Francis Scott Key Bridge (I-695) complete collapse after large ship hits it

[epzik8]

It wasn't a defect, just a flaw in the design from day 1.

Imaginably, it wasn't regarded as such in 1977.

[rickmastfan67]

[bwana39]

honestly, the method of collapse is a well known thing at this point, truss was overloaded when a major pier was removed. It wasn't a defect, just a flaw in the design from day 1.

I said this above. If you take out a pier or a tower on any bridge , it is going to fall. Maybe not as quickly as a truss bridge, but if you lose a support like this unless you have duplicate supports (and virtually nothing does,) it is going to fall.

This collapse goes well beyond the definition of "fracture critical". Fracture critical USUALLY means the failure of a single SUBORDINATE part can cause a collapse. The loss of a pier (or a tower on a suspension or cable stayed bridge) will allow the bridge to collapse. It might even cause it to collapse when it is damaged or fails.

That's because you have the piers holding up several hundred feet of roadway. Unlike normal bridges where the spans are far less.  Here you had both sides of the bridge holding each other in place. Once the trickle effect hit the middle it than loosened the other side of the bridge throwing it off balance to then fall itself. Even when it got to the other pier, the other side of that became top heavy and fell backwards itself.

This design relied on all of its parts together holding the bridge up and steady on its two pylons.

True, if it were a different design only two of the truss sections would have fallen as opposed to all three.    

[jeffandnicole]

honestly, the method of collapse is a well known thing at this point, truss was overloaded when a major pier was removed. It wasn't a defect, just a flaw in the design from day 1.

I said this above. If you take out a pier or a tower on any bridge , it is going to fall. Maybe not as quickly as a truss bridge, but if you lose a support like this unless you have duplicate supports (and virtually nothing does,) it is going to fall.

This collapse goes well beyond the definition of "fracture critical". Fracture critical USUALLY means the failure of a single SUBORDINATE part can cause a collapse. The loss of a pier (or a tower on a suspension or cable stayed bridge) will allow the bridge to collapse. It might even cause it to collapse when it is damaged or fails.

That's because you have the piers holding up several hundred feet of roadway. Unlike normal bridges where the spans are far less.  Here you had both sides of the bridge holding each other in place. Once the trickle effect hit the middle it than loosened the other side of the bridge throwing it off balance to then fall itself. Even when it got to the other pier, the other side of that became top heavy and fell backwards itself.

This design relied on all of its parts together holding the bridge up and steady on its two pylons.

True, if it were a different design only two of the truss sections would have fallen as opposed to all three.   

And we'd still be in the same position we are now:  A missing bridge, expensive steel if it were to be rebuilt to original specs, different design standards then vs. now, etc. 

[jmacswimmer]

On Monday, the closure point on the Dundalk side is moving back from exit 43 to exit 42. I'm assuming it's due to an unrelated project that was set to begin when the collapse happened (MDTA had tweeted about it 2 days prior, shown below) - makes sense to just go ahead and do a full closure versus the long-term single-lane-per-direction that had been planned.

[Mr. Matté]

They're actually going to let go of a speed camera zone??

[MASTERNC]

They're actually going to let go of a speed camera zone??

They'll just deploy them to a second spot in the I-95 toll lane construction

[TheGrassGuy]

Google Maps just removed the Key Bridge from the maps lol

[bwana39]

I can still do the street view and it says "temporarily closed" on the main map.

[Rothman]

Google Maps just removed the Key Bridge from the maps lol

"Just"?  It was quite some time ago and was already reported on the forum.

[epzik8]

I can still do the street view and it says "temporarily closed" on the main map.

I hope the street view stays forever. It's all we have resembling a real trip along the bridge now.

[74/171FAN]

I can still do the street view and it says "temporarily closed" on the main map.

I hope the street view stays forever. It's all we have resembling a real trip along the bridge now.

Roadwaywiz, Mileage Mike, and Roadsounder99 amongst others have that taken care of for you. 

[The Ghostbuster]

Maybe when the Francis Scott Key Bridge is rebuilt, one could head over to Fort Carroll and watch the reconstruction. Of course, one would probably need binoculars or a telescope to get a good view of the construction.

[RobbieL2415]

On Monday, the closure point on the Dundalk side is moving back from exit 43 to exit 42. I'm assuming it's due to an unrelated project that was set to begin when the collapse happened (MDTA had tweeted about it 2 days prior, shown below) - makes sense to just go ahead and do a full closure versus the long-term single-lane-per-direction that had been planned.

And because it's MD, AES will be on regardless of whether or not workers are present.

[ARMOURERERIC]

Seeing reports that FBI has launched a criminal investigation.

[ixnay]

Seeing reports that FBI has launched a criminal investigation.

