Originally Posted by http://www.biglines.com/articles_readmore.php?article=1&read=3161
Strategic shoveling:
Over the last decade avalanche transceiver technology has improved dramatically and a range of effective methods for their use has been the focus of recreational avalanche education. Search times have decreased so much that now the majority of time is in most avalanche companion rescues is spent digging once the victim has been located. As a result, the greatest potential for a decrease in
rescue times (and mortality rates) is in the extraction phase. Last winter Bruce Edgerly of Backcountry Access Inc developed a strategy for digging that promises not only to improve rescue times but also excavation quality.
People who have been buried in avalanches generally die of asphyxiation. Thus the key thing to remember is that the point of digging is not just to reach a victim but to provide the victim with an airway. Nearly 50% of avalanche victims are found lying face down and need to be rolled over before they can breathe. In extreme cases the act of digging haphazardly has even caused a
victim’s air pocket to be crushed by the weight of rescuers working directly above. Thus there is a real need for some care and planning to be taken in the excavation process.
Digging with no strategy creates holes in which it is nearly impossible to roll and treat a victim. Digging straight down invariably creates a cone shaped whole from which it becomes increasingly difficult to clear snow the deeper you go.
Strategy:
To prevent this problem clearly define the excavation area before you start digging.
The most effective way to dig is by terracing the downhill side of the hole, with each level getting closer to the victim.
1. Leave the probe in place. The probe should not be perpendicular to the snow’s surface but run vertically strait down to the victim. Probes with depth markings are extremely valuable in seeing how far you still have to dig and in determining the size of your starter hole.
2. Start by digging a starter whole beginning a little above the probe strike and extending 1.5 times the burial depth down the fall line. The width of this hole can be determined by the number of rescuers. If you are alone the hole can be as little as 1.25m wide to ensure adequate working space. If there are more shovelers then the hole can be extend to 2m wide to increase the probability of locating the victims head.
3. Begin digging from a kneeling position - throwing snow to the sides. Dig by chopping blocks and then removing them from the hole.
4. Start digging at the downhill side of your starter hole and work your way up to the level of the probe.
5. Once the sides of the entire starter whole are up to the shovelers waist then start digging a new terrace throwing snow downhill. This downhill end of this new whole should begin about half the way to the probe.
6. Sit on the downhill terrace and and again dig upwards towards the probe.
7. Once the victim has been reached determine the location of the head and focus on revealing the victims face. The key is to establish an airway as quickly as possible.
If there is more than one rescuer, then two should dig side by side. With more than two diggers, people inevitably will get in each others way in the hole. In these situations it is far more efficient for rescuers to rotate between shoveling and resting every couple of minutes.
This technique for digging shows promise for decreasing overall companion rescue times and improving workspace during victim recovery. However as with any avalanche rescue, the key is not needing to get rescued at all.
