Western Canada Mine Rescue Manual Chapter 11 Rope Rescue PDF

Western Canada Mine Rescue Manual Chapter 11 Rope Rescue 11-2 OBJECTIVES The primary objective of mine rescue work is the safe recovery of casualties, often from dangerous and inaccessible places. This will frequently require the use of ropes and harnesses to allow mine rescue workers to reach the i...

Western Canada Mine Rescue Manual Chapter 11 Rope Rescue 11-2 OBJECTIVES The primary objective of mine rescue work is the safe recovery of casualties, often from dangerous and inaccessible places. This will frequently require the use of ropes and harnesses to allow mine rescue workers to reach the injured and to raise or lower them to safety. Upon completion of this chapter, the trainee shall be able to demonstrate competency in:  Rope rescue personal protection equipment  Key concepts and definitions  Ropes, webbing, hardware, and related equipment, and their uses in rescue work  How to tie a number of knots, bends and hitches used in rescue work  How to prepare rescue harnesses and secure a patient to a rescue stretcher  How to set up a safe anchor system  How to build mechanical advantages  How to build safety belays and the radium release hitch Introduction The basic goal of any rescue recovery operation is to remove the casualty from his or her predicament as quickly as possible with maximum safety provided to both the rescue team and the casualty. Rope rescue is a dangerous activity. Safety must be stressed at all times, such as when selecting equipment, techniques, and personnel. Technical rescue is a hazardous activity. Risk management is a result of experience, training, and good personal judgement. The skills and techniques shown in this chapter are for expert use only. It is your responsibility to seek competent, hands-on instruction as well as to obtain quality equipment and to follow safety procedures. 11-3 PERSONAL PROTECTION EQUIPMENT Equipment Gloves: All rescuers handling a moving rope must wear protective gloves. These will provide protection from rope burns and to some degree from pinch points. They should be snug for dexterity and increased gripping ability. Only use gloves made of leather or with thick synthetic palms to resist abrasion. Photo Pliers: Used to free a jammed carabiner. Knife or Suitable Cutting Tool: Used to cut open jammed systems. Must be kept sharp. Rescue Harnesses: Must be commercially manufactured, NFPA certified Class III. The harness style needs to have the capability of providing two separate frontal tie-in points, one at the chest level for belay attachment and one at the waist level for front load-bearing attachment. A third dorsal D attachment point for fall arrest is also required. Lanyard: Used as an attachment between the rescue harness and secure anchor point. Must meet minimum relevant health and safety legislation of jurisdiction. All safety precautions must be in place before freeing a jammed system by cutting. 11-4 ROPE AND WEBBING Rope Design and Construction Rope is used for rescue or recovery work and climbing. Being able to use rope properly is important in both underground and surface mine rescue. Bringing an injured patient out of a stope is no different from raising an accident casualty up over a bench in an open pit mine or over a natural obstacle on the surface. Synthetic Rope Synthetic ropes have replaced natural ropes for mine rescue work. Synthetics are resistant to mildew and rot, and stronger for equivalent diameters. They are resistant to abrasions and easy to handle. Kernmantle Kernmantle rope is rope that is not twisted. Instead, the “kern” or interior core is made of units of nylon fibers. The mantle is then woven around the outside of the nylon fibers. Most rope rescue operations use nylon kernmantle ropes. The nylon core supports as much as 90% of the load’s mass, while the mantle protects the rope. Some kernmantle ropes have a coating on top of the mantle that is designed to protect the rope from water, cuts, and other damage. However, the coatings make ropes slippery and therefore unsuitable for rope rescue. Low-Stretch Ropes (Static Kernmantle - Rescue): Kernmantle rope  Strongest of the common rope types  Thicker sheath, more abrasion resistant  Tend to be stiffer than climbing ropes  Stretches approximately 3–5% with a one-person load or 2% with a 200-lb. load High-Stretch Ropes (Dynamic Kernmantle - Climbing):  Not suitable for rescue operations except where single-person climbing is required  The mantle is thinner than static ropes, susceptible to abrasion and dirt  Stretches approximately 5–9% with a 200-lb. load  Designed for single person load  The high stretch absorbs shock in cases such as a falling lead climber (climbing above anchor points). Lead climbing is beyond the scope of this training manual and program. Site specific training must be provided to rescue personnel who may be required to climb. Rope Attributes Tensile Strength is the ability to withstand force that is applied slowly to the point of failure, e.g., with a weight suspended from a rope. Breaking Strength is the amount of force required to break the rope with a straight pull, such as in a tugof-war where the amount of pull gradually increases. 11-5 Safe Working Load, or load capacity, is the weight or force that can safely be applied to a rope. The maximum safe working load is a percentage of the breaking strength. Safety Factor is the ratio of the rope's breaking strength to its maximum safe working load. The safety factor is meant to account for wear and tear and reduction of integrity under operating conditions. Do not consider the safety factor of a rope as reserve strength to be used for additional capacity. Safe Working Load The safe working load (SWL) for rope uses a factor of ten as a safety margin. It can be calculated by using this formula: 𝑺𝑾𝑳 = 𝑴𝑩𝑺 ÷ 𝟏𝟎 where SWL is the Safe Working Load and MBS is the minimum breaking strength Consult your specific rope manufacturer for breaking strength. At a minimum, ropes used in rescue work should meet the guideline in NFPA 1983 for “General Use”. The ropes must also maintain a 10:1 safety factor. Force: Something that causes or restrains motion. The formula for calculating force is: 𝑭 = 𝑴(𝑨) where F is Force, M is Mass, and A is Acceleration. A Newton (N) is the measurement used to represent the amount of force needed to move one kilogram of mass at the rate of one meter per second squared (1N = 1 kg m/s²). The most commonly used unit of measurement for the forces encountered in rope rescue is the kilonewton (kN, 1 kN = 1,000 N). Classification Rope Diameter Rated Load (Persons) Rated Load (Weight) Minimum Breaking Strength Personal Escape Rope 19/64” (7.5 mm)– 3/8” (9.5 mm) One 300 lb (136 kg) 3,034 lbf (13.5 kN) Light-use Life Safety Rope 3/8” (9.5 mm)–1/2” (12.7 mm) One 300 lb (136 kg) 4,496 lbf (20 kN) General-use Life Safety Rope 1/2” (12.7 mm)– 5/8” (16 mm) Two 600 lb (272 kg) 8,892 lbf (40 kN) Source: NFPA 1983, Standard on Life Safety Rope and Equipment for Emergency Services Always check the manufacturer’s specifications to determine the strength of the rope being used. 11-6 Caring for Rescue Ropes Inspection  Inspect new ropes prior to service and after every