MSA- S3M2 Winter Crevasse Rescue Course Physiology of a Glacier: 1 Bergshrund a long transverse crevasse where the glacier separates from a mountain side 2 Nunatak an exposed rock outcrop which a glacier flows around 3 Firn Line The line that separates the accumulation zone form the abalation zone. In summer season there is snow on the glacier above the firn line and none below 4 Transverse Crevasses are the most common crevasse type and they form in a zone of extension where the glacier is accelerating as it moves downslope. These crevasses stretch across the glacier transverse to the flow direction 5 Serac Glacier ice that spills over a cliff or steep bulge causing unstable transverse crevasses which shear off 6 Marginal Crevasses extend downward from the edge of the glacier pointing upglacier. These crevasses form because of the higher speeds of the glacier near its centerline relative to its margin 7 Lateral Moraine are mounds and ridges of debris that have been pushed up by the sides of a glacier during its movement 8 Moats are gaps along the side of a glacier where it separates form the rock 9 Longitundinal Crevasses form parallel to flow where the glacier width is expanding 10 Terminal Moraine mounds and ridges of debris that have been push up the toe of the glacier or when a glacier and when it recedes 11 Radial Crevasses form where the glacier turns due to friction where the outside turn ice moves faster than the inside turn ice 12 Toe The end of the glacier 13 Accumulation Zone is above firn line where snowfall accumulated exceeding melt 14 Ablation Zone is below firn line where snow seasonally melts, evaporates, etc
Physiology of a Glacier: 1 13 3 2 4 6 5 7 9 11 14 8 10 12
MOUNTAIN SKILLS ACADEMY 3-4 Person Crevasse Rescue/Step by Step: Important Knots: Several online videos do a great job to refresh your knot tying skills Figure eight on a bight: Clove- Hitch: Results in a secure multi- directional tie in loop Auto- locks & adjustable Munter- Hitch: Girth- Hitch: Sliding knot with adjustable speed for Used for tying sewn slings onto something belaying/lowering/rappelling Garda- Knot: Munter- Mule: A ratcheting knot To tie off munter knot
Dividing the Rope: details single rope or half rope is acceptable 5+ team members = 50 Meter plus rope, 4 and less team members = 40 Meter rope Dividing the rope; create figure 8 on a bight clip in intervals of 7-12 meters of equal spacing between rope team members. Each member clips into the rope clip in points For two people- middle rope is found by stacking rope ends simultaneously until middle is reached, from the middle take 4 meters of rope each way and tie a figure 8 on a bight tie in knot. Each rope team member takes one of the remaining rope ends in their pack or as body coils If anticipating possible crevasse fall pre- rig system: Put 2 prussic s onto the rope and daisy chain. Tuck into leg loop. Middle rope team members put a prussic on each side of clip in knot All members clip in with either one triple action carabiner or 1 non- locker and 1 locker gates opposed, into the clip in loops Systems Notes: Remember that a prussic and garda are each half systems. Two half systems equals one full system The main rope clipped into a locker with clove- hitch or figure eight on a bight is a full system. An auto- block is a full system Crevasse Rescue: T- slot details Arrest the fall For ski T- slot anchor rope team members farthest from victim hold the fall while closest surface member is freed to dig T- slot anchor Probe the area to be dug out to make sure no crevasse is below Be sure the T- slot will be perfectly perpendicular and centered to the crevasse and victims rope Dig T- slot length of ski s. Wide enough for skis to be put into the slot. Be sure to create a chimney in the middle of the T- slot (perpendicular), starting from the very bottom of the slot and rising towards the surface at a low angle. Remember that quality of snow dictates how deep the T- slot should be. In some cases the snow needs to be packed down and let sit a few minutes to firm up. Be sure not to disturb the front retaining wall of the T- slot Once dug, ski s are strapped together and edges padded. A DL sling is then girth hitched around the skis. Run the sling up the chimney and the end loop is the anchor tie in point Back- fill the hole- Again do not disturb haul side wall Now you are ready to transfer the victims load to a prussic put onto the victims rope and clipped with a figure 8 on a bight with a locker to the anchor. Rescuers move forward to test anchor. Anchor holds? Yes - back up victims main line behind the prussic with clove- hitch/fig8 on a bight to anchor w/locker Now the rescuers are freed from the system and the victims load is onto the anchor
