St. Louis Gateway Arch is rusting

The landmark Gateway Arch, part of a National Park Service site on the banks of the Mississippi River in St. Louis, is corroding, and no one seems to know the extent of the damage.

That’s the word from the St. Louis Post-Dispatch, which studied reports on the corrosion dating back to 1984.

The culprit seems to be moisture leaking into the Gateway Arch – a sophisticated engineering feat made up of stacked triangular sections of carbon steel, concrete and stainless steel.

The big question is whether the streaks of rust and other discoloration, which can be seen on the upper portions of the outside of the arch, are merely cosmetic or more severe.

Let’s remember that this monument is not just pretty to look at — people ride up to the top of the Arch in a vertical tram system.

National Park Service officials insist that there is no safety issue at the Arch, for now. The agency has just funded a study to determine whether the 45-year-old arch just needs a cleaning, or whether a full-blown restoration will be required.

[Image credit: Flickr user chutme]