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I doubt the solution would be about the structural column itself. It would be independent structures or landfill. This is all common in bridge design. (I'm not an expert.)
I'd be *shocked* if even in perfect condition that column was designed to withstand a direct hit from a 300m(1000ft) vessel. That ship is nearly 100k tons empty. No clue how much it weighs fully loaded, but could it weigh nearly as much or more as the bridge itself. That column took a direct hit from the ship and it disintegrated. The weight of the bridge xferred to the other column which then immediately overloaded causing the failure. I could be wrong, but I struggle to see how maintenance would play a part in this particular collapse, given the forces it was subject to.
I am with you. Old bridge not designed for modern ship, if it even can be.
I was just noting the concept that even a bridge designed to resist such a massive impact won't perform as designed if it is not maintained and elements become weakened over time.
In a best case scenario, a bridge would be damaged by such a massive ship but would not collapse. You would have to condemn and replace the bridge, but it would not be a catastrophic failure, no loss of life, faster dismantline, less disruption to marine traffic.
This was an old bridge designed from obsolete codes.
Maybe it is not cost effective to design a bridge to withstand such a hit. I would think today you could build a solid concrete barrier some distance in front of bridge pier footings that would absorb a great deal of energy from a rogue ship, that would very much reduce the impact on the pier/columns when finally struck.
I don't know. Just thinking out loud here.
In any event, this was a bridge designed 50 years ago, when freighters were much smaller and lighter.
How Container Ships Have Changed Over the Decades
1960-1970s –
Many ports didn't have dock-side cranes built until around the 1970s. Ships were now able to carry cargo below deck as well, increasing capacity to up to 2,500 TEU.
2000s –
In 2000, the Post Panamax II debuted with even more cargo capacity than its predecessors. The ability to transport 6,000 – 8500 TEU meant that this ship could hold around 100 times more than the McLean's SS-Ideal X did in 1956.
2010s -
In June of 2016, a Panama Canal expansion project was completed. The promise of this expansion led to new ship designs to take advantage of the canal's new dimensions. These ships are called New- Panamax and have a capacity of up to 12,500 TEU.
I read that the ship cried MAYDAY and 90 seconds later the bridge went down. There were only 90 seconds to stop the traffic from coming onto the bridge from either way. I hope they did have time to stop any oncoming traffic. It's bad enough that the vehicles that were already there were lost. So far not much word on finding any survivors except the two. No word on how many were on the bridge at the time and could be lost.
There is a reason they did not allow that ship to sail under the bridge during rush hour, but waited until 1:30 in the morning when traffic is sparse. They planned for the near-zero probability of such an accident. Sadly, it was not a zero probability.
I have a feeling we won't really have a full understanding of the scope of disruption this is going to cause.
Once the debris is cleared and the waterways reopened, it's going to cause years of traffic disruption for Baltimore. But what I was thinking is that it just as easily could have been the Chesapeake Bay Bridge. If that bridge collapsed, it would pretty much sever the entire Eastern Shore from the rest of the state, save for a little sliver up near Wilmington, DE.
The most disruption will be shipping to and from the Port of Baltimore, which is almost in the top 10 busiest US ports.
Bad news skippy.
Of course vehicle drivers are going to suffer much longer. I am sure they are pulling out the stops to rip that bridge debris out of the main shipping channel to get the Port of Baltimore back up and running.
Meanwhile, they haven't even started designing the new bridge, unless it was slated for replacement recently.
The Governor needs an emergency declaration to suspend the environmental process for the new bridge, including federal NEPA waivers (National Environmental Protection Act). They need to replace that bridge ASAP and it is not time to worry about some obscure fish or nesting bird holding up the process.
Last edited by Igor Blevin; 03-26-2024 at 01:57 PM..
The most disruption will be shipping to and from the Port of Baltimore, which is almost in the top 10 busiest US ports.
Bad news skippy.
