Chapter 7: Passenger Vehicle Stabilization Operations Flashcards
Vehicle Stabilization
Providing additional support to key places between a vehicle and the ground or other solid anchor points to prevent unwanted movement.
Good stabilization ____ to prevent ____.
- the area of contact between the vehicle and the ground
* any sudden or unexpected movement of the vehicle.
The initial phase of stabilization
Includes using wedges, wheel chocks, and step chocks.
The secondary phase of stabilization
Includes using struts, chains, straps, and cribbing.
The ongoing phase of stabilization
Includes the reassessment of current stabilization and the application of new stabilization as necessary.
Center of gravity
Point through which all the weight of a vessel and its contents may be considered as concentrated, so that if supported at this point, the vessel would remain in equilibrium in any position.
When most passenger vehicles are empty, the center of gravity is ____
slightly forward of the front door in the center of the vehicle.
Longitudinal axis
(horizontal) Imaginary horizontal line that extends lengthwise from the front to the rear of the vehicle and passes through the center of the passenger compartment.
Vertical axis
Imaginary vertical line that extends from the top of the vehicle to the bottom of the vehicle, stops at the ground, and passes through the center of the passenger compartment.
Lateral axis
Imaginary horizontal line that extends from the outside of the passenger side of the vehicle to the outside of the driver side of the vehicle, and passes through the imaginary center point of the passenger compartment.
What directions will an unstable vehicle move?
- Horizontal - forward or rearward on the longitudinal axis or horizontally along the lateral axis
- Vertical - up or down in relation to the ground while moving along the vertical axis
- Roll - side to side while rotating along the longitudinal axis but remaining horizontal in orientation
- Pitch - up or down on the lateral axis causing the front or rear of the vehicle to rise or fall
- Yaw - twist or turn on the vertical axis and causes the front and rear portions to move in a left or right direction in relation to their original position.
In most cases, responders should attempt to obtain ____ or ____ point stabilization, however, some situations may require more points of contact to effectively achieve the desired level of stabilization.
four or six
Rescuers must make an effort to ensure that any stabilization point does not ____
impede or block potential victim access, egress, or extrication operations.
Most wheel resting vehicles can be stabilized by ____
using cribbing or step chocks strategically located at the strongest or most structurally sound points of the vehicle.
The strongest, most structurally sound points on passenger vehicles are ____
the frame components where the pillars or posts meet the frame.
Rescuers should strive to use ____ components of the vehicle as stabilization points.
fixed
If necessary rescuers may use undamaged dynamic components for stabilization, such as ____
the suspension system.
Rescuers should not use other vehicle components for stabilization, such as ____ and ____
- exhaust system
* drivetrain
Prior to lifting an object off of the vehicle, rescuers should ____
capture the suspension
Never rely on the vehicles ____ as the only means of stabilization. Use them only in conjunction with other methods.
mechanical systems
When using pneumatic lifting bags or cushions to lift a vehicle, rescuers should ____
use solid pieces of plywood or heavy duty mat material at least as large as the bags to protect the bags from damage.
Safety procedures for using pneumatic lifting devices:
- Control hazards
- Determine victim location and provide care
- Crib the vehicle and insert the bag under the vehicle in a way that allows maximum surface contact.
- Maintain vehicle stabilization
- Protect the bag from punctures
- Lift an inch, crib an inch
Do not place pneumatic lifting devices near vehicle ____
exhaust system’s catalytic converter
When using high pressure lifting bags during extrication operations perform the following actions:
- Assess the load to be lifted
- Calculate the load to be lifted
- Use the proper lifting bag for the load to be lifted
- Insert the bag under the object to provide a straight upward lift
- Ensure appropriate load capture throughout the lifting operation.
- Inflate the bag
- Adjust the lifting platform higher
- Repeat the above steps until meeting desired lift.
Low and Medium pressure lifting cushions should only lift the object ____
enough to remove the victim.
When using Low and Medium pressure lifting bags, rescuers must ____ to avoid crushing the victim.
crib the pivot side (opposite side of the lift) of the object,
Follow these guidelines when using jacks during extrication:
- Crib the vehicle specifically for the type of jack and/ or lift
- Establish a firm base to set the tool against so that the tool will not push into the ground when lifting. Use cribbing or a platform to provide a good base.
- Capture the load throughout the lifting operation
- Move only the material the amount needed to extricate the victim.
Lever
Device consisting of a bar pivoting on a fixed point, using power or force applied at a second point to lift or sustain an object at a third point.
Fulcrum
Support or point of support on which a lever turns in raising or moving a load.
To calculate the potential mechanical advantage of a lever, measure the distance between:
- The load and the fulcrum (load side)
- The fulcrum and the point of applied force (force side)
If the length of the lever is three times as long on the force side of the fulcrum as on the load side, the lever has a 3 to 1 mechanical advantage. A load weighting 300 pounds will require 100 pounds of force to lift.
Class 1 Lever
Consists of an applied force at one end, a load at the opposite end, and a fulcrum between the two. This is the most efficient use for moving objects vertically.
