Water dynamics at the surface and midstream. Water is fastest… at the surface and midstream. along banks and bottom. Water slows down… along banks and bottom. at the outside of bends and slower on the inside of bends. Water is faster… at the outside of bends and slower on the inside of bends. in front of dams and other obstructions. Water slows down and deepens… in front of dams and other obstructions.
Time for float to travel 100 feet Velocity: measured in feet per second Surface Velocity Throw a floating object (e.g. stick) in the water and record the time it takes to travel 100 feet
Force of moving water Rule of thumb... x 2x 4 Water Velocity x 2 = Water Force x 4 (double the velocity = quadruple the force)
Forces exerted by moving water... The force exerted on an object in water is proportional to the surface area that is exposed to the force. Double velocity, quadruple the force River Rescue, Ohio Department of Natural Resources, 1980
Pillow Swelling on the surface caused by an underwater obstruction Obstruction is usually just beneath the surface Rock or obstruction Pillow
Created by water dropping vertically over an obstruction The larger the drop, the more defined the hole Hole Rock or obstruction
Eddies Caused by obstructions in current that extend above the water’s surface Water flows around obstacle and reverses direction to flow upstream Eddy Rock or obstruction
Standing waves Wave stands in one place as it crashes into shallower water Normally found in chutes, bends in river and downstream Vs Increase in water speed as it descends chute
Upstream & Downstream Vs River right River left Upstream V created by water hitting an object and going around it Upstream V Downstream V Downstream V caused by water flows converging at point of least resistance
Curren t Downstream V
Upstream V Current
Moving water always follows the path of least resistance. This is generally the safest and least obstructed path of travel in laminar flow. “Look for downstream Vs”
Categories of swiftwater Class I Class II Class III Class IV Class V Class VI Few obstructions, very small waves Easy rapids up to 3 feet wide, obvious clear channels High irregular waves, narrow channels, requires scouting Difficult long rapids, turbulent water requires scouting, rescue is difficult Violent long rapids, scouting is mandatory, extremely dangerous rescue Almost impossible to navigate, rescue is almost impossible
Summary Moving water always follows the path of least resistance. Look for downstream Vs. This is generally the safest path to travel in the laminar flow.
Lesson 2 Hazard Awareness
Natural and man-made hazards are an ever present threat to the victim and rescuer! Drowning Entrapment Trauma Hypothermia
Strainers allow water but not solids to pass through
Fence lines create deadly strainers that often go unseen…
Low head dam Backwash Boil Outwash Escape route Cross section of Low Head Dam
Other hazards... Slippery, unsure footing Difficult topography access, cliff faces, drop-offs Environmental conditions weather, cold water Bio-hazards flood waters, runoff from agricultural products Local hazards?.
Summary Know your area and preplan!
Lesson 3 Preplanning & Equipment
Preplanning... …is the key to safe and effective water rescue operations! Preplanning saves time and lives!
Risk/Benefit Always consider the Risk/Benefit Analysis of every operation!
Accident Site Evaluation Preplanning Accident Site Evaluation Low flow Medium flow High flow Flood stage
Map and photograph potential accident sites during low water...
...toprovide insight on what to expect during high water.
Record width, depth, velocity, river characteristics Locate natural and manmade hazards Record access routes, launch sites, high danger areas Determine ability to control flow Accident Site Survey Preplanning Accident Site Survey
Personal Protective Equipment for Shore-Based rescuers... Always wear a PFD (equipped with whistle & knife) in and near the water Wear proper environmental protection Have appropriate foot protection Leather gloves for rope management Helmet (when necessary) Multiple throwline bags.
Thermal protection PFD with knife & whistle Helmet Swiftwater rescue board Hand & foot protection Fins/mask/snorkel Throwline bags PPE for Swiftwater Rescue
Swiftwater team equipment Throwline bags Line gun (w/ hearing & eye protection) Tag line buoy Multi-chambered inflatable boat Rope rescue equipment/hardware Communication equipment Additional PFDs & helmets Other specialized equipment.