use  Examine for damage: o History of impact by an object o Melting o Flattened or soft spots that cannot be worked back into shape o Bulges and other irregularities o Cuts or core showing through the outer sheath o Extreme sheath slippage o Discolouration or any other signs of exposure to contamination Usage         Avoid stepping on ropes. Protect from falling objects such as rocks. Avoid dirt or grit that may work into the core and cause damage not immediately visible. Do not let moving ropes cross against stationary ropes or webbing as friction can cause melting. Use edge protection to prevent abrasions. Avoid twisting or kinking. Use pulley blocks that are four times the width of the rope being used. Do not smoke around ropes and rigging equipment during rescue operations. Storage  Protect from exposure to chemicals, high temperatures, and direct sunlight  Dry, coil, or bag properly after each use  Maintain an inventory and rope service log for each rope in use Cleaning  Wash ropes with a rope washer or by hand with a brush  Ropes can also be cleaned in a washing machine but only if they are properly chained and the washing product is suitable. Retirement  Retire rope if it does not pass inspection or after it has been in service for five years.  Retire rope if experiencing high sheath abrasion, i.e., if more than 50% of the rope appears worn, or 30% of the fibres of the webbing are worn.  Once retired, cut rope into small pieces so that they cannot be used. Cordage There are two basic classes of cordage, each with their own special uses: Prusik and Accessory Cord. Prusik Rope is designed to be flexible enough to grip rope. A rescuer should be able to squeeze cordage together between two fingers.  Used for self-rescue, rope grabs, belaying, and release hitches.  Prusik rope is 8–9 mm in diameter when used for rope rescue systems and must be a minimum of 2 mm smaller than the rope it is being tied to. 11-7 Accessory Cord is any narrow diameter rope made from nylon, polyester, Spectra, Kevlar or combination thereof.  Not pliable enough to be used for prusiks.  Accessory cord used for radium load release hitches and other applications in technical rope rescue is 100% nylon with a diameter of 8–9 mm. Webbing Webbing is primarily used for harnesses and slings. It can be best described as flat rope. Flat Webbing is constructed of a single layer of materials, just like seat belt webbing. Tubular Webbing is used in highangle environments because it is more flexible. You can recognize tubular webbing because it is hollow and forms a tube when two ends are squeezed inward. Tubular webbing is:  Sometimes preferable to rope  Constructed of nylon or polyester  More comfortable than rope against the body for harnesses  Has a wide, flat surface so it can be more abrasion resistant in many rigging applications L-R: Tubular, Flat HARDWARE Rescue teams use a number of pieces of hardware in their operations, including carabiners, brake bars, descending equipment, pulleys, steel O rings, anchor plates, tri-links, stretchers, and more. Proper use and care of the core pieces of hardware is described below. Carabiners are metal connectors that link the elements of a rescue system. The basic parts of a carabiner include the spine, hinge, lock, gate, and latch. Carabiners used in rope rescue:  Must be inspected before and after every use  Must be tested as per manufacturer's specifications Basic Carabiner Shapes Carabiners are manufactured in a variety of shapes. Each shape is designed for specific uses. The strongest design is the D-shaped carabiner. The D-shaped spine is longer than the gate side, and the top and bottom of the carabiner flare toward the spine. This design causes ropes attached to the carabiner to slip into position along the spine, where the carabiner is strongest. Claw Lock Spine Locking Gate Hinge 11-8 Warning: Locking carabiners can come open after being locked. Additional Concerns for Locking Carabiners If a carabiner frequently unlocks without an apparent cause, then it should be retired from service. Carabiners are designed to be locked only to light-finger tightness. In their concern for safety in highangle environments, some people will over-tighten a locking carabiner and then be unable to unlock it. This situation commonly occurs when a person tightens down hard on the seat harness carabiner while someone is hanging in the harness. If a carabiner locking mechanism becomes “frozen” through over-tightening, the following procedure typically releases it: 1. If the carabiner is not already on a seat harness, attach it to one. Have the wearer move to a secure position, such as away from the edge of any drop. 2. Attach the carabiner via a sling to a convenient anchor mode. 3. Reload the carabiner by sitting down with it attached to the anchor point. 4. In many cases, the locking nut can then be easily loosened. 5. If it still cannot be loosened, try tightly wrapping a short piece of webbing around the lock nut to gain leverage. 6. If this does not work, using pliers may be the only remaining option. Care and Maintenance  Do not drop or strike against other objects  Avoid chemical and particulate contamination  To prevent accumulation of grit, do not apply oil excessively All rescue equipment must be maintained and used in accordance with manufacturer’s recommendations. Using Carabiners Properly A carabiner is strongest when loaded along its spine. Improper loading transfers the load to weaker areas of the carabiner. This will dramatically reduce the strength of the attachment. Tri-Links Tri-links are designed to be loaded in three directions. They are very useful for anchoring or rigging situations in which a carabiner would not be suitable due to undesirable side loading. Pulleys Pulleys are used to change the direction of a pull on a rope. Some pulleys are rated for single-person rescue only. The NFPA General Use minimum breaking strength is 36 kN (8,093 lbf). For rope rescue, use the 4:1 pulley-to-rope ratio, meaning that the pulley size (also known as the “tread diameter”) is four times the diameter of the rope. Nut Side plates Nut Bearing Sheave 11-9 Types of Pulleys Single and double sheave pulleys are used primarily for building mechanical advantage systems. Most double sheave pulleys come with a becket. The becket is an anchor point for attaching a carabiner to secure the end of the rope. Prusik Minding Pulleys (PMPs) are designed to prevent the prusik from passing through the pulley. Swivel pulleys with side plates have side plates that can be opened while under load, making them more versatile than regular pulleys. They come in single and double sheave. Knot Passing Pulleys have a large throat that enables knots or bends (that attach two ropes together) to pass through the pulley. This pulley can also be used for directional changes or edge protection. L-R: Single Pulley, Prusik Minding Pulley, Swivel Pulley, Knot-Passing Pulley Descent Devices If given a choice for rope rescue operations, lowering systems are preferred because:  They are simpler  They require less rigging  They use gravity as an advantage  They require fewer personnel to operate Other commercially made devices are approved for rescue systems. Operating this equipment requires specific training. If using these devices, follow all manufacturer’s instructions. Brake bar racks consist of a number of brake bars attached to a rack designed for the purpose of braking. The amount of friction applied to the rope can be adjusted by adding or removing bars and increasing the space between the bars. Brake bar racks:  Have a minimum breaking strength of 10,000 lbs (4,536 kg) Threaded Brake Bar Rack  Should be tested annually  Are tied off with two wraps around the rack and two half hitches around the main load line  Are variable friction devices, some have a thicker second bar or hyper bar, which improve control and help dissipate heat  Use in-line operation, can control two ropes simultaneously. Can have up to six bars and worn out bars can be replaced.  