Kevin C. Smith Did not the Penn central lose a couple spans of its brindge at Shock's Mill (sp?) after hurricane Agnes (1972)?
Yes, it most certainly did - about the center 1/4 of it. From a ''Wikimapia'' article on it, at - http://wikimapia.org/1557066/Shocks-Mill-Bridge - also known as the ''Shocks Bridge'':
"The bridge was closed during the flooding caused by Hurricane Agnes in late June 1972. After the flooding had begun to abate, subsidence was noticed at the center of the bridge on June 27, 1972. On July 2, 1972, the six center spans collapsed into the river. The collapse of the bridge crippled the Penn Central Railroad, removing 75% of its capacity. With Federal aid, the bridge was rebuilt with nine concrete piers supporting steel girders replacing the destroyed center section."
See pages 20 and 21 of 24 of the 'PDF' format version of the Penn Central Post employee magazine for August-September 1972, at [CAUTIONARY NOTE: This is approx. 10.7 MB in size !] -
http://www.unlikelypcrr.com/page3/Welcome_files/PC_POST_1972-08.pdf
And also ''Shocks Bridge is Restored'' on pages 14 and 15 of 16 of the 'PDF' format version of the Penn Central Post employee magazine for September 1973 [approx. 1.82 MB in size], at -
http://www.unlikelypcrr.com/page3/Welcome_files/PC_POST_1973-09.pdf
The latter has a low-level, poor resolution photo of the repaired bridge. Somewhat surprisingly, I didn't find any decent photos of the present bridge on-line. Unless I'm missing something, there's an opportunity to do something this summer - it's about 6 miles upstream/ west-northwesterly from the U.S. Route 30 crossing of the Susquehanna River at Columbia, PA and kind of out in the country - but there seems to be a 'Riverside Park' about a mile below it on the river-left bank = east or northerly bank, so that may be a good launching place for a canoe to get southerly light on the bridge for a current photo . . .
- Paul North.
Paul_D_North_Jr narig01 Some years back one of the bridges across the Susquehanna(?) river in or near Harrisburg, Pa had a major structure failure. The bridge did not collapse but a chunk of it, I think, fell into the river. I do not remember the year but this was a former Pennsylvania Railroad bridge, built in the 1800's. I think this happened after the Conrail breakup. Thx IGN I believe you're referring to the Rockville Bridge - consisting of many stone arches - which leads from the northern part of Harrisburg over to Marysville and the Enola Yard there. Some of the masonry over one of the piers did indeed collapse, as I recall - it may have occurred in mid-winter due to freezing and thawing, and the piers may be a little hollow or just filled with earth, which would have allowed that to occur. I believe the damaged and repaired pier/ section in just in front and below the lead locomotive in this linked photo, where the light-colored concrete and shiny metal railing is: http://www.railpictures.net/images/d1/7/2/1/6721.1240660517.jpg - Paul North.
narig01 Some years back one of the bridges across the Susquehanna(?) river in or near Harrisburg, Pa had a major structure failure. The bridge did not collapse but a chunk of it, I think, fell into the river. I do not remember the year but this was a former Pennsylvania Railroad bridge, built in the 1800's. I think this happened after the Conrail breakup. Thx IGN
I do not remember the year but this was a former Pennsylvania Railroad bridge, built in the 1800's. I think this happened after the Conrail breakup.
Thx IGN
I believe you're referring to the Rockville Bridge - consisting of many stone arches - which leads from the northern part of Harrisburg over to Marysville and the Enola Yard there. Some of the masonry over one of the piers did indeed collapse, as I recall - it may have occurred in mid-winter due to freezing and thawing, and the piers may be a little hollow or just filled with earth, which would have allowed that to occur. I believe the damaged and repaired pier/ section in just in front and below the lead locomotive in this linked photo, where the light-colored concrete and shiny metal railing is:
http://www.railpictures.net/images/d1/7/2/1/6721.1240660517.jpg
It was a couple years before the ConRail breakup, and the bridge - which has 48 arches ! - was built in 1900-1902. Here's a little narrative from a website on Pennsylvania's historical roadside markers, at:
http://explorepahistory.com/hmarker.php?markerId=638
"On August 19, 1997, the accumulated effect of repeated freeze-thaw cycles forced some of the bridge's stones out of alignment at Pier 19 (the nineteenth pier from the east shore). When a heavy coal train passed over the weakened spot, the south spandrel wall failed, sending tons of stone, rails, ties, and four 100-ton loaded hopper cars into the Susquehanna. The repair and cleanup cost about $1 million, approximately the original price of the entire bridge. Since then, crews have strengthened the structure with steel tie-rods and braces, a process that continued under the ownership of Norfolk Southern Corporation, which added this portion of Conrail to its system on June 1, 1999."
