IMPROVISED RESCUE TECHNIQUES

Transcription

1 Chapter 7 IMPROVISED RESCUE TECHNIQUES The previous chapter covered rescues using the full range of specialist equipment available to an RAF MRT. However, the situation may occur when team members become involved in an incident where some, or all, of that equipment may not be readily available and immediate action is required. Such a situation could occur whilst you are carrying out routine climbing training and an accident occurs nearby. Every situation is unique and will therefore require a unique sequence of actions to solve a particular problem. For this reason team members should be familiar with the various components which can be put together to perform an improvised rescue rather than learning set piece solutions. The ability to think clearly, logically and imaginatively is the key to improvised rescue. It is not intended to cover every technique within this chapter, however, the techniques described will allow a simple crag rescue to be effected without the use of specialised equipment and should serve as an introduction to the many and varied methods of improvised rescue. See Chapter 13 for details of knots used in this Chapter. Improvised Harnesses Both sit harness and chest harnesses can be constructed from the long Superblue tape sling carried by all RAF MRS personnel. Sit Harness. The Dulfer seat is the most commonly used improvised sit harness. Pass the sling behind the back but do not step into it. The knot or sewn joint should be positioned in the middle of the back where it will be out of the way and least uncomfortable. Pull a loop either side of your body and one up between your legs. Clip all three loops together at the front with a large pear-shaped karabiner, which can be further clipped in the waist belt or rope for extra security and to prevent the Dulfer seat from continually falling around your knees. Chest Harness. The simplest and most effective improvised chest harness is the Parisienne Baudrier. Put an arm through the sling, pass it round your back and tie the 2 loops together with a Sheet Bend. It is very important to ensure that you do not pass the end of the sling through the loop that goes over the shoulder. If you do, the resulting knot will be a slip knot and any load will only tighten the sling around the body causing asphyxiation and possible death. The harness should be snug but not tight enough to cause restricted movement. The loop left after tying the knot is used as the connecting link to the sit sling or harness. See Fig

2 FIG:44 Improvised Sit and Chest Harness Alternatively, it is possible to construct a simple allin-one harness using bights of rope and a Thompson Knot as shown in FIG:45a and b. Fig 45a A Thompson Knot tied in the end of the rope 7-2

3 Fig 45b Improvised Harness - Thompson Knot The Thompson knot is tied by taking 2 large loops at the end of the rope, from roughly shoulder height to the ground, thus making 5 strands in all as shown in Fig 45. Take all 5 strands and tie an overhand knot in the middle to form 4 loops, ensuring that the live rope is coming out of the top of the knot. Step into 2 of the loops and pass the other 2 over your head and under each arm. The position of the overhand knot when tied must be adjusted so that it is above the navel. This harness should only be used for lowering. 7-3

4 Escaping from the System IMPROVISED RESCUE TECHNIQUES This is a term used to describe the process by which you remove yourself from the belay system and the end of the rope whilst safeguarding the security of your climbing partner, with the live rope under tension. There are a number of reasons why you might need to carry out this technique, although a typical scenario would be where your climbing partner has been injured, say by a falling rock, and you must escape from the system so as to descend to his position to administer first aid or to leave to summon help. The method described assumes that the different anchor points have been linked to create one central point. The basic method for escaping from the system is shown in Fig 45c. a. Hold the weight on the belay plate and lock it off. b. Attach a French prusik to the live rope; extend it with a sling which is then clipped to the central anchor point. (If the central anchor point cannot be reached, then a further French prusik or Klemheist can be placed on the rope attaching the belayer to the anchor, which is then clipped as shown). c. Push the live rope French prusik down the rope until it is fully extended and under tension, then unlock the belay plate and gradually allow the load to transfer onto the prusik and central anchor point. Tie an Italian Hitch* in the dead rope and attach it to the central anchor point (if you cannot reach the anchor refer to sub-para b). d. Remove the belay plate and take in any slack rope before locking off the Italian Hitch. Carefully releasing the French Prusik on the live rope will transfer the load from the Prusik back on to the main rope. The belayer may now untie from the end of the rope, if necessary, making sure that a knot is tied in the end of his tie-on rope to prevent any likelihood that the Prusik might slip off the free end. The belayer must also ensure that his personal security is not compromised at any time. Note: * Employing an Italian Hitch to attach the rope to the main anchor allows the rope to be released and the load to be easily lowered, if required at a later stage. A Clove hitch may be used instead of an Italian Hitch, although this does remove the flexibility provided by an Italian hitch. 7-4

