Peter L. Reid
Train Attendant
What happened to delay the CZ in SLC for so long both ways? I apologise if this has already been asked
but I can find nothing relating.
but I can find nothing relating.
CZ Delay
- Thread starter Peter L. Reid
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Ted Bell
Service Attendant
I wondered the same thing when I saw #6 south of SLC around 11:00am. The only information I was able to find was on http://www.trainorde...d.php?4,2967451
I wondered if it was the cold. I happened to see that SLC was in the single digits yesterday or the day before.
Ted Bell
Service Attendant
What kind of problems are caused by cold temperatures? Do rails expand/contract significantly? Do switches malfuntion?
From the TrainOrders thread:
"Broken rail problems across the desert... extremely cold conditions cause pull-aparts that require MOW crews to heat up the rail w/ a kerosene-soaked rope, light it on fire, then joint-bar it back together after it expands."
EDIT: Posted it twice
"Broken rail problems across the desert... extremely cold conditions cause pull-aparts that require MOW crews to heat up the rail w/ a kerosene-soaked rope, light it on fire, then joint-bar it back together after it expands."
EDIT: Posted it twice
Last edited by a moderator:
Swadian Hardcore
Engineer
What if it happens repeatedly? That would stink big time.
What if it happens repeatedly? That would stink big time.
It can, though more often due to expansion in the summer than contraction in the winter. And with global warming we're going to see larger and larger extreme temperatures, mostly hotter but also colder, which is going to make it ever harder to lay the rail in a way that prevents damage at the temperature extremes. There was a very informative thread last spring about ways railway engineers deal with this now, but little about how they might continue to cope in the future. It's a really difficult engineering problem, especially with continuous welded rail (CWR), which is by far the most cost-effective rail design.
It can, though more often due to expansion in the summer than contraction in the winter. And with global warming we're going to see larger and larger extreme temperatures, mostly hotter but also colder, which is going to make it ever harder to lay the rail in a way that prevents damage at the temperature extremes. There was a very informative thread last spring about ways railway engineers deal with this now, but little about how they might continue to cope in the future. It's a really difficult engineering problem, especially with continuous welded rail (CWR), which is by far the most cost-effective rail design.
On the subject of thermal expansion and contraction here is another number that you foamers can digest. In surveying class half a lifetime ago I learned the coefficient of thermal expansion is .00000645 inches per inch per degree Fahrenheit. This translates to the fact that 1 mile (5280.0') of track at 120 degrees is 40 inches shorter at 20 degrees. The CWS tracks are welded at very hot temperature. If it gets very cold sometimes the welds break.
The old style of joining rails sometimes involved rails that had wedge shaped ends that passed by the end of the next rail.
If the ends of the rails are square and not to be welded, the temperature of the rail and the length of the rail determine what the spacing is between the ends.
I'm wondering why we have not had a problem with contraction of the rails near Chemult Oregon.
One morning last week the temperature dropped to -12F.
The old style of joining rails sometimes involved rails that had wedge shaped ends that passed by the end of the next rail.
If the ends of the rails are square and not to be welded, the temperature of the rail and the length of the rail determine what the spacing is between the ends.
I'm wondering why we have not had a problem with contraction of the rails near Chemult Oregon.
One morning last week the temperature dropped to -12F.
Tom - Yup, that sounds like the right number. Whether the rail breaks at -12 depends greatly on the temperature at which the rail was layed (assuming it's CWR). Maybe Chemult doesn't get as hot in the summer as does the Utah desert, and so they layed the Chemult track at a lower ("neutral") temperature. Here's the link to the previous discussion. George Harris gave a really good summary of how it's done and what the issues are.
http://discuss.amtraktrains.com/index.php?/topic/49261-heat-problems-long-term-solution/
I have to say I'm a bit surprised this train was able to make up some time after its really big delay. Seems like the past few trains that were very late got more delays as they went on. Since this one didn't lose time, I got to see come through Iowa in daylight:
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