie a water knot in it, connecting the two ends. 2. Place the large loop of webbing behind you and hold the water knot at the small of back. (Figure 42) 3. While wrapping the loop around waist, reach between legs from the front and grasp each side of the webbing loop behind you. (Figure 43) Figure 42 Figure 43 4. Grab the webbing with each hand and pull a bight through the webbing your arms are under (in front of you). (Figure 43) As you pull on the two bights, they should form a large Lark’s foot around your waist and each leg. (Figure 44) 5. A carabiner should be attached to both bights (Figure 45) and will provide the attachment point for the lowering/hauling system. Section 306.003 Page 39 of 63 Figure 44 Figure 45 THE RESCUE LITTER The rescue litter, or Stokes basket as it is often referred to, has been the standard for victim removal over rough terrain. It is designed for lifting and lowering the victim with a rigging system or for being hand carried. This device is not used by itself for spinal immobilization. However, it may be used with other devices to achieve spinal immobilization. Due to its size, it is not easily used in a confined space or limited access area. This device is bulky and will require at least two rescuers to carry it to the victim, unless it is transported by a rigging system. Steel Frame Rescue Litter Components 1. 2. 3. 4. 5. 6. Main Frame Ribs Skids Inserts Chicken Wire Nylon Mesh Care and Maintenance Rescue litters should be inspected for bends, cracks, or breaks in the main frame, broken welds, and damage to inserts. Normal cleaning can be accomplished by using soap and water. Decontamination shall be done as per Department procedures. Section 306.003 Page 40 of 63 Victim Lashing The victim lashing in a rescue litter consists of a pelvic lash and a chest lash, which is referred to as the interior lash. The interior lash keeps the victim from sliding out of the rescue litter at the head or foot ends. The exterior lash keeps the victim from coming out of the top of the rescue litter. All three lashes should be made with 20foot lengths of webbing. Depending on the size of the victim, different lengths of webbing may be necessary. In order to lessen abrasion to the lashing from other surfaces, do not wrap the main frame. Chest Lash 1. Before beginning the chest lash, the webbing used for the pelvic lash should be placed in the litter. (Figure 46) 2. Lay a 20-foot piece of webbing across the litter with the middle at the point where the victim's crotch will be. 3. Form an 18-inch loop in the middle of a 20-foot piece of webbing and lay it in the litter so the top of the loop is where the top of the victim's head will be. (Figure 46) Figure 46 4. Pass the loop over the victim's head to nipple line. 5. Wrap the webbing ends under each arm and pass through loop at chest. 6. Remove slack ensuring crossed webbing at victim's shoulder blades does not ride up on neck. Section 306.003 Page 41 of 63 7. Tie an overhand knot in the webbing around the loop at the point it passes over the nipples on each side. (Figure 47) Figure 47 Tie a round turn and two half hitches at the ends of the webbing around a rib below the victim's waist where the rib meets the main frame. (Figure 48) Figure 48 Section 306.003 Page 42 of 63 Pelvic Lash 1. Pull midpoint of webbing between legs, up to victim's waist, creating a 6inch triangle. (Figure 49) Figure 49 2. Pass ends of webbing around thighs and through triangle pulling up towards shoulders to remove slack. Section 306.003 Page 43 of 63 3. Tie an overhand knot in the webbing on each side at the point it passes through the triangle. (Figure 50) Figure 50 4. Tie a round turn and two half hitches at the ends of the webbing around a rib near the victim's shoulders where the rib meets the main frame. (Figure 50) Section 306.003 Page 44 of 63 Exterior Lash 1. Place a 20-foot piece of webbing across the victim's legs with the midpoint at or below the knees. 2. Pass the ends of the webbing around the rib at or below the victim's knees on both sides where the rib meets the main frame. 3. DO NOT WRAP THE MAIN FRAME! 4. Cross the webbing and pass the ends of the webbing around the next rib moving towards the head. 5. Repeat this operation until webbing passes around the ribs near the victim's shoulders. 6. Tie a round turn and two half hitches at one end of the webbing around the rib to secure the end. 7. Remove slack by pulling webbing from the secured end toward the free end. 8. Tie a round turn and two half hitches with the free end around the rib to secure the webbing. (Figure 51) Figure 51 Section 306.003 Page 45 of 63 Rescue Litter Rigging The rescue litter can be rigged for horizontal lift, vertical lift, and low angle carry. To rig the rescue litter, a commercial stretcher harness, rope pre-rig, or improvised pre-rig is required to connect the rescue litter to the rope rescue system. The Department employs the rope pre-rig. (Figure 52) Rope Pre-Rig Figure 52 PRE-RIG CONSTRUCTION Rope Pre-Rig (Two Are Required To Rig A Rescue Litter) 1. Tie a Figure 8 on a bight in the middle of a 16-foot rescue rope. 2. Tie a Figure 8 on a bight at the end of each leg of the pre-rig. 3. Attach a prusik loop above each Figure 8 on a bight with a three-wrap hitch. 4. Attach a carabiner to the bight and the prusik loop on each leg of the prerig. Improvised Pre-Rig with Webbing (Two Are Required To Rig A Rescue Litter) 1. Tie a Figure 8 on a bight in the middle of a 20-foot length of webbing. 2. Tie an overhand on a bight 1 foot down from the center knot on each tail. 3. Pull the webbing ends through the same attachment points on the litter as those used for the rope pre-rig. 4. Pass the ends of the webbing through the overhand on a bight and adjust length so that the victim's head is slightly higher than the feet. 5. Tie off the ends of the webbing with two half hitches. Section 306.003 Page 46 of 63 Low Angle The low-angle rescue litter rigging can be rigged for a three- or a four-person carry. The number of litter tenders may depend on the victim's weight or available members. Three-Litter Tenders 1. Rig a litter for vertical raising at the head of the litter. A 5-foot length of webbing is the preferred length for this sling. 2. Attach the Figure 8 on a bight knots in the end of the main and belay lines to an anchor plate or multi-directional ring with a steel carabiner. (Figure 53) Figure 53 3. Attach the sling at the head of the rescue litter to the anchor plate with a steel carabiner. 4. Attach the center Figure 8 on a bight from one half of a pre-rig to the anchor plate. The ends of this half pre-rig are where the front two litter tenders will be attached to the system with carabiners to their pelvic harnesses. One rescuer will be positioned on either side of the litter. The prusiks attached to these tails will allow the tenders to better position themselves along the side of the litter. 5. Untie the middle Figure 8 on a bight in the other half of the pre-rig. This length of rope will secure the