There are different ways of figuring which are the top ports. I was told Baltimore is the second busiest on the East Coast, just after NY/NJ. There are over 800,000 vehicles imported/exported every year through the port of Baltimore.
There will be no miracle rebuilding of this bridge like we have seen in other bridge incidents over the past few years. They will need to build a bridge similar to what you mentioned and that will take time. Plus I'm sure they will want to take the time to make it look nice since it will be there for at least a half century or longer.
The time it takes to build a modern bridge over a large span depends on the bridge's length and size. Smaller bridges, such as pedestrian or rural bridges, can take several months to a year to build. Medium-sized bridges can take 1-3 years to complete, and large bridges that span major rivers or valleys can take several years or even a decade to build.
The real issue is the port traffic, trucks etc, that use this port daily. There is no easy route for them to get to and from the port.
Everything is a lot faster when you expedite sole-source contracts under an emergency basis. No low bid/fly by night contractors here. They are going to hire the best contractors willing to do the work, which they all will want to do because money-wise, they are going to make a killing on it, especially if they beat the deadline. On emergencies like this, contractors get bonuses for early delivery, and usually the more early it is done, the bigger the bonus.
I am sure that all sufficient money will be thrown at this bridge replacement to that end. It is all just a matter of how many crews, how much equipment, working 3 shifts per day 24/7, including holidays. This bridge will be replaced in record time.
It is amazing how fast you can get things done when you throw out the environmental process. No public hearings. No lobbying from various political groups and special interests. No lawsuits from wacko groups that usually tie projects up for years.
This bridge is going to be quick and dirty. Strictly engineering without most of the usual BS. "Git her done" and money no object.
The ship lost power, twice, before hitting the support. That pilot struggled to get the ship in between the supports but the second power loss made that impossible.
It reminds me of when the skyway bridge collapsed into Tampa bay in the 90s.
Or the Queen (Port) Isabel Causeway collision (attended the post briefing on that one from the diver side)
Or the SS Esso Brussels/MV Sea Witch collision; that's required learning, too.
People say fortunately it was at 1 AM so not much traffic on the bridge.....but I remember my briefing of Queen Isabel collision and while I don't there was any actual collision video associated with it....the screams of those on the bridge still rattle in my brain.
On how long it will take to resume, well, that depends. When the swing bridge at Hilton Head Island went into the drink, they restored traffic by using Army pontoon bridge. https://www.locallifesc.com/the-icon...f-hilton-head/
Don't underestimate what the Corps of Engineers can do,
Last edited by TamaraSavannah; 03-26-2024 at 02:16 PM..
If there is a silver lining to this tragedy, it's that a replacement bridge could be built high enough to accommodate larger ships. Or, they could replace it with a tunnel, thus achieving the same end. Admittedly, there's still the Bay Bridge to deal with. But at least one piece of the puzzle could be dealt with. If they replace the Key Bridge with another one of the same clearance, they'll be sealing the port's doom as a cruise port.
I don't think there is time to build a tunnel, but I like how you think outside the box.
This is a "steel arch continuous through truss bridge". Each end of the arch works together to support the structure. I am a mechanical engineer so I have no expertise in large structures. That said, as I understand it each side of the arch works in tandem to support the entire structure. In a catastrophic failure, if one side fails, the other side isn't strong enough to hold itself up. In essence they hold each other up. Perhaps someone with more knowledge of these structures can correct me.
That seems accurate to me. The concrete footings are the main support, and the metal structure between the footings support some of the weight of the roadway and traffic and steel (and wind loading) in between the footings.
It seemed like in the video, you can see a large chunk of concrete fall over first. Once that support was gone, it was just a matter of time.
I have seen a few articles about the ships/shippers insurance, its great that the feds are offering monetary support, but does the state/fed have any recourse from the shipper. Plus, this was a toll bridge, was it paid off? If the feds play for the replacement, will it be free?
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