Key Facts About The Collapse Of Baltimore’s Francis Scott Key Bridge

[ombugge]

gcaptain newsletter carries this article from Reuters today:

Key Facts About The Collapse Of Baltimore's Francis Scott Key Bridge

WHAT FACTORS PLAYED A ROLE IN THE BRIDGE COLLAPSE?
Bridges such as the one in Baltimore are classified as “fracture critical” by the federal government – meaning that if one component or “member” of its primary structural frame fails, all or most of the span will collapse. There are more than 16,800 such bridges in the U.S., according to the Federal Highway Administration.
The head of the National Transportation Safety Board said “fracture critical” spans structural engineering redundancies that are common to newer bridges and thus make them less vulnerable to catastrophic collapse.
The Key Bridge opened in 1977 – three years before a similar vessel collision of the Sunshine Skyway Bridge in Tampa Bay, Florida, killed 35 people, and prompted bridge designers to implement better protections for foundation piers.

PS> My highlights.

How many of those bridges are exposed to possible hit by ships, barges, large debris, flooding etc. is not mentioned, but probably quite a few.

How many older bridges that has been fitted with “adequate protection” since the Sunshine Skyway Bridge collapsed in 1980 is not mentioned either.