When using a Class 1 lever, consider the stability and strength of the surface upon which the fulcrum rests. The fulcrum and the foundation must be capable of holding ____ the weight of the load to be lifted.
twice.
Class 2 Lever
Consists of a fulcrum at one end, a load in the middle, and a force on the other end. Ex wheelbarrows, furniture dollies, and pulleys
Class 2 levers move objects ____
Horizontally
Class 3 Lever
Places a load on one end, the fulcrum on the opposite end, and the force in the middle. Ex shovels, and brooms,
A class 3 lever sacrifices ____
force for distance.
A hitch consists of a ____, regardless of type, attached to a load
sling
Sling
Assembly that connects the load to the material handling equipment.
Four common types of slings:
- chain
- wire
- rope
- synthetic round
- synthetic web
A vertical hitch uses ____ of rope, chain or webbing to support a load.
a single leg
When should rescuers not use a vertical hitch?
- Load is hard to balance
- Center of gravity is hard to establish
- Load is loose
- Load extends past the point of attachment
Basket Hitch
The sling passes under the load and attaches both ends to the hook or a master link. This hitch does not keep a load balanced or stabilized.
Double Basket Hitch
Uses two slings, each attached to one central hook but each wrapped at separate locations around the load.
Double Wrap Basket Hitch
A double basket hitch that makes contact all the way around the load surface, increasing the security of the load, and works well for cylindrical loads.
Bridle Hitch
Attaches two or three legs to the load that are secured to single points on the load.
Choker Hitch
Passes one end of the sling under the load and through the other end of the sling. This sling is secured back onto itself and creates a vise like grip on the load. This hitch prevents a problem of load stability.
Double Choker Hitch
Features two single slings spread apart around the load. This hitch does not make full contact with the load surface, but it can be double wrapped to help control or hold the load.
When using straps in pairs for double choker hitches rescuers should arrange ____
hooks on the straps so that they pull form opposite sides to create a better gripping action.
Rescue chain is a minimum of ____, Grade ____ or ____, also called ____ or ____, alloy steel chain for all rescue applications.
- three-eighth-inch
- 8 or 10
- Grade 80 or Grade 100
When conducting overhead lifting operations with chains, only use ____
rescue chain
Precautions to take when using chains:
- Do not exceed the listed safe working load of the chain. Working load in on the chains attached tag
- Remember that links break without warning
- Place padding between the chain and the load to create a better gripping surface and protect the chain from damage
- Use padding such as planks or heavy fabric, around sharp corners on the load to protect the chain.
- Do not expose the chain to cold temperatures for extended periods of time
- Do not permit the chin to kink or twist under stress
- Seat the load in the hook
- Do not attach chain hooks to the loads.
- Avoid sudden jerks in lifting and lowering the load. Do not shock load the chain
- Remember that chains may create a sparking hazard
- Do not tie a knot in a chain
- Chain can be slippery when lifting steel. Watch for shifting loads
- Use a chain gauge regularly to check for fatigue and stretching
- Destroy damaged or worn-out chains
- Do not re-weld broken links on alloy chain.
When inspecting chains look link by link for ____
Cracks, nicks, gouges, bent links, corrosion, elongation, or any other defects.
What is the strongest type of material used for slings?
Wire rope
What are the different type of wire rope construction forms?
- Braided wire rope - a wire rope formed by plaiting component wire ropes.
- Cable laid rope - a wire rope composed of six wire ropes wrapped around a fiber or wire rope core.
- Strand laid rope - a wire rope made with strands (usually six or eight) wrapped around a fiber core, wire strand core, or independent wire rope core.
Types of wire rope terminations:
- Flemish eye
- Wedge socket
- Fold back eye
- Cable clips
The ____ wire rope termination is the most reliable and efficient, does not reduce capacity, and must be done in a shop.
Flemish eye
The ____ wire rope termination reduces capacity 10 to 20 percent.
Wedge socket
The ____ wire rope termination is the least reliable and should not be used for rescue work.
Fold back eye
Cable clips reduce capacity of wire rope by about ____.
20 percent
when using cable clip to create a wire rope termination, use a ____ when attaching the wire rope to a hang point that would cause the cable to bend sharply. This guides the cable into a natural curve, and helps protect the wire rope.
Thimble
Important points about wire ropes:
- Keep it from kinking to avoid damage and loss of integrity
- Sharp ends or edges will damage it. Use edge protection
- Do not tie it into a knot
- Remember that wire rope stores kinetic energy while under a load. In the event of failure it is very dangerous.
- Destroy wire rope when removing it from service due to wear or damage
Signals to discard wire rope:
- Broken wires
- Crushed strands
- Kinks, birdcages (outer strands displaced from the core forming a cage), and protruding core
- Stretch, diameter reduction
- Abrasion and corrosion
- Fatigue and electric arc
Characteristics of synthetic slings
- Tend to mold around the load, adding additional holding power
- Do not rust or spark
- Easier and safer to rig due to their light weight
- Have no sharp edges, thereby reducing injury potential
- Absorb shock loading better than wire ripe or chain due to their elasticity
- Resist many chemicals and do not respond to moisture
- Are damaged more easily than cable slings
- Require protection from sharp edges in a rescue situation
- Unable to resist temperatures greater than 200° F if made of Nylon or polyester
When ever using any sling responders must observe the following practices:
- Destroy any damaged or defective slings
- Do not shorten slings with knots, bolts, or other makeshift devices.
