Unbelievable! Workers were on the bridge and possible vehicles. Beyond he initial tragedy this will create a long term problem in terms of use of the harbor and a major traffic issue for the east coast
https://x.com/ThatUchihaGuy/status/1772587001318875542?s=20
https://x.com/rawsalerts/status/1772583287375954349?s=20
It's surreal how that could have resulted in the complete demolition of the bridge. Even with the weight of that vessel, the other sections should have been independently supported. Linda told me she was on that bridge over a decade ago and it was scary back then.
Last time such a disaster took place was on the Sunshine Skyway Bridge in the 80's...a bridge I've crossed many times. Hard to go over it now without recalling all the news at the time that shook the daylights out of me. Cars going over as well as a Greyhound bus with passengers
My mother was born and raised in St. Pete, so it was a regular visit as I grew up to meet up with relatives. Anyway, as soon as I saw that bridge in Baltimore go down in this morning's news, it snapped my memory right back into the collapse of the Sunshine Skyway. Horrible disaster
https://x.com/postlocal/status/1772638010707767761?s=20
Quote from: Ed Vette on March 26, 2024, 09:16:59 AMIt's surreal how that could have resulted in the complete demolition of the bridge. Even with the weight of that vessel, the other sections should have been independently supported. Linda told me she was on that bridge over a decade ago and it was scary back then.
Bridges are engineering marvels. The problem with engineering marvels is that all the forces are balanced throughout the structure. Take out one section using a massive cargo ship, and everything else will fail.
Quote from: MightyGiants on March 26, 2024, 10:56:12 AMBridges are engineering marvels. The problem with engineering marvels is that all the forces are balanced throughout the structure. Take out one section using a massive cargo ship, and everything else will fail.
https://www.texasstandard.org/stories/fisherman-reveals-role-in-survivor-rescues-20-years-after-queen-isabella-causeway-collapse/
https://www.mysanantonio.com/news/local/texas/article/South-Padre-pauses-to-remember-bridge-collapse-2172603.php
Quote from: Ed Vette on March 26, 2024, 11:03:47 AMhttps://www.texasstandard.org/stories/fisherman-reveals-role-in-survivor-rescues-20-years-after-queen-isabella-causeway-collapse/
https://www.mysanantonio.com/news/local/texas/article/South-Padre-pauses-to-remember-bridge-collapse-2172603.php
That is a different type of bridge construction. That type is essentially just planks of roadway laid on a series of supports. You take out a section the other sections are unaffected. The bridge in Baltimore is a truss-style bridge.
With this bridge, there is also an arch, which makes the force distribution more complex.
(https://www.enr.com/ext/resources/News/December/03_Truss_FrancisScottKey.jpg?t=1452033072&width=1080)
If you watch the video as the main section collapses, it snaps in half at the next support; without the inner section to offset the forces of the outer section, that section just pulls itself off the untouched support.
Quote from: MightyGiants on March 26, 2024, 10:56:12 AMBridges are engineering marvels. The problem with engineering marvels is that all the forces are balanced throughout the structure. Take out one section using a massive cargo ship, and everything else will fail.
Yes they are...fascinating feats of engineering. One of the smartest things they did when they rebuilt the Sunshine Skyway Bridge was to add massive concrete barriers before the bridge supports. So if a ship gets off course (because of wind and other climate issues - or just play human error), the barriers take out the ship before the ship takes out the bridge. Very few bridges have that safety function. I would think all big bridges (Golden Gate, George Washington, etc., would have those barriers
(https://i.postimg.cc/1twXnFdX/01be8fa7-f56c-4b71-a0be-0891304b2ef0-1140x641.jpg) (https://postimages.org/)
Quote from: MightyGiants on March 26, 2024, 11:13:02 AMThat is a different type of bridge construction. That type is essentially just planks of roadway laid on a series of supports. You take out a section the other sections are unaffected. The bridge in Baltimore is a truss-style bridge.
With this bridge, there is also an arch, which makes the force distribution more complex.
(https://www.enr.com/ext/resources/News/December/03_Truss_FrancisScottKey.jpg?t=1452033072&width=1080)
If you watch the video as the main section collapses, it snaps in half at the next support; without the inner section to offset the forces of the outer section, that section just pulls itself off the untouched support.
