chapter 3 - Apparatus Safety and Operating Emergency Vehicles Flashcards
What can overthrottling result in?
an excessive amount of carbon particles in the exhaust, oil dilution and additional fuel consumption.
When does engine lugging occur?
Example?
When the throttle is applied when a manual transmission is in too high a gear for the demand on the engine.
example: trying to accelerate while a vehicle is moving up a steep grade
Who might recommend using the transmission to slow vehicles and maintain safe speeds on decent?
Who specifies this as a measure to extend the life of service brakes?
- jurisdictions
- local policy
Should you coast out of gear or “freewheel” while driving downhill?
Why or why not?
- it is unsafe and may be illegal
- failure to use the alternate methods to slow vehicle may cause brake failure = vehicle runaway
Why should you limit downhill speed to lower than maximum RPM?
to prevent engine damage
-The engine governor cannot control engine speed downhill. The wheels turn the engine and driveshaft as gravity pulls the vehicle downhill.
When should you use the service brake, auxiliary brake as well as manual shifting?
driving downhills to lower gears to limit speed
Bad weather = Rig might not keep going
Weigh rig after loaded with equipment and personnel…what is the
1. Side to side axle load balance %?
2. Front to back?
- 7%
2. within the axle ratings
Keep rig properly loaded! Poor weight distribution can make handling unsafe! Give 4 examples.
- too much weight on steering axle = hard steering = damage to axles and tires
- under loading front axles (weight shifting too far to rear) can make steering axle too light to steer safely
- too little weight on driving axles = poor traction
- the drive wheels may spin easily
Keep weight transfer to a minimum by steering __________ and __________ and maintain a speed that is slow enough.
- only as much as needed
- in a smooth and fluid motion rather then a series of multiple turns
Hazardous conditions like skidding and possible roll over can be caused by these?
- too much speed in turns
- harsh or abrupt steering actions
- driving on slopes too steep for a particular rig
- of PARTICULAR concern = water tanks that are improperly baffles/partially filled with liquids (water/foam concentrate)
Lateral weight transfer can cause or contribute to?
skidding or possible roll overs
Whenever a vehicle undergoes a change in speed or direction, weight transfer takes place relative to ______ and ______.
- rate
- degree of change
Weight transfer follows the law of….
inertia…“objects in motion tend to remain in motion; objects at rest tend to remain at rest unless acted upon by an outside force”
Failure to realize the 3 angles and what can be safely traversed can result in what?
damage to apparatus and property of others if it “bottoms out” while crossing an obstacle
What is the angle formed by level ground and a line from the point where the rear tires touch the ground to the bottom of the frame at the wheel base midpoint?
breakover angle
- HAVE A KEEN AWARENESS
What is the angle of departure?
angle formed by level ground and a line from the point where the rear tires touch the ground to the lowest projection at the rear of the apparatus
-HAVE A KEEN AWARENESS OF
What is the angle formed by level ground and a line from the point where the front tires touch the ground to the lowest projection at the front of the apparatus?
angle of approach
-HAVE A KEEN AWARENESS OF
What should an aerial keep in mind when traversing steep ramps, curbs, speed bumps and similar obstacles?
- front (angle of approach)
- middle (breakover angle)
- rear (angle of departure)
The bumper on the cab and the rear of the vehicle are projections. What else should you be aware of?
aerial device hanging several feet off the front or back
front/middle/rear of aerial truck
What kind of transmission should consult the operator’s manual? (2)
- 2 speed rear axles
2. transmission with more than 5 speeds
Who might still have manual transmissions?
- mobile water supplies
- older model apparatus
Some jurisdictions may recommend manually shifting on an automatic rig. Why?
In preparation for a stop. Local policy may specify this practice to extend the life of service brakes.
Eliminating what will produce the likelyhood of the engine sustaining damage from lugging?
decision making regarding when to shift gears (automatic transmissions)
Side/rear view mirrors and cameras should always be….
clean