5 Fig 45c HOISTING There are 2 basic types of hoist used in rescue situations; the assisted hoist and the unassisted hoist. Before undertaking a hoist in a rescue situation you should be absolutely certain that this is what you need to do. If the victim is a dead weight on the end of the rope it may be impossible for one person to hoist efficiently. In any hoist, however, the pulling effort required is reduced if the victim can walk his feet up the rock or ice. Assisted Hoist The assisted hoist is simple and effective providing the victim is not more than one third of the rope s length below the rescuer and is not physically incapacitated. It does not even require you to escape from the system if you are using a belay plate or other similar device. It does however require good communication between rescuer and victim, to ensure that all instructions are clearly understood. First the belay plate is locked off and a French prusik attached to the live rope below the plate. The French prusik is then clipped back into the belay karabiner, making sure that it is not so long as to move out of reach when under load. Take a bight of spare rope, clip a locking karabiner to it and lower or throw this to the victim who clips it to the knot loop or strong point on his harness. Under windy conditions it may be possible to slide the karabiner with its bight of rope down the tensioned rope to the victim. Ensure that there are no twists in the rope. Carefully unlock the belay plate and lower the victims weight onto the French prusik. You are now ready to hoist. The victim should be instructed to pull on the middle rope which is the only one that travels towards him, while the rescuer 7-5

6 pulls up on the third rope. Both the rescuer and the victim pull simultaneously, and if the victim can walk up the crag or the slope it can be a simple matter to hoist him up. The French prusik is held open by the belay plate as the first rope moves through it, and if a rest is needed, the victim can be lowered slightly until his weight is again taken by the French prusik. The prusik also acts as a back-up should the rescuer let go of the haul rope for any reason. See FIG:

7 Fig 46: THE ASSISTED HOIST The victim pulls down on the middle rope which runs down to him and the belayer pulls up on the third rope 7-7

8 Unassisted Hoist Should you find yourself in a position where the victim is unable to offer any assistance, for example, if he is unconscious, or if there is insufficient rope available to perform an assisted hoist, it may be necessary for you to perform an unassisted hoist. These require a good deal of effort from the rescuer and strength plays an important part in the effectiveness and choice of hoist to be set up. Other factors such as load to be lifted, equipment available and the location of the lifting site will also play a part in the decision making. There are a number of ways of hoisting, however, the systems used in improvised rescue do not generally use pulleys and karabiners are used at each turn of the rope. This has the effect of creating friction within the hoisting system which can quickly negate any mechanical advantage gained. In fact, there are so many factors that go against hoisting that it is important to establish that it is really necessary before you begin. Although not strictly necessary, it will often be more efficient if you escape from the belay system before setting up the unassisted hoist. The following assumes that you have already escaped and are now ready to construct the pulley system: With the victim hanging on the rope which is secured to the anchor by a prusik loop and backed up by the main rope, two prusiks are placed on the rope, one as near to the victim as possible and the other as close to the anchor as possible. The prusik used to escape from the system can often double as the lower prusik. The upper prusik must be either a French prusik or a Bachmann and is attached to the anchor as shown in Fig 47. When the back-up knot has been removed, the rope is taken through a karabiner at the anchor which will act as the top pulley, and is then clipped into the lower prusik so that, by pulling on this rope a mechanical advantage of 3:1 is created. When the system is set up, the original prusik can be taken off if it has not been incorporated in the Z pulley, and the victim lifted by pulling on the free rope. As the load rope moves up, the top prusik opens, allowing it to slide around the top pulley. Once the rope has been pulled up as far as possible, the load is again lowered on to the top prusik to allow the lower one to be pushed back down as far as possible and another pull taken. This procedure is repeated as required to hoist the victim to the desired position. If using a Bachmann knot below the top pulley, ensure that the karabiner round which it is tied is larger than the pulley karabiner, to avoid it being pulled through and inverted. Variations on the pulley system can be constructed, using the above method as a basis although it is worth remembering that additional karabiner pulleys will increase the friction within the system. One way of improving the basic system is to attach a prusik and karabiner to the pulling rope to act as an additional pulley. By anchoring the free end and passing the rope through this karabiner, it is possible to achieve a mechanical advantage of 6:1, see Fig

