A recent “Seconds from Disaster” about the Bayou Canot accident asserted that the investigators determined that the bump from the barge should not have damaged the bridge, and in fact part of the bridge that was contacted (the non-swing part) did not move. The problem was that the bridge was a swing bridge whose swing mechanism was “decomissioned” improperly.
Unfortunately, only the rails were holding the bridge in place. When the barge struck the bridge part of it hit the swing span and the rails deformed enough to allow the bridge to move several inches.
Had the swing span been fastened in place the accident would not have happened. The barge impact would have had little to no effect.
Of course the barge should not have been in the canot, but the bridge should have been fastened correctly.
HAd a trestle collapse under a loco in 2008 in Columbus Jct Iowa. Also Turkey River bridge ( not sure if it was 2008 still or earlier for this one) up on the Marquette sub. Two bridges one railroad. Kinda rare these days.
From the Transportation Research Board’s publication “EVALUATION AND FIELD TESTING OF THE DAN RYAN RAPID TRANSIT STRUCTURE” at - http://pubsindex.trb.org/view.aspx?id=210102 [emphasis added - PDN] -
"The Dan Ryan rapid transit structure is a 40-span, 4,000-ft-long elevated structure that carries Chicago Transit Authority (CTA) rapid transit trains into and out of the Chicago Loop. The structure, which was completed in 1969, consists of welded stringers and is supported by steel box-girder bents. Splices in the stringers are field bolted. The steel stringers carry two sets of track on a ballasted concrete deck. In January 1978 major brittle fractures ocurred in three of the steel box-girder bents. Since discovering the bent fractures, C
I have been reading this string and keeping quiet, but I think some things need to be said.
While I have never seen an episode of “Seconds from Disaster”, I do have to take issue with the assertion that the barge hit (not a bump) should not have damaged the bridge.
The NTSB report clearly shows the impact point was on the pier under the north end of a 165’ truss and the south end of the 140’ TPG and on the center pier of that TPG. The TPG was, according to the report, built in 1909 to replace a truss span. The intention seemed to be to create a swing span. No machinery was ever installed. The south pier of the TPG is concrete. The south end was the expansion end, the north end was the fixed end, hence no direct anchoring of the span to the pier. It was fastened correctly.
The south end of the TPG “was displaced 38” by the barge and was subsequently destroyed when tran 2 struck the displaced girder" to quote from the NTSB report. That is hardly a “bump”
Please, when you are commenting on incidents such as this, it helps if you take a little time and consider what sources you are referencing.
I also recall most of what steve14 posted above about that disaster, and hence agree with him on that. (BY the way, ‘‘TPG’’ = Through Plate Girder.) I looked earlier and was not able to find the full report - maybe it was moved to someplace I’m not familiar with ? - the best I could find was the below summary of the NTSB report, which didn’t address the precise issue here. Nevertheless, my recollection is that it was a definitely a fixed portion of the bridge that was distorted on the order of 3 ft. out of line by the barge tow’s impact - I thought it was more like trestlework than a pier and the TPG, but my memory is not clear or certain on that. Simple consideration of the mass/ weight of that tow moving at a couple miles per hour tells you that when it hit that fixed structure, serious damage was going to be done - there’s no energy absorption or attenuaiton device or arrangement on either one, other than the distortion and deformation resulting from the collision damage, which is what finally brought the barge tow to a stop.
RAILROAD-MARINE ACCIDENT REPORT Adopted: September 19, 1994 DERAILMENT OF AMTRAK TRAIN NO. 2 ON THE CSXT BIG BAYOU CANOT BRIDGE NEAR MOBILE, ALABAMA SEPTEMBER 22, 1993
A couple years ago, a U.P. train running on the ex-M&StL line from Chaska, MN to Merriam Junction, crushed a short (50’ long) timber trestle spanning a watercourse draining into the adjacent Minnesota River and dumped several cars into the water. Due to having only one customer on the line, U.P. abandoned it rather than rebuild the trestle. Interestingly, that same trestle was struck by lightning and set ablaze in the 1910-1915 era, and an CMStP&O freight broke through the smoldering timbers before the engineer realized the bridge was on fire.
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.
Paul–I must have down loaded the report early enough to get the whole thing, because only the Summary shows on the NTSB web site now.
Aegrotatio–The TPG span was destroyed by the train, yes that is fact. The key point is that the barge moved the span over 38" so as to be in line for the train to hit it. With the force of impact of the barge, no amount of anchor bolts would have held that end of the bridge in place.
I don’t really think anyone slandered the NTSB. Are you referring to Blue Streak 1’s differentiation between an FRA accident report, which is confined to facts, and an NTSB report which brings in a great deal more analysis and recommended changes, etc?
If there was additional info developed for that show, it would be nice to see it and know who and how it was developed. As Paul said-- TV show vs NTSB, who ya’ gonna believe?
Sure, TV show vs. NTSB report, but be careful of the association fallacy. This isn’t the only show you may encounter that adds extra evidence and research to a long-held problem. The thing lacking would be peer review, but just because it’s on TV doesn’t mean it’s wrong.
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?
An episode of theNational 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 seriesSeconds 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.
Although there were signals on the line operated by track circuits, the long welded rails did not break and did not cause the bridge approach signal to change to red. Had jointed rails still been fitted, the signal may well have dropped to red, as such rails would more likely have broken at the joints.
The span had actually been designed to rotate so that the bridge could be converted to aswing bridge
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.
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
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:
"Hernan Solarte was abridge engineer whoreally liked his work. He was “into” bridges. Every workdaymorning, Hernan would look out of his inbound Jesse James* <
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?
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.
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 th