They are pretty rare. Back in the earl 90's or late 80's the Wisconsin & Calumet RR had a bridge failure do to ice at Lone Rock, WI. The train lost 4 covered hoppers of grain in the Wisconsin River and came within inches of having some coal follow them in. The wreck was in the Wisconsin State Journal.
And the IC&E had a few a couple of years ago when we had all the flooding in the Midwest.
Paul_D_North_Jr Other than damage caused by moving water - such as washouts, undermining, or scour, etc. - yes, really rare. Offhand, I can't think of a single failure of either concrete or masonry bridges other than those causes. Sure, they'll spall and drop chips and rocks, but that's usually more cosmetic and just disturbing to those below than as an indication of loss of structural capacity. A lot of those bridges are still standing 100 years later - like the DL&W's - or 150 years - Starrucca and Thomas Viaducts. Also around almost as long are the James J. Hill Bridge over the Mighty Miss at St. Paul, and the PRR's/ CR's / NS' stone Rockville Bridge across the Susquehanna River; also the stone bridge in Johnstown that took the brunt of the 1888 (?) flood, and 2 or 3 more since then, and is still there and carrying heavy traffic. - Paul North.
Other than damage caused by moving water - such as washouts, undermining, or scour, etc. - yes, really rare. Offhand, I can't think of a single failure of either concrete or masonry bridges other than those causes. Sure, they'll spall and drop chips and rocks, but that's usually more cosmetic and just disturbing to those below than as an indication of loss of structural capacity.
A lot of those bridges are still standing 100 years later - like the DL&W's - or 150 years - Starrucca and Thomas Viaducts. Also around almost as long are the James J. Hill Bridge over the Mighty Miss at St. Paul, and the PRR's/ CR's / NS' stone Rockville Bridge across the Susquehanna River; also the stone bridge in Johnstown that took the brunt of the 1888 (?) flood, and 2 or 3 more since then, and is still there and carrying heavy traffic.
Did not the Penn central lose a couple spans of its brindge at Shock's Mill (sp?) after hurricane Agnes (1972)?
narig01 The San Francisco-Oakland Bay Bridge eyebolt crack is something that has failed before elsewhere. In the late 60's or early 70's a bridge over the Ohio River failed and was traced back to a metal problem with a cast eyebolt. The eyebolt had a flaw in the casting with the steel when it was poured. The bridges that have this kind of architecture are few and far between.
The San Francisco-Oakland Bay Bridge eyebolt crack is something that has failed before elsewhere. In the late 60's or early 70's a bridge over the Ohio River failed and was traced back to a metal problem with a cast eyebolt. The eyebolt had a flaw in the casting with the steel when it was poured. The bridges that have this kind of architecture are few and far between.
You're thinking of the Silver Bridge collapse of December 15, 1967. It was an eyebolt suspension bridge, where the eyebolt was a single point of failure. Primary lesson learned was to design bridges with more structural redundancy, unfortunately the I-35W bridge was designed before the Silver Bridge collapse.
The Bay Bridge was built with some redundancy, even though one piece of the upper deck fell in the Loma Prieta quake, the rest of the structure was intact.
blue streak 1One of the most important bridge failure is one that did not occurr on the Oakland Bay bridge. 1989 world series earthquake failed a section but it fortunately fell on the lower deck. That got California DOT to plan a replacement. The first stage was replacing of a segment that shut the bridge over labor day. An in depth replacement inspection found potential eyebolt cracks which extended the shutdown. More inspections later found other eyebolt cracks that again shut the bridge to traffic. These are DOT engineers that are really doing their job. However any large earthquake that has an earth shift would bring the present bridge down. A report today states that parts of Chile moved 10 ft to the west. Old bridges designed for that ? No. Newer bridges? maybe. Suspect suspension bridges might do better? PDN any comments?
One of the most important bridge failure is one that did not occurr on the Oakland Bay bridge. 1989 world series earthquake failed a section but it fortunately fell on the lower deck. That got California DOT to plan a replacement. The first stage was replacing of a segment that shut the bridge over labor day. An in depth replacement inspection found potential eyebolt cracks which extended the shutdown. More inspections later found other eyebolt cracks that again shut the bridge to traffic. These are DOT engineers that are really doing their job.
