GREENUP — You haven’t heard loud until you’ve stood a foot away from the open hood of a demolition derby car while the driver gooses the gas pedal.

Afterward, you probably didn’t hear much of anything for a couple of minutes, until your brain and aching ears were able to shake out the aural memory of the engine’s angry roar.

The sound combines the buzz of a thousand angry wasps with the noise a dump truck would make dropping a load of rocks onto a herd of stampeding bison.

Put 10 or 20 of them into a big dirt arena and you’ve created what may be the loudest, craziest, messiest and dirtiest sport this side of elephant polo.

Derby drivers like it that way. There’s no better way to spend a Saturday night than strapped into the single seat remaining in a windowless clunker car, breathing exhaust fumes while slamming into the other cars in an attempt to be the last car moving under its own power.

“Holding it to the floor and ramming somebody — what’s not fun about that?” said Clarence McGranahan of Catlettsburg. McGranahan was one of the drivers who began filing into the fairgrounds at mid-afternoon in a procession of pickups and trailers laden with the rag-tag remnants of what had once been roadworthy cars.

McGranahan’s derby car is a 1981 Chevy Impala station wagon, although you wouldn’t know it without asking. Standard practice in the sport calls for removing all the glass, ripping out the interior to the bare metal, except for the driver’s seat, and wiring or welding shut the doors.

Also, Greenup’s derby was the car’s third. He found and bought it in Wurtland, where it had been parked for who knows how long in a back yard.

“It probably was going to Mansbach,” said McGranahan, who will likely be heading that way himself, since he figures the car has one more derby in it before the scrapyard. “That will be the end of it,” he said.

McGranahan has been driving in derbies for about five years. Arnold Biggs of West Portsmouth figures he got his start at least 25 years ago.

Saturday he brought his 1976 Lincoln. A former police cruiser, the car is deceptively beefy under its dented and torn sheet-metal skin.

A typical derby car is good for three to five events; Biggs figures his Lincoln has survived eight so far.

What gets into a man to put him in car that’s more baling wire than nuts and bolts? The chance to smash into competitors and be rewarded for it, Biggs figures. “You can’t hit someone on the road and not go to jail. Here, you get to hit them and have fun.”

Technique is simple: keep the front end clear of the competition and hope the motor lasts, he said. Driving is done mostly in reverse to try and ram the rear of the car into the competitor’s engine compartment and disable it.

Heavy steel tubing welded around the driver’s seat protects against serious injury but driving backward takes its toll, Biggs said. “You got a stiff neck the next day. You’re sore.”

Technique is something Gary Clark said he would have to learn by experience, and quickly — the South Shore man was a novice in Saturday’s derby.

A longtime fan, he has previously raced on the dirt-track circuit but was itching to try his hand at more of a contact sport.

He brought a 2002 Impala; it was his wife’s car she sacrificed. Clark painted it with silver paint from a spray can.

The result wasn’t a factory finish but Clark shrugged. “It’s going to be all beat up in the end anyhow,” he said.

MIKE JAMES can be reached at mjames@dailyindependent.com or at (606) 326-2652.