Another Addition to the Heap of Worries

The complete collapse of Baltimore's Francis Scott Key Bridge when one vertical support was struck by a container ship highlights a similar vulnerability in thousands of U.S. bridges. In this group eight major U.S. bridges are "fracture critical":

At least seven bridges, some of them twin spans, have clearance similar to the Key according to the National Bridge Inventory, a collection of the inspection records done on the nation’s thousands of highway bridges, based on last year’s version of the data released by the Federal Highway Administration. An eighth has piers that stand on or next to land. The eight are part of important transportation systems in California, Maryland, Oregon, New York and Washington.

All but one are older than the Key, and all contain what is known as “fracture critical members,” meaning the failure of even a single steel component in tension could cause a collapse.

The San Francisco Bay Area is fortunate that a supersize container vessel hasn't gone astray and damaged either of its iconic bridges, but the lack of capital reserves means that this addition to the heap of worries won't be relieved anytime soon.