However any large earthquake that has an earth shift would bring the present bridge down. A report today states that parts of Chile moved 10 ft to the west. Old bridges designed for that ? No. Newer bridges? maybe. Suspect suspension bridges might do better? PDN any comments?
The most well known other that the cantilever section of the SF Oakland Bay Bridge I can think of is the Queensboro Bridge in NYC connecting Manhattan with Queens.
Most bridges are built with a fair amount of give built in, to take some of the normal stresses of varying loads.
I close with this comment, I am not any kind of expert on this subject just read a lot of odds and ends.
Rgds IGN
Some years back one of the bridges across the Susquehanna(?) river in or near Harrisburg, Pa had a major structure failure. The bridge did not collapse but a chunk of it, I think, fell into the river.
Paul_D_North_Jrthe stone bridge in Johnstown that took the brunt of the 1888 (?) flood
Paul, you missed it by one year (I did have to look it up); the flood came down 5/1/1889. you were off by 1 out of 121.
Your mentioning this flood reminded me of warnings such as, "Don't play with matches; remember the Chicago fire." On hearing this, one little boy responded, "Don't spit; remember the Johnstown flood."
Johnny
Paul_D_North_Jralso the stone bridge in Johnstown that took the brunt of the 1888 (?) flood, and 2 or 3 more since then, and is still there and carrying heavy traffic.
Yes, Paul...that's a famous one.....and has been added to {in width} many decades ago to accept 4 tracks. Floods of: 1889....1936 and 1977.
Quentin
You got it right - those DL&W bridges will be there for a loooonnng time. Back then the technology was so new that a huge factor of safety was used. And, the concrete was made locally, so it wasn't too much more expensive to just use more. Plus, the dead-load weight of the bridge dwarfs the live-load weight of the trains, which is usually just a small fraction more. Concrete gradually gains a little more strength as it cures, which is technically a never-ending process, too. Fnally, they're so massive that the train loads are spread out over very large areas, so the unit stresses are much lower than for steel or wood structures that are constructed of built-up members.
Are failures on concrete bridges really rare? I was reading about some of the concrete bridges on the DL&W (?). They looked like they were built like a brick sh......station house. Some of the rock viaducts/bridges appear to be just as well built.
Thanks to Chris / CopCarSS for my avatar.
Murphy Siding Would a fallen wood bridge genrally be replaced with a metal bridge? Do the railroads still build new wood bridges?
Depends - on a lot, including the span distances, the height, the required clearance widths and heights underneath, availability, economics, detour routes and disruption to the subject route and the detour routes, etc.
Recall that the longish - 3,000 ft. ? - UP trestle across the Sacramento River and mainly its floodplain (if I'm remembering right ) that burned from an arson about 2 years ago was replaced by pre-cast concrete sections that UP just happened to have already stockpiled for other projects elsewhere on the system.
Here in the East, a 50 ft. long 2-arch-span concrete and masonry bridge on the ex-Reading Railroad SEPTA double-track R-5 route was washed out in a heavy rain storm - Tropical Storm Allison - in 2001. It was repalced with a 3-span steel ballasted deck-girder bridge over twice as long - 114 ft. - in about 5 weeks. The rush project was the subject of a paper at the AREMA 2002 Conference, which was still available 'on-line' as of last week. See Emergency Bridge Replacement – SEPTA R-5 Line Undergrade Bridge 15.54 at -
http://www.arema.org/eseries/scriptcontent/custom/e_arema/library/2002_Conference_Proceedings/00012.pdf
[19 pages, about 3.34 MB in size for this 'PDF' format version]
Falcon48 Bucyrus blownout cylinder Bucyrus On that same line, there is a much larger, multiple span deck girder bridge on stone piers spanning the Minnesota River at Carver, MN. In earlier times, the M&StL routinely had commercial divers enter the river and inspect the bedding of the stone piers. Over the last 20 years or so, one of those stone piers has settled unevenly, apparently due to the river scouring out the bedding for the pier. Before operations ended, that pier was tipped toward downstream so that its top was about 12”-18” out of alignment. It was very visible as a large dip and offset in the bridge deck, and in just looking at the pier compared to the rest of the piers. I found it hard to believe that U.P. continued to use the bridge when the pier bedding was so obviously compromised. How could you be sure of the pier performance at any given train event when the condition of the pier was obviously changing over time? How many degrees can you tip a GP-38 before you concentrate so much extra loading on the tipped pier that it tips further? What I'd like to know is how often trains were put through in a day and how fast they would run. I know there would have been restrictions but---- Also what would that offset do to the piers next to the tipped pier----I'd love to have seen what kinds of side loading would have occured with, say, 15 cars loaded---- Here is a link showing the bridge at Carver, MN over the Minnesota River: http://www.johnweeks.com/bridges/pages/rm01.html In the first photo, you can see the misalignment toward the far end. In the bottom photo, you can see the defective pier, which is third from the left. In this photo, the river flows toward the camera, and you can see the pier tipped toward the camera as