The only thing missing from “Unstoppable” is an Ozzy Osbourne-fueled credit sequence.

The crazy train in director Tony Scott’s thriller is a half-mile-long freight locomotive carrying explosive toxic chemicals. After a dimwitted employee leaves the train on auto-pilot, a slew of railroad executives, operators and local law enforcement try to stop the thing from derailing in a highly-populated area.

“Unstoppable” is kinda inspired by a true story, but in this case, the embellishments are the film’s strong points. Scott has crafted a trim, old-school entertainment that builds to an exciting confrontation between man and machine. Even through its silliest moments, “Unstoppable” establishes enough plausibility to make each turn of the track an edge-of-your-seat moment.

It helps to have two charismatic actors as the Everyman Heroes — Denzel Washington and “Star Trek” breakout Chris Pine play railroad employees in pursuit of the 70 mph beast. Washington’s Frank is on the verge of early retirement, while Pine’s Will is the confident newbie with marital woes on his mind. The characters may be stock, but Washington and Pine share enough natural chemistry to bring energy to the establishing scenes.

Of course everything that could go wrong with an out-of-control train goes wrong. Greedy railroad execs fail miserably with risky, cost-saving solutions, and the stalwart yard master (Rosario Dawson) scolds them appropriately. There are near misses involving children and horses, and both Washington and Pine have a couple close calls with really-fast moving pavement.

Scott, the guy who brought us “Man on Fire” and a few other Washington-led action vehicles, utilizes his typical hyper-kinetic camera style, cutting ferociously between every twist and turn. The antics work for “Unstoppable,” especially since most of the action is stunt-oriented and less reliant on computer-generated tricks.

And right on through the B-movie-inspired climax, Washington and Pine bring their A-game. You care about these guys enough to cringe whenever they attempt a death-defying leap, even when you know they’re going to survive it.

“Unstoppable” doesn’t try any high-brow subtext either. It’s just a good runaway train movie. Popcorn optional but encouraged.

Grade: B+