Should be operated as per manufacturer’s recommendations. To avoid falling, make certain to pre-tension the brake rack. Rescuers pre-tension brake racks every time the bar is used. To pretension the brake rack: 1. Establish a plumb point. Hold the load-side knot tight about two inches past the access 11-10 edge and then around the first bar of the brake rack. 2. Tie off the rescuer holding the load side while making sure the load-side rescuer maintains the plumb point. 3. The other rescuer then weaves the rope through the remaining bars and locks the brake rack. 4. Attach the safety belay to the load, followed by the main line. Slowly work the belay system until it is loaded. Steel O-Rings are used for rigging anchor systems, and are also used as a Master Point of Attachment.  They are very strong, with a strength margin of at least 20:1.  They can safely accommodate a main line, safety belay line, and rigging harness.  They have an inside diameter of three inches. Steel O-Ring Anchor Plates for anchor systems make an excellent collection point and allow rescuers to set up their systems quickly and cleanly. Edge/anchor protection prevents damage to the rope and is commonly used when attaching rigging to anchors. There are commercial products available or they can be improvised on-site. Every effort should be made to prevent damage to the rope. Anchor Plates Rescue Stretchers A variety of stretchers are available, but only ones designed for rope rescue should be used. Carry and evacuation stretchers are not designed to handle the same stresses. Most stretchers are either plastic or metal, and some come equipped with head protection and attachment points for carabiners. Read all manufacturer's instructions and specifications when determining which stretchers to use. Stretchers should be inspected before and after every use. Metal: has a metal tubing frame. Some are lined with wire or plastic. This type is very rugged. Flexible plastic: Portable, light, fits through small openings. Plastic: made of high-density polyethylene shell with a metal frame. Works well on dirt, grass and snow surfaces. Two piece: easier to carry to remote locations. Fiberglass/Composite: durable, light weight, not affected by extreme cold. 11-11 KNOTS, BENDS, AND HITCHES Knots are essential components of all rope rescue operations. The knot you use depends on the situation and environment of the rescue. Rescuers must be able to tie the following knots, bends, and hitches in all conditions. When deciding on a knot, consider the following factors:  The knot must have been proven to be safe for its intended use.  The knot must be strong enough for its role in the operation.  It must be easy to tie and untie. All knots reduce the strength of the rope. The knot must not affect the strength of the system beyond the acceptable safety factor. For animations of the following knots, bends, and hitches, please visit http://www.animatedknots.com. Terminology Knot: A connection method used in rope or as in webbing to tie it to itself. Bend: A tie that connects the ends of two ropes or webbing together. Hitch: A tie that attaches a rope or webbing to another object such that if the object were removed the tie would fall apart. Bight: A bight is an open turn formed when a rope is doubled back upon itself making a turn but not crossing over itself. Standing Part: The inactive section of rope during the process of tying a knot. Running End: The end of rope that threads through to complete the knot. Loop: A turn of rope that crosses itself. Tail: The free end of rope that extends from a knot. Safety Knots: Used to prevent fraying and to stop from sliding through a block, hole, or other knot. Name Notes Diagram Overhand Knot Basic safety knot Figure Eight Basic safety knot 11-12 Knots Name Notes Bowline A loop that will not jam, slip, or fail Bowline on the Bight Creates a double loop Figure of Eight on a Bight Creates a loop that forms the main point of attachment Double Figure of Eight Creates two loops that form the main point of attachment Butterfly Knot Creates a loop in the standing part of the rope that provides an attachment point for multidirectional use Diagram 11-13 Bends Name Notes Double Sheetbend Used for tying two ropes of unequal size together Double Fisherman's Used to join two ropes of equal diameter Ring Bend For connecting webbing to webbing Figure of Eight Bend Used to tie two rope ends together end-to-end, in order to extend them. Figure of Eight Follow-Through Used to anchor a rope around an object without the need of other equipment. Diagram 11-14 Hitches Name Notes Clove Hitch Used for securing a rope to a pole or post. It is often used as a starting point in lashing. Timber Hitch Used to hoist or drag timber or pipes Munter Hitch Used for single-person belaying in low-angle situations Prusik Friction hitch used to attach a larger diameter rope without knotting the rope. For hauling and brakes, use a three-wrap prusik. Tensionless Hitch Used for anchoring a rope Diagram Two Round Turns Used to secure rope to a post or with Two Half pipe. Will take heavy strain without Hitches slipping or jamming. Cat’s Paw Used to secure rope to hooks and rings 11-15 HARNESSES Harnesses are designed to protect and hold the user's body. The type of harness used depends on the task to be carried out. In rope rescue, they are most commonly used to raise or lower a casualty. Butterfly Harness (Fig. 11-43) The butterfly harness is used when only a rope is available to safely lower or raise a casualty from one height to another. It is not to be used as a working or rescue harness. Any impairment to the circulation to parts of the casualty’s body can have serious consequences. The rope diameter should be 11mm or greater. Rescuers must also ensure that the duration of suspension is kept as brief as possible. 1. Measure four double arm lengths (approx. 20 feet, 6 m) of rope across the body to provide enough working line and tie an ordinary slip knot to form the first loop for one of the casualty’s legs. 2. Place the loop around the casualty’s right thigh, well up into the crotch. The rescuer’s left hand holds the eye of the slip knot in the center of the casualty’s body just below the chest. 11-16 3. Wrap a second loop around the casualty’s left thigh, well up into the crotch and form a third loop. Push the third loop through the eye that is held secure by the rescuer’s left hand. 4. Place the third loop under the casualty’s left arm and over the right shoulder, then thread back through the eye. Make sure the rope enters through the eye as shown. 