well. My impression is that the misalignment progressed significantly further than shown here. During the final operations over the defect, trains were minimal in size, speed, and frequency. They would consist of one engine (GP-38) and 1-6 cars. Speed was very restricted over the bridge, to perhaps 10mph or less. The defect appears to involve only one of the piers. There is no indication of a structural problem with the integrity of the stone pier itself. Instead, it appears to be a case of the whole pier being tipped 5-10 degrees due to a loss of footing in the riverbed. Trees float down the river and lodge against the bridge piers. Over the last 20 years of operation, the U.P. and previous owner C&NW allowed the trees to accumulate into a huge floating mass covering maybe an acre or more. Then the company would stage a rail crane and grapple on the bridge to pick the trees out of the mass, and place them on the downstream side of the bridge. When these tree massing events reached their maximum, they apparently restricted the river to a narrower flow, which accelerated the bottom scouring around the affected pier. I know that yard tracks can become shockingly misaligned and still pass trains without derailment. But I found it rather surprising that the company would accept running trains over this bridge defect when is was obviously in the process (although a slow process) of developing abrupt, catastrophic failure. Moreover, the consequences of reaching that failure point while riding over it in an engine would be quite dreadful for the crew. Ironically, though, the eventuality of a pending catastrophic failure of this bridge was precluded by the abrupt, catastrophic failure of a small trestle only about mile south, which ended operation over this line. My understanding is that this bridge was inspected much more frequently than other bridges because of its condition. The continuing deterioration of the bridge would have ultimately led to abandonment of the line, since there wasn't enough traffic to justify a rebuilding once the bridge became unsafe. But the failure of the trestle you mention hastened the end.
Bucyrus blownout cylinder Bucyrus On that same line, there is a much larger, multiple span deck girder bridge on stone piers spanning the Minnesota River at Carver, MN. In earlier times, the M&StL routinely had commercial divers enter the river and inspect the bedding of the stone piers. Over the last 20 years or so, one of those stone piers has settled unevenly, apparently due to the river scouring out the bedding for the pier. Before operations ended, that pier was tipped toward downstream so that its top was about 12”-18” out of alignment. It was very visible as a large dip and offset in the bridge deck, and in just looking at the pier compared to the rest of the piers. I found it hard to believe that U.P. continued to use the bridge when the pier bedding was so obviously compromised. How could you be sure of the pier performance at any given train event when the condition of the pier was obviously changing over time? How many degrees can you tip a GP-38 before you concentrate so much extra loading on the tipped pier that it tips further? What I'd like to know is how often trains were put through in a day and how fast they would run. I know there would have been restrictions but---- Also what would that offset do to the piers next to the tipped pier----I'd love to have seen what kinds of side loading would have occured with, say, 15 cars loaded---- Here is a link showing the bridge at Carver, MN over the Minnesota River: http://www.johnweeks.com/bridges/pages/rm01.html In the first photo, you can see the misalignment toward the far end. In the bottom photo, you can see the defective pier, which is third from the left. In this photo, the river flows toward the camera, and you can see the pier tipped toward the camera as well. My impression is that the misalignment progressed significantly further than shown here. During the final operations over the defect, trains were minimal in size, speed, and frequency. They would consist of one engine (GP-38) and 1-6 cars. Speed was very restricted over the bridge, to perhaps 10mph or less. The defect appears to involve only one of the piers. There is no indication of a structural problem with the integrity of the stone pier itself. Instead, it appears to be a case of the whole pier being tipped 5-10 degrees due to a loss of footing in the riverbed. Trees float down the river and lodge against the bridge piers. Over the last 20 years of operation, the U.P. and previous owner C&NW allowed the trees to accumulate into a huge floating mass covering maybe an acre or more. Then the company would stage a rail crane and grapple on the bridge to pick the trees out of the mass, and place them on the downstream side of the bridge. When these tree massing events reached their maximum, they apparently restricted the river to a narrower flow, which accelerated the bottom scouring around the affected pier. I know that yard tracks can become shockingly misaligned and still pass trains without derailment. But I found it rather surprising that the company would accept running trains over this bridge defect when is was obviously in the process (although a slow process) of developing abrupt, catastrophic failure. Moreover, the consequences of reaching that failure point while riding over it in an engine would be quite dreadful for the crew. Ironically, though, the eventuality of a pending catastrophic failure of this bridge was precluded by the abrupt, catastrophic failure of a small trestle only about mile south, which ended operation over this line.
