RME CMStPnP BaltACD My take on that was that some of the ties are varying length for the switches and so they temporaily bypassed them, instead of mixing them.... until they get in the longer concrete switch ties? Not sure. It was my understanding that there were at least two reasons for maintaining conventional ties at these points. First, the economics of concrete ties largely depend on getting a consistent 'unit' out of a mold, with standardized hardware that has a predictable geometry and 'automatable' installation and removal of attaching and anchoring hardware. If you look at switch and crossover ties, each one is not only different but, in concrete, would have to be very precisely molded, or post-treated with grinding, epoxy, etc. for the necessary precision. For wood ties, you'd just align the various components and spike them down. Similarly, NVH and lateral shock reduction at these points can be important. Concrete ties are not good in this respect, and neither are many of the 'tubular track' systems; even a little differential lateral motion or settling can put ties at risk of cracking right where gauge-holding integrity is most significant. To the extent there may be 'more maintenance', it's essentially limited to a few hundred feet worth of track mileage, and I for one have never questioned that it makes sense. Back in the day I was concerned with the idea that the track needed to be 'tuned' approaching and leaving the more compliant area, but Amtrak conducted research that said bridge approach tuning (which I consider more significant in a number of dynamic respects) is not really useful [except at very high speeds, where you'd be using ballasted-deck or top-down-monobloc-cast structure anyway]. I'm looking forward to hear from the experts on this.
CMStPnP BaltACD My take on that was that some of the ties are varying length for the switches and so they temporaily bypassed them, instead of mixing them.... until they get in the longer concrete switch ties? Not sure.
BaltACD
My take on that was that some of the ties are varying length for the switches and so they temporaily bypassed them, instead of mixing them.... until they get in the longer concrete switch ties?
Not sure.
It was my understanding that there were at least two reasons for maintaining conventional ties at these points.
First, the economics of concrete ties largely depend on getting a consistent 'unit' out of a mold, with standardized hardware that has a predictable geometry and 'automatable' installation and removal of attaching and anchoring hardware. If you look at switch and crossover ties, each one is not only different but, in concrete, would have to be very precisely molded, or post-treated with grinding, epoxy, etc. for the necessary precision. For wood ties, you'd just align the various components and spike them down.
Similarly, NVH and lateral shock reduction at these points can be important. Concrete ties are not good in this respect, and neither are many of the 'tubular track' systems; even a little differential lateral motion or settling can put ties at risk of cracking right where gauge-holding integrity is most significant.
To the extent there may be 'more maintenance', it's essentially limited to a few hundred feet worth of track mileage, and I for one have never questioned that it makes sense. Back in the day I was concerned with the idea that the track needed to be 'tuned' approaching and leaving the more compliant area, but Amtrak conducted research that said bridge approach tuning (which I consider more significant in a number of dynamic respects) is not really useful [except at very high speeds, where you'd be using ballasted-deck or top-down-monobloc-cast structure anyway].
I'm looking forward to hear from the experts on this.
Johnny
BaltACDWhat I find interesting is that where concrete ties have been installed, all the switches and crossovers are wood ties.
BaltACD CMStPnP https://www.youtube.com/watch?v=cb6ZrKhGY90 Cool Stuff!!! What I find interesting is that where concrete ties have been installed, all the switches and crossovers are wood ties.
CMStPnP https://www.youtube.com/watch?v=cb6ZrKhGY90 Cool Stuff!!!
https://www.youtube.com/watch?v=cb6ZrKhGY90
Cool Stuff!!!
What I find interesting is that where concrete ties have been installed, all the switches and crossovers are wood ties.
About two years ago, as I was going east, I noticed long sretches of concrete ties in Iowa--and new wood ties being put into place in Illinois (as I remember the states).
Never too old to have a happy childhood!
Gramp Nice to both!!! Interesting that Paris has numerous other train movements while LA has one.
Nice to both!!! Interesting that Paris has numerous other train movements while LA has one.
In some cases Gare de L'Est has more movemenets than some countries networks. In reality that is possiuble because there's a lot of main (I believe 9 in the first 8 kilometres) tracks (30 stub tracks, plus the passing tracks of Magenta subterranean station, used by RER services). Also having so many t main tracks - 4 for the main line, plues 5 for the RER and some commuter services -, makes possible some fierce railroad action. Typically the main tracks are used by TGV, 'Intercités' (intercity), regioal and T'Translien' outer suburban routes, with all other tracks available for RER and deadhead movements
On a typical weekday approximately 175 passenger trains depart or arrive at L A Union Station. Included in the mix are six Amtrak long distance trains - when the Sunset Limited departs or arrives, 23 Pacific Surfliner trains, and 146 Metrolink trains.
Rio Grande Valley, CFI,CFII
CMStPnP I am especially impressed with the new flyover the Chief is using over what I would guess are the Intermodal rails to the Pacific Port of Long Beach? Just guessing.
Yes, that is a new flyover built as part of the Alameda Corridor construction almost 20 years ago. Only freight traffic on it is BNSF running to their 'storage' yard just north of Amtrak's. SCRRA (Metrolink) owns and dispatches both banks of the river north of the AC (where UP and BNSF connect).
Another YouTube poster has made some great videos of SoCal passenger rail, including this one from LAUS to San Diego:
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! ***
I would say that that is not bad at all for a US train, but still far from what we have here in Europe. Here's an example, with video of how fast trains acelerate away from terminals over here. In this particular example it's a regional train serving the region of Paris (maybe the english designation 'outer suburban' is the most adequate). After some 0,8 miles of track (precisely at kilometre 1,2, track speed rases from 18 Mph (30 kmhr) to 74,5 Mph ( 120 kmhr), and it only descends from that level in maybe one place (the train seen here uses the fast tracks and reaches a maximum speed of 100 Mph). Ah and it's a so called 'Bi-mode' (diesel and electric) railcar that swiches between modes at crca 87 Mph
I wonder what excuses and rationalizations are/will be given for why we cannot? They are able to accelerate quickly in other counties on conventional trackage.
C&NW, CA&E, MILW, CGW and IC fan
I was impressed to watch this footage of the Southwest Chief leaving LA. Note the fast exit from LA Union Station and the rapidly receeding skyline of LA in the first part of the video below. This is how it should be in every major city of the United States for both LD rail and Cooridor rail trains. I am especially impressed with the new flyover the Chief is using over what I would guess are the Intermodal rails to the Pacific Port of Long Beach? Just guessing.
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