Report: Skyway Bridge needs a ‘vulnerability assessment’

In a report released Friday, the National Transportation Safety Board included the Sunshine Skyway Bridge among 68 over-water bridges, around the country, that require immediate vulnerability assessments.

The recommendation was included in an NTSB report on the March 26, 2024 incident in which the container ship Dali struck and collapsed the Francis Scott Key Bridge in Baltimore Harbor. Six construction workers on the bridge were killed.

The Sunshine Skyway, which opened to traffic is 1987, was constructed before the American Association of State Highway and Transportation Officials (AASHTO) developed its guidelines for “acceptable risk levels” in 1991.

The list included, among others, the Golden Gate Bridge (San Francisco), Chesapeake Bay Bridge (Maryland), Talmadge Bridge (Savannah, Georgia), Verrazano Narrows Bridge (New York), Brooklyn Bridge (New York), George Washington Bridge (New York) and the Napoleon Bonaparte Bridge (Jacksonville, Florida).

The NTSB report emphasized that the organization “does not suggest that the 68 bridges are certain to collapse. The NTSB is recommending that these … bridge owners evaluate whether the bridges are above the AASHTO acceptable level of risk.”

Friday’s “investigative update” – meaning the investigation into the Key Bridge collapse is ongoing – reported that the Maryland structure “was almost 30 times above the acceptable risk threshold for critical or essential bridges” according to AASHTO guidelines.

Preliminary reports suggest the Dali was having serious power-system issues, and that a sudden loss of power caused the collision.

The Bob Graham Sunshine Skyway Bridge was constructed in the aftermath of a May 9, 1980 vessel strike. In the midst of a sudden storm and macroburst, the freighter Summit Venture was blown off course as it was nearing the then twin-span bridge.

The subsequent collision caused the western span to collapse, sending passenger vehicles and a Greyhound bus plunging 150 feet into Tampa Bay. Thirty-five people were killed.

Construction on the replacement bridge, at a total cost of $244 million, included a series of large concrete-and-stone “dolphins,” bumpers strategically placed on each side of the structure to deflect wayward vessels.

The AASHTO guidelines were developed, in part, as a response to the 1980 disaster.