blownout cylinder Bucyrus On that same line, there is a much larger, multiple span deck girder bridge on stone piers spanning the Minnesota River at Carver, MN. In earlier times, the M&StL routinely had commercial divers enter the river and inspect the bedding of the stone piers. Over the last 20 years or so, one of those stone piers has settled unevenly, apparently due to the river scouring out the bedding for the pier. Before operations ended, that pier was tipped toward downstream so that its top was about 12”-18” out of alignment. It was very visible as a large dip and offset in the bridge deck, and in just looking at the pier compared to the rest of the piers. I found it hard to believe that U.P. continued to use the bridge when the pier bedding was so obviously compromised. How could you be sure of the pier performance at any given train event when the condition of the pier was obviously changing over time? How many degrees can you tip a GP-38 before you concentrate so much extra loading on the tipped pier that it tips further? What I'd like to know is how often trains were put through in a day and how fast they would run. I know there would have been restrictions but---- Also what would that offset do to the piers next to the tipped pier----I'd love to have seen what kinds of side loading would have occured with, say, 15 cars loaded----
Bucyrus On that same line, there is a much larger, multiple span deck girder bridge on stone piers spanning the Minnesota River at Carver, MN. In earlier times, the M&StL routinely had commercial divers enter the river and inspect the bedding of the stone piers. Over the last 20 years or so, one of those stone piers has settled unevenly, apparently due to the river scouring out the bedding for the pier. Before operations ended, that pier was tipped toward downstream so that its top was about 12”-18” out of alignment. It was very visible as a large dip and offset in the bridge deck, and in just looking at the pier compared to the rest of the piers. I found it hard to believe that U.P. continued to use the bridge when the pier bedding was so obviously compromised. How could you be sure of the pier performance at any given train event when the condition of the pier was obviously changing over time? How many degrees can you tip a GP-38 before you concentrate so much extra loading on the tipped pier that it tips further?
What I'd like to know is how often trains were put through in a day and how fast they would run. I know there would have been restrictions but----
Also what would that offset do to the piers next to the tipped pier----I'd love to have seen what kinds of side loading would have occured with, say, 15 cars loaded----
My understanding is that this bridge was inspected much more frequently than other bridges because of its condition. The continuing deterioration of the bridge would have ultimately led to abandonment of the line, since there wasn't enough traffic to justify a rebuilding once the bridge became unsafe. But the failure of the trestle you mention hastened the end.
I would suspect that they would have been really keeping an eye on that Carver bridge as it deteriorated, although I don’t have any specific information about their observations and conclusions.
But just considering the nature of the defect that was developing, I find it hard to imagine how one could establish a threshold where a certain amount of the defect was okay to run on, and once the defect grew beyond that threshold, it would not be okay to run on. It would seem that to establish that threshold, one would have to assume that the defect was growing at an even rate. However, I suspect that such a tip-over event would be growing at an accelerating rate. And learning the exact rate of acceleration would be practically impossible.
Bridges can collapse with no visible indication of a problem, so I am amazed that such an obvious, serious, and fundamental problem as a loss of footing that is tipping a pier would not condemn the bridge until it was repaired.
In a way, it is rather prophetic that the risky operation over that deteriorating Carver bridge was finally ended permanently by the catastrophic collapse of another bridge on the same line less than a mile away.
The irony is that they had a defective bridge on which they were relying on their own expert assessment of the growing danger to continue operation. And yet that same expertise on which they were relying for the Carver bridge completely failed them on a bridge less than a mile away. In retrospect, I wonder what would have happened had not that other bridge failed, and they kept assuring themselves that it was okay to continue operation over that Carver bridge.
steve14 I found the link to the full NTSB report on Bayou Canot. http://ntl1.specialcollection.net/scripts/ws.dll?websearch&site=dot_railroads Go there and click on the year 1993. It is the first rpeort, noted as Amtrak. Also a good source for older accident reports
http://ntl1.specialcollection.net/scripts/ws.dll?websearch&site=dot_railroads
Go there and click on the year 1993. It is the first rpeort, noted as Amtrak.