Even before taking advanced engineering courses, I learned that the strongest way to build a race car cage, or horizontal beams (like a gantry), construction cranes, trusses, etc., was to use "triangles", that give it incredible strength. I was taught that as a teen when I worked with a stock car driver and we were building a cage around the driver. Ever notice overhead signs over multi-lane highways are nothing more than an enormous number of triangles? https://letstalkscience.ca/educational-resources/backgrounders/why-a-triangle-a-strong-shape
The first thing I noticed on the Baltimore Bridge was the "H-Shaped" foundations that struck me as an engineering flaw
Quote from: Jolly Blue Giant on March 26, 2024, 11:16:16 AMYes they are...fascinating feats of engineering. One of the smartest things they did when they rebuilt the Sunshine Skyway Bridge was to add massive concrete barriers before the bridge supports. So if a ship gets off course (because of wind and other climate issues - or just play human error), the barriers take out the ship before the ship takes out the bridge. Very few bridges have that safety function. I would think all big bridges (Golden Gate, George Washington, etc., would have those barriers
(https://i.postimg.cc/1twXnFdX/01be8fa7-f56c-4b71-a0be-0891304b2ef0-1140x641.jpg) (https://postimages.org/)
Ric,
It appears three factors are at play (to explain why all bridges lack this sort of protection)
1) Ships have grown substantially in size
2) The cost is considerable for those sorts of protection systems
3) Lack of political will. Perhaps this very high profile disaster will change that
Quote from: Jolly Blue Giant on March 26, 2024, 11:28:45 AMEven before taking advanced engineering courses, I learned that the strongest way to build a race car cage, or horizontal beams (like a gantry), construction cranes, trusses, etc., was to use "triangles", that give it incredible strength. I was taught that as a teen when I worked with a stock car driver and we were building a cage around the driver. Ever notice overhead signs over multi-lane highways are nothing more than an enormous number of triangles? https://letstalkscience.ca/educational-resources/backgrounders/why-a-triangle-a-strong-shape
The first thing I noticed on the Baltimore Bridge was the "H-Shaped" foundations that struck me as an engineering flaw
Ric,
Nothing short of the system you posted in that picture would be able to withstand the force of a 900+ foot loaded cargo ship plowing into it.
The way I figure it, clearing navigation will take a couple of weeks (first, the search and rescue efforts need to finish) as they will need to get large floating cranes in the area to remove the debris. I figure at most a month
Replacing the bridge will take years, probably 5 years, give or take a couple of years.
Baltimore is the biggest port of importing cars so likely car prices will take a short term hit
Quote from: MightyGiants on March 26, 2024, 11:51:00 AMThe way I figure it, clearing navigation will take a couple of weeks (first, the search and rescue efforts need to finish) as they will need to get large floating cranes in the area to remove the debris. I figure at most a month
Replacing the bridge will take years, probably 5 years, give or take a couple of years.
Baltimore is the biggest port of importing cars so likely car prices will take a short term hit
Not to mention, the Baltimore port is where servicemembers ship their vehicles through when going to and returning from overseas.
Now I'm in my "engineering mode" and will share this last bit of potential interest
When constructing long structures holding large signs that are subject to incredible winds at times, you never see one of these structures fail...even in hurricanes when buildings around the same area are reduced to rubble. Lightweight triangle structures are the heart of architects' arsenal of understanding strength. Notice that these gantries over highways don't even sag :no:
For the last 50 years of my life, I cannot help myself but to always look at the structure overhead signs on highways as well as bridges. It's innate to me. Actually fascinating...to me anyway
(https://i.postimg.cc/VLMMyFbV/OVerhead-strong-structure.jpg) (https://postimages.org/)
(https://i.postimg.cc/sfW11gDB/Overhead-structure-for-signs.jpg) (https://postimages.org/)
Even the support columns are built with triangles
(https://i.postimg.cc/8CqNVLvZ/Overhead-structure-end-supports.jpg) (https://postimages.org/)
Imagine the force of wind against these signs
(https://i.postimg.cc/pXDZQvkr/Overhead.jpg) (https://postimg.cc/bswk8K7f)
Quote from: Jolly Blue Giant on March 26, 2024, 11:28:45 AMEven before taking advanced engineering courses, I learned that the strongest way to build a race car cage, or horizontal beams (like a gantry), construction cranes, trusses, etc., was to use "triangles", that give it incredible strength. I was taught that as a teen when I worked with a stock car driver and we were building a cage around the driver. Ever notice overhead signs over multi-lane highways are nothing more than an enormous number of triangles? https://letstalkscience.ca/educational-resources/backgrounders/why-a-triangle-a-strong-shape
The first thing I noticed on the Baltimore Bridge was the "H-Shaped" foundations that struck me as an engineering flaw
Something ancient Egyptians or whoever built the pyramids knew.
If anyone is interested, here is a report on the protection used on the Sunshine Bridge that Ric posted
https://www.e-periodica.ch/cntmng?pid=bse-re-003:1983:42::52
Quote from: MightyGiants on March 26, 2024, 12:34:22 PM
Incredible video and commentary. My first thought is the possibility of a terror attack. The big question, "Why did the ship lose all it's electronics just as it entered the underpass?"