5. Continue the line and lay it across the left side of the casualty’s neck. Continue along the casualty’s back and under the right arm and bring it back through the eye on the chest forming the fourth loop at the eye. Note: There will now be an X pattern from the rope on the casualty’s back. 11-17 6. Tighten the eye snugly on all four loops by pulling on the hauling line which closes the eye. Adjust the harness for both tightness and comfort. Secure the eye to the loops with two half hitches to prevent slipping and tightening of the knot on the casualty’s body. 7. Tighten the half hitches to complete the harness. A safety knot can be tied in the harness rope tail or the tail can be connected to a separate rope line. If possible, place padding between the rope and the casualty’s body where there are points of pressure. 11-18 Webbing Harness (Upright) Made from webbing, this harness is for an upright person who requires an easy, quickly made full-body harness. It is to be used for short periods of time only, especially if suspended. There are many variations of this method, including a commercially made ready-to-use type. Start by building the seat portion, and then build the chest portion. Finish by connecting the two together. Avoid placing the knot at locations that will cause pressure points on the wearer’s body. Seat Harness 1. Use a 15 foot length of webbing tied together in a loop with a ring bend. If the fit of the harness is too large, it can be adjusted at the ring bend by lengthening the tails. 2. Hold the webbing at the waist line, hang a bend behind and in between the legs of the wearer. Pull the hanging bend through the legs to the front to meet the two made at waist level. VERSION A: 3. Connect all the bends together with a carabiner. 11-19 VERSION B (Fits smaller people better): 3. Grab the hanging bend that came from beneath the legs, separate, and pass it under each bend created at the waist. Pull these outwards to adjust fit, bring them together in front of the casualty, and attach them with a carabiner. 4. Have the wearer hold the carabiner while checking the fit and then begin building the chest portion. In some cases it is easier to build the chest portion first and let the carabiner hang. When the web seat is ready attach the two portions together to form the full body harness. 11-20 Chest Harness 1. Use a 12-foot length of webbing connected in a loop with a ring bend. If the harness is too large for the wearer, it can be adjusted at the ring bend by lengthening the tails. Avoid placing the knot in such a way that it creates pressure points on the wearer’s body. 2. Twist and hold the webbing so that there is a loop for each arm. Check that there is a crossover of the web on the person’s back. Modifications may be required if physical injuries are aggravated by the webbing. 3. Pull the two arm loops to the front of wearer to snug and adjust the length if required. 11-21 Connect the seat and chest harness together with the carabiner to form the full body harness. Complete the following checks:  Have the wearer lean back slightly while holding the carabiner. The weight should be on the seat portion and it should be comfortable.  The harness should be snug so that it will not slip off during movement.  Tie safety knots on any hanging ring bend tails that could interfere with rigging.  The carabiner must not be side loaded and gate lock must be checked before and after attaching rope rigging systems. 4. If there is a long distance between the seat and chest connection points that prevents the use of a single carabiner to attach together, the following methods can be used as long as both harnesses are securely attached to each other:  Add another carabiner and connect one to the seat and other to the chest harness. To complete connect the carabiners directly to each other.  Add another carabiner. Use a short webbing or prusik cord to connect between chest and seat harness carabiners. 11-22 Webbing Harness This harness is used for casualties who are either unconscious or supine and require a rapid rescue. 1. Use a 24-foot (7.3 m) webbing tied together 2. Lift legs and pull the webbing up through the with a ring bend to form a large loop. Encircle the thighs. casualty that requires rescue. 3. Grab a portion of web lying on the floor by 4. Take the web portion that lays across the chest casualty through the loop end from the legs. area. Pull and place it behind the casualty’s neck. Option: Pull the two new bends to snug the webbing around the wearer or connect them together with a carabiner. Rescuers can now drag or pull the casualty to be rescued like a sled. 11-23 5. Pull on the webbing to snug the harness to the wearer. The casualty can now be dragged or pulled from a hazardous location to a safer area by the rescuers. 6. If the web was placed behind the neck, the rescuers can also lift the casualty off the floor or obstacles by putting webbing straps over their own shoulders. The rescuers can now move together to a safe area in an almost full standing position. For a rapidly applied harness, the webbing and the part behind the head causes minimal discomfort. 11-24 Blanketing a Stretcher There are various methods to blanketing a stretcher but the objectives are the same:  Provide the casualty with warmth for shock or environmental conditions.  Comfort the casualty by ensuring there is nothing that can cause pressure points on the casualty’s body.  Allow a rescuer to quickly access the vital signs and injuries of the casualty.  Keep the blankets from being loose and potentially getting into rigging systems. 1. Lay blankets as shown. Avoid 2. Load casualty in, leave a space 3. Wrap around legs. any bumps that could cause a at least 4” from head to the rail if Keep loose at feet if a rope tiepressure point possible in is to be used. 4. Finish by pulling the upper body blanket over and tucking it in. 11-25 Basket Stretcher Tie-In Basket stretcher tie-in procedures are used to ensure the casualty:  is secured sufficiently to reduce aggravation of injuries for during transport  does not slide around or slip out of basket when transporting over uneven ground  well secured while moving from one height to another  does not move within the basket when it needs to be moved from partial tipping to a full vertical position  is fully secured in the basket when the rescuer cannot accompany them for the duration of a rescue There are many tie-in methods due to the variation of styles and design of rescue basket stretchers. One method may work perfectly on one basket and not well on another. Tie-in procedure may need to be modified due to factors such as:  basket width and length  location and number of support rails and cross members  plastic versions that require a method that does not put pressure directly on the plastic portion which can cause ripping  size and shape of the casualty  orientation of casualty in the basket such as on their side (lateral)  type and location of the injury and access to casualty’s body parts  the speed at which the casualty requires to be moved for safety reasons (danger)  webbing/rope for tie in is too short or too long Commercial tie-in kits are available, ranging from seat belt style to webbing kits designed specifically for certain baskets. Blanketing is required to protect for the casualty from tie in contact points to the body. Padding underneath the casualty is required when long travel times are encountered. Rolled blankets can be used to make up spaces to reduce movement between the feet and the stretcher, casualty’s head and stretcher, or at their sides. Using padding reduces sliding, provides comfort and can protect injuries. The casualty’s arms should be placed under the blanket and at their sides whenever possible to make the tie-in process easier. Items such as oxygen therapy units must be secured in the basket if there is a possibility of them falling out. Care must be taken to protect the casualty’s face from being whipped by the tie-in material. The tie-in must be tight enough to provide the tension needed but not so much that it will cause patient discomfort. If conscious, ask casualty as the tie progresses for any concerns. 11-26 Herringbone Tie-In The herringbone tie-in can be accomplished with either webbing or a rope (use a large diameter such as 11mm to avoid discomfort to the casualty). The common length of a dedicated tie-in web or rope is at least 60 feet (18 meters). If done correctly the herringbone can be easily “unzipped” after undoing the last securing knots, which can be useful if a casualty needs to be removed from basket quickly and transferred to an ambulance cot. 1. Using a dedicated tie in length, thread half of it through the bottom section of the stretcher, below the lowest cross member. Half the tie will be each side of the stretcher. 2. If using a rope, lay the center of the tie in on top of the stretcher rail (1st loop), wrap around the feet with a clove hitch, pull the loop between the feet over the clove hitch. This can also be accomplished by wrapping the casualty’s feet, making a clove hitch then pulling some slack to make the first loop that is then placed from the feet bottom over and between the feet. Twist the loop if it is too long. 3. If using webbing, form bights on each side of stretcher. Pull one through the stretcher and push through the 1st loop at the feet. Repeat with the other side to make a third. Keep tension as the tie in progresses. If there are double rails on the stretcher, it is preferred to thread under the bottom one as this pulls downward for a tighter fit. 11-27 4. Work up the stretcher repeating Step 3 using each cross member in turn. Maintain tightness as it progresses. Avoid placing bight ends over knees, groin, diaphragm (just under rib line) and any injuries. The last bight loop must be well away from throat. 5. When you reach the top cross member, tighten each running end over the casualty’s shoulders making sure they are well padded. Tie off on the stretcher frame with clove hitches. 11-28 6. Check tightness of the whole tie-in starting at feet. Move final clove hitch towards stretcher cross member near casualty’s shoulder or fully trap the knot by tying around both sides of it. Place left over rope or webbing under all to keep from falling out or interfering with rigging systems. Bottom Right: Tiein using webbing. Releasing the herringbone basket stretcher tie-in to let patient out of stretcher: 1. Undo last part of tie-in 2. Pull bends out each side 3. Unwrap feet Example of trapping cross member with a clove hitch: 11-29 Diamond Lashing This method is uses webbing to secure a casualty in a stretcher. It takes longer to remove from a stretcher than the herringbone method. 1. Start with an 18 m (60 ft) length of webbing (minimum diameter 25 mm). Fold in half and wrap around the centre of the top rung on the foot end of the stretcher. 2. Looking from the bottom of the stretcher, with the right tail go around the outside of the left foot and continue along the top of both feet to the opposite (right) foot, then go around and up through the middle. This tail will continue through to the left side when looking from the foot end of the stretcher. START HERE 11-30 3. Looking from the bottom of the stretcher, go around the outside of the right foot with the other web tail and continue along the top of both feet to the opposite (left) foot. Go around and up through the middle. This tail will continue through to the left side when looking from the foot end of the stretcher. Start Here 4. Both web tails will continue up to the opposite sides to the first rung on the stretcher incorporating the first post. 11-31 5. Continue to crisscross up the patient to the opposite sides of the stretcher creating diamonds across the body incorporating the posts. Always use the bottom rung. 6. The last cross should be across the chest area and over the shoulders to hold them down. 11-32 7. Continue to the head of the stretcher tying a clove hitch on the top rung, making sure to incorporate the post. 8. Repeat the same with the opposite side. 11-33 9. Secure the loose ends OPTION: Follow down the two sides tying half hitches. 10. When done the patient should be secured to the stretcher with no excessive slack in the webbing and patient should not be choked with the last cross on the chest. To test the system, lift the head end of the stretcher up to vertical, the patient should not drop within the lashing. 11-34 Furley Stretcher Tie-In This tie-in securely lashes a casualty to a furley stretcher. Stretcher Bridle Examples Typical stretcher attachment tied with webbing Attachment that works well for plastic baskets. The web tails can be used to secure an inner support piece such as a spine board. Example of a commercially manufactured bridle Commercially available stretcher attachments 11-35 ANCHORS High forces are often encountered during rope rescue operations. Anchors that are solid and unmovable relative to the load being applied (“bombproof”) are needed to connect the systems. Because it is often difficult to assess the strength of an anchor, rescuers should be incorporating two or more anchors into the system whenever possible. Anchor Leverage: To reduce leverage on a vertical anchor, secure the anchor attachment close to the ground. Minimizing the effects of leverage will maximize the strength of the anchor. Critical Angle: Sometimes, anchors will not be in line with the rescue. In these instances it might be necessary to build a bridle anchor from two anchor points. These angles will create vector forces on the chosen anchors. It is imperative mine rescuers understand these forces. Fig. 11-1: Different angles and their respective vector forces 11-36 Anchors need to be examined by the team prior to attaching webbing or rope for:  Location  Strength  Direction the load will be travelling  Stability  Sharp edges  Abrasive surfaces  Contaminants  Hot surfaces  Whether to use high or low anchor points  Whether there is enough space to operate safely Natural Anchors Trees are the most common anchors used by rescuers, but even large trees might not be suitable. When selecting a tree to use as an anchor:  Use large, healthy, and living trees.  Make sure the tree is well rooted and doesn’t rock.  Use a tree with a diameter of more than 25 cm (10 in) if possible.  