First learned that this morning through https://www.city-data.com/forum/politics-other-controversies/3465714-fbi-key-bridge-collapse-now-criminal.html ...

...but here I link a Baltimore media source (Charm City's NBC affiliate)...

https://www.wbaltv.com/article/criminal-investigation-key-bridge-collapse-started-fbi/60497901

[epzik8]

I can still do the street view and it says "temporarily closed" on the main map.

I hope the street view stays forever. It's all we have resembling a real trip along the bridge now.

Roadwaywiz, Mileage Mike, and Roadsounder99 amongst others have that taken care of for you. 

As it happens, I have video of my own last trip across the bridge from this past Christmas.

[Alex]

Wow, seeing is believing... The most recent pass of the Sentinel 2 remote sensing satellite on April 14 reveals the extent of the Francis Scott Key Bridge collapse:

[bluecountry]

Heading south on I-95 right now, crossing I-695.  Very strange knowing we're so close to the site of  international news story...  The VMS messages are all clear about the closure but the regular signage hasn't been patched or anything yet.  We're late enough today that it looks like both tunnels are free and clear.

Don't think they would have been able to fab patches this fast to be honest.  Probably by the weekend more 'permanent' signage fixes might be ready, if not sometime next week.

Another way would be to simply cover up the signs with a black tarp, which can be removed once the replacement bridge opens. For now, I-695 will just become another "Highway to Nowhere", as there's no way across the river on it (although the two tunnels are more than capable of taking on the extra traffic).

A possibility I thought that could be implemented, since this likely going to be several years before a replacement bridge is completed, is to temporarily renumber the Baltimore Beltway south of I-95. This would be similar to what Delaware did with I-95/495 during the Wilmington Viaduct reconstruction from 1979 to 1982, when Interstate 895 was temporarily designated.

Since the beltway is actually MD 695 east of I-97 to Hawkins Point and south of the eastern junction with I-95 to Sparrows Point, those remaining segments could be renumbered as state route spurs. Then to provide continuity to I-97 without having to place orange signs along the portion of I-695 to the southwest, just extend I-97 to I-95 at the west junction with I-695 near Halethorpe.

Since I've been taking GIS classes, I thought for added practice to create a map showing what I imagined could work:



MD 995 for the western spur, as the existing MD 995 is not marked, and that could just be reassigned as MD-995A. MD 595 for the eastern section, as MD 595 is not assigned and there would be no conflict with I-595, since it is not signed.

MD 995 could also just as well be MD 397, as that number is also unused.

How long did it take you to make sure the road labels were the right size and orientation   

[bluecountry]

I can pretty much guarantee the Key Bridge won't be rebuilt to the original design.

*  When this happens with waterway crossings that have lost spans due to vessel collisions, typically a large fraction of the bridge has survived--this happened with the Tasman Bridge in Australia, I-40 at Webbers Falls in Oklahoma, and the Queen Isabella Causeway in Texas.  The part of the Key Bridge that collapsed represents about half of the over-the-water length but probably at least 80% of the construction cost and nearly all of the complexity.

*  Once the Port of Baltimore reopens, a lot of the pressure to "do something" about the bridge will vanish.  The Key Bridge was one of three major crossings but represented just one-quarter of the capacity.  It contributed a smaller share of the total MdTA revenue pie than the Harbor Tunnel (7% versus 12%) despite their having the same lane count.  The absence of the bridge does not even inconvenience local commuters that much, since the Harbor Tunnel is a relatively close detour.  (The Tasman Bridge is a useful counterexample--its collapse in 1975 turned a five-minute journey from one end of the bridge to the other into a 45-minute trip involving the Bridgewater Bridge much further upstream.  This situation led not only to provision of a temporary ferry, but also construction of the Bowen Bridge midway between the repaired bridge and the erstwhile detour to improve network redundancy.)  It is the ruins of the bridge blocking the shipping channel, and not its unavailability to road traffic, that really drives costs.

*  To rebuild the Key Bridge as-is would be to recreate its safety deficiencies (no shoulders) and its vulnerabilities (piers that cannot be protected without impinging on the shipping channel).  I believe this would be politically completely unacceptable, especially with the precedent set by the Sunshine Skyway.  No politician is going to want to go before the voters and say, "Well, in Florida they can rebuild with better defenses, but here in Maryland we're just going to have to go with the cheap solution that is not actually all that cheap and eat the risks associated with it."

So you would expect the replacement bridge, at the very least, would be 10-12-12-10_10-12-12-10 per side (2 12 foot travel lanes, 2 ten foot shoulder lanes per side) if not more?
If so would this also become the real I-695 vs MD 695?

for 4-lane divided, the inside shoulders can be 6' preferred, 4' minimum.

So at the very least it will be 2 12 foot lanes per side, 4-6 foot inside and 10 foot outside shoulders?
Think they will just go ahead and give it a 3rd trade lane per side?

