The tragic collapse of the Francis Scott Key Bridge has dominated transportation news in recent weeks. Americans have learned a lot about the enormous size of today’s container ships and the potential vulnerability of some major bridges. However, other important lessons from the disaster in Maryland may not yet be widely understood by lawmakers and the public.
I think it’s fair to say that most people know that the Key Bridge had no real protection of its piers from impacts by major ships, even though some U.S. bridges over waterways serving ports have either “dolphins” or “rock islands” to protect their piers.
The disaster has also introduced a new term to taxpayers—“fracture-critical”—meaning a structure that is vulnerable to the loss of a single member, as happened when a Key Bridge pier collapsed leaving its truss structure totally vulnerable.
Today’s container ships are far larger than those of 40 years ago when early pier protection efforts began. And no one really knows how effective current dolphins and rock islands would be in protecting a bridge in a future mega-ship collision with a bridge pier.
Despite the assertion by some in Maryland’s congressional delegation that the state should not have to pay anything toward replacing the Key Bridge, the state’s failure to protect the piers suggests it bears some responsibility for the collapse.
What is not well-understood, at least by many politicians, is that the Key Bridge will not be “rebuilt,” as Sen. Ted Cruz (R-TX) has implied in stating that there should be no need for any environmental studies since the new bridge will be just like the old one. Rebuilding a fracture-critical bridge would be irresponsible, as any civil engineer would attest.
Hence, since a new design is required, this is an obvious opportunity to consider aspects such as height, number of lanes, and the best pier protections. The new bridge will likely take years to design, and unless Congress explicitly excludes the project from environmental review, additional years in that process before construction can begin.
Fortunately, the Key Bridge served less highway traffic than other bridges and tunnels in the Baltimore area. Restoring the channel so that the port can resume full operations is far more important to the Baltimore economy.
In the wake of the Key Bridge collapse, Americans’ eyes are also being opened to other realities involving ports and bridges. There have been other incidents of cargo ships losing power near U.S. ports; the country appears to have many other fracture-critical bridges; and there’s no realistic assessment of pier protection for major bridges near America’s largest ports.
In an April 16 article, The Washington Post reported that in Baltimore alone, cargo ships lost power nearly two dozen times in the three years before the bridge collapse. Overall, The Washington Post’s investigation found that 424 cargo ships longer than 600 feet reported losing power in U.S. waters over the past three years, and the Coast Guard identified several cases of “dead ships” striking objects after losing propulsion.
A 2017 report by maritime insurer London P&I Club found that ships are especially vulnerable to losing power “in confined waters such as ports.” According to Coast Guard records, 103 of the 424 dead ship incidents took place near a port, bridge, or other infrastructure.
In a March 29 article, The Wall Street Journal identified “These Eight U.S. Bridges Are Vulnerable to a Repeat of the Baltimore Crash.” The Journal’s frightening list is as follows:
- Tacoma Narrows Bridge, Washington
- Lewis and Clark Bridge, Oregon-Washington
- St. Johns Bridge, Oregon
- San Francisco-Oakland Bay Bridge, California
- Golden Gate Bridge, California
- George Washington Bridge, New York-New Jersey
- Verrazzano Bridge, New York
- Chesapeake Bay Bridge, Maryland
The WSJ article says that all of them contain “fracture-critical members.” That’s certainly true of the aging truss bridge in Oregon, but it may also apply to the trusses making up the decks of the suspension bridges and/or the towers supporting the suspension structure. Judging from photos posted online, most of the piers are in the water rather than on land, and it’s difficult to discern whether they are protected by either rock islands or dolphins.
To check on those claims, I accessed the Federal Highway Administration’s National Bridge Inventory, obtaining a spreadsheet of the 100 fracture-critical bridges with the highest level of average daily highway travel. Three Hudson River crossing segments were included in the top 10, as were two segments of I-80 across the San Francisco Bay. I did not find the Verrazzano Bridge or the Golden Gate Bridge on that list. Of the top 100, nearly all were listed as being in “fair” condition, and only eight were listed as “poor/structurally.”
Drawing on all this information, I suggest a number of post-Key Bridge policy recommendations.
First, state departments of transportation (and, where applicable, toll agencies) should prioritize identifying the pier protection needs of bridges over waterways traversed by major cargo ships and developing plans to add rock islands and/or dolphins where they are absent.
Second, state transportation departments and toll agencies should prioritize the replacement of high-traffic fracture-critical bridges as part of their long-term transportation plans.
Third, where adequate pier protection is lacking, and until it is provided, the Coast Guard should develop requirements for tug boat assistance to guide major cargo ships into and out of ports past vulnerable bridges. Vessel operators will resist this because of the cost of tug services, but that cost is legitimate until the relevant bridges are protected.
Fourth, consistent with the coming transition from per-gallon fuel taxes to per-mile charges to fund the reconstruction and maintenance of roads and bridges, all major bridge replacements should be at least partly toll-financed, on the users-pay/users-benefit principle. This could be a requirement for bridge replacements receiving partial federal support.
The collapse of the Francis Scott Key Bridge is a tragedy. It should also be a wake-up call. We must do a better job of protecting critical bridge and port infrastructure. The Key Bridge has shown us that America has a much larger problem than most people realize.
A version of this column first appeared in Public Works Financing.