bca TRACKER2 Manual De Instruccions página 9

Special Search Techniques
In most cases, multiple burials are approached as a series of single
burials. However, special techniques might be helpful in "special
cases" if there are several rescuers available, the victims are in very
close proximity, and their beacons cannot be turned off. These tech-
niques are mainly recommended for use by professional guides.
Three-Circle Method: This technique is used in search (SE) mode.
Take three steps away from the found victim (Figure H). With the
searching beacon on the snow surface, walk in a circle of this radius
around the victim, attempting to acquire another signal in SE mode.
If no other signal is acquired, take another three steps back and
repeat up to a maximum of three circles (nine steps). If a new signal
is acquired, complete the search by bracketing. If no other signal is
acquired, return to the point where you abandoned the signal search
and continue the search (in SE mode) from there.
Figure H
When using the three-circle
method, walk around beacon
1 in concentric circles until
you detect the signal of
beacon 2. During the first
circle, keep the searching
v
beacon as close as possible
to the snow surface.
Special Mode: For greater efficiency in "special case" close-
proximity multiple burials, use special (SP) mode. This mode enables
the Tracker to display the distance and direction of signals other
than those of the closest beacon (Figures I, J). It also reduces the
Tracker's search "window" to the center three directional lights,
enabling the searcher to mask out beacon 1 and differentiate it
from beacon 2. SP mode is used to determine approximately what
direction and distance to go to get closer to beacon 2. Once you are
closer, always switch back to SE mode.
To use SP mode, hold the Tracker steady at the lowest possible
distance reading. Switch the Tracker to SP mode, then rotate—do
not sweep—the Tracker slowly until another signal is detected
(beacon 2), most likely with a larger distance reading. If the Tracker
is rotated more than about 40 degrees away from the signal of
beacon 1, that signal will disappear, allowing you to focus on the signal
from beacon 2. However, it is possible to capture more than one signal
in SP mode.
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Special Search Techniques
If no other signal is captured in SP mode and you suspect victims are
nearby, stand up and try again at chest height. If still no other signal is
detected, take three steps back and repeat (or revert to SE mode and
use the three-circle method).
Figure I
In search mode (SE), only the
strongest signal (beacon 1) is
shown. Signals further away
are received (beacon 2), but
not shown in the distance and
direction display.
Once you have located another signal in SP mode, begin to move in
that direction. If the distance consistently decreases, you are going
in the right direction. Travel far enough in SP mode to confirm the
distance is decreasing and which way the signal is trending. If more
than one signal is being displayed and it becomes unclear which one
to pursue, continue in the direction you have been searching. Always
switch back to SE mode when you think you are getting closer to
beacon 2 than beacon 1.
Figure J
In special mode (SP), all signals
are shown, but Tracker2 acts as
a "spotlight" with narrowed vision:
approximately 75 degrees in front
and in back of the searching beacon.
Only the signals within this angle
(beacon 2) are shown. This 75° angle
corresponds to the Tracker's center
three lights.
Always switch back to search mode
(SE) when you're more than halfway
from beacon 1 to beacon 2.
After finding a victim, if no further signals are detected in SP mode,
then continue the search if there are still missing victims. Revert
to search mode and perform a signal search of the remaining
unchecked areas within the debris pile. Resume your signal search at
the point where it was originally abandoned.
For more details on multiple burials, please refer to our website:
www.backcountryaccess.com.
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