Baltimore Key Bridge collapss

[GreatLakes]

If some drunk idiot in a sail boat took out the bridge there would be reason for specation. I'm not sure any bridge of that type is surviving a ship that big hitting it. There might be different types that would have lost less roadway but that is really the best toud find with ships that big.

 

[NotUrsula]

The timeline for rebuilding will absolutely be long, because with the age of that bridge it is very unlikely that the same design will be rebuilt. I expect that the replacement will probably look a lot like the Arthur Ravenel Jr. bridge in Charleston, SC, which is a cable-stayed design with footings specifically designed to help prevent collapse from a ship collision. (Collapse, not damage; damage is inevitable. The construction of the Ravenel bridge took 5 years, *not* including the design phase.)

The port will probably re-open very quickly, however. It probably won't take very long to get a couple of cranes on barges out there to clear rubble out of the ship channel itself; I would be surprised if that took more than 2 weeks to do and probably less. There are probably crews already beginning that work. (My brother was a welding diver.) My guess is they will send crews in to cut the truss debris into manageable chunks to be moved aside and anchored, then they will probably put a dredge to work scraping out that bit of the fallen road bed to restore the center channel depth.

 

[Dead2009]

There are definitely no crews starting the process of getting rid of the debris right now.

 

[NotUrsula]

There are definitely no crews starting the process of getting rid of the debris right now.

Not onsite yet, but I'd bet that analysis and fitting out for the work have started.

 

[NYCgrrl]

That was one hit and the whole entire thing went down! That is just awful but doesn't it seem like that was maybe a little flimsy to go down like that? Or is it me?

Watching the Twin Towers crumble cured me of thinking engineers are gods

Nothing can survive an impact from a plane going 500 MPH and fire from jet fuel. Blame the terrorists, not the engineers.

Not denigrating engineers. Just noting a change in my perceptions.

Isn’t that interesting about perceptions? Personally, I found little impressive about the day.

Fortunately for the majority of people on the Francis Scott Key Bridge they were able to escape the rapid fall of the structure.

Really? I was impressed with the stories of courage and selflessness in the face of unimaginable tragedy.

Again it’s all about perceptions and I’m happy you found good in the day. I’m sure it’s comforting.

You previously perceived engineers as able to design skyscrapers to withstand impacts from airliners? I'm absolutely taken aback at the implication that there was an engineering failure that contributed to the collapse of the world trade center towers!

Reading the above I’m wondering what you think you are reading?
Your impassioned conclusion doesn’t seem in line.

 

[Kathryn Merteuil]

Unbelievably bad

 

[Dead2009]

Not onsite yet, but I'd bet that analysis and fitting out for the work have started.

Nope. They're still investigating. NTSB was here today. Plus they just found 2 of the 6 that were missing, AND it's raining. More than likely it's going to start happening next week.

 

[Lsdolphin]

Oh no. I didn't know there were guys up there too. Oh how horrible.

There was a work crew repairing pot holes and six of them went into water…

 

[Karin1984]

Really? I was impressed with the stories of courage and selflessness in the face of unimaginable tragedy.

You can be impressed by more things at once. At the same time you can be impressed by the tragedy and the construction of a building.

This is a thread about construction, so... it makes sense to focus on that part of 9/11 in this thread.

 

[hrhdhd]

Not onsite yet, but I'd bet that analysis and fitting out for the work have started.

Totally agree. My DH's company repaired the Beachline overpass that was damaged after a fire (obviously a much smaller job), and they were estimating for the bid minutes after the FDOT announced that it would need to be replaced.

ETA: For a job this size, you can bet that the MDOT is making a plan, contacting contractors, etc., already.

 

[Christine]

Just read that they've stopped any recovery efforts due to hazardous materials leaking into the water.

 

[QueenIsabella]

You can be impressed by more things at once. At the same time you can be impressed by the tragedy and the construction of a building.

This is a thread about construction, so... it makes sense to focus on that part of 9/11 in this thread.

Okay, Karin. Didn't realize you were the arbiter of what can be discussed.

On another note, I don't understand the need to blame engineers for a tragedy such as this. Sometimes, the engineers truly are at fault--see the Verrazano Narrows Bridge collapse for a great example of a poorly designed bridge. Much more often, the engineers say that we need XYZ to be safe, and they're overridden by cost or scheduling concerns. A good example of this is the Challenger disaster, when the engineers said ahead of time, the o-rings will be brittle due to temperature, and they were overridden by management.

