Nothing lasts forever, but manhole covers come close — visiting a foundry that makes them for Chicago

A finished city of Chicago manhole cover emerges from a shakeout — a machine that rattles away sand from castings — at Neenah Foundry in Neenah, Wisconsin, which has been producing much of the city’s manhole cover supply and other infrastructure for more than 100 years. (Ashlee Rezin / Sun-Times)

NEENAH, Wis. — This is where they undergo their fiery birth, those overlooked essentials of urban life.

Most of us seldom notice them, even though they can brave the extremes of weather for 100 years while being run over by trucks without deteriorating, and we depend upon their steadfast operation to keep us from falling into open sewers.