This feature is part of our Fire Chief Digital Edition, a quarterly supplement to FireChief.com that brings a sharpened focus to some of the most challenging topics facing fire chiefs and fire service leaders everywhere. To read all of the articles included in the Summer 2018 issue, click here.
Though vehicle crashes account for 25 percent of firefighter deaths in the line of duty, firefighters riding aboard today’s fire apparatus are safer than ever before [1].
Improvements and changes in design and engineering play a big part in making fire apparatus some of the safest heavy trucks on the road today. The following seven apparatus safety features are helping to protect firefighters in transit.
1. Vehicle data recorders
Used for operator training and ensuring safety SOGs are followed, vehicle data recorders identify safety lapses and offer legal protection in the event of a crash.
NFPA 1901: Standard for Automotive Fire Apparatus specifies that all fire apparatus should be equipped with vehicle data recorders that collect the following information when the vehicle is in motion:
- Vehicle speed
- Acceleration (from speedometer)
- Deceleration (from speedometer)
- Engine speed
- Engine throttle position
- Anti-lock braking system event
- Seat occupied status
- Seatbelt status
- Master optical warning device switch
- Time
- Date
2. Rollover stability
Rollover crashes are one of the most common types of accidents involving fire apparatus. The typical pumper or aerial device has a high center of gravity, making it more susceptible to rollover during a side impact or an uncorrected skid.
Electronic stability control (ESC) is a proactive measure that helps the driver maintain control of their apparatus on slippery roads using a vehicle yaw sensor, a lateral accelerometer and individual wheel brake controls in conjunction with the vehicle’s braking system [2].
Both understeering and oversteering on the driver’s part can cause an apparatus rollover. Understeering happens when the vehicle is traveling faster than it should for the road conditions and the front wheels lose traction with the road surface. The fire apparatus continues moving forward, rather than turning, until it strikes an immovable object.
Oversteering is just the opposite: the fire apparatus turns further than the driver intended, causing the rear wheels to slide. At that point, a passenger car would spin, but the top-heavy fire apparatus rolls over.
Using continuous monitoring, looking for differences between steering and the direction the apparatus is headed, the ESC can activate one or more individual brakes and control the throttle to slow the apparatus.
3. Seatbelts and airbags
Evolutions in seatbelt technology increase firefighter safety and compliance. Fire apparatus manufacturers have developed sensors that detect when a seating position is occupied, but the firefighter is not belted in, and will notify the driver and officer.
Many lap and shoulder belt systems now have pre-tensioning systems that tighten and pull the firefighter back into the seat when crash sensors detect conditions that indicate potential for a rollover crash.
Airbag systems continue to evolve as well. Today, fire apparatus are equipped with frontal crash airbags for the officer and driver positions up front, as well as airbags that deploy from under the dash to protect their legs during a frontal collision.
Side airbags that protect occupants from side impact or rollover crashes have become an industry standard and are being integrated into collision detection systems so they can activate before impact.
Pierce Manufacturing has integrated side airbags into the individual seats so that they deploy to form a protective “cocoon” for the firefighter before a crash occurs. Spartan Emergency Response deploys its larger side airbags from locations that cover cab windows to prevent occupant ejection and debris from entering the cab.
Airbags are also becoming safer. Pierce, for example, uses a combination of high-pressure stored argon and helium to deploy side airbags. This reduces the risk of burns to the seat’s occupant because the gas temperature is relatively low (below 180° F) and the cushion is sealed.
4. Chassis and cab
The crew cabs on fire apparatus are stronger than ever before. A crew cab on fire apparatus with a gross vehicle weight rating of more than 26,000 pounds must meet requirements from the Society of Automotive Engineers or the Economic Commission of Europe. Both test the cab’s ability to withstand a frontal impact, a roof impact and a side impact while still maintaining its integrity and protecting the occupants.
5. Crash sensor systems
Fire apparatus manufacturers have positioned sensors around the apparatus that continually monitor the vehicle’s vertical orientation to avoid those conditions that can lead to a side roll crash.
When the system detects an unacceptable deviance from the vehicle’s normal orientation, it alerts the driver to take evasive action to prevent a rollover. If the vehicle’s vertical orientation continues to deviate from the 90-degree upright position, this triggers seatbelt pre-tensioning and deploys the side airbags.
6. Collision avoidance systems
Fire apparatus are also acquiring many of the collision avoidance technologies that are commonly found in today’s passenger vehicles, including:
- Blind spot detection systems employing radars or cameras to scan the areas beside and behind the vehicle, looking for vehicles entering or lurking in the driver’s blind zones. When a hazard is detected, an illuminated icon appears in or near the appropriate side-view mirror. If the driver signals a turn while a car is in the blind zone, most systems send a stronger alert, such as a blinking light or louder chirps.
- Rear cross-traffic alerts warns the driver of traffic approaching from the sides as they back up.
- Forward-collision warnings and autobrake can be stand-alone, or a combination of radar, laser or camera-based systems that warn drivers of an impending collision by using visual, auditory or physical cues. Most vehicle systems also pre-charge the brakes and take other steps to prepare for impact. If the driver ignores the warnings, systems with autonomous braking, or autobrake, will apply partial or full braking force [3].
7. Optics
Split-screen displays give fire apparatus drivers a 360-degree bird’s-eye view around the apparatus. Displays change depending on what the vehicle is doing (e.g., automatically switching to the side view when turning or the rear view when the vehicle is backing up), enabling them to see pedestrians and obstacles near the vehicle in real-time.
While these features are great advancements in driving technology and firefighter safety, they are not a substitute for driving defensively and appropriately for current weather and road conditions.
References
1. NFPA. Firefighter deaths by cause and nature of injury. Available at: https://www.nfpa.org/News-and-Research/Fire-statistics-and-reports/Fire-statistics/The-fire-service/Fatalities-and-injuries/Firefighter-deaths-by-cause-and-nature-of-injury
2. Hall-Geisler K. How electronic stability control works. Available at https://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/electronic-stability-control1.htm
3. Linkov J. Collision-avoidance systems are changing the look of car safety. Available at: https://www.consumerreports.org/car-safety/collision-avoidance-systems-are-changing-the-look-of-car-safety/