9 Fig 47: Hoist using a Bachmann knot at the anchor karabiner pulley and a simple prusik knot further down the rope It is also possible to perform an unassisted hoist whilst still in the belay system, although this is physically much harder and is generally less efficient. Fig 48 An improved 3:1 hoist where a further 2:1 pulley has been attached to the original haul rope and the free rope end clipped through this pulley. The mechanical advantage has been increased to 6:1 by adding a single pulley to the system 7-9

10 Other hoisting methods such as the Hip Hoist, Hanging Hoist and Yosemite Lift are outside the scope of this publication. They are, however fully described in Fyffe and Peters Handbook of Climbing (see Useful Reading ). Assisted Evacuation - The Crag Snatch Assume that a climber has fallen off and is swinging free on the rope, unable to help himself. You are in such a position that he cannot be lowered to a ledge or the ground, and it is impractical to attempt to hoist him to your location. Using the following method, the rescuer abseils to the climbers position and transfers the climbers weight onto the rescuers own rope, before continuing the abseil to safety. The method described should be regarded as an emergency procedure and not as a routine rescue technique. These are described under Pick-off rescues in Chapter 6. Before embarking on the abseil, the rescuer must set up a system as illustrated in Fig 49, using a descending device (in this case a figure 8), extended from his sit-harness by a sling. This is then backed up by a French prusik auto block, attached to the harness strong point below the abseil device. A second short sling is attached to the descending device, ready to clip in to the victims harness, while a further sling or extension is made ready to clip directly from the rescuers harness strong point to that of the victim. Alternatively this can be achieved by using a 120cm sling and tying 3 overhand knots or clove hitches in it to form a triangle. When all is ready the rescuer abseils to the victim. He will then complete the following series of actions: a. Attach the victim to the descending device using the short sling which is clipped to the victim s harness strong point, ensuring that the French prusik auto block has locked. Should the victim not be wearing a harness, it will be necessary to construct a Dulfer seat. b. Attend to any injuries the victim may have and make him comfortable using an improvised chest-harness (Parisienne Baudrier) where necessary and an additional sling to the upper descending device. c. Attach the short sling or extension from his own harness strong-point to that of the victim. d. After explaining his next actions to the victim and TAKING GREAT CARE not to damage his own rope, cut the victim s rope, allowing the full weight to come on to the rescuer s rope. e. Release the French prusik auto block and continue the descent. It is necessary for the rescuer to decide upon his intended position in relation to the victim before cutting the victim s rope, as once this has been done, it is very difficult to make adjustments. For the same reason, and to avoid frightening both rescuer and victim(!), every effort must be made to prevent the victim from dropping too far before his weight is taken by the short sling and rescuer s rope. 7-10

11 The following guide-lines may be of help when deciding which position will be most comfortable and suitable for both rescuer and victim. a. Vertical or overhanging cliff / unconscious victim - across the rescuers lap or hanging below. However, beware of causing further injury with your feet if the victim is hanging below. b. Slabby terrain / unconscious victim - between the rescuer s legs with the victim s legs pointing out from the crag. c. Any terrain / walking victim - side by side. Fig 49a: The Crag Snatch 7-11