The 10 step Canadian Drop Loop system (CDL): See schematic page Closest (2 nd ) person arrests fall and usually this person becomes the anchor person CDL Step 1: Farthest members hold the weight while closest digs T- slot anchor CDL Step 2: Skis are padded and girth hitched with double length sling CDL Step 3: Anchor person member transfers the load to the T- slot with a prussic on victims rope CDL Step 4: Anchor person backs up the main rope by clipping it behind prussic with a locker and figure eight on a bight to the anchor Farthest members moves up slightly to test anchor If anchor seems solid, other team members then deploy their prussic's (clipped to harness focal point w/locker), remove fig. 8 tie in point and advance towards anchor while bringing up slack with prussic and probing thus guarding their fall potential into another crevasse while on approach to anchor Communicate with victim Radio for help? Clip end of rope into anchor CDL Step 5: 3 rd team member approaches the crevasse lip with prussic while probing. Shovel- prep and pad the lip- secure lip pad with ski pole, ice axe, etc Is there an easy option for victim to walk, ski or climb out of the crevasse? Are you dealing with an un- roped victim? Do you need to rappel into crevasse? Un- roped victim: If victim is un- roped or needs attention the next step is to stabilize the victim Rappel to victim- set up harness & drop loop. If victim is conscious/able, send them drop- loop Rappel into crevasse: From the dynamic side of victim s main line clipped into anchor, put on munter or belay device with prussic back- up (prussic is set in rope ascension mode- tied through harness foot and waist focal points)- rappel down- administer first aid- clip drop loop onto victim and prussic out Prussic out of crevasse: Prussic out using auto block and prussic.
Initiate Crevasse Rescue: Canadian drop loop system CDL Step 6: If victim can help, drop a loop w/locker from surface to victim- ensure they clip in with locking carabiner locked- keep ropes uncrossed and neat. Anchor extension? Set up z- pulley CDL Step 7: Put a ratchet onto anchor (Auto block preferred: Reverso or ATC guide or garda. If using garda it must be backed up by taking up the slack on the original victims rope while they are being hauled. Tip: Clear snow from beneath ratchet and anchor area for a cleaner system Put haul side of drop loop into ratchet- test ratchet CDL Step 8: In front of ratchet, put a hauling prussic onto haul side of drop loop. Tie a haul knot (overhand knot) onto the prussic as close to the prussic barrel as possible- a carabiner is into this haul knot for hauling If using garda, one can also back up garda by tie this hauling prussic directly to the anchor - no need if using auto block CDL Step 9: Clip haul rope from the haul side into the hauling prussic and slide prussic as close to crevasse lip as safely possible. Begin to haul CDL Step 10: Reset prussic and continue. Be sure drop loop runs over lip pad Beware of lip chunks falling on victim when hauling Instruction to Victim to help hauling Reverse raise to a lower: If you need to reverse the system go back to default position; Reverse the auto lock with a munter hitch backup *Be sure to always have either 2 half systems or one full system holding the victim
Crevasse MOUNTAIN SKILLS ACADEMY Canadian Drop Loop & Z- Pulley Schematic: *10 Steps * Do not forget to be clipped into the rope with a prussik as you move forward probing towards the lip. 6 Drop loop w/locking carabiner V V Victim 5 Pad crevasse lip & secure lip pad 8 Prussic with haul knot for hauling. 9 Hauling carabiner clipped to prussic Original strand 3 Load transfer prussic clipped into anchor w/locking carabiner 10 Re- direct haul rope from auto- block and pull here 7 Rope end tied to anchor Ratchet (Garda) 2 A Sling girth- hitched to skis Anchor 4 Original main rope clipped into anchor with/locking carabiner to backup prussic Ski s 1 T- slot hole (prob to ensure no crevasse below!