If an informant’s tip or an alert officer’s observation of suspicious activity leads your agency to believe a vehicle bomb has been planted in your jurisdiction, would your command know how large an area to evacuate around the potential threat to minimize human casualties?
This table, created by the Bureau of Alcohol, Tobacco, Firearms and Explosives, may be helpful.
| Vehicle Type | Max. Explosive Capacity | Lethal Air Blast Range | Min. Evacuation Distance | Falling Glass Hazard |
| Compact sedan | 500 lbs. (in trunk) | 100 ft. | 1,500 ft. | 1,250 ft. |
| Full-size sedan | 1,000 lbs. (in trunk) | 125 ft. | 1,750 ft. | 1,750 ft. |
| Passenger or cargo van | 4,000 lbs. | 200 ft. | 2,750 ft. | 2,750 ft. |
| Small box van (14-ft. box) | 10,000 lbs. | 300 ft. | 3,750 ft. | 3,750 ft. |
| Water/fuel truck or box van | 30,000 lbs. | 450 ft. | 6,500 ft. | 6,500 ft. |
| Semi-trailer | 60,000 lbs. | 600 ft. | 7,000 ft. | 7,000 ft. |
Elements of this grid were developed from a long-running research program code named Dipole Might, a collaborative involving ATFE, the National Security Council’s Technical Support Working Group on counterterrorism, and the U.S. Army Corps of Engineers.
The figures should be regarded as approximations and are always subject to unexpected variance, although these estimates are based on the comprehensive, scientific analysis of actual explosions. The tests behind these conclusions involved C4 and ANFO (ammonium nitrate/fuel oil) explosives.
In issuing these guidelines for law enforcement, ATFE adds these footnotes:
• “Minimum evacuation distance” is the range at which a life-threatening injury from blast or fragment hazards is unlikely. However, non-life-threatening injury or temporary hearing loss may still occur at that distance.
• Hazard ranges are based on open, level terrain. The minimum evacuation distance may be less when the explosion is confined within a structure.
• A confined explosion may cause structural collapse or hazard from flying building debris. Even in an open area, there may be additional hazards from vehicle debris.
• “Falling glass hazard” range is based on line-of-sight from the explosion source to windows. The danger is from falling shards of broken glass.
An ATFE senior special agent told PoliceOne: “Every supervisor should print out copies of this chart and have officers rubber-band them to their squad car visors. The same can be done for firefighters, EMS, and tow truck drivers.
“And then for an interesting practical exercise, imagine that a bomb-laden vehicle is discovered parked in front of your department. How would you proceed?”
For more information on the threats posed by explosives, contact your local ATFE office. If you suspect unlawful possession or use of explosives or bombs, contact that agency’s bomb hotline at 888-ATF-BOMB.
