MARC Service Alert <alert@mtamarylandalerts.com> Amtrak has issued heat-related speed restrictions for parts of the Penn Line. Trains must reduce their speed to 80mph between Washington and New Carrollton and 100mph between New Carrollton and West B
blue streak 1 MARC Service Alert <alert@mtamarylandalerts.com> Amtrak has issued heat-related speed restrictions for parts of the Penn Line. Trains must reduce their speed to 80mph between Washington and New Carrollton and 100mph between New Carrollton and West B To MTA Maryland Alerts Subscriber Today at 1:16 PM Amtrak has issued heat-related speed restrictions for parts of the Penn Line. Trains must reduce their speed to 80mph between Washington and New Carrollton and 100mph between New Carrollton and West Baltimore. Minor delays are possible. The above is just one example of all the heat speed restrictions everywhere during this heat wave. The A&WP sub of CSX has been slowing trains down from about noon to 2000. Know of others ?
CSX Heat orders are in effect from 1300 to 1900 CSX Time. Welded rail is a technology that has yet to be MASTERED for all weather conditions.
Never too old to have a happy childhood!
There's certainly a heat restriction on me! It's been so damn hot here in Richmond the past few days I haven't gone out of the house unless it's been absolutely necessary!
And on welded rail, that's something that's always struck me as a violation of the laws of basic physics, you know, heat expands things, cold contracts them? Maybe more than you'd like or want to admit? But what do I know? I'm just a railfan, not a professional.
For every 10 degree (F) change that the rail experiences, one mile of track increases or decreases in length about 4-1/4". That means if the rail experiences 20 degrees on a cold day and 120 degrees (rail temperature, not air temperature - rail gets hot just from the sunshine), it is trying to expand about 43 inches per mile. This is why it is installed at a neutral temperature that favors heat, not cool. Thus, for the above situation, it would probably go in at temperatures in the mid-90s or so. AREMA has two formulas to use - one for the minimum installed temperature and one for the maximum installed temperature. The neutral temperature is between these.
Interested in the formulas?
Minimum Temperature (F) = {[(2 x highest annual rail temperature) + (lowest annual rail temperature)] / 3} + 10 degrees
Maximum Temperature (F) = {[(2 x highest annual rail temperature) + (lowest annual rail temperature)] / 3} + 25 degrees, then plus or minus 5 degrees
In efforts to combat welded rail's attempts to generate 'sun kinks' in hot weather, the carriers have been adding additional ballast to their track profiles and making a wider 'ballast shoulder' off the end of the ties in an effort to increase the restraining forces to keep the ties and rail in place.
A great example of why heat restrictions are needed found this on another site
blue streak 1 A great example of why heat restrictions are needed found this on another site
Rio Grande Valley, CFI,CFII
Having side by side tracks act differently is normal - each is built individually. If one track doesn't quite have the same amount of ballast, hasn't been installed properly at the right neutral temperature, etc., it will be the one to move. I've seen this many times of mainlines where one track is fine and the other has a problem.
Looking at the photo, there seems to be small voids in the ballast where the track has moved away, a general event during a sun kink. However, it does look funny that each kink is about the same size, and they are evenyly distributed. Normally, one or two kinks will solve the entire problem. However, if the track was installed with ballast placed, but no rail temperature work, the entire track will react.
It is just a strange picture.
bartman-tn Having side by side tracks act differently is normal - each is built individually. If one track doesn't quite have the same amount of ballast, hasn't been installed properly at the right neutral temperature, etc., it will be the one to move. I've seen this many times of mainlines where one track is fine and the other has a problem. Looking at the photo, there seems to be small voids in the ballast where the track has moved away, a general event during a sun kink. However, it does look funny that each kink is about the same size, and they are evenyly distributed. Normally, one or two kinks will solve the entire problem. However, if the track was installed with ballast placed, but no rail temperature work, the entire track will react. It is just a strange picture.
Search around the net - there are companion pictures taken from the opposite direction.
There's a good possibility that picture was taken with a telephoto lens, which would have the effect of exagerrating the bends in the track.
Still, it IS strange to see those tracks to the left arrow-straight while the track on the right would do credit to an amusement park ride.
Firelock76 There's a good possibility that picture was taken with a telephoto lens, which would have the effect of exagerrating the bends in the track. Still, it IS strange to see those tracks to the left arrow-straight while the track on the right would do credit to an amusement park ride.
The track on the left likely has a higher neutral temperature the the main subject of the photo. The difference could be due to a number of things.
I think it was doctored and with a telephoto. Look at the ties and ballast. Do they also move in lockstep with the rails in reality? This is a question for our track maintenance folks.
