Action-director Tony Scott and Denzel Washington teaming up for their second train movie doesn't sound like a particularly thrilling idea — surprisingly, however, Unstoppable proves to have all the excitement that was missing in their previous locomotive collaboration, The Taking of Pelham 123.

Unstoppable's premise is so simple as to sound simplistic — a freight train carrying loads of toxic cargo is on the move with no driver. In its path are a train full of school kids on an educational outing, a rookie conductor Will Colson (Chris Pine) on a training mission with veteran engineer Frank Barnes (Denzel Washington), and the city of Stanton where it is predicted the train will derail and explode, if not stopped before.

Counterbalancing all these noisy trains on the move are the folks on the ground, trying to come up to speed with the potential disaster. Connie (Rosario Dawson) is the competent yardmaster trying to deal with the twin misfortunes of “a missile the size of the Chrysler Building” and an incompetent boss (Kevin Dunn). For quite a while the decisions of damage control oscillate between them, with the star protagonists nowhere in the picture.

It's slightly unusual detailing like this — i.e. keeping the stars away from the main action for a considerable length of the film — that keeps Unstoppable interesting, despite the by-the-numbers plot.

Equally noteworthy is the build-up to the disaster that gives audiences a welcome break from terrorist plots. Instead, we are offered a carefully choreographed series of tiny mistakes, small lapses of judgment and bad luck that meld together into a perfect storm of trouble: the explosive cargo train thundering amok. Sound effects, incidentally, are an integral part of the movie's impact.

Also interesting are the supporting cast of characters such as Dewey (Ethan Suplee), the slacker technician who inadvertently sets the locomotive rolling, and federal safety inspector (Kevin Corrigan) who can call a situation correctly based on gut instinct and intelligence.

Unstoppable, apparently, was inspired by a real-life case in Ohio in 2001, but Scott's is a spiced up version. Everything is kept tight, from the script by Mark Bomback to the look of the film with production designer Chris Seagers creating an almost sentient monster — coloured red — in the runaway train. Cinematographer Ben Seresin keeps the focus on this red fiend while also capturing the feel of the locomotive yard.

Washington and Pine tender a credible rookie-mentor pairing. “I only have one rule,” Barnes tells Colson. “Do it right, and if you don't know, ask,” Each have their personal and professional struggles, gradually revealed. Compared to the problems posed by the thundering mass of steel, their worries seem small-scale, but that's pretty effective too.

The movie works because it keeps it simple. On one side of the boxing ring is the explosive choo-choo, on the other side are the brave folks who can potentially stop the juggernaut. Together they provide non-stop action, all you need to bring to the match is your own popcorn.

Unstoppable

Genre: Action/Adventure

Director: Tony Scott

Cast: Denzel Washington, Chris Pine, Rosario Dawson

Storyline: An engineer and his conductor must stop a runaway train and its cargo of dangerously toxic chemicals.

Bottomline: Non-stop action guaranteed on this choo-choo ride