Semper Salus! CERT Disclaimer 3/4/2014. Lamorinda Community Emergency Response Team. Safety is Always the Number One Priority!

Transcription

1 Lamorinda Community Emergency Response Team Rescue Ropes, Anchors and Knots Semper Salus! Safety is Always the Number One Priority! CERT Disclaimer This 2 hour presentation will NOT qualify you to perform Technical Rope Rescue! Do not put a life in jeopardy by exceeding your training. We are here to present a series of knots, anchors and other material to familiarize you with the proper tools for LOW ANGLE emergency use. Practice the knots as often as possible on household chores. 1

2 Rope Rescue Definitions Low angle rope rescue refers to an environment in which the "on-rope" rescuers are predominately supported by the rescuers themselves (feet on the ground) and not the rope rescue system. High angle rope rescue refers to an environment in which the "on-rope" rescuers are predominantly supported by the rope rescue system. Safety Factors Ropes, webbing, carabiners and other hardware have tensile strengths (minimum breaking strength or MBS) rated in pounds or kn. 1 kn = 220 pounds. Safety Factors are used to limit the chance failure. NFPA Life Safety 15:1 NFPA Utility 7:1 Mountain Climbing 10:1 Strength Loss Caused by Knots 2

3 Rope Types - Utility A Utility Rope is one that is used for hauling supplies or securing objects. A Utility Rope must NEVER be used to support the weight of a person. Rope Types - Utility Utility Rope materials: 3

4 Rope Types Life Safety A Life Safety Rope is normally a Static Kernmantle nylon rope. ½ inch, MBS 9,000 lbs. Safety Factor 15:1 Working strength 600 lbs. Static kernmantle (low stretch) Used to support personnel Parallel fiber core prevents stretch Dynamic kernmantle (high stretch) Shock-load absorbing ability Mountain climbing line Twisted or Laid core allows stretch Static ropes are typically manufactured in one color and have a contrasting color as a tracer. Dynamic ropes come in three to four colors. Rope Types Life Safety Kernmantle is constructed with High-strength continuous fiber inner core (kern) Braided outer sheath (mantle) Kern is the load bearing element (about 70%) protected by the mantle Webbing Used for Tying anchors Lashing victims into a litter Tying personal harness Most common 1 inch, spiral weave, tubular, nylon MBS 4,000 lbs. 4

5 Webbing Sold in cut lengths that conform to color code standard followed by most rescue teams throughout North and South America: Green 1.5M 5 Ft Yellow 3.5M 12 Ft Blue 4.5M 15 Ft Orange / Red 6 M 20 Ft 7.5+M Ft To remember the colors in order: Get Your Boots On Webbing Flat Webbing Single layer of fabric Hard to tie into knots MBS 3,000 lbs. for 1 Mainly used for straps and harnesses Tubular Webbing 2 types: Spiral Weave (Shuttle Loom) Edge Stitched (Needle Loom) Easy to tie into knots MBS 4,000 lbs. for 1 Rope and Webbing Care Inspect before and after use Inspect for- Visual damage Loose Mantle Kinks Store away from sunlight, heat and chemicals Wash and air dry 5

6 Rope Use and Limits Do not submit Life Safety Rope to shock loads Do not step on rope, you will grind in dirt Use edge protection on all ropes crossing sharp edges and on dirt slopes Keep a written log on all Life Safety Rope Damaged or worn Life Safety Rope can be decommissioned into Utility Rope with appropriate markings. Anchors An anchor is used to support the complete weight of the victim and the rescuers with all equipment An anchor must be bomb-proof Anchors may be natural or manmade Trees Rocks BFR, a very large rock Trucks Buildings 6

7 Anchors Select anchors that are in line with the pull of the system Consider that the direction of the pull may change with the movement of the load Do not use trailer hitches or tow hooks as anchor points. Use main frames or axles for stable points of attachment. Anchors Picket systems require more resources and time Multi-point anchors can distribute shock load better and offer redundancy if a single anchor fails Redundant anchor points should be as strong as the main anchor point Back-up anchors must have little slack in case of shock loading Anchors Angle between the legs should not exceed 90 Load-distributing anchor systems share the load and provide readjustment if a point fails 7

8 Anchors Wrap 3 Pull 2 with webbing Load is off knot and web is doubled for strength Anchors Load Sharing with Webbing Load divided among 3 anchor points Anchors Tensionless Hitch Minimum 3 wraps, more if surface is smooth Anchor at least 8x diameter of rope Aligns with direction of pull Same strength as rope because no load on knot 8

9 Anchors Picket Anchor System A single picket driven 2 feet into firm soil has a safe working load of approximately 700 lb. A combination picket or three pickets in line and lashed together will hold about 1,800 lb. Anchors Triangle Picket Anchor System 9