[cockroachking]

I can pretty much guarantee the Key Bridge won't be rebuilt to the original design.

*  When this happens with waterway crossings that have lost spans due to vessel collisions, typically a large fraction of the bridge has survived--this happened with the Tasman Bridge in Australia, I-40 at Webbers Falls in Oklahoma, and the Queen Isabella Causeway in Texas.  The part of the Key Bridge that collapsed represents about half of the over-the-water length but probably at least 80% of the construction cost and nearly all of the complexity.

*  Once the Port of Baltimore reopens, a lot of the pressure to "do something" about the bridge will vanish.  The Key Bridge was one of three major crossings but represented just one-quarter of the capacity.  It contributed a smaller share of the total MdTA revenue pie than the Harbor Tunnel (7% versus 12%) despite their having the same lane count.  The absence of the bridge does not even inconvenience local commuters that much, since the Harbor Tunnel is a relatively close detour.  (The Tasman Bridge is a useful counterexample--its collapse in 1975 turned a five-minute journey from one end of the bridge to the other into a 45-minute trip involving the Bridgewater Bridge much further upstream.  This situation led not only to provision of a temporary ferry, but also construction of the Bowen Bridge midway between the repaired bridge and the erstwhile detour to improve network redundancy.)  It is the ruins of the bridge blocking the shipping channel, and not its unavailability to road traffic, that really drives costs.

*  To rebuild the Key Bridge as-is would be to recreate its safety deficiencies (no shoulders) and its vulnerabilities (piers that cannot be protected without impinging on the shipping channel).  I believe this would be politically completely unacceptable, especially with the precedent set by the Sunshine Skyway.  No politician is going to want to go before the voters and say, "Well, in Florida they can rebuild with better defenses, but here in Maryland we're just going to have to go with the cheap solution that is not actually all that cheap and eat the risks associated with it."

So you would expect the replacement bridge, at the very least, would be 10-12-12-10_10-12-12-10 per side (2 12 foot travel lanes, 2 ten foot shoulder lanes per side) if not more?
If so would this also become the real I-695 vs MD 695?

for 4-lane divided, the inside shoulders can be 6' preferred, 4' minimum.

So at the very least it will be 2 12 foot lanes per side, 4-6 foot inside and 10 foot outside shoulders?
Think they will just go ahead and give it a 3rd trade lane per side?

To the first question, I would hope yes, but then again, (1) it is not an Interstate albeit signed as one (officially MD-695), and (2) MDTA just built the new Nice Bridge with microscopic shoulders, so I wouldn't bet on it.

To the second question, (1) traffic counts really don't justify it (3x,000 AADT is pretty low, especially in MD), and (2) see above  for MDTA's value engineering history.

[MASTERNC]

I can pretty much guarantee the Key Bridge won't be rebuilt to the original design.

*  When this happens with waterway crossings that have lost spans due to vessel collisions, typically a large fraction of the bridge has survived--this happened with the Tasman Bridge in Australia, I-40 at Webbers Falls in Oklahoma, and the Queen Isabella Causeway in Texas.  The part of the Key Bridge that collapsed represents about half of the over-the-water length but probably at least 80% of the construction cost and nearly all of the complexity.

*  Once the Port of Baltimore reopens, a lot of the pressure to "do something" about the bridge will vanish.  The Key Bridge was one of three major crossings but represented just one-quarter of the capacity.  It contributed a smaller share of the total MdTA revenue pie than the Harbor Tunnel (7% versus 12%) despite their having the same lane count.  The absence of the bridge does not even inconvenience local commuters that much, since the Harbor Tunnel is a relatively close detour.  (The Tasman Bridge is a useful counterexample--its collapse in 1975 turned a five-minute journey from one end of the bridge to the other into a 45-minute trip involving the Bridgewater Bridge much further upstream.  This situation led not only to provision of a temporary ferry, but also construction of the Bowen Bridge midway between the repaired bridge and the erstwhile detour to improve network redundancy.)  It is the ruins of the bridge blocking the shipping channel, and not its unavailability to road traffic, that really drives costs.

*  To rebuild the Key Bridge as-is would be to recreate its safety deficiencies (no shoulders) and its vulnerabilities (piers that cannot be protected without impinging on the shipping channel).  I believe this would be politically completely unacceptable, especially with the precedent set by the Sunshine Skyway.  No politician is going to want to go before the voters and say, "Well, in Florida they can rebuild with better defenses, but here in Maryland we're just going to have to go with the cheap solution that is not actually all that cheap and eat the risks associated with it."

