No Slide Title
Download
Report
Transcript No Slide Title
Swiftwater
Rescue II
Lesson 1:
Characteristics
of Moving
Water
Powerful
Relentless
Predictable
Site reference
Upstream
River Right
River Center
River Left
Downstream
References
remain the
same even
when the
perspective
is reversed
Water dynamics
two general categories of
moving water...
Laminar flow
Layers of moving water
Helical flow
Circular flow of water along the
bank, forcing water to midstream
Laminar flow
Fastest
Fast
Slow
Slowest
Straight Section
Fastest
Fast
Slow
Slowest
Outside Bend
Helical & Laminar flow
Laminar Flow
Helical Flow
Water dynamics
Water is fastest…
at the surface and midstream
Water slows down…
along banks and bottom
Water is faster…
at the outside of bends and slower
on the inside of bends
Water slows down and deepens…
in front of dams and other
obstructions
Separating fact from
fiction...
Lesson 2:
The Human
Body in Water
Fact...
In still water, the weight of
a body will cause it to
settle in a near vertical
drop to the bottom
In moving water...
Faster
Slower
Since current moves faster at the surface and
slower along the bottom, a body will drop through
the layers of laminar flow as it is transported
downstream and deposited on the bottom.
The distance downstream depends
on the velocity of the laminar flow
Fiction...
A body will be swept
downstream in any current
Fact...
Adult drowning victims
submerged in moving water
tend to resist lateral movement
in currents less than 1.5 mph
Fact...
When a drowning occurs in an area
of white water, the body will probably
continue to move with the current until
it becomes lodged or the current slows
and allows the body to settle
Body type and clothing...
Lighter, less resistant body types will be more
easily transported
Amount of body fat and air trapped in clothing will
contribute to buoyancy
Depending on body type and clothing, some
infants and small children may never sink
Clothing may increase the potential to snag and
hold a victim stationary in a strong current
Clothing usually adds little to the
weight of the victim under water but
may affect buoyancy and drag.
The phenomenon of
body refloat...
Once decomposition begins the process
of gas formation in the victim’s body,
buoyancy can change drastically
Fact...
Unless the victim is snagged or
wedged, gas formation may eventually
allow the body to raise to the surface
where it could be transported
downstream by the faster moving
surface current
Physiology of body
refloat
Time
Temperature
Depth
Victim
considerations...
Victim considerations
Body type
Diet
Clothing
Trauma
(pre and post immersion)
Not all bodies will refloat!
Under certain conditions, a body may
remain snagged, trapped in a strainer,
held in a water hydraulic or become
covered with silt and stay undetected
for years
Lesson 3:
The search of moving
water is at best difficult
and challenging. Such
activities present great
obstacles for swiftwater
rescue teams and often
expose searchers to the
threat of personal injury
or death.
Safety
Considerations
Safe and effective search
operations near moving
water depend on proper...
Preparation
Training
Equipment.
Hazards include...
Water hydraulics
Strainers
(barb wire, tree limbs, log jams, debris)
Slippery, unsure footing
Topography
(access, cliff faces, drop-offs)
Manmade obstructions
(dams, bridges, debris)
Cold water
Associated risks include...
Drowning
Entrapment
Hypothermia
Blunt trauma
Cuts and lacerations
The safety of
all personnel must
always be the highest
priority!
Always consider
the Risk/Benefit
Analysis of every
operation!
The role of search teams is
to facilitate clue location...