Also a good source for older accident reports
Thanks much, steve14 ! That's what I surmised happened to it. I'd seen that website recently, but it doesn't seem to be linked or clearly referenced from the NTSB's main on-line site. So that's a good one to save for future reference. For what it's worth, I got a slightly different URL for the INVESTIGATIONS OF RAILROAD ACCIDENTS 1911 - 1993 - Table of Contents page -
http://ntl1.specialcollection.net/scripts/ws.dll?toc&ds=82
And here's the direct link to the Amtrak No. 2 - Sunset Limited Bayou Canot accident report - it's 70 pages, approx. 4.23 MB in size for the 'PDF' format version:
http://ntl1.specialcollection.net/scripts/ws.dll?file&fn=6&name=*S%3A%5CDOT_56GB%5CRailroad%5CWEBSEARCH%5CRAR-94-01.pdf
Thanks again.
Not a railroad bridge, but one of history’s more catastrophic bridge failures nevertheless. Here, the Minneapolis I35W Bridge poses innocently in the sun, making no mention of its imminent plan to become famous on August 1, 2007.
http://www.johnweeks.com/bridges/pages/ms16.html
Paul_D_North_JrThere's a little table of 11 bridge failures over the 150 years from 1857 to 2007; the Ashtabula Ohio bridge in 1876 is the 2nd entry, and the I-35W bridge in Minneapolis in 2007 is the last. Notably, 6 of the 11 are railroad bridges; but the last one before the 1993 Big Bayou Canot Amtrak wreck was the 2nd attempt to bridge the St. Lawrence River at Quebec in 1916 - the other 5 in the last 40 years since 1967 are all highway bridges. This excerpt is also illuminating [emphasis added - PDN]:
There's a little table of 11 bridge failures over the 150 years from 1857 to 2007; the Ashtabula Ohio bridge in 1876 is the 2nd entry, and the I-35W bridge in Minneapolis in 2007 is the last. Notably, 6 of the 11 are railroad bridges; but the last one before the 1993 Big Bayou Canot Amtrak wreck was the 2nd attempt to bridge the St. Lawrence River at Quebec in 1916 - the other 5 in the last 40 years since 1967 are all highway bridges. This excerpt is also illuminating [emphasis added - PDN]:
Nothing about the Custer Creek bridge washout on the Milwaukee? This happened in 1938 a few miles northeast of Miles City. MT. OTOH, a washout is a bit of a different prblem than a straight bridge failure.
- Erik
BucyrusIIRC, there is a Mississippi River bridge whose location escapes me (Vicksburg?)-a cantilever, I believe-that has/had one pier out of alignment almost from the day of opening. Apparantly it's not too noticeable...but just knowing that would always give me pause before crossing (but I get nervous when it comes to heights, anyway...)
Yes that is a KCS RR bridge at Vicksburg, Ms. When I was in college drove over the bridge which was a narrow 2 lane toll road with the IC track on the south side. Naturally was on the bridge at night with a 4 unit diesel train crossing along side of me. The bridge shook so much I finally almost stopped until train vacated bridge at about a 10 MPH speed. Bridge closed to automobiles the day I-20 bridge over Mississippi river opened.
A few years ago the western bridge support column was found displaced and KCS shut down the route until repairs made. Think it was caused by scouring of foundation but not sure? This bridge IMHO probably is the one choke point that could shut down the "speedway" at any time. Could happen this spring when the Mississipppi River will be high from all the winter snow melt runoff.
I found the link to the full NTSB report on Bayou Canot.
Kevin C. Smith Bucyrus On that same line, there is a much larger, multiple span deck girder bridge on stone piers spanning the Minnesota River at Carver, MN. In earlier times, the M&StL routinely had commercial divers enter the river and inspect the bedding of the stone piers. Over the last 20 years or so, one of those stone piers has settled unevenly, apparently due to the river scouring out the bedding for the pier. Before operations ended, that pier was tipped toward downstream so that its top was about 12”-18” out of alignment. It was very visible as a large dip and offset in the bridge deck, and in just looking at the pier compared to the rest of the piers. I found it hard to believe that U.P. continued to use the bridge when the pier bedding was so obviously compromised. How could you be sure of the pier performance at any given train event when the condition of the pier was obviously changing over time? How many degrees can you tip a GP-38 before you concentrate so much extra loading on the tipped pier that it tips further? IIRC, there is a Mississippi River bridge whose location escapes me (Vicksburg?)-a cantilever, I believe-that has/had one pier out of alignment almost from the day of opening. Apparantly it's not too noticeable...but just knowing that would always give me pause before crossing (but I get nervous when it comes to heights, anyway...)