So you would expect the replacement bridge, at the very least, would be 10-12-12-10_10-12-12-10 per side (2 12 foot travel lanes, 2 ten foot shoulder lanes per side) if not more?
If so would this also become the real I-695 vs MD 695?

for 4-lane divided, the inside shoulders can be 6' preferred, 4' minimum.

So at the very least it will be 2 12 foot lanes per side, 4-6 foot inside and 10 foot outside shoulders?
Think they will just go ahead and give it a 3rd trade lane per side?

To the first question, I would hope yes, but then again, (1) it is not an Interstate albeit signed as one (officially MD-695), and (2) MDTA just built the new Nice Bridge with microscopic shoulders, so I wouldn't bet on it.

To the second question, (1) traffic counts really don't justify it (3x,000 AADT is pretty low, especially in MD), and (2) see above  for MDTA's value engineering history.

Given the heavy truck traffic, it might be worth three lanes, even with the lower AADT.  The old bridge prohibited passing by trucks because of the uphill grade.  Adding a third lane would allow slower trucks to not obstruct both cars and non-loaded trucks that can travel faster.

[Henry]

I can pretty much guarantee the Key Bridge won't be rebuilt to the original design.

*  When this happens with waterway crossings that have lost spans due to vessel collisions, typically a large fraction of the bridge has survived--this happened with the Tasman Bridge in Australia, I-40 at Webbers Falls in Oklahoma, and the Queen Isabella Causeway in Texas.  The part of the Key Bridge that collapsed represents about half of the over-the-water length but probably at least 80% of the construction cost and nearly all of the complexity.

*  Once the Port of Baltimore reopens, a lot of the pressure to "do something" about the bridge will vanish.  The Key Bridge was one of three major crossings but represented just one-quarter of the capacity.  It contributed a smaller share of the total MdTA revenue pie than the Harbor Tunnel (7% versus 12%) despite their having the same lane count.  The absence of the bridge does not even inconvenience local commuters that much, since the Harbor Tunnel is a relatively close detour.  (The Tasman Bridge is a useful counterexample--its collapse in 1975 turned a five-minute journey from one end of the bridge to the other into a 45-minute trip involving the Bridgewater Bridge much further upstream.  This situation led not only to provision of a temporary ferry, but also construction of the Bowen Bridge midway between the repaired bridge and the erstwhile detour to improve network redundancy.)  It is the ruins of the bridge blocking the shipping channel, and not its unavailability to road traffic, that really drives costs.

*  To rebuild the Key Bridge as-is would be to recreate its safety deficiencies (no shoulders) and its vulnerabilities (piers that cannot be protected without impinging on the shipping channel).  I believe this would be politically completely unacceptable, especially with the precedent set by the Sunshine Skyway.  No politician is going to want to go before the voters and say, "Well, in Florida they can rebuild with better defenses, but here in Maryland we're just going to have to go with the cheap solution that is not actually all that cheap and eat the risks associated with it."

So you would expect the replacement bridge, at the very least, would be 10-12-12-10_10-12-12-10 per side (2 12 foot travel lanes, 2 ten foot shoulder lanes per side) if not more?
If so would this also become the real I-695 vs MD 695?

for 4-lane divided, the inside shoulders can be 6' preferred, 4' minimum.

So at the very least it will be 2 12 foot lanes per side, 4-6 foot inside and 10 foot outside shoulders?
Think they will just go ahead and give it a 3rd trade lane per side?

To the first question, I would hope yes, but then again, (1) it is not an Interstate albeit signed as one (officially MD-695), and (2) MDTA just built the new Nice Bridge with microscopic shoulders, so I wouldn't bet on it.

To the second question, (1) traffic counts really don't justify it (3x,000 AADT is pretty low, especially in MD), and (2) see above  for MDTA's value engineering history.

Given the heavy truck traffic, it might be worth three lanes, even with the lower AADT.  The old bridge prohibited passing by trucks because of the uphill grade.  Adding a third lane would allow slower trucks to not obstruct both cars and non-loaded trucks that can travel faster.

While it would be nice to have a third lane each way, the same problem that the old bridge suffered will be present on the new bridge as well: it'll have the steep climb over the river necessary to let ships and barges pass underneath, and I still believe it'll be rebuilt the same way that the Sunshine Skyway was. I can't help but wonder how Baltimore's citizens would feel about a new cable-stayed bridge on the Beltway...

[roadman65]

I've been hearing stories that the new bridge will not be named the Francis Scott Key Bridge due to a second verse of his poem that became our nation's anthem. Apparently the song we recite at ball games etc, has more lyrics to it that we never sing as well as even know about.

I don't know what they are as it's news to me that the anthem even had another verse. However MD lawmakers are listening to public opinion already not to rename the bridge its existing name.

[ran4sh]

I can't seem to find what the controversy about that verse is though. For example, the Wikipedia article about the song doesn't mention any lyrics being controversial.