C&NW, CA&E, MILW, CGW and IC fan
schlimm I think it was doctored and with a telephoto. Look at the ties and ballast. Do they also move in lockstep with the rails in reality? This is a question for our track maintenance folks.
I'm no expert, but it seems reasonable to me. The rails are spiked to the ties, so I think it would be reasonable that they would move together. Also, as Bartman pointed out, look at the ballast. It's bunched up over the ties where they moved outward, and there are voids on the opposite sides.
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"A stranger's just a friend you ain't met yet." --- Dave Gardner
Sunkinks happen in two basic manners. The first is where the fasteners (spikes, clips, etc.) are weak and fail to hold the rail. Generally when this happens, one rail kicks out and leaves the other rail and ties in place. In a number of cases, the result is simply wide track gage.
Situations where the entire track moves is also very common. This generally happens where the track structure is good, but the ballast is insufficent to handle the stress of the rail expansion. This happens often in curves or at the approaches to bridges where pumping is taking place.
I've made repairs and handled kinks with both conditions over the years.
One of the worst ones I have even seen was so kinked that you couldn't get a hirail over the line. The line was kinked for several miles. The CWR was installed on a cold day and the weather turned warm very quickly. The track kinked badly before the railroad got back to adjust the rail's neutral temperature and dump ballast.
I see and that makes sense.
The source of the picture is a private album of Curtis Wells on Photobucket. I wonder how it ended up here?
I rode #79 yesterday and south of Petersburg VA we were hit with heat orders for about 20 miles (reduced speed) followed by 30 miles of flash flood warnings (restricted speed) followed by another 40 miles of heat orders. Put us late into Rocky Mount. It was unbelievably hot and humid in RMT. I had never experienced a heat/flood combination before.
matthewsaggieI rode #79 yesterday and south of Petersburg VA we were hit with heat orders for about 20 miles (reduced speed) followed by 30 miles of flash flood warnings (restricted speed) followed by another 40 miles of heat orders. Put us late into Rocky Mount. It was unbelievably hot and humid in RMT. I had never experienced a heat/flood combination before.
The imfamous 'Hot Water' warning.
Yet we have hundreds of miles of rails in the Desert Southwest, in often 120-degree heat, and we never hear of sun-kink problems.
azrail Yet we have hundreds of miles of rails in the Desert Southwest, in often 120-degree heat, and we never hear of sun-kink problems.
How much snow and Zero degree days happen in the desert SW? In the NE and Mid & South Atlantic areas yearly temperatures range from the low 100's to below Zero - along with rain and snow as appropriate.
BaltACD azrail Yet we have hundreds of miles of rails in the Desert Southwest, in often 120-degree heat, and we never hear of sun-kink problems. How much snow and Zero degree days happen in the desert SW? In the NE and Mid & South Atlantic areas yearly temperatures range from the low 100's to below Zero - along with rain and snow as appropriate.
from www.weather.com:
"More than 7 inches of snow fell at the National Weather Service's Flagstaff office, which is actually located just west of the city, in Bellemont, Arizona. (NWS Flagstaff)"
May not be the same extremes as elsewhere, but it can get cold in the high desert regions.
Dragoman BaltACD azrail Yet we have hundreds of miles of rails in the Desert Southwest, in often 120-degree heat, and we never hear of sun-kink problems. How much snow and Zero degree days happen in the desert SW? In the NE and Mid & South Atlantic areas yearly temperatures range from the low 100's to below Zero - along with rain and snow as appropriate. from www.weather.com: Late-Season Snow Falls in Flagstaff, Arizona Published: May 15 2015 12:00 AM EDT "More than 7 inches of snow fell at the National Weather Service's Flagstaff office, which is actually located just west of the city, in Bellemont, Arizona. (NWS Flagstaff)" May not be the same extremes as elsewhere, but it can get cold in the high desert regions.
I do believe Flagstaff is in the mountains and at an elevation of over 5K feet and not exactly a desert, as the snow indicates.
DragomanNo need to get into a pissing contest here, because your point about extremes may well be a relevant one here. But so may the earlier poster's. Flagstaff (used as an example because it is on the Santa Fe mainline) has had record highs of 97 degrees F., and record lows of -30. Snow has been known to fall in Death Valley, the hottest place on the continent. So, the Southwest can -- and does -- also have temperature extremes. That's all I was trying to say.
Records are one thing - normal yearly extremes are something else.
Another issue is how fast the temperature changes. If it slowly changes from cold to hot, or stays hot for long periods of time, then the track adjusts itself pretty well. It is the quick cold snaps (broken welds and pull-aparts) or sudden heat waves that drive railroad nuts.
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