You don't have to be a Pittsburgh native to know that Dorothy 6 was a steelmaking blast furnace, the heart of U.S. Steel's Duquesne Works. But you have to have been at home here for some time to understand how dumb machinery could be the focus of obsession, possessiveness and even affection.

That's what it is in James McManus' 2004 drama, "Dorothy 6," now in the final week of a capable, gritty revival at Pittsburgh Playwrights, Downtown. It's 1984 and even though Big Steel is losing the battle with Japan, Steamboat, a grizzled, 50-something, laid-off steelworker, is leading a quixotic if not hopeless protest to get the idle furnace back into action, perhaps by having union members buy it and operate it themselves.

As I remember it, in reality the plan didn't seem so foolish, and I just found an article in The Nation from a year later when it still seemed to have some chance of success. But no matter: McManus exercises the playwright's privilege of narrowing a story down to a single family and a couple of friends, leaving us to intuit the larger ramifications.

For all his apparent self-serving pigheadedness, what Steamboat really loves is the honest work and solid livelihood Dorothy 6 made possible. No wonder that its name personifies the mill, because it provided a home, pride, sustenance and self-definition.

But Steamboat is also purposefully self-delusive -- better that than face up to other problems, both societal (steel's position in the world, the imperatives of individualist capitalism) and more personal (an angry daughter, a disappointed wife, one addicted friend and another who is developmentally challenged).

The strategy of the play is to drive us to distraction with Steamboat's evasions, even while we realize he has something perversely noble. Revelations follow. The texture of the play is very August Wilson, although the language does not summon an equivalent poetry.

Marcus Muzopappa directs with assurance, and I love his set: a largely empty diner in front, with the locked mill gate and protest site behind and the looming furnace behind that.

John Gresh is rumpled and solid if somewhat unvaried as Steamboat (a role that must have been written for Bingo O'Malley), and he's very well supported by Paul Stockhausen's caustic, fragile friend, Pigeon, Judy Kaplan's frustrated wife, Dolly, and Claire Fraley's shrewish Viola.

The best support comes from the two younger characters, Deanna Tangeman as the angry purple-haired daughter, Rosy, and Nathan Hollabaugh as the not-so-hopelessly challenged Oates.

About Oates, there are revelations that lead to a kind of reconciliation, until another twist drives the play into the tragedy with which it flirts all along. On the one hand, I feel the ending is a little too easy for the playwright, who hasn't quite earned it, but on the other, I'm not sure what might work better.

Maybe we would feel Steamboat's tragedy more if we admired him more along the way. But as is, "Dorothy 6" is a painful and potent tribute to a dying culture.