Only personnel appropriately trained
in swiftwater rescue should enter the
water to recover any object
Have preplan in place for appropriate
action prior to object location
There is safety in numbers
Never search alone; search teams should
consist of three or more person/teams
Searchers should have knowledge of
self-rescue and victim-rescue techniques
Exercise caution, continually re-evaluate
the Risk/Benefit Analysis and be prepared
to assist teammates in an emergency
Be properly equipped
Shored-based
Personal Protective
Equipment
PFD
with whistle & knife
Environmental
protection
Gloves
and boots
Throwline
Helmet.
bags
Water-based PPE for
swiftwater rescue
Thermal protection
PFD
with knife & whistle
Helmet
Swiftwater rescue
board
Hand & foot
protection
Fins/mask/snorkel
Throwline bags
Swiftwater team equipment
Throwline bags
Line gun
Tag line buoy
Multi-chambered, inflatable boat
Rope rescue equipment and
hardware
Communication equipment
Additional PFDs & helmets
Other specialized
equipment
Search equipment
includes...
Probe device
Binoculars
Polarized sunglasses
Flagging & permanent marker
Rope and climbing equipment
GPS.
Lesson 4:
Scene
Evaluation
The critical stage of search
operations
Scene evaluation...
Begins with the initial call
for assistance but continues
throughout the entire
operational phase of
the search
Start the process early
A systematic and objective size-up
or assessment of the incident is
particularly crucial at the onset of
the search
A good scene evaluation
identifies...
Incident type
Location and access
Time of occurrence
Environmental conditions
Resource needs
Witness identification
Ability to control water volume
The primary operational
objective is to establish a
“Last Seen Point”
Determining the
Last Seen Point (LSP)...
Physical evidence
Witness interviews
Reference objects vs.
reference points
Knowledge &
experience as SWR
scene evaluator
Witness interview
The witness interview is perhaps
the most critical component of a
scene evaluation and is essential
for determining the LSP
Witness
interview
Control and organize
witnesses
Separate and interview
individually
Question thoroughly and
methodically
Don’t ask leading questions
Go slow, stop & listen
Qualify witnesses by order
of importance.
Establish a subject
profile listing
Physical description
Clothing type and colors
Shoe pattern
Equipment or personal items
Intended plans
Experience level, etc.
“Last Known Activity”
In cases involving an unwitnessed
or poorly witnessed drowning,
the last known activity may
provide the only clue to the
location of the body
And most important
Write it down!
Compile all statements, information and
documented clues in a centralized
collection point
Use this material to develop a scene
sketch for future reference
Components of scene sketch:
LSP- Last Seen Point
Location of physical evidence
Location of witnesses
Permanent landmarks used to triangulate
Access points (e.g. dock, boat ramp)
Current speed
Summary
Developing a thorough scene evaluation
and determining an accurate Last Seen
Point may be the most important tasks
you will perform during the initial stage
of any search operation.
Lesson 5:
Establishing
Operational
Objectives
Photo by Lucas Gilman
Search
planning
Is largely driven by information
gathered during scene evaluation
A successful search operation
depends on an accurate
assessment of the situation
Rescue vs. recovery
search operations
The choice of tactics may vary
during a search, especially in
the initial phase
The operational mode will help
drive the tactical considerations
and assist in Risk/Benefit
Analysis
Initial search objectives…
Determine the LSP
Evaluate the current’s capacity to
move objects downstream
Estimate size of search area
Identify resource needs
Identify potential hazards for rescuers
Define/prioritize high probability areas
Ongoing search objectives…
Segment search area as needed
Determine effective search
methods necessary to
thoroughly cover areas
Assign resources according to
skill level
Perform ongoing evaluation
of process
The search should always begin
with an investigation of the
Last Seen Point
Never assume that the body of a
missing victim has floated away until
the LSP has been thoroughly
searched
Review of drowning
characteristics...
Bodies tend to resist current
less than 1.5 mph
The body will generally drop to the
bottom
Current on the surface is greater than
the bottom current
Bodies of adult drowning victims
generally weigh between 7 and 16
pounds in water
Identify all high probability areas and
concentrate search first in sections
where water slows down or where
strainers and other objects may
snag victim
High
probability
areas
include
LSP
Strainers
Boulder sieves
Low head dams
Bridge abutments
Hydraulics
Eddies
Holes
Where water slows down.