10 Names of rope parts A rope has many parts, each with a name To avoid confusion, here are the part names Names of line parts Bight - a bend in the rope that does not cross back across itself. Loop - a bend in the rope that DOES cross itself. Elbow the crossing of the rope Standing end the long end, not the knotted end. Standing part the middle of the rope. Working end the end where the knot is tied Stoppers A knot that stops a rope from exiting a pulley A knot that stops a primary knot from loosening by securing the working end 10

11 Stoppers Overhand Knot Used to back up other knots Stoppers Double Overhand Stopper Knot Reliable, moderately large stopper Stoppers Figure Eight Stopper Knot Used to stop rope travel through a device Basis of the Figure Eight family of knots 11

12 Loops Non slipping loops Slipping loops Attachment points Anchor knots Loops Figure Eight Loop Can be attached to an object with a carabiner Non slipping loop Loops Figure Eight Follow Through Tied around an object Non slipping loop 12

13 Loops Figure Eight on a Bight Can be attached to an object with a carabiner Non slipping loop Loops Double Loop Figure Eight Forms two individual loops Creates more bearing surface for the load More efficient than the normal figure eight loop Loops Directional Figure Eight Loop Forms loop in the middle of a rope Takes strain in one direction only Strain from other direction collapses loop 13

14 Loops Alpine Butterfly Designed to be pulled in any of 3 directions Can be tied mid-line No back ups needed One Side of the Butterfly forms an X or Cross The Other Side has Two Parallel Ropes Loops Bowline Non-slipping loop MUST be backed up Lower efficiency than figure 8 family 14

15 Loops Bowline on a Bight Non-slipping loop Double loops Loops Handcuff Loop Slipping loop Used to secure wrists or ankles of victim Hitches A knot that ties around an object The object may be the standing end of the rope 15

16 Hitches Half Hitch Basic knot Used in multiples, i.e. 2 half-hitches or 3 half-hitches Hitches Clove Hitch Can be tied with webbing also Hitches Girth Hitch or Lark s Foot Basis of the Prusik Hitch Not to be used with webbing in anchor point because it can cut itself 16

17 Hitches Tensionless Hitch Minimum 3 wraps, more if surface is smooth Anchor at least 8x diameter of rope Aligns with direction of pull Same strength as rope because no load on knot Hitches Prusik Hitch Triple wrap in tandem for rescue loads Should slip before failure Hitches Marlinspike Hitch Use to secure the top of a stake for driving 17

18 Hitches Trucker s Hitch Use to attach, then tension rope Can be doubled up Bends For Joining Two Ropes Bends Fisherman s Bend Can be used as back up knot 18

19 Bends Double Fisherman s Bend Suited for ropes of equal diameters Commonly used to tie Prusik Loops Requires no back up knot Parallel Ropes Bends Figure Eight Bend Suited for ropes of equal diameters Bends Sheet or Becket Bend Join ropes of unequal diameters When tied the bight goes in the larger rope 19

20 Utility Knots Square Knot or Reef Knot A binding knot, not a joining bend Used to keep objects together Not to be used with synthetic ropes Not a load bearing knot Very low efficiency Lose over half of rope strength Utility Knots Thieve s Knot Result of improperly tied Reef (Square) Knot Bitter ends on opposite sides It is said that sailors would secure their belongings in a ditty bag using the thief knot, often with the ends hidden. If another sailor went through the bag, the odds were high the thief would tie the bag back using the more common reef knot, revealing the tampering, hence the name. Square Thieves 20

21 Utility Knots Granny Knot Result of improperly tied Reef Knot Loops are over/under Bitter ends on same side Comes loose easily Can jam and be hard to untie Utility Knots Water Knot An overhand follow through Mainly used for webbing Primary use is creating loops of webbing Prusik Loops Use 8mm kernmantle rope on ½ rescue rope Tie with pair of Double or Triple Fisherman s Knots Short is 60 Long is 72 Use different colors for long and short 21

22 Prusik Loops Fist Width Between Prusiks Triple Wrapped Knots off set from apex One to pull, two to haul Practice A Rescue Team that handles rope only once a year can not be proficient in knot tying. Practice Practice Practice Practice Semper Salus! 22

23 Other Resources Animated Knots by Grog TM available as Windows or Mac Desktop App or Mobile App on iphone and Android platforms. Office of the State Fire Marshal. Low Angle Rope Rescue Operational Instructor and Student Manual. Sacramento, CA: State Fire Training, Accessed 21 Feb Credits Original presentation created by Sherry Balon for Rural/Metro Corporation, Division of Training. Made available in the public domain at: Additional material from N.C. Rope Rescue Tech presentation, California Low Angle Rope Rescue Operational Manual and many others Adapted and enhanced for Lamorinda CERT by Duncan Seibert 23