IIRC, there is a Mississippi River bridge whose location escapes me (Vicksburg?)-a cantilever, I believe-that has/had one pier out of alignment almost from the day of opening. Apparantly it's not too noticeable...but just knowing that would always give me pause before crossing (but I get nervous when it comes to heights, anyway...)
I can understand how experience can judge how much misalignment you can run a train over without significant risk of derailment, and thus why some degree of misalignment is often tolerated. And, if there were a permanent misalignment on a bridge, simply due to a construction mistake, they might just live with it.
However, this misalignment on the Carver bridge is clearly the result of a progressing structural failure of the bridge. It is hard to believe that would be tolerated at all. Bridges are inspected to seek any indication of a failure that might occur because once the failure begins, it might progress as an instantaneous collapse with no further warning.
About two miles downstream from the Carver bridge was another bridge over the Minnesota River that carried the Milwaukee Road original Hastings & Dakota RR. That was a steel through truss center pivot swing bridge. Around 1988, I noticed that the bridge was obviously in the process of falling over due to a tipping of the center support that carried the swing bearing. This was an undermining of the riverbed just like what is occurring at the Carver bridge today. With the H&D bridge, I could see the tipped pier, one of the end roller bearings lifted off of its support base, and some of the tension bars coming off of the center “A” frame were buckled in compression. Clearly, the bridge was slowing falling over into the downstream side of the river.
By that time, that Milwaukee line had been abandoned and converted to a trail, so I called the state DNR and told them the bridge was falling over. They poo-pooed my report as being not credible. They said they routinely had commercial divers inspect the river bottom for evidence of scouring and pier undermining. They told me not to worry about it because they had engineers and bridge experts who would make sure that the bridge was safe.
In 1998, that bridge suddenly began to tip faster day by day, giving sure indication that it was going to fall over. So the DNR blew it up for safety. It was a tragic and needless loss of a magnificent structure dating from the 1890s, and a treasured feature of interest on the trail. So that was a catastrophic bridge failure in very slow motion. It took over fifteen years from start to finish.
Paul--Thank you pulling out all of this trivia (bridge geeks like this stuff) and clearing up the "basis" of the claims made in the TV show. Sensationalism over substance. It would be interesting to know who the people were that developed these opinions.
I can send you a hard copy of the report if need be. The report makes note of the CWR over the bridge and that the signal system was not interrupted by the barge hit but offers no opinion on whether jointed rail would have come apart. This is hardly suprising. One of the many examples we use in the AREMA Bridge Scour seminar shows a bridge where the roadmaster had gone over suring a severe weather inspection and wanted to run back over the same route before letting trains go. The diapatcher argued with him saying his board showed all green. The roadmaster won and came back to the bridge which he had gone over only a couple hours before to find 2 of the 4 double track TPG's in the river.
The question we ask is "what color are the signals?"
We have many other examples of scary things you find on bridge inspections in AREMA's Bridge Inspection seminar also.
CShaveRR I remember one near failure of a bridge here in Chicago. It was the CTA's connecting line between the old south side "L" to the new line in the median of the Dan Ryan Expressway. Somebody riding under this bridge on a commuter train noticed what he thought was a crack in one of the girders--and he was right. Things were very hastily shored up, and the line was returned to service in a relatively short time. I don't know to what extent the bridge was rebuilt, but it is now used by the CTA's Orange Line trains to Midway Airport.
As promised - from Trains, June 1986, Vol. 46, No. 8, "Disaster du Jour, and other stories", by E. W. ‘Ed’ King, Jr., pp. 30 - 36, at pg. 35, cols. 1 and 2, and pg. 36, col. 1:
[Several paragraphs omitted - PDN]
*The ''Jesse James'' coaches were ''steam-heated, 2500- and 2600-series ''Jesse James'' (or ''Harriman'') open-window coaches from the mid-1920's. Some commuters swore that there were holes in them from bullets and arrows.'' - per pg. 32, col. 1.
Here is a link showing the bridge at Carver, MN over the Minnesota River:
http://www.johnweeks.com/bridges/pages/rm01.html
In the first photo, you can see the misalignment toward the far end. In the bottom photo, you can see the defective pier, which is third from the left. In this photo, the river flows toward the camera, and you can see the pier tipped toward the camera as well. My impression is that the misalignment progressed significantly further than shown here.
During the final operations over the defect, trains were minimal in size, speed, and frequency. They would consist of one engine (GP-38) and 1-6 cars. Speed was very restricted over the bridge, to perhaps 10mph or less. The defect appears to involve only one of the piers. There is no indication of a structural problem with the integrity of the stone pier itself. Instead, it appears to be a case of the whole pier being tipped 5-10 degrees due to a loss of footing in the riverbed.
