Conceived for years, the proprietors of this Pittsburgh amusement park has the world’s newest, zippiest, loopiest, scream-inducingist new ride

The Steel Curtain, three years in the making at a cost estimated at $20 million, opened in mid-July making lovers of Kennywood Park in West Mifflin, Pennsylvania, exceedingly happy.

For more than 20 winters, Jerome Gibas, has driven almost every day from his home outside Pittsburgh, Pennsylvania, past the old steel mills scattered about Allegheny County across the McKeesport-Duquesne bridge to a place called West Mifflin for work on a site that —…