In the case of the Key Bridge, I don't know if you could have truly engineered a way to survive this impact. That ship is humongous. Another bridge design MIGHT have had a less catastrophic outcome, but likely would have sustained a great deal of damage.

 

[Dan Murphy]

Verrazano Narrows

Tacoma Narrows?

 

[livih99]

In the case of the Key Bridge, I don't know if you could have truly engineered a way to survive this impact.

Structural engineer here who works mostly in bridge inspections and a bit in bridge design. I think someone else mentioned it earlier, but it is highly unlikely that the bridge was designed to withstand being hit (especially at a critical mid-bridge pier) by a huge cargo ship. That would have required the engineers to completely overdesign the bridge which would cost MDOT (at least I assume they own the bridge) A LOT more money and wouldn't have been seen as necessary.

As far as rebuilding, I'm sure the design-bid-build for the new bridge will be fast-tracked as much as they safely can due to the overall traffic nightmare that will be happening. I wouldn't be surprised if they try to build a temp bridge to help get traffic under control in the meantime. But if MDOT has to follow the same rules as MassDOT (the DOT my office is contracted under), they will have to put the project out for bid, which always takes more time. For example, I started a bridge design project back in the fall and we submitted the 25% design in January. When doing the cost estimates for the project, MassDOT told us to assume the start of construction will be 5 years from the beginning of the design phase. That doesn't include the actual construction itself, just the design and bid process. Once again, I'm sure MDOT will move this to the top of the priority list and try to shave time off wherever they safely can, but designing a bridge to cover a span that long will take a decent amount of time.

I'm also just interested in quite a few people saying the bridge being built in the 70's makes it old. This might be a perception thing, but working up here in Massachusetts, while we obviously have newer bridges (big dig and all that), we deal with bridges much older than this one fairly often. So I guess for me seeing 70's really doesn't feel that old when I've inspected some bridges from the 40's and 50's.

 

[mom2rtk]

What I don't understand is why there weren't barriers around the support pillars like there are at many other bridges to prevent this from happening? Just no infrastructure budget to pay for it like usual?

Did we not just recently pass more than a trillion dollars in an infrastructure bill?

 

[soccerdad72]

Did we not just recently pass more than a trillion dollars in an infrastructure bill?

It takes more than a few months to start work of that scale, even if that bridge was being included on the list of work to be done with the infrastructure bill, it could be years before the updates would be in place.

 

[QueenIsabella]

Tacoma Narrows?

You're right, my mistake. Too early, and I was going on memory. The footage of it collapsing is impressive.

 

[Mackenzie Click-Mickelson]

This might be a perception thing, but working up here in Massachusetts, while we obviously have newer bridges (big dig and all that), we deal with bridges much older than this one fairly often. So I guess for me seeing 70's really doesn't feel that old when I've inspected some bridges from the 40's and 50's.

It's still old by most people's standards. The thing about bridges (metal, concrete, wood, etc) is they all have to be maintained as the years go on and nationally we have sucked in bridge maintenance so I won't fault people for wondering if a bridge built that long ago is structurally sound no matter the repeated conclusion by experts that the bridge, regardless of age, was not going to withstand that type of hit. In addition we learn as time goes on how materials used are affected as the years go on and how weather impacts things.

Bridge inspections is also something that nationally we have way too few of people to do. An entire state could have only 1 state assigned bridge inspector some states don't even have an inspector for dams for instance. And in some cases the inspectors are not doing their jobs, one close to 2 years ago in my state resigned when a collapse occurred because they did not notify the appropriate person when they saw signs of issues. And that's obviously bad but circling back around it is likely that the inspectors are overwhelmed with the amount of inspections they are required to do.

It's not quite related to the actual bridge collapse on this thread just that I understand why questions are swirling from the public regarding it. It's not up to date with actual figures but John Oliver covered some of this information back in 2015 that may help others (not you as you're an inspector).

 

[amylevan]

Structural engineer here who works mostly in bridge inspections and a bit in bridge design. I think someone else mentioned it earlier, but it is highly unlikely that the bridge was designed to withstand being hit (especially at a critical mid-bridge pier) by a huge cargo ship. That would have required the engineers to completely overdesign the bridge which would cost MDOT (at least I assume they own the bridge) A LOT more money and wouldn't have been seen as necessary.