Check the bottom of the tree where webbing or rope will be attached for things that might damage the anchoring material.  Make sure the roots are not damaged and soil is undisturbed. Rocky outcrops and boulders can provide a very strong anchor. When selecting rocky outcrops and boulders:  Make sure they are large and stable enough for the load weight of the rope system.  Make sure they are not fractured and shaped so that the web or rope won't slip up and off.  Avoid sharp edges if possible. If that is not possible, add padding to the edges to protect the anchor system.  Find level, stable ground not that does not slope downwards toward an edge.  Avoid boulders sitting on a bed of smaller rocks as they can be moved with little force. Structural Anchors Man-made structures can also be used as anchors. Examples of good structural anchors include:  Reinforced concrete columns  Steel I-beams larger than 15 cm (6 in) wide  Engineered anchor points such as window washer fall protection  Large brickworks Examples of bad structural anchors include:  Large pipes that are suspended primarily to support just their own weight  Chimneys made from brick and mortar that are not made from vertically reinforced concrete.  Surfaces with sharp edges that can damage attachment materials  Structures or machinery capable of moving under load  Unsound railings, ductwork, facades (face of building) or decorations  Rusty moving anchor points 11-37 Vehicular Anchor Vehicles can be used if there are no suitable natural or structural anchors nearby. When selecting a vehicle:  Use the largest and heaviest vehicle available.  Park the vehicle at 90 degrees to the load direction if possible.  Use a rescue vehicle with a dedicated anchor attachment point. Make sure the wheels are chocked and the emergency lights are on.  Park the vehicle on a firm surface. Try to avoid wet or icy ground and loose gravel.  Do not use bumpers, as they might be weak or have sharp edges.  Do not use open toe hooks and trailer hitches. Instead, anchor to the vehicle frame.  Remove keys and engage the park brake.  Place a guard, sign or barricade around the vehicle. Underground Anchors An anchor will depend on many factors including the mining methods used, the type of ground support, competency of the ground in the area and access to rock drills.  For many rescue operations the quickest way to establish an anchor is to use a piece of mobile equipment. Refer to vehicle anchor points for details.  In mines with threaded resin rebar or dywidag bolts, a D-nut can be used as an effective anchor. These simply attach to the end of the bolts, and very easily create multiple anchor points for a rescue operation.  Floor pins can be used in production stopes with pre-drilled production holes in the floor. Floor pins can be manufactured onsite following an engineered design for the given load requirements. The floor pin is inserted into the pre-drilled hole and connections are made directly on the floor pin.  When you have access to rock drills, you can drill holes to insert pins of cold rolled steel to create anchors. This type of anchor requires pre-planning as the correct angle for the hole has to be determined. Consideration of the competency of the rock is very important. Setting this up can take a lot of time to complete as part of a rescue operation.  Mines that use split sets (friction bolts) as part of their ground support plans can use commercially manufactured anchors. Most are designed as fall protection anchor points which are rated for 5,000 lbf (22 kN).  When establishing anchor points in underground environments, in many cases there are severe space limitations. For all underground anchors, establish the integrity and structure of the ground in which the anchor will be installed. Winter Anchors Winter anchors are used in locations with lots of snow and ice. These anchors are site-specific, and require additional training beyond the scope of this manual. Anchor Attachments Various methods exist for creating an anchor attachment point that connects to rope rigging systems. This is accomplished by wrapping webbing, ropes or using commercially made equipment such as rated wire slings or anchor straps. When using two or more rope systems, each system must be connected to an independent attachment point unless using an O-ring or multi-plate, as these can accommodate multiple attachments. Rated wire sling 11-38 There may be cases where there is only a single bombproof anchor to use. When this happens, separate attachment points must be put in place. (Example: Two independent webbing wraps with their own separate connection points. Another method is to use a rated manufactured multi-anchor point plate.) Anchor attachment points can be extended from the bombproof anchor to a more favourable location for rigging. An example of this is adding an extension and making the anchor attachment point more accessible for rescuers working around the edge of a fall area. The rescuers can then connect their harness in the extended anchor point for fall protection or fall restraint. Rope Anchor Attachments Figure 8 follow through with a Figure 8 on a Bight: Requires three feet of rope plus length needed to wrap around anchor. The Figure 8 on a Bight is the working end. Tensionless hitch: Used on cylinder shaped anchors. Rope is wrapped three or more times. The anchor should be at least 10 times the rope’s diameter. Use a figure of eight on a bight with a carabiner or a figure eight follow through to secure the loose end of the rope. Simple Slung (Single Loop) Wrap a single strand of webbing around an anchor and join the ends with a ring bend. The ring bend will be extremely difficult to untie once loaded. When the internal angle of the sling legs is less than 90°, it can bear forces as high as 22 kN, which is only suitable for a single person load Basket Hitch Keep the angle between the legs to less than 45°. Any greater angle may result in the carabiner being side-loaded. Not recommend for use where the direction of pull is changing because the legs of the hitch will not load evenly. This will significantly reduce its strength. It is suitable for a two-person or rescue-size load. Wrap-3-Pull-2 Wrap-3-Pull-2 is an anchor attachment that can be tied with webbing. Very little strength is lost when tied properly with the tied ends of the webbing facing the load and against the anchor. Advantages   Tying 1. 2. 3. 4. Allows carabiner to slide around equalize to avoid side loading. When tensioned, it cinches on to the tree to allow secure placement of high-point directional pulleys. Wrap three times around the anchor point. Tie the long leg with an overhand trace back with the short leg to create a ring bend. Position load side against the anchor point. Pull the two unknotted loops forward and clip with a carabiner. 11-39 Picket Anchor Systems The picket system is one alternative when no anchors are available in a wilderness area. However, picket systems require a great deal of time to prepare for rescue use. Picket System Set-Up 1. The pickets should be 1 in (2.5 cm) diameter and have a length of 4–5 ft (1.2–1.5 m), so that there will be a minimum of 2/3 of the length in the ground. 