12 Whichever of the possible positions the rescuer decides upon, the method of attachment is basically the same. There is only one important variable to consider, and that is the length of the sling attachment for both the rescuer and the victim to the descending device. For example, if the victim is to be across the rescuer s lap, the victims attachment must be shorter than that of the rescuer. If both are to descend side by side, then they must obviously be of equal length. Wherever possible, the Crag Snatch should be performed using a double rope, to give additional strength and friction. Where this is not possible, and the lack of friction is a concern (eg when the casualty is very large or when using a new rope), assuming that a Figure 8 descender is being used, it is possible to provide increased friction by double wrapping the descender. This is achieved by passing the bight of rope down through the large ring as normal and around the small ring and over the waist of the device. Next, push the bight of rope through the large ring again, between the two strands already there, bringing the centre of the bight back over the waist and finally pulling the strands tight. The Figure 8 is now attached to the harness in the normal way. Quick Counterbalance Abseil / Rescue If you have decided that is beneficial to your casualty/partner to descend the cliff rather than raise them to your belay stance, an effective method of achieving this is by setting up a Counterbalance Abseil. In a multi-pitch situation this has the advantage over a Crag Snatch in that it allows you to retrieve your climbing ropes at the end of each pitch and so carry on down, leaving only the anchor system components behind. Having escaped from the system (described earlier) to the point where the casualty s weight is held by the French prusik clipped into the central anchor, backed up by a Clove hitch or locked-off Italian hitch on the main rope, the following actions are carried out: See Fig 49b. a. Clip a second screw-gate karabiner into the central anchor point and run the climbing rope through it. Remove your belay plate from your tie-on knot loop (taking care not to drop it!) and re-attach it to your harness strong point, extended as for a normal abseil, with a French prusik back-up, so that the anchor is now between you and the casualty. Move up close to the anchor, taking in any slack. b. Untie your rope from your harness and throw the end down the crag, alongside the casualty. Remove the Clove hitch / Italian Hitch and it s karabiner and lean back on the anchor to provide a counterbalance to the casualty s weight. 7-12

13 Fig 49b: Counter Balance Abseil c. Gradually release the prusik on the casualty s rope, so that his weight comes on to your harness (via the anchor). Recover any non-essential equipment from the belay stance, leaving only the anchor system in place. d. Abseil down to the casualty, retrieving any equipment as you go. Once at the casualty administer first aid and improvised chest harness as appropriate. Remember that from this point on, you are counterbalancing the weight of the casualty and must ensure that you do not un-weight the rope at any time. e. Using a short sling or extender, connect the casualty s harness strong point to your own and continue the abseil to the next stance. f. Once at the stance, secure yourself and the casualty, retrieve the rope and continue as required. This method has been described using a single rope. For twin ropes the method is similar, however only one rope should be clipped through the anchor, passing the knot on the way down if necessary. 7-13

14 Multi Person Abseil This technique may be useful in situations where 2 climbers need to descend together from a stance, such as when one is ill or too fatigued to look after himself. Rescuer and casualty are attached to a descending device by slings, usually set up so that the rescuer s is longer than the casualty s, dependant on the situation (a 120cm sling with an Overhand knot on the bight is ideal). A French prusik back-up from the rescuers harness strong point is placed on the rope below the descending device. The abseil proceeds as normal, with the rescuer controlling the rate of descent while the casualty simply walks backwards down the cliff, assisted as necessary by the rescuer. This method may also be used where it is necessary for a number of rescuers to descend a single rope rapidly, although for reasons of safety, no more than 2 people should descend at any one time and single 9mm ropes should not be used for multiperson abseils. Lowering Lowering is a method used to safety protect a person or a group while descending steep ground. It removes the potential problems involved in throwing ropes and repeated individual abseils. Prior to starting it should be determined that the rope will reach safe ground especially if inexperienced people are to be lowered. If the rope will not reach a safe place then an alternative route or multi pitch abseiling tactics should be employed. Ensure the anchor is sound. Connect the belay device directly into anchor, ensuring it can be locked off once lowering has commenced. Coil the rope so the rope going to the person(s) being lowered is on the top of the pile. The person(s) being lowered will then start walking backwards towards the edge under the control of the person lowering (ensuring that no slack is allowed to build up). Continue lowering until safe ground is reached. Note The belayer controls the speed of descent. Using two ropes it is possible to lower two people at once. If using a single rope to lower two people an isolation loop should be used. If necessary the friction may be increased using a karabiner clipped behind the belay device and re-directing the rope through it. When lowering down steep ground with ledges there is a chance that inexperienced people may stop at the ledge, there-by allowing slack to build up in the system. A good brief should be given prior to commencement to avoid this. In addition the rope should be paid out at a steady pace and the person lowering should endeavour to maintain eye-contact with the person(s) being lowered. 7-14