One positive note, is that it occurred at about 1:30 AM so the bridge wasn't packed with traffic. What a nightmare for drivers at that time. I noticed an 18-wheeler that appears to have just made it across in time
The main structure looks to be very strong according to using triangles, but there is only one support for that stretch of overhead. Once that support is gone, it now relies on the "H-Style" supports on both sides of it. Seems to me, anyway, that it is an engineering design mistake
Personally, I don't feel comfortable going across major bridges. There is a bridge over the Susquehanna River between the J.C. traffic circle and Binghamton University. Whenever traffic has stopped, and I'm on the bridge, I can feel myself going up-and-down and back-and-forth. Not a good feeling! I've studied the structure of that bridge and I don't like it
I've read that there are response teams on both sides of the Chesapeake Bay Bridge because of people freaking out and can go no further. They find drivers on the floorboard of their cars, sometimes in a fetal position praying their hearts out. They have to be rescued. Happens several times a week I guess. I've been over that bridge multiple times and it doesn't bother me. The tunnel portion is something that I fret about though because you can't see the structure of it as it holds back enormous tons of pressure :o
Quote from: Jolly Blue Giant on March 26, 2024, 12:56:59 PMIncredible video and commentary. My first thought is the possibility of a terror attack. The big question, "Why did the ship lose all it's electronics just as it entered the underpass?"
One positive note, is that it occurred at about 1:30 AM so the bridge wasn't packed with traffic. What a nightmare for drivers at that time. I noticed an 18-wheeler that appears to have just made it across in time
The main structure looks to be very strong according to using triangles, but there is only one support for that stretch of overhead. Once that support is gone, it now relies on the "H-Style" supports on both sides of it. Seems to me, anyway, that it is an engineering design mistake
Personally, I don't feel comfortable going across major bridges. There is a bridge over the Susquehanna River between the J.C. traffic circle and Binghamton University. Whenever traffic has stopped, and I'm on the bridge, I can feel myself going up-and-down and back-and-forth. Not a good feeling! I've studied the structure of that bridge and I don't like it
I've read that there are response teams on both sides of the Chesapeake Bay Bridge because of people freaking out and can go no further. They find drivers on the floorboard of their cars, sometimes in a fetal position praying their hearts out. They have to be rescued. Happens several times a week I guess. I've been over that bridge multiple times and it doesn't bother me. The tunnel portion is something that I fret about though because you can't see the structure of it as it holds back enormous tons of pressure :o
Ric,
I understand that a mayday was issued by the ship that it had lost power. That warning allowed them to shut down traffic before the ship hit (I noticed in the video there didn't appear to be any more vehicles after the truck you mentioned). I think the causalities were among the work crew that was on the bridge repairing potholes.
The loss of power wasn't too surprising as the video noted the ship had just been released by the tugs so the engines were powering up. The fact that the power went on and off strikes me as being a malfunction rather than terrorism. Plus, in terms of terror attacks, this seems like a really challenging one with a limited chance of payoff (it's possible that even without power, the ship could have missed the bridge). it's not easy to get on these vessels (there is the whole not-in-America immigration thing).
I have heard urban legends of some bridges employing drivers to drive the cars of people too scared to cross.
I am usually too distracted by the bridges and their often awesome scenery to worry about the remote chance of a collapse.
I got thinking about structures of tunnels, and it appears that all tunnels are cylindrical, like the shape of a pipe. Besides the concrete structure, they are reinforced with steel ribs, sorta like whales and their ribs that sometimes go close to 2 miles deep. Makes me feel a little better when driving a mile underwater in the Chesapeake Bay...lol
Doing this for my own benefit as I have a phobia of tunnels and have never researched it. I always thought I'd be afraid to go through the Chunnel from England to France...now, not so much
(https://i.postimg.cc/6307DhcR/image2.jpg) (https://postimages.org/)
(https://i.postimg.cc/NGnGLVKF/2016-ME-Mc-Cook-Walsh-18foot-tunnel-1-477x477.jpg) (https://postimages.org/)
(https://i.postimg.cc/6pWBPNSH/JuneTT1.jpg) (https://postimages.org/)
https://www.businessinsider.com/chesapeake-bay-bridge-tunnel-construction-2017-6
I cruise out of Baltimore all the time. This will have to affect the cruise industry, at least until they can clear the debris and open the port.
(https://pbs.twimg.com/media/GJm-Tt3XMAI5Q0D?format=jpg&name=900x900)
Ignore the comments by the Tweeter, but the video is interesting
https://x.com/Dragonsoul9Fire/status/1772678704935620923?s=20
Not sure if this was already mentioned, but the crew of the ship radioed a Mayday and because of that, people on the bridge closed it to other traffic which saved more lives.
A good article on the whole situation
https://www.yahoo.com/news/know-baltimore-bridge-collapse-170841942.html