That is an impressive switch being assembled.
Looks like movable point frogs.
The way it is sitting it almost appears equilateral or they will be having the diverging route go under the bridge.
Thanks for this later video. My judgment tells me this is to solve a drainage -erosion situation where the original 1882 single track can no longer withstand the almost 140 years of infrequent but occasional flash flooding.
The soon to be former south track will be stabilized with riprap or other deterents to protect the north track which was built in the 1920's I think. Anyone with further info will be welcome.
New Truxton Video.
Had to google this...
https://ntlrepository.blob.core.windows.net/lib/42000/42800/42879/rr0803.pdf
Always learning something new from everyone here.
BaltACDWelded rail is a technology that still has not been fully mastered by the industry to be able to adapt to wide temperature swings without creating either the failure mode of sun kinks or broken rail/rail separations.
Whether that is worth the additional cost is a different matter entirely. But there is no doubt that if you want high speed and heavy axle load together, there is at present no better solution, certainly not one that involves individual lateral elements with a suddenly fluidizable shear layer in the subgrade...
OvermodLast I heard was that asphalt in the upper subgrade (the one place the mid-'70s competition on asphalt for railroading appeared to have borne potential fruit) had been somewhat deprecated due to increased lateral instability and sun kink in very hot weather. I suspect it was supplanted by some form of roller-compacted concrete with less thermoplastic binder... It would be interesting to see accounts or video of how it is still used, perhaps in conjunction with geotextile material.
It would be interesting to see accounts or video of how it is still used, perhaps in conjunction with geotextile material.
Welded rail is a technology that still has not been fully mastered by the industry to be able to adapt to wide temperature swings without creating either the failure mode of sun kinks or broken rail/rail separations.
Never too old to have a happy childhood!
Last I heard was that asphalt in the upper subgrade (the one place the mid-'70s competition on asphalt for railroading appeared to have borne potential fruit) had been somewhat deprecated due to increased lateral instability and sun kink in very hot weather. I suspect it was supplanted by some form of roller-compacted concrete with less thermoplastic binder...
SD60MAC9500Another item. Is BNSF still using asphalt for subgrade?
I've only see them use it in wetter climates with marginal drainage - see Alva OK for instance.
BTW here is the latest video on the Truxton flyover: https://www.youtube.com/watch?v=z05vyaWPGWA
Per posts on The Other site, pile driving for the second bridge over Lake Pend Oreille has begun. Just to the RR east the siding upgrades to full CTC are complete.
Links to my Google Maps ---> Sunset Route overview, SoCal metro, Yuma sub, Gila sub, SR east of Tucson, BNSF Northern Transcon and Southern Transcon *** Why you should support Ukraine! ***
diningcar Any news about the Truxton flyover progress??
Any news about the Truxton flyover progress??
Track construction is in progress across the flyover. Looks like possibly next month or Dec the flyover will be open.
Update of progress at Truxton, AZ.
Ok thanks for the correction. I worded my question wrong. Another item. Is BNSF still using asphalt for subgrade? I remebmer seeing this when they were doing work in the panhandle back in the early to mid 2000’s.
P.S. Came across this on youtube
SD60MAC9500 asks, What’s the gradient from Ash Fork to Williams?
Ash Fork has not been on the 'transcon' since 1960. The 44 mile Williams - Crookton line change moved the 'transcon' north away from the 1880(s) line.
The 44 mile new line has only 1% or less grades and 1 degree curves or less. Passenger trains - Amtrak - can and does operate at 90 MPH over this 44 miles.
While a flyover is indeed a great way to avoid stopping trains. What’s the gradient from Ash Fork to Williams? How often are trains held for opposing traffic? As you said Diningcar I noticed the wash from the linked video, and it does appear this is a problem. Monsoon season isn’t a great season with frequent flash flooding. I noticed there’s concrete embankment to keep the RoW stabilized. So perhaps this is a combination of factors. Keeping trains moving while avoiding any more work to keeping the wash in check.
Yes Overmod, but this RR has been here since 1885 +- and the engineers know the history. Perhaps the plan is to enhance the existing south track embankment to keep the historical erosion issue diverted from this 'historic problem site'.
