heat/cold speed restrictions

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Midland Valley

Lead Service Attendant
Joined
Feb 14, 2005
Messages
408
Location
Dodge City, Kansas
Some of you have been talking about heat restrictions on CSX. Don't all railroads have some type of heat/cold restrictions? I thought it used to be 100 f and zero f with reductions to 60 mph.
 
I have never heard of heat/cold speed restrictions other than if the track inspector finds a defective condition until about 2002 after the "Auto Train" had its mishap occur in Putnam County, FL (north of Seville FL in Volusia County FL). I know the extreme cold causes the rail to become "brittle" so to say, and with the change in temperature from highs to lows, the expansion can cause the rail to break. Broken rails are common in the winter months especially in the South where the temps fluctuate. I am also aware of the extreme heat of the summer can cause the rail to "kink" and become misaligned. My personal opinon is I believe CSX is a little overly cautious of that situation in the summer months, combined with the fact a "heat kink supposedly existed" within that section of track. On the name of safety, I would rather play it safe and go with CSX's slower speed, but realistically I feel the threat is low, and the passenger train should be able to operate maximum authorized speed of 79mph where able. I will point out the "Auto Train" mishap of 2002 occured in an "S" curve section of track with a 50 mph speed restriction, so who's to say the "heat orders" are actually necessary? The track owner (CSX) obviously thinks so! OBS...
 
OBS, actually the Auto Train wreck occured in a 60 MPH curve. The rule on heat restrictions says that a passenger train is to reduce their maximum speed by 20 MPH on all track, but not below 40. So for example, 79 MPH main track becomes 59, 75-55, 70-50, 65-45, 60-40, 55-40, 50-40, etc. Now any restriction 40 or below remains the posted speed, 30 is still 30. Now, the Auto Train is considered to run at Passenger speeds, but is limited by equipment (the carriers) to 70 MPH. So for example on the RF&P Sub where the maximum speed is 70 for passenger trains, AT runs 70. So if we were to say that heat restrictions were in effect for the accident site in Crescent City, Auto Train would've been coming out of a 40 MPH curve, instead of a 60 Curve.
 
Living up here in North Dakota, I've experienced my fair share of below 0 temps, as does the Empire Builder, during the months of January and February. I've waited for the train a few times, when it is - ....alot degrees, and the conductor always mentions, they can't go at track speed. So I assume they go 59 mph or less. I can't even imagine those steel and iron even functioning properly being that cold. Trust me, -44 is BITTER COLD, for those who've never experienced it. Its when your nose hairs freeze in about 5 seconds.
 
OTOH, you have NS telling VRE they inspect their track enough to the point where heat restrictions are not an issue with them.

The VRE website is incredibly diplomatic in describing the differences between the two RRs policies.

Kinda makes you wonder, doesn't it?
 
battalion51 said:
OBS, actually the Auto Train wreck occured in a 60 MPH curve. The rule on heat restrictions says that a passenger train is to reduce their maximum speed by 20 MPH on all track, but not below 40. So for example, 79 MPH main track becomes 59, 75-55, 70-50, 65-45, 60-40, 55-40, 50-40, etc. Now any restriction 40 or below remains the posted speed, 30 is still 30. Now, the Auto Train is considered to run at Passenger speeds, but is limited by equipment (the carriers) to 70 MPH. So for example on the RF&P Sub where the maximum speed is 70 for passenger trains, AT runs 70. So if we were to say that heat restrictions were in effect for the accident site in Crescent City, Auto Train would've been coming out of a 40 MPH curve, instead of a 60 Curve.
Typo..... that "50" was supposed to be a "60" when I indicated that regarding the "Auto Train" deal in 2002! :lol: :D

As far as the heat orders, I was well aware of how they are set up from the begining, however, I feel CSX is a little over cautious with this issue! The "Silver Service" trains should be able to operate at normal speeds in my opinion as well as "Auto Train" should be able to operate at its normal speed. In the name of safety, I go with it being the host RR has made the decision to follow through with this new rule. The schedules should be adjusted to reflect that (hopefully they will be this Aug)! The passenger should be able to make some sort of plans for when they are gonna be at a certain time (or at least close to that time). OBS...
 
I know a guy that is a track inspector for UP in Illinois and whenever the temps are 90 or above, he has to ride the rails inspecting for heat problems.
 
Heat and cold restrictions are a fact of life with continuous welded rail (CWR) and the way the track structure (rail, ties, anchors, ballast, subgrade) has to resist the thermal changes in rail length.

Obviously, lacking resistance, a steel rail gets longer when it gets hot and shorter when it gets cold. That is exactly how jointed rail worked. The rail joints between the short rail sections had a small space between the rail sections to accommodate the small changes in length between the hottest summer days and the coldest winter days.

Use of CWR changed all that. Rail was now laid in 1/4-mile lengths and then those lengths welded together into continuous sections miles long. Physical spacing for actual expansion or contraction of the rail was no longer practical or even possible. So accommodation of the thermal effects had to take another route: stress. Push hard enough on a section of rail and it will shorthen: pull hard enough and it will lengthen. So take those miles-long sections of rail, tie them tight to the ties, anchor the ties firmly into the ballast, and ensure the ballast is heavy and well supported by the subgrade. If all that is done just right, when the rail gets hot it will not lengthen but instead will be resisted by high compressive forces (pushing), and when the rail gets cold it will not shorten but will be resisted by high tensile forces (pulling).

When you reach extremes of weather: hot or cold, the risk gets greater that something in this high-force balance of power will go haywire. If in the hot weather there is a soft spot in the track structure, particularly on a curve, the compressive force in the rails can cause the track to buckle: a “heat kink”. In the cold weather, the high tensile forces can find a weak spot or defect in the rail and cause a fracture. 99.99% of the time everything works as designed, but when extremes are reached, it is prudent to be cautious and increase inspections and reduce speeds to reduce track forces and lessen the potential severity of a failure. Every railraod, including the Amtrak NEC, has its own definition of when such temperature extremes trigger speed restrictions.
 
What was the reason