SANE Always use the SANE approach to swiftwater rescue! Simple approach S imple approach Adequate backup A dequate backup Never take chances N ever take chances Eliminate the “beat the water” attitude E liminate the “beat the water” attitude
Lesson 4 Fundamental Rescue Techniques
Self-rescue techniques (defensive maneuvers) On your back Face up Horizontal posture Feet downstream Ferry angles Swimming in current (defensive maneuvers) Body positioning... On your back Face up Horizontal posture Feet downstream Ferry angles
Swiftwater maneuvering River left ferry angle
Swiftwater maneuvering River right ferry angle
Self-rescue techniques (aggressive maneuvers) Head first, swim/up and over strainers/hazards Avoiding entrapment (aggressive maneuvers) Body positioning... Head first, swim/up and over strainers/hazards Dangers of foot entrapment in strong current
Victim rescue Scene assessment Safety first Evaluate Risk/Benefit Victim contact make attempt to talk with victim Always choose rescue methods that provide the highest degree of effectiveness while minimizing the risk to the rescuer.
As a rescuer... Never tie yourself (or a victim) to a rope when working in moving water Never tie a line across the river, perpendicular to the flow, in hopes of catching a victim Never enter swiftwater wearing firefighter turnout or bunker gear Remember, specialized ice rescue suits are not designed for swiftwater
Rescue Methods in order of preference... Reach Throw Row Go
“Reach” Method Simple technique used when the victim is close to shore Makes use of any object that can be extended to the victim for them to hold Victim must be able to assist in rescue by holding on to object extended to them Maintains high degree of safety for rescuer
“Throw” Method Throw method is used when distance to victim exceeds ability to use the reach method Method limited by distance and throwing accuracy of the rescuer Victim must be able to assist in rescue by holding on to object thrown to them Still maintains high degree of safety for rescuer
Water rescue throwline bags There is a right way... …and a wrong way.
Water rescue throwline bags Throwline bags are a highly effective tool in swiftwater rescue Easy tool to master but requires some practice Dynamics of throw bag use: stay on shore stay on the move coach victim Terrain considerations/victim access
“Row” Method This method enables rescuers to close the gap between victim and the shore Incorporates use of watercraft and allowing rescuers a safe approach to victim A reach, throw or go rescue can now be attempted
“Go” Method Most dangerous method of victim rescue Requires approach and direct contact with victim in water Last resort when reach and throw methods will not work or the victim is unable to help themselves Places rescuer in greatest danger Decision to “go” requires an accurate assessment of the victim and potential dangers of the situation
The “Go” method is potentially dangerous! Swimming while trying to control a victim is difficult even over short distances Know your own capabilities Have back-up rescuer ready to assist. PFD and thermal protection Helmet Fins Swiftwater rescue board Be prepared with proper equipment PFD and thermal protection Helmet Fins Swiftwater rescue board
Shallow water crossing Single person Multi-person line Multi-person wedge
Lesson 5 Technical Rescue Systems
Swiftwater maneuvering River right ferry angle River left ferry angle
Technical rescue systems Two-line tether Four-line tether High line system Two-boat tether
Technical rescue systems Two-line tether
Four-line tether Technical rescue systems
Proper tag line management Technical rescue systems
High line system
Rescue hand signals...used where verbal communication is not effective Team leader Select good vantage point Use whistle
Rescue hand signals Help-Emergency Also, give 3 long blasts on a whistle and wave a helmet or paddle over your head
Rescue hand signals Direction Point and hold indicating proper direction
Rescue hand signals Stop! Also, blow one long blast on whistle
Rescue hand signals “OK” Signal Touch top of head with a controlled and deliberate motion
Rescue hand signals Lengthen line (slack) Arms moving out from center
Rescue hand signals Shorten line (tension) Fists moving up and down from elbow
Rescue hand signals Near shore Arms moving backward and hold, indicating direction
Rescue hand signals Far shore Arms moving forward and hold, indicating direction
Lesson 6 General Patient Care
Medical considerations Hypothermia Near drowning Trauma C-spine care Cuts and lacerations Broken bones Proper patient handling & transportation
Field management Maintain local standard of care Proper airway management/ ABC’s Prevent further heat loss Proper immobilization Gentle handling Proper packaging and transport.
A special note on hypothermia: Water conducts heat from the body 25 times faster than air of same temperature Hypothermia can occur in water below 91 0 Body core temperature quickly loses heat in cold water and hypothermia can have a rapid onset