Patrol cars clear intersections via vibrating sound waves

In Washington, D.C., 49 patrol cars were recently equipped with a new intersection-clearing system called the Rumbler.

When activated by a police officer, Rumbler emits low-frequency sound waves that briefly shake solid materials from about 200 ft. away. Nearby vehicle operators and pedestrians can feel these sound waves and perhaps even see the vibration through a shaking rear-view mirror. An onboard safety timer then automatically shuts off the vibrating tones after about 10 seconds.

Goals of the siren system are to grab the attention of motorists and pedestrians to safely and quickly clear intersections for police officers responding to emergencies.

The siren system is said to be ideal for dense urban environments that have a steady stream of vehicular and pedestrian traffic. In addition, compared to traditional audible sirens, the vibrating tones cater to people who are deaf or hard of hearing.

Made by Federal Signal Corp., based in University Park, Ill., the complete Rumbler system consists of an amplifier, a timer, two subwoofers, and vehicle-specific mounting hardware. The system can be paired with most 100- to 200-w. emergency siren amplifiers to provide the low-frequency tones that penetrate and shake the area.

The system is activated via a horn ring on the steering wheel of an emergency vehicle.

Besides taking to the streets of Washington, D.C., Rumbler is currently being used or tested in New York City and Alexandria, Va. Other customers include police departments in Reading and Plymouth Township, Pa., as well as Tequesta and Plantation, Fla.

For more information about the Rumbler, visit http://www.fedsig.com/.