Shoreline
Sand bars
River bends
Summary
Understanding water dynamics, body
characteristics in water, safety concerns
and resource capabilities allows rescuers
to determine areas of high probability and
establish search priorities.
Lesson 6:
Search
Tactics
Search tactics may vary
depending on
circumstances of the event
Witnessed incident vs. unwitnessed
vs. general missing persons report
Rescue vs. recovery
Risk vs. benefit.
Initial actions in
rescue mode...
Establish an initial
containment area based on
current speed and time of
incident
Contain and control...
Assign hasty teams to search from
LSP downstream
Post containment teams
downstream at bridges and other
vantage points
Assign additional teams to high
probability areas
Search banks for possible exit
points downstream
Tactical considerations for
every rescue team...
Are site conditions too dangerous
to put anyone in the water?
Are there sufficient resources
available to cover the search area
quickly and effectively?
Is it possible for searchers to
effectively cover the area?
Will more manpower allow greater
coverage in a shorter period of
time?
Ongoing concerns...
As additional resources arrive, stagger
teams throughout search area
Assign teams based on experience level
and search priorities
Establish land-based searchers to assist
swiftwater teams with object retrieval
If available, assign dog teams to work LSP
A slow, careful scan of the
river is necessary. Study any
irregularities in color, shade or
shape of the surface
Study every section from at
least two vantage points
Probe search...
The ideal probe is a
7-foot, 3/4”
aluminum pole
Improvise as
needed to meet the
situation at hand
Tap and “feel” the
bottom with the
pole from the
downstream side
Exercise extreme
caution when working
along the shore!
Search shorelines
including vegetation
along banks.
Search sharp bends or curves in
the river and areas of natural
entanglement or entrapment
using a probe pole
Line searching may be effective where
water is shallow and predictable
Whenever possible,
post an observer as an
overseer and additional
safety personnel
downstream for the inwater search teams
Suggested team assignments
LSP
Team 1
A
Team 2
DP 2...
DP 1
Team 3
Current
Team 4
Team 5
B
Team 7
In-water Teams
Team 6
Team 8
Swiftwater teams work down from LSP
and concentrate on areas of high
probability
Team 9
C
Team 10
Extended search
operations...
Hasty search is followed up by a
controlled, methodical search of the
banks and river hydraulics
Rule out “rest of world”
Identify resource needs
Ongoing scene evaluation
Consider trained SAR dogs.
“Don’t just look for a body,
search for clues!”
Tracks
Disturbances in vegetation
Articles of clothing
Equipment
Perceptions & expectations...
The body may blend into
the color & textures of the
surrounding environment
Flesh tones tend to blend
with white water
Skin color may appear
very white to luminous
Floating debris, strainers and overhanging
branches can easily hide or camouflage a
body in swiftwater
Conditions often require a slow and
methodical search of the area
While it is necessary to have a good
clothing and physical description of the
victim, be aware that clothing and jewelry
are often stripped away in the forces of
moving water and the body
may be nude
Once the body is located
Mark it…
identify location with flagging,
GPS, etc.
Secure it...
with rope if safe to do so
Stay with it...
remain with victim and monitor until
recovery team arrives
If there are suspicious
circumstances surrounding
the incident, take special
precautions so as not to
destroy evidence
Photograph and record body
position, obvious trauma, etc.
Bag hands and feet
Considerations for
family & media...
Have a preplan for action in place
before the victim is found
Assign a team member or “trained”
victim’s advocate to the family
Assign a team member or PIO as
representative
Quietly notify team and
command staff
Trauma often
associated with moving
water fatalities...
Whenever possible, have the family
escorted from the scene before the
victim is removed from the water
Encourage the family to wait until the
body is at the morgue or hospital
before viewing their loved one
Consider the need for CISD
If victim is not located...
Gas formation may occur days, weeks or
months later and body refloat could move
the victim outside the initial containment
area. As a result, continual monitoring of
the area over an extended period may be
necessary.