Demolition Derby

Demolition derby is a motorsport usually presented as a comedic attraction at county fairs and festivals in the USA.

While rules vary from event to event, the typical demolition derby event consists of 10 or more drivers competing by deliberately ramming their vehicles into one another. The last driver whose vehicle is still operational is awarded the victory.

Demolition derby can be very dangerous, but serious injuries are rare. To make the event safer, all glass is removed from the vehicle, and deliberately ramming the driver's-side door area is usually forbidden. Most demolition derbies are held on dirt tracks or open fields that are usually soaked to become muddy to further slow the vehicles. Drivers use the back end of the vehicle to ram to protect the engine compartment from damage.

Most demolition derby competitors are amateurs, though some professional teams tour events. Competitors have traditionally used junked full-size American sedans, especially those from the 1960s and 70s, which were larger, heavier, and had more robust frames than later full-size vehicles. (The mid-1960s Chrysler Imperial achieved near-legendary status for its crashworthiness, and is still banned from several derby events.) Vehicles are purchased from junkyards and private owners, usually for less than $500. A vehicle may be patched up and re-used for several derbies.

With the dwindling availability of these older vehicles, smaller full-sized vehicles of the 1980s are more frequently encountered today. A separate class of demolition derby for compact cars is increasing in popularity. Compact car events have the advantages of an abundant supply of useable vehicles, which also tend to be more mobile and thus, more entertaining to fans. However, this increased speed, coupled with the fact that compact cars tend to be less crashworthy, makes injuries more frequent. Vehicles from the 1990s and later are thusfar rarely used as their more complex engine emisions controls are difficult or impossible to re-tune for derbying.

Bizarre versions of the sport using combine harvesters and lawn mowers have been practiced in various parts of the world. Larger vehicles such as pickup trucks and SUVs are rarely used in demolition events. School bus demolitions are a notable exception.

The vehicles are stripped of interior fixtures and glass, and repainted, usually in loud, garish designs. Additional modifications include trimming sheet metal from around the wheel wells, welding the doors shut, relocating the battery, and occasionally cutting an escape hatch in the roof. In many instances, roll bars, fire extinguishers, and other safety equipment is installed.