Trees float down the river and lodge against the bridge piers. Over the last 20 years of operation, the U.P. and previous owner C&NW allowed the trees to accumulate into a huge floating mass covering maybe an acre or more. Then the company would stage a rail crane and grapple on the bridge to pick the trees out of the mass, and place them on the downstream side of the bridge. When these tree massing events reached their maximum, they apparently restricted the river to a narrower flow, which accelerated the bottom scouring around the affected pier.
I know that yard tracks can become shockingly misaligned and still pass trains without derailment. But I found it rather surprising that the company would accept running trains over this bridge defect when is was obviously in the process (although a slow process) of developing abrupt, catastrophic failure. Moreover, the consequences of reaching that failure point while riding over it in an engine would be quite dreadful for the crew. Ironically, though, the eventuality of a pending catastrophic failure of this bridge was precluded by the abrupt, catastrophic failure of a small trestle only about mile south, which ended operation over this line.
Perhaps one of the most famous because of film recording of it's failure would be the Tacoma Narrows Bridge back in 1940.
The famous pictures of the automobile out on the bridge, and I believe it also showed a person trying to make his way back on foot to safety, while the wind has the bridge starting to sway and buckle until it finally tears apart and falls into the water.
I believe both bridge towers remained standing thru it all....The bridge was cable supported, and they finally snapped and much of it collapsed.
'Original Post' for this thread -
Murphy Siding Other than last year, when a bridge (or trestle?) on a shortline railroad collapsed while hauling something big for NASA, are railroad bridge failures rare?
I ran across this while looking for the NTSB report on the Amtrak Big Bayou Canot wreck. It's pretty instructive, I think, for the original question:
''What the Profession Can Learn from Failure of its Bridges.''
from
at - http://content.asce.org/files/pdf/HHNewsletterMay08.pdf
[It's 3 pages, approx. 369 KB in size]
''In summary, six of the failures were the result of a failed connection, two by ship impact, one by a compression member failure, one by scour and one by a train running off its tracks. The journals and newspapers of the time sensationalized each failure. Over time the profession modified procedures and specifications to minimize future failure. The Minneapolis Bridge failure, however, indicated we still have a ways to go before bridge failures are a thing of the past. Henry Petroski, Chair of the H & H Committee, has written extensively on bridge failures and has written as early as 1993 “that the cable stayed genre was a most likely candidate to experience the next major bridge failure.”
It is recommended that the training of Civil Engineers include an exposure to the History of the profession in general but more specifically in the study of failures and subsequent actions by ASCE and the specifying agencies to correct flaws in the specifications, design procedures and inspections.''
Finally, on the 3rd page under the heading ''Banner Images'' are a couple of paragraphs on the Kate Shelley Bridge, its Engineer, and its then-pending replacement. I ought to post a link to it in one of those threads, too . . .
Some more details in the ''Seconds from Disaster'' vein, from -
http://en.wikipedia.org/wiki/Big_Bayou_Canot_train_disaster#Analysis [usual disclaimers apply - PDN]
An episode of the National Geographic Channel [National Geographic Channel, also commercially abbreviated as Nat Geo, is a subscription television channel that airs non-fiction television programs produced by the National Geographic Society...] documentary series Seconds From Disaster [Seconds from Disaster is a documentary television series that aired from July 6, 2004 to March 7, 2007 on the National Geographic Channel. The program investigates historically relevant man-made and natural disasters...] examined this accident in detail.
This analysis seems to me to be of a ''If pigs had wings . . . '' nature. It completely skips over the fact that 'but for' the towboat skipper getting lost and then hitting the bridge, the wreck would have never happened. Also, there's a circular fallacy here about barge traffic posing a regular hazard - if that had been a designated river channel, the points might have some merit - but it wasn't. So why should the railroad have equipped the bridge to withstand a collision from a marine tow that wasn't even supposed to be near there in the first place ? Note that of all the many recommendations made by the NTSB to the several agencies and organizations as a tresult of this tragedy, none of them pertained to this aspect. To suggest as the above quote does that jointed rails are better on bridges because they might be more likely to break if impacted and thereby trip the signals to red - and ignoring the other benefits of welded rail - is to invent facts and rationales where none exist or have actual support in reality. May as well say that the engineer should have run 5 minutes ahead of schedule - then the train would have been past the site when the barge impact occurrred.
Still looking for the full text of the NTSB report to see if it thought this even warranted mentioning, and what treatment it was given . . .
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