Just a a thought waiting for an answer from BNSF.
diningcarAfter studying the site with the aid of google earth I am suspecting that Truxton Wash erosion is a contributing factor - perhaps the major factor.
After studying the site with the aid of google earth I am suspecting that Truxton Wash erosion is a contributing factor - perhaps the major factor.
I suggest there will be further explanation(s).
diningcar jmonier, that was my question also; as I suggested the Belen to Truxton 477 mile distance did not seem to me to be a reasonable explanation for the flyover.
jmonier, that was my question also; as I suggested the Belen to Truxton 477 mile distance did not seem to me to be a reasonable explanation for the flyover.
Here's a comment that was said on TO about the truxton flyover
"Date: 01/22/20 01:20
Re: New BNSF Flyover at Truxton ArlzonaAuthor: slug96
diningcar: My question to you is: If all the 50 mph crossovers, etc. make it so easy, why is a flyover being built at all and why is it being built specifically in that location? That was the point of my post.
The addition of 2MT CTC has not changed the grades, so there is still a considerable advantage to left handed running Winslow to Belen. If traffic is not too heavy in the opposing direction, then changing traffic directions via crossovers is acceptable (as was done for many years). With the heavy traffic now on the Transcon, it's another story entirely.
Seems like a few sections of a 3rd main could have releived that bottleneck as well.
Interesting
Yes rdamon, there are grade advantages to the continental divide summit in NM. Those also can be accomodated with the 50MPH crossovers which the dispatcher who handles the Belen to Gallup segment. The heavy trains can be manuvered just like the Amtrak 3 and 4.
The dispatcher who handles the Winslow to Seligman segment must deal with the AZ summit just west from Flagstaff in a similar manner. The former Williams to Seligman grade problems were mitigated with the 1960 line change which reduced the max grade to 1%. All of these locations have the 50 MPH crossovers.
I recall some grade advantages running left hand uphill on both sides of the divide.
BNSF has CTC/TCS all the way from Belen to Barstow with 50 MPH xovers spaced every 10 +- miles. If you ride #3 or #4 you will experience many crossovers as BNSF attempts to keep Amtrak on schedule as it competes many freight trains. Left hand running no longer exists.
The reason for this flyover is because there has always been left hand running from west of Winslow to Belen to get the most favorable grades. Both tracks were originally signalled for one direction only (no CTC) and there was a flyover near Ashfork. When Ashfork (and thus the flyover) was bypassed in the 60's the first CTC was installed from Seligman to Winslow and the burden was on the dispatcher to switch trains to the proper track somewhere in that segment. With the increase of traffic that has caused big delays and that is the reason for the new flyover.
MikeF90, thanks for the video. Seems surprising to me that a flyover at Truxton (MP 477) would be the location to elleviate a fueling access situation at Belen (MP0). The southern Transcon has 50 mph xovers every 10+- miles which allows multiple opportunities to cross from the south to the north or vice versa.
I suggest this Truxton construction has another justification. MC, have you heard about this?
Besides the ongoing Emporia sub construction, BNSF contractors are building a flyover near Truxton, AZ on the Seligman sub. Their media pages have been near silent since early this year so I don't have details from there.
Here is one of two YT videos found on the subject: https://www.youtube.com/watch?v=cYbF3O7JRjQ&t=5s
As I've read, the purpose is to move eastbounds to the north track for easier access to the fueling racks at Belen, NM. Construction is well along with completion due later this year.
Also no recent status of the siding upgrade work between Sandpoint, ID and Whitefish, MT. I'm no signaling expert, but wayside cabinets seen in recent Kootenai River sub videos look pretty new and IIRC include PTC antennas.
This BNSF carload shipping network map gives a comprehensive view of the BNSF subdivisions:
http://www.bnsf.com/ship-with-bnsf/maps-and-shipping-locations/pdf/carload_map.pdf
samfp1943, the Emporia Sub does not proceed toward Topeka.The connection to the KC-Newton line is at Ellinor, 12.6 miles west from Emporia. The line from Emporia through Topeka to Holliday is not the principal freight line but is the AMTRAK line, with occasioinal local freight.
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