Dezeen Magazine

Carlo Ratti Associati proposes replacement for collapsed Baltimore bridge

Italian architecture studio Carlo Ratti Associati has proposed a replacement design for the Francis Scott Key Bridge in Baltimore following its collapse in early 2024.

In collaboration with structural engineer Michel Virlogeux and the construction group Webuild, the proposed design will feature primary support pillars "well away from the navigation channel used by large vessels".

Cable stayed bridge
Carlo Ratti Associati has designed a proposal for a replacement of a collapsed bridge in Baltimore

The previous Francis Scott Key Bridge (Key Bridge), which stretched across the Patapsco River, collapsed in late March 2024 after one of its piers was struck by a container ship that suffered an electrical blackout.

Carlo Ratti Associati has designed a replacement cable-stayed bridge with a main span of 2,230 feet (700 metres), an increase from the 1,200-foot (365 metre) span of the collapsed Key Bridge, which will place the central supports farther apart than the previous design.

A bridge spanning river in Baltimore
The Francis Scott Key Bridge collapsed in early 2024 after a container ship collision

"Opting for a cable-stayed solution enables the piles to be positioned at a safe distance, well away from the navigation channel used by large vessels and hence preventing the risk of a tragedy such as the one of March 26 happening again," said Carlo Ratti Associati founding partner Carlo Ratti.

In contrast to a cable-stayed bridge, the former Key Bridge was a steel arch continuous through truss bridge, an option that while strong, can be expensive and time-consuming to construct.

This means it's more material-efficient and ultimately sustainable, according to the team.

"In terms of sustainability, Baltimore's cable-stayed design is one of the most material-efficient ways to build at the proposed span, minimizing the project's embodied carbon," said the team.

"Moreover, it avoids the need to construct artificial islands to protect the pillars, which would considerably disturb the ecosystem of the Patapsco River," it continued.

Photovoltaic panels would also be installed "across the whole span".

Other updates would include the addition of a new lane on either side, bringing its total width to six lanes as opposed to four to accommodate high traffic and an increase in clearance from 185 feet (56 metres) to 230 feet (70 metres) in adherence to the shipping industry's latest standards.

It would also include integrated "smart features" that build upon Ratti's Good Vibrations research as a professor at MIT – which included capturing vibration data from smartphones placed in vehicles crossing the Golden Gate Bridge.

A bridge spanning river
The replacement design would widen a central passage

The replacement will also reconnect Baltimore "socially". It is unconfirmed if the design will be taken up by the city.

"This approach also provides a light-weight solution to reconnect two sides of Baltimore, both socially and economically–what American infrastructure should be striving to do in the 21st century," said Ratti.

According to the New York Times, the incident remains under the process of investigation, while Reuters reported Maryland officials aim for a 2028 completion of a replacement, with proposals requested by the end of May 2024.

Meanwhile, the resulting closure of the Port of Baltimore is causing delays in the global supply chain, with officials hoping to reopen the passage by the end of May.

Elsewhere, a recent report by the Norwegian Safety Investigation Authority criticised parties involved in the construction and design of a bridge that collapsed in Norway in 2022.

The images are by Brick Visual.