2. Drive the pickets at an angle of 15 degrees away from the force to be anchored. 3. Connect the pickets in each row together by lashing from the top of the first picket (the one closest to the load with a clove hitch) to the bottom of the next picket three to four times and tie off at base. Continue in this manner until all rows of pickets are lashed together. Use 12.7-mm (1/2 in) rope or webbing approximately 50 ft (15 m) long. 4. Tension the lashings by twisting with a stick four to six turns. Drive this stick into the ground to secure it. 5. Connect the main line by clipping it to the front picket in each row. Multiple anchor points may be required to establish a bombproof anchor. Remember the 10:1 safety factor. 11-40 MECHANICAL ADVANTAGES Mechanical advantages (MA) are built by the use of pulleys and ropes. They are used in rescue operations where a load needs to be lifted. MA pulley systems assist in raising loads by reducing the amount of force needed. For example, a system with a MA of 5:1 requires only a fifth of the force used in a 1:1 system. This MA will require five times more length of rope to be pulled (pulling a rope five metres in a 5:1 pulley system will move the load one metre). Simple systems use ropes attached directly to the load or anchor while the other end of the rope is where to apply the force to move the load.    The MA will always be an odd number when the rope is tied to the load. It will be even when tied to the anchor. An easy method to determine the MA of a simple pulley system to count how many ropes are used in the system. Note: If the final rope is being pulled in the opposite direction of the load travel, it is considered a change of direction and is not counted toward the calculation of the total MA. Make certain that pulleys are aligned and avoid having a rope crossover within the MA causing friction or twisting. Simple systems with a MA of more than 5:1 are more likely to encounter this problem and should be avoided if possible. In these circumstances consider a compound system. 11-41 11-42 Prusiks The prusik grab point (or haul prusik) is the prusik wrap that attaches one MA to another in compound systems and allows one to pull the other. Placed in a Z-Rig, it allows a mechanical advantage to pull on itself (same rope). It is the component that slides for a reset when the pulleys become chocked (too close together). Only one prusik of 8mm or 9mm is used for this operation. A slipping prusik is a good indicator of excessive forces being applied in the system. Some mechanical rope grab devices can cause damage to rope, if using manufacturer procedures must be followed. A ratchet prusik is placed in a haul system to safely hold a load (park brake) while resetting the pulling mechanical advantage in compound and Z-Rig setups. It also acts as a safety on the haul line. For large loads (> one person 300 lbs (136 kg)), use tandem prusiks. Adding a prusik minding pulley allows the prusiks on the haul line to operate the same as a Tandem Prusik Safety Belay when raising a load. There are commercial devices available that provide the same functions of this rigging. Compound systems add a second or more pulley systems to the first pulley system (MA pulling a MA).  To determine the MA of a compound system, multiply the MA of the two systems to determine the total MA. E.g., if one system is 3:1 and the other is 2:1, the total MA is 6:1 (3x2).  If resetting a compound pulley system in which the two systems have different Mas, attach the system with a lower MA to the load and pull this with the higher MA. In some circumstances this rule of thumb will not work for the task at hand.  Ideally separate anchors are used for each MA, spread apart by a metre or more. 11-43 Z-Rig Mechanical Advantage Systems Z-Rigs are used extensively in rope rescue systems. A Z-Rig MA is a 3:1 MA made with a single rope and can easily be changed to a higher MA. The Z-rig gets its name from the shape it forms when constructed. 11-44 Complex Mechanical Advantage Systems A complex MA system involves combining two simple MA systems so that the travelling pulleys collapse together. The main advantage of complex systems is that they need less equipment to accomplish a larger MA. 11-45 Change of Direction A change of direction (COD) within a MA is where the pulling force on the rope end is traveling in the opposite direction of the load travel. Example: Pulling downwards on a MA while the load is traveling upwards. In some rope rigging situations, a COD pulley on a separate bombproof anchor might be required. (If the distance between a highpoint COD and the ground creates a drop high enough to cause harm, then the rigging should be run at ground level.) Examples of when to use a COD:  Structural situations where a COD is needed because of limited space to rig  Situations where the main anchor point causes the haul line to not align with the load  For embankment-type rescues where MA hauling and reset distances are limited  Using building support beams as High Directional Anchor (HDA)  Rigging for a cliff or severe edge where a high point is needed, such as on an A frame. 11-46 Large Mechanical Advantage Systems Most rescues can be accomplished with a 6:1 pulley system. 8:1 and 9:1 systems are generally not recommended because of the amount of rope and space required. They also have less “feel” for the load being pulled, leading to too much force being exerted and potentially damaging the system. Safe working loads of rigging equipment must be considered in terms of force applied by these larger MAs. Rescuer Pulling Force The average rescuer can pull with a maximum force of 23 kg (55 lbs). Before using a pulley system, calculate roughly how much force will be exerted by the rescuers and the MA. A prusik will slip at around 500 kg (1100 lbs). Rescuers need to do a system check and re-examine the load weight including the pulling forces being applied when this occurs. BELAYS Belaying is used to protect a person or load from falling. Some methods are designed for light loads, such as a single person. For heavier loads, rescuers use a safety belay system. Munter Belay techniques can be used for a single person safety line on low-angle consolidated slope. The advantage is quick setup in situations where a critical casualty requires immediate first aid. 11-47 Munter belay techniques are not to be used for any technical rescue operations, such as highstructural or cliff rescues, in which a serious fall could occur. These belay methods do not pass the Whistle Test: If, in theory, at any point a whistle were blown that signals all personnel to stop and remove their hands from the system, nothing catastrophic will occur to the live load. Safety Belay Systems Main rope rescue lines can fail due to equipment failure, human error or environmental conditions. The best practice for mine rescue rope rigging is the use of a second independent rope system as a back-up when lowering or raising loads. Functions of a safety belay system:  Catches the load of the main line if it fails without an operator to engage it. Normally the safety belay system should never come under tension unless there has been a failure. (Note: The use of two-line systems with each line acting as both load and safety belay are used in some rescue operations. This technique requires specific training and is not included in this manual.)  