American Society of Civil Engineers’ Post

*Sunday with Sanjay CHITNIS* Dear friends, Good morning The Francis Scott Key Bridge was a steel arch continuous through truss bridge that spanned the lower Patapsco River and outer Baltimore Harbor / Port. The main spans and part of the northeastern approach of the bridge collapsed on March 26, 2024 after the Singapore-registered container ship MV Dali lost power and collided with the southwest supporting pier of the main truss section. The powerless Dali was drifting at 8 mph, the VDR recorded "sounds consistent with the collision of the bridge. The bridge opened on March 23, 1977, and was named for poet Francis Scott Key , the author of the lyrics to the American national anthem "The Star-Spangled Banner" The main span of 366 m was the third longest span of any continuous truss in the world and the total length was 2,632 m long. Modern bridges, designed for ultra large shipping containers, are typically built with stronger piers or protection systems around the piers that can either absorb or deflect the force of ship collisions. The National Transportation Safety Board, indicated that Key Bridge was constructed prior to the introduction of redundant support structures, which are widely used in modern bridges, and would have prevented such a collapse. NTSB investigators have asked Maryland officials to provide extensive information on 10 years’ worth of fracture-critical, routine and underwater bridge inspections as well information on “pier protection” for all four Maryland Transportation .Investigators will also examine whether dirty fuel plyed role in accident. Rather than designing a pier to withstand an impact of hundreds of millions of newtons, engineers said, you can help safeguard a bridge by creating protective systems — such as “fenders,” artificial islands, or structures called dolphins — that would spread out the force, slow the ship prior to impact or divert it from the pier. Safety standards could also be revised to require that tug boats accompany large ships for longer periods, until they are safely away from infrastructure. The steps necessary to reopen the Port of Baltimore involve clearing debris from the channel, then moving the Dali cargo vessel that struck the Key Bridge and removing the rest of the bridge debris from the waterway. The powerful floating crane, the Chesapeake 1000, can lift 1,000 tons and will help with extraction efforts. Stay healthy,agile,busy & cool. Enjoy yr Sunday Reference Washington post New york times # Baltimorw#ship crash#bridge#safety

A concise and informative video. Demonstrates the need for diligence in bridge management.

Moffatt & Nichol's latest blog release offers valuable insights into the critical issue of bridge safety, in response to the recent collapse of the Interstate 695 Francis Scott Key Bridge in Baltimore, Maryland, while also delving into the broader history of bridge collisions. This tragic event serves as a poignant reminder of the vulnerability of major highway bridges over waterways to extreme event loads, prompting ongoing efforts to enhance design and safety measures. Check out the full article here https://ow.ly/Z0Bg50RGkkf to learn more about Moffatt & Nichol's contributions to shaping industry standards in bridge safety and design. #CreativePeoplePracticalSolutions #bridgecollision #bridgesafety

This is an interesting question. My initial response is that it is cost prohibitive to design/construct for this extreme and unlikely case in every instance. Making ship owner the responsible party for this type of accident would put the burden on them to ensure they maneuver carefully and don't have power outages around the bridges. That is a no cost to the public, and would be more likely to get drive results.

On the Baltimore bridge accident - Often safety professionals get asked after accidents how they can prevent future accidents and implement controls to prevent them from happening again. This accident has created a large discussion related to the safety protocols and engineering controls in place for our infrastructure. While hindsight is indeed 20/20, the question arises: could more have been done in terms of engineering controls to prevent this disaster? - I did a lot of research tonight on this and found out the Federal Highway Administration already has recommendations via the American Association of Highway and Transportation Officials (AASHTO) handbook on the vessel collision design of highway bridges. While the handbook acknowledges the scarcity of data on collision forces, it still offers valuable insights into preventive measures against bridge collisions and these recommendations are already being implemented in newer bridges. Bridges, such as the one in my state of South Carolina at the port of Charleston (built in 2005) which already has these preventative measures in place to prevent vessel collisions. So I'm curious to see if regulatory bodies or state governments will mandate or pass reform to retrofit existing older bridges to incorporate these protective systems. #safety #baltimore

In 1980, a 606-foot freighter crashed into the southbound span of the Sunshine Skyway causing a 1,200-foot section of the roadway to collapse. Our team at American Bridge Company was a part of the team that replaced the bridge with the iconic structure standing today. AB was part of a joint venture that constructed the new 8,858-foot precast segmental bridge. The bridge is made up of three major parts: 4,859-feet of twin segmental roadways, 1,720-feet of single high-level post-tensioned segmental roadway, and a 2,280-foott by 85-foot wide precast segmental cable-stayed structure with a 1,200-foot main span, erected by the balanced cantilever method. The construction of this bridge brought along innovation for protecting bridges in major ports. Read the article below for more information on the bridge and innovations that came with the project. https://lnkd.in/efD6NMap

... Lessons from disaster So what are the lessons apparent at this early stage?  First, it’s clear the protection measures in place for this bridge were not enough to handle this ship impact. Today’s cargo ships are much bigger than those of the 1970s, and it seems likely the Francis Scott Key Bridge was not designed with a collision like this in mind. So one lesson is that we need to consider how the vessels near our bridges are changing. This means we cannot just accept the structure as it was built, but ensure the protection measures around our bridges are evolving alongside the ships around them. Second, and more generally, we must remain vigilant in managing our bridges. I’ve written previously about the current level of safety of Australian bridges, but also about how we can do better.  This tragic event only emphasises the need to spend more on maintaining our ageing infrastructure. This is the only way to ensure it remains safe and functional for the demands we put on it today. #Safety #Engineering #Shipping #Bridges #Urbaninfrastructure

We dig into the Ground Coffee archives on this blog which looks into ESALs and their impact on road construction with Andrew Lees? Learn how a single pass of a standard axle load can cause damage and how vehicles are measured in terms of ESALs. Click the link to dive into this fascinating topic: https://ow.ly/pRku50SF4T0 #geotechnicalengineering #construction #roads #highways

Ship hull survey in the drydock