- Prevent sling legs from kinking or twisting
- Do not load slings used in excess of their rated capacity
- Balance the loads of slings used in a basket hitch to prevent slippage.
- Securely attach slings to their loads.
- Protect or pad slings from the sharp edges of their loads
- Keep suspended loads clear of all obstructions
- Keep all personnel clear of loads
- Never place hands or fingers between the sling and its load while the sling is being tightened
- Avoid shock loading.
- Do not pull a sling from under a load when the load is resting on the sling. Create space under the load using lumber or other materials
- Do not drag slings on the ground or floor
Slings should be inspected on both sides and in good light ____
every 30 days and after each incident
In a round sling, ____ determines its strength.
the number of strands in the sling
Rescuers may use round slings for ____, ____, ____ ,or ____ slings
vertical, choker, basket, or bridle
Commonly available web slings include:
- Endless
- Standard eye
- Twisted eye
Endless web sling
Both ends of one piece of webbing lapped and sewn together to form a continuous piece.
Standard eye web sling
A single piece of webbing sewn with an eye at either end in the same plane as the sling body.
Twisted eye web sling
A single piece of webbing with the eye at either end, sewn at 90 degrees to the plane (tapered or full width) of the sling. The twisting allows for better rigging of choker slings.
Rigging
Ropes or cables used with lifting or pulling devices such as block and tackle.
Basic rigging components include:
- hooks
- shackles
- eyes for termination points
Types of tighteners used with rigging
- Wire rope tighteners
- Manual cable winch - AKA come-a-long, or Griphoist
- Powered cable winch
Winches obtain their rated capacity in ____ pull with a minimum of ____ wrapped around the drum.
- straight line
* one layer of wire rope
The rated capacity of the winch decreases when the angle of pull ____, and with ____ on the drum.
- does not align directly with the winch
* each successive wrap placed
Load binders are most commonly used with ____
chain assemblies.
Rescuers should ____ the handle of load binders for safety.
wire tie
Ratchet type load binders have a ____ ratchet action, but only an ____ take up.
- 50:1
* 8 inch
A chain hoist can lift up to ___ with 100 pounds of force. Rescuers must not over pull by using more than one person. These tighteners have a large take up of ____, and some only require ____ clearance.
- 6 tons
- up to 10 feet
- 12 inch
Responders use turnbuckles to do ____
the final tightening of tiebacks, freeing a cable wince to do other jobs.
The maximum take-up of a turnbuckle ranges from ____
8 to 24 inches
The hook ends of turnbuckles are only ____ as strong as the eye or jaw ends.
2/3
Rescuers should use ____ when loads are too heavy for hooks to handle safely.
shackles
To prevent horizontal movement of the vehicle rescuers should:
- Chock the wheels
- Place automatic transmissions in park
- Place manual transmissions in gear
- Set the vehicles parking brake
At least ____ step chocks are required to provide adequate stabilization on a wheel resting vehicle.
4
Most wheel resting vehicles may require ____ to ____ points of contact for adequate stabilization.
4 to 6
Six point stabilization is most often needed:
- to support a vehicle in danger of collapsing in the middle, such as when doors are open or removed or when the roof is removed from a unibody vehicle.
Do not deflate any tire mounted on a ____
split rim
Stabilizing a side resting vehicle.
- Assess the vehicles construction, condition, and integrity.
- Identify the support locations, and purchase points
- Use wedges and/or cribbing to initially control the vehicle
- Use struts to complete the stabilization
Three common methods to stabilize a side resting vehicle with struts.
- Same side, opposing force system
- Opposite side, opposing force system (tensioned buttress)
- Opposite side, independent system
The ____ is considered to be the safest form of stabilization in a side resting vehicle system because ____.
- Same-side, opposing force system
* rescuers are performing the majority of work on the undercarriage side of the vehicle.
The same side opposing force stabilization system for side resting vehicles.
After initial stabilization rescuers capture the vehicle by creating a bridle on the undercarriage of the vehicle with a capable tensioning system like a come along or griphoist. After making the attachment to the undercarriage rescuers secure a substantial anchor and leave the system slacked while two struts are placed. After strut placement, the tensioning system is loads the system, and stabilization is reassessed.
A tensioned buttress system
uses two struts placed on opposite sides of the vehicle with their bases connected with a tensioning strap.
A opposite side independent system
similar to the tensioned buttress system, but the bases are connected to low points on the vehicle with tensioning straps.
In an opposite side independent system rescuers should place the strut on the ____ side first.
passenger compartment side
Marrying is the process of ____
connecting multiple dynamic objects together into one fixed object.
After completing the marring operation, rescuers should ____
proceed with stabilization operations between the married object and the ground or other solid surface.