Must be able to survive the event sufficiently undamaged and allow load to move up or down.  The Maximum Arrest Force (MAF) must not cause injury to the rescuer or casualty, nor may it cause a system failure such as pulling out an anchor or cutting the rope on an edge.  The stopping distance must be short enough to prevent the load from hitting obstacles.  Must work in any environment.  Rescuers must be able to operate the load under tension after it has been engaged with a loadreleasing hitch. A variety of belaying equipment is commercially available. If any equipment used is not mentioned in this manual, please follow the manufacturer’s recommendations to avoid misuse. Belay Operation 1. The Prusiks should be held together in one hand in a thumbless grip (belay hand), to facilitate releasing. The thumb does not wrap around the Prusiks. 2. The hand should be held thumb up and with the opening towards the load by twisting the wrist. This wrist-twisting allows the belayer to monitor the amount of slack in the belay rope so that it can be kept to a minimum without the Prusiks accidentally grabbing. It also positions the Prusiks 90° to the direction of the belay line which aids in their ability to grab. 3. The second hand is used to pull the belay rope up through the Prusiks held in the belay hand. 4. Make sure the Prusiks remain snug on the rope through the operation. 11-48 5. In the event of a failure of the load system the pull of the belay rope should snap the Prusiks out of the operator’s hands and allow them to grab quickly and without the belayer having to do anything. Radium Release Hitch The radium release hitch is designed for releasing loads on ropes such as jammed safety belay prusiks and passing knots in the main line system during lowers. They are also used when you need to be able to lower a leading-edge directional pulley to allow a load to pass. Use two large locking 'D'-shaped carabiners and a 10-m length of 8-mm cordage. 1. Place two carabiners on the ground with the gates facing right, claws facing the position of function bottom down, top up. 2. Tie a small figure eight-on-a-bight in one end of the cord and clip it into the load-side of the carabiner. 3. Wrap the top carbiner and then (3) back down through the load carabiner, then back up to the anchor carabiner and incorporating a (4–5) Munter hitch on that carabiner on its gate side. 2. 1. 5. 4. 6. 3. 9. 10. 8 7. 11. 13. 12. 4. Complete the Munter hitch wrap around all of the cordage strands (6–7). Pull a long loop through the bight created (8), and snug this up tight against the Munter. 5. Ensure that the Munter hitch is in the release position with the in-feed rope on the gate side of the carabiner. Secure with an overhand safety around the entire stem. (9–13) 11-49 Tandem Prusik Safety Belay The tandem prusik belay system is designed to capture rescue-size loads. It also incorporates a load releasing hitch (Radium Release Hitch). A single prusik will slip if overly loaded and the spacing between the wraps allows them both to work without interfering with each other. Components of a Prusik Safety Belay  A Radium Release Hitch attached to the anchor attachment point. The Munter hitch is on the anchor side  A Prusik Minding Pulley (PMP) attached to the release hitch. Note: Not required for a lowering operation but very beneficial when retrieving, such as when raising rigging.  A short prusik approx. 5 ft (1.5 m) long and a long prusik approx. 6 ft (1.8 m) long attached to load release connection and then both triple prusik wrapped around the belay rope. The shorter prusik is set closer to the anchor with approximately two fingers to a hand-width of space between its wraps and the second longer prusik wraps. Note: These lengths work well for 2-in (5-cm) or 3-in (7.5-cm) PMPs. 11-50 RAPPELLING Rappelling is the act of descending a rope with the use of a descent control device operated by the rescuer. There are many devices that can be used for this but most rescue teams use a “personal” brake bar or micro rack. There are various other commercial devices designed for this application. The descending device is connected to the rescuer’s harness with a locking carabiner. For mine rescue rappelling operations over 30-degree (steep or high) angles, a safety belay line must be connected from a separate bombproof anchor point to the rappelling rescuer’s harness. The belay system must include tandem prusiks or an approved commercial belay device. Rescuers must be trained and competent in using the device and be able to stop part way in the descent and able to either use a tie-off procedure or a locking mechanism in some devices. Dangerous errors include using an inappropriate reeve of the rope on a brake bar and inserting rope in the wrong direction in a commercial descent device. Before Beginning a Rappelling Operation  Completely check anchors, rope systems, attachment points, carabiner locks, rescuers harness and PPE.  Ensure rappel distance does not exceed rope length.  Connect the main line to the waist ‘D’ attachment. The belay is connected to the sternal (chest) or dorsal (back) attachment depending on the situation.  Person assigned to operate and monitor the safety belay line must be ready to provide appropriate slack throughout and remain with that task until the rappel has been completed.  Check that rescuers working near edges are on fall restraint or fall arrest rigging.  Add edge protection to prevent rope damage, look for sharp or loose edge materials such as rocks and building flashings.  Check the surface of the face that the rescuer will travel along for hazards, ice, slippery wet, loose materials, and snags.  Consider rope stretch on initial load on rappel line at transition point (edge).  Review rope angles. If a high anchor point is not available, the rappel person may have to crawl over edge to get set rather than use the “stand and lean back” rappel procedure.  Check that the starting point is not directly over a hazard, casualty, or fellow rescuer.  Avoid creating the potential for swinging by starting too far away from the direct line (vertical fall line) of rappel in relation to the anchor attachment point. 11-51 During Rappelling  Descending too fast can create problems such as high heat from friction or a loss of control by rescuer.  Do not jump from side to side, as this can cause abrasions to the rope.  Rescuers’ leg stance depends on the type and shape of the footing surface. Good balance and avoiding foot slippage is critical. In general, rescuers should attempt to place their feet a small distance apart, approximately the same as shoulder width.  If there is a rescuer on the ground, they can take control of the descent by controlling tension on the rappel rope from the bottom Arriving at the Bottom  Bend knees slightly before stopping. Once down, stand upright.  Disconnect rappel devices from rope. Leaving them on may subject the device to heat damage and there may be another rescuer that will be using this line.  Disconnect from safety belay line.  Notify Captain or rescue officer when off each line. 11-52