15 Ascending a Fixed Rope In certain situations it may be necessary to ascend a fixed rope. This could be during the rescue of an injured climber, or as a method of self-rescue following a fall where you end up dangling in space. Whatever the reason, with a little practice, it is possible to climb a rope using either loops of cord or, if available, mechanical ascending devices. Experience of both methods will soon show that the use of mechanical devices such as Jammers, Cloggers or Jumars is far more efficient that the use of prusik loops. Such devices may not always be available however and it is wise to be practised in both means. A variety of friction knots may be used for ascending a rope, although the classic prusik knot remains popular. Whichever method is to be employed, the basic technique is the same. A long sling is used for the foot and a shorter one attached to the harness. To increase the margins of safety, the sit harness loop should be attached to the rope above the foot loop. The lengths of the loops will depend on the size and agility of the individual and should be adjusted for comfort and efficiency. The greater the efficiency of your system, the greater the amount of ascent with each straightening of the leg in the foot loop. Movement up the rope is achieved by straightening the leg in the foot loop and moving the sit harness loop up; sitting back on the harness loop and repeating the process as necessary. Try to keep an upright posture at all times and avoid hanging back on the loops, as this is both tiring and inefficient. A chest harness, or Parisienne Baudrier, attached to the rope by a karabiner will help maintain a more upright position. Fig 50: ASCENDING A FIXED ROPE USING PRUSIK LOOPS 7-15

16 In this diagram two tape slings have been attached to the rope using Bachmann knots and a Lark s Foot has been tied in the lower loop to prevent it from slipping off the boot. Note also, that as a safety precaution the rope has been attached to the climber s harness using a Clove Hitch and HMS karabiner. As you ascend, a Clove Hitch is tied and clipped into an HMS karabiner on the strong point of your harness as shown in Fig 50. The knot is adjusted regularly during ascent to create a short dead man s loop as a safety precaution. If you are carrying a large or heavy rucksack on your back, it is wise to remove it and attach it to the rope below for pulling up afterwards, or, alternatively, hang it from a karabiner clipped into the dead mans loop while you climb. This will avoid the weight of the bag pulling you over backwards and will also make it easier to slide the prusik loops or ascending devices up the rope. Note The use of French prusiks to ascend a rope is not recommended, due to their ability to release under load. Improvised Rope Stretchers Although rope stretchers are rarely used, the technique required to make one is knowledge that all trained mountain rescue personnel should have. Practice is essential as a poorly or incorrectly constructed rope stretcher is worse than useless. Improvised rope stretchers should never be used where any spinal injury is suspected. The original Piggott rope stretcher has been extensively modified and the method detailed below is considerably easier to tie and adjust and can be completed in minutes. The Improvised Rope Stretcher - Construction (Refer to diagram at FIG:51) 1. Starting from one end of the rope and leaving enough for a carrying loop (to go over the head and shoulder of a carrier), tie a series of loops with Overhand knots as illustrated. The finished loops should be about one metre in length and should initially be tied next to each other to avoid too-wide spacing once tension is applied (Fig 51.1). Tie sufficient loops to give full support to the casualty (usually when approximately two-thirds of the rope length has been used) and tension the rope to tighten the knots (Fig 51.1a). The spare rope is used to join the ends of the loops to form the other side of the stretcher. 2. Lay the stretcher on the ground and make a Slip knot in the rope on the opposite side of the last loop tied, again leaving enough rope for a carrying loop at the foot of the stretcher (Fig 51.2). 3. Thread the loop through the Slip knot (Fig 51.3a), adjusting the width of the stretcher to fit the casualty, then pull the Slip knot inside out to form a Sheet Bend (Fig 51.3b). The end of the loop should be long enough to tie a Half-Hitch once the stretcher is finished, and may be used as a small handle (Fig 51.3c). Repeat this, until all the loops are tied off. The knots should ideally be about 4 apart at weight bearing parts of the stretcher (where shoulders, head and hips will be). 7-16

17 Apply tension to the stretcher to tighten all knots and prevent slippage. 4. Finally, tie the ends of the rope to form a carrying loop at the head of the stretcher. Always pad the stretcher before loading the patient (Fig 51.4). 7-17

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19 Improvised Techniques - Conclusion IMPROVISED RESCUE TECHNIQUES It should be emphasised again that each situation is unique, and therefore each solution will also be unique. The only way to prepare for such situations is to practice with a variety of equipment and in different locations, whilst always remembering that any practice situation should not be so serious to threaten injury or worse, should the chosen improvised solution not work or prove ineffective. 7-19