As far as rebuilding, I'm sure the design-bid-build for the new bridge will be fast-tracked as much as they safely can due to the overall traffic nightmare that will be happening. I wouldn't be surprised if they try to build a temp bridge to help get traffic under control in the meantime. But if MDOT has to follow the same rules as MassDOT (the DOT my office is contracted under), they will have to put the project out for bid, which always takes more time. For example, I started a bridge design project back in the fall and we submitted the 25% design in January. When doing the cost estimates for the project, MassDOT told us to assume the start of construction will be 5 years from the beginning of the design phase. That doesn't include the actual construction itself, just the design and bid process. Once again, I'm sure MDOT will move this to the top of the priority list and try to shave time off wherever they safely can, but designing a bridge to cover a span that long will take a decent amount of time.

I'm also just interested in quite a few people saying the bridge being built in the 70's makes it old. This might be a perception thing, but working up here in Massachusetts, while we obviously have newer bridges (big dig and all that), we deal with bridges much older than this one fairly often. So I guess for me seeing 70's really doesn't feel that old when I've inspected some bridges from the 40's and 50's.

It’s an MTA owned bridge, not MDOT.

It's still old by most people's standards. The thing about bridges (metal, concrete, wood, etc) is they all have to be maintained as the years go on and nationally we have sucked in bridge maintenance so I won't fault people for wondering if a bridge built that long ago is structurally sound no matter the repeated conclusion by experts that the bridge, regardless of age, was not going to withstand that type of hit. In addition we learn as time goes on how materials used are affected as the years go on and how weather impacts things.

Bridge inspections is also something that nationally we have way too few of people to do. An entire state could have only 1 state assigned bridge inspector some states don't even have an inspector for dams for instance. And in some cases the inspectors are not doing their jobs, one close to 2 years ago in my state resigned when a collapse occurred because they did not notify the appropriate person when they saw signs of issues. And that's obviously bad but circling back around it is likely that the inspectors are overwhelmed with the amount of inspections they are required to do.

It's not quite related to the actual bridge collapse on this thread just that I understand why questions are swirling from the public regarding it. It's not up to date with actual figures but John Oliver covered some of this information back in 2015 that may help others (not you as you're an inspector).

It’s not old.

And every bridge in the US over 20 feet long is federally mandated to be inspected every 2 years. There’s an entire industry of engineers whose job it is to do those inspections. (Mine included.)


A direct hit by a cargo ship of that size is a huge design load. Yes accidents can happen, but you have to analyze risk. Can you mitigate risk by locating piers far enough out of the channel to make collisions a statistical anomaly? Can you add a fender system? (In this case with this size ship, I’m not sure it would have helped.)

 

[QueenIsabella]

Structural engineer here who works mostly in bridge inspections and a bit in bridge design. I think someone else mentioned it earlier, but it is highly unlikely that the bridge was designed to withstand being hit (especially at a critical mid-bridge pier) by a huge cargo ship. That would have required the engineers to completely overdesign the bridge which would cost MDOT (at least I assume they own the bridge) A LOT more money and wouldn't have been seen as necessary.

As far as rebuilding, I'm sure the design-bid-build for the new bridge will be fast-tracked as much as they safely can due to the overall traffic nightmare that will be happening. I wouldn't be surprised if they try to build a temp bridge to help get traffic under control in the meantime. But if MDOT has to follow the same rules as MassDOT (the DOT my office is contracted under), they will have to put the project out for bid, which always takes more time. For example, I started a bridge design project back in the fall and we submitted the 25% design in January. When doing the cost estimates for the project, MassDOT told us to assume the start of construction will be 5 years from the beginning of the design phase. That doesn't include the actual construction itself, just the design and bid process. Once again, I'm sure MDOT will move this to the top of the priority list and try to shave time off wherever they safely can, but designing a bridge to cover a span that long will take a decent amount of time.

I'm also just interested in quite a few people saying the bridge being built in the 70's makes it old. This might be a perception thing, but working up here in Massachusetts, while we obviously have newer bridges (big dig and all that), we deal with bridges much older than this one fairly often. So I guess for me seeing 70's really doesn't feel that old when I've inspected some bridges from the 40's and 50's.

I hear you on the "old" business--do people not know how long ago the Brooklyn Bridge or the Golden Gate Bridge were built?

I'm an electrical engineer, so this isn't directly in my wheelhouse. DH works for the Army Corps of Engineers, and mostly inspects dams--again, another engineering structure that typically dates back decades. And he's taking a class in locks up in Sault Ste Marie this summer, which I'm sure will include a field trip or two to the Soo Locks. I think the general public takes a lot of engineering feats for granted--they're just part of daily living, until there's a catastrophic failure.