Last year, more firefighters were killed in collisions and rollovers in firefighting vehicles than in working fires, according to statistics from the National Fire Protection Association (NFPA). In 1999, the Oak Ridge National Research Laboratory in Tennessee stated, “Of the 15,000 truck rollovers each year, 4,000 could have been prevented with the rollover alert system.”1

The LG Alert™, manufactured by Stability Dynamics Ltd. of Campbellford, Ontario, Canada, is designed to minimize rollover risk in nonarticulated vehicles by alerting drivers to unsafe conditions while there is still time to take corrective action. The product was originally designed for aircraft rescue and firefighting (ARFF) vehicles. These vehicles have a predisposition to roll over because of their high center of gravity, dynamic load (water and foam), and common use on uneven surfaces at “emergency response” speeds.

The rollover alert system has been so successful in reducing the incidence of rollovers in ARFF apparatus that devices of this type are now mandated safety equipment under NFPA 414, Standard for Aircraft Rescue and Fire Fighting Vehicles.

Now available for all types of emergency response vehicles, this rollover alert system may be specified on new fire trucks from many leading manufacturers or may be ordered as an after-market system and retrofitted to existing fleet vehicles in less than an hour.

The LG Alert™ system includes a base unit (black box), a display module, a remote horn, interconnecting cables, and adjustable mounting brackets.

The base unit is approximately 1 1/2 × 4 1/2 × 7 inches and houses accelerometers, which measure G forces that are exerted on the vehicle in the lateral (side to side), axial (front to rear), and vertical (up and down) directions. One G is a unit of force equal to the force exerted by gravity. These G-force values are transmitted from the base unit, which may be connected to data acquisition equipment for use in driver training, vehicle monitoring, and accident investigation applications. The lateral acceleration information is most meaningful to the driver and is provided to the display module during operation of the vehicle.

The display module, mounted within the driver’s field of vision, provides stepped visual and audible alarms as lateral acceleration on the vehicle increases during cornering maneuvers and operation on side slopes (photo).

Photo courtesy of Stability Dynamics, Ltd.
Click here to enlarge image

As acceleration increases, the visual display progresses through six green, two yellow, and two red warning levels. At the second yellow indication, an audible warning tone is generated to provide a higher level of alert to the driver. At the second red indication, the display flashes and the remote horn activates, producing a high output (100 dBA) tone that can be heard over other warning sirens on the vehicle. This indicates that the stability of the vehicle is about to be compromised.

The display is bidirectional, allowing an intuitive response from the driver to steer away from the unsafe operating condition or reduce vehicle speed.

Sensitivity of the rollover alert system is fully adjustable to suit any vehicle configuration. Once the vehicle’s safe operating parameters have been identified by the fleet manager, training officer, or mechanical staff, the rollover alert system can be adjusted to reflect the maximum operating limits under which the vehicle is to be operated. With the device installed and calibrated, the system helps trained drivers stay within safe speed, grade, and turning parameters. The rollover alert system provides the trained apparatus driver, supervised as required by an officer, a means to carry out his responsibility for the safety of the crew and vehicle.The human and financial costs associated with apparatus rollover incidents are the impetus behind significant technological advances in recent years, including the development of active rollover avoidance systems. This rollover alert system may be used in conjunction with these systems on new vehicles, providing a driver with a dynamic safety reference point and training aid. The system may also be used as a stand-alone system on new and older vehicles.

Whether an agency is covered by a third party or a reciprocal agreement or is self-insured, preventable accidents increase the cost of service delivery. Even in cases where there may be no negligence or fault assigned to the department, it typically takes a year for a replacement vehicle to be designed and manufactured. The rollover alert system can help fire departments meet NFPA 1451, Standard for a Fire Service Vehicle Operations Training Program, which identifies the need for crash- and injury-prevention training. The benefits include protecting not only the liability of municipalities and the investment in equipment but also, most importantly, the lives and safety of firefighters.


1. “ORNL part of team to keep trucks on wheels,” press release, Oak Ridge (TN) National Laboratory, March 25, 1999.

DAVE CONNOR is a district chief with Mississauga Fire and Emergency Services in Ontario, Canada, and a 26-year veteran of the fire service. He is a graduate and former faculty member of the fire service program at Seneca College in Toronto.

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