Starting a new thread on this to prevent hijacking the already long two-tracking thread. Please repost any comments here to consolidate the story.
Overmod Starting a new thread on this to prevent hijacking the already long two-tracking thread. Please repost any comments here to consolidate the story.
This is posted [as noted on the aforementioned 2Tracking Thread]:
Possibly, the 'Moderators' can move it, and correct the post as it was on the Thread re: "Sunset Route Two-Tracking Update" ???
One end of the Union Pacific bridge in Tempe Arizona over the Tempe Town Lake has collapsed. The train on the bridge derailed and caught fire. Unknown if the derailment caused the bridge to collapse, or vice versa.
I am curious how a car load of packaged lumber caught on fire? Or was burning because of another fire that spread to the lumber?
Ed Burns
Retired Class 1
Found the following linked article in the U.S. edition of "The Sun":
link @ https://www.the-sun.com/news/1220603/bridge-collapses-train-derails-arizona/
"TRAIN DISASTER:Arizona bridge COLLAPSES after a train derails & bursts into flames leaving firefighters battling huge blaze" ByLaura Gesualdi-Gilmore Jul 29 2020, 12:26 ET,Updated: Jul 29 2020, 13:15 ET
Article includes a number of photos and limited information.
Which came first ? Did a derailment cause the bridge to collapse, thence the fire ? Or, did the bridge collapse first, causing the wreck.
Looks not too unlike the work of Gomez Adams !
Steve
I live in the area.
On June 26th, there was another derailment on this bridge involving 12 cars. Again there was a fire and some ties were damaged. This did not make the news here.
Today's derailment is particularly interesting. The approaches on both ends of the bridge were/are of wooden trestle design. The span that collapsed was a smaller span that abuts to the southern trestle approach. All of this apparently burned.
The bridge itself is 108 years old and is overbuilt, overengineered steel as many such structures dating to the time are. The only flammable substance on the bridge are the creosote soaked wooden ties.
There has been a lot of protest action in the area over the last couple of months due to some things which happened and which I am sure we all know.
Not saying anything but the Tempe police department is looking for anyone who might have saw anything near the bridge in the hours before the derailment occurred.
steve24944 Which came first ? Did a derailment cause the bridge to collapse, thence the fire ? Or, did the bridge collapse first, causing the wreck. Looks not too unlike the work of Gomez Adams ! Steve
From the eye witness descriptions, it sounds like there was no fire before the train arrived. They describe loud bumping or breaking sounds that were much louder than the rolling action of the train. They said at first they thought that loud sound was just the normal sound of the train, but the sound grew much louder as the souce of the sound got closer. So the sound they describe were not just loud, individual booms or bang, but more like a continous roar.
I would assume that the train had a deralied car that was being dragged, and that was the loud noise the witnesses desribe. Then that derailed car eventually fouled the bridge structure and tore it down.
I assume that the dragging derailed car dropped sparks as the wheels and truck frames tore into the rail and other steel track structure; and those molten metal sparks ignited the creosoted ties.
They said the fire was originally at the end of the bridge where it was collapsed, and then burned progressively out onto the bridge for several car lenths.
This is a very low speed location; probably 10 mph. The damage here appears to be much greater than would occur under normal speed and operations.
Given the current climate in our country there may be a 'sabatoge' situation here.
Questions
A. Will the fire cause too much damage to the steel to be reused? How about Piers ?
B. Up might rebuild the bridge as a solid closed deck bridge with no truses ? Anyone know span lengths ?
C. Why does UP keep gettting burned (sorry) by the many SP wooden bridges ?
D. How will UP get the many customers cars yarded as the present yard is east of the bridge and has been reported on other threads as almost always jammed ?
E. What is present train count Tucson - PHX ?
This accident may have several cosequences.
1. Immediately traffic will need to be routed over BNSF's Peavine that has many slow sections. Close in rerouting not easy as either El Paso or Los Angeles to get on BNSF. Longer reroutes on BNSF or UP to Vaughn then BNSF.
2. BNSF may need to work on some of the Peavine's sidings ? What are max lengths of trains on the Peavine. Imagine that stringlining a real posssibility ? BNSF might not want additional haz mat on the Peavine ?
3. BNSF will need to qualify / requalify some crews.
4. UP may consider reopening the PHX - Yuma line that had approximately 80 (?) miles out of service. The bridge is not going to be repaired quickly. Actually 140 miles from Welton - PHX would need ballast and surfacing. Does anyone know if there are any washout or track impediments that could slow reactivation ? Any storred cars that would have a problem locating elsewhere? If service restored over this sector absolute work windows will be needed to upgrade rail and crossties.
5. It might be that reactivation would cost less that replacing the bridge ? That woould require replacing the signaling and PTC implementation. Reactivation could give an opportunity for AZ to kick in some funds if UP would agree to allow PHX- LAX passenger Train(s) ?
5. If UP reactivates of course qualifying crews on the sector could be done before 1st revenue operations.
6. No matter what UP does the yarding of trains remains a problem.
UP's Phoenix yards are West of the bridge, in Downtown Phoenix and the Campo Yard between 35th-43rd Aves, most of their customers are on the West side of town. From what I understand the Wellton line is still operable - they store cars on it -but it would be slow speed. All the business from Tempe East would have to be serviced from Tucson, including the mines and the CBRY.
This is the second UP derailment in the Phx area that involved fire this year, several weeks ago a local switching in the Downtown area derailed, causing one of the locos to catch fire (fuel tank puncture?)
Only UP could knock out a chunk of a bridge that has stood for over 100 years and multipule 100-year old river floods.
blue streak 1A. Will the fire cause too much damage to the steel to be reused? How about Piers ?
Whether the propagated tie fire caused irremediable damage to the other spans is something mudchicken or diningcar would be more competent to rule on. If not, I suspect a replacement temporary span might be put in quickly, if the line is as important as indicated, probably designed so a permanent replacement can be built 'parallel' to it on a more cost-effective schedule and slid in to replace the temporary when ready.
What environmental or other government-associated complications to replacement are posed by the location and 'surroundings'?
It's been super hot there this week. Pull-apart or kink due to expansion/contraction?
It will be interesting to find out exactly what happened.
https://www.azfamily.com/news/train-derailment-massive-fire-on-bridge-over-tempe-town-lake/article_ce292ef0-d19e-11ea-a57f-7bc720db639f.html
"Hours after the incident, the Tempe Police Department put out a tweet asking anyone "who witnessed or many have any information about the train derailment and fire" to call its non-emergency line."
York1 John
York1 It will be interesting to find out exactly what happened. https://www.azfamily.com/news/train-derailment-massive-fire-on-bridge-over-tempe-town-lake/article_ce292ef0-d19e-11ea-a57f-7bc720db639f.html "Hours after the incident, the Tempe Police Department put out a tweet asking anyone "who witnessed or many have any information about the train derailment and fire" to call its non-emergency line."
Apparently, this is the SECOND derailment that has happened in this area! Posters: Silicone212 and Azrail mentioned that this was the second derailment. Also that FIRE was an unusual element, in both instances.
Then the report of the police lookng for information; regarding unusual actrivity, and poss. Trespassing?
I have no ideas as to any unusual 'political activity' in this Tempe area, but in light of what seems to be happening Nationwide...Anything becomes a possibility?
This location is within walking distance of Downtown Tempe, where there have been a few demonstrations over the last several weeks. There was a large demonstration that occurred there the night before the derailment. It is also within walking distance of ASU, where demonstrations have also occurred. The demonstration that occurred Tuesday night was at the Tempe Beach Park, which runs underneath the bridge at the location where the derailment occurred.
OvermodWhat environmental or other government-associated complications to replacement are posed by the location and 'surroundings'?
The bridge is in the floodplain of the Salt River, so they will need to notify the appropriate agency. Since the collapsed section is over a parking lot I can't imagine that the process would be onerous.
This is a picture of the southern approach to the bridge, before the accident. The first span you see past the trestle is the span that collapsed.
silicon212 This is a picture of the southern approach to the bridge, before the accident. The first span you see past the trestle is the span that collapsed.
That scenario is supported by the theory that a derailed dragging car was moving intact with the train, but was running off center to the line of track. Then the tighter clearance of that first bridge truss was not sufficient to clear the derailed dragging car. So that car snagged the truss and caused the truss to move off its supports, and totally collapse under the train.
If one were to inspect the piled up cars, I suspect it would be easy to determine which car was derailed and dragging and to find the first contact evidence on that car and the bridge truss. Damage to the ties would also indicate where the car first derailed.
If this had occurred further out on the bridge, the fouling condition would have been immediately created, and thus the point of derailment would be close to the point of truss impact damage. However, since it occurred at the first truss encountered, the point of derailment could have been anywhere ahead of that encounter with the first truss. It could have derailed hundreds of feet or more ahead of the bridge, for instance.
Euclid, after looking at the latest photos showing the pile trestle approaches to the steel truss bridge I think your analysis is the likely cause of this accident.
Euclid, after viewing the photo of the pile trestle approach to the steel girder bridge I think your analysis is the likely cause of this bridge collapse.
EuclidThat scenario is supported by the theory that a derailed dragging car was moving intact with the train, but was running off center to the line of track. Then the tighter clearance of that first bridge truss was not sufficient to clear the derailed dragging car. So that car snagged the truss and caused the truss to move off its supports, and totally collapse under the train.
Not quite. It is highly improbable that the "truss would move off its supports". Instead a derailed car likely took out one or more of the vertical or angled truss chords, which are non-redundant structural members. Lose one, and most of the strength is instantly lost. The span will collapse.
Looks like the southernmost span that still stands will come down tomorrow morning.
https://www.azfamily.com/news/tempe-town-lake-bridge-demolition-scheduled-for-sunday/article_303fcdd2-d439-11ea-8394-db2c54739aa7.html
Guess they did a controled blast to break up part of the bridge.
https://www.yahoo.com/news/arizona-bridge-partially-detonated-train-160431152.html
Probably used shaped charges to cut the steel precisely and drop it so it can easily be removed in convenient-size-and-shape pieces without torching or cutting ancient painted metal that might be lead primed.
Video of demolition blast is in the link which follows:
https://www.azfamily.com/news/damaged-portion-of-tempe-town-lake-bridge-demolished-sunday/article_912770be-d4d4-11ea-9381-03d7a8644f9c.html
They should just put the West Phoenix line back in service!!
silicon212Video of demolition blast
Loved how the birds took off a split second before the blast, then as the dust is settling, birds come back to the next span.
UP has announced that the bridge will be open next week (8-10-15) and will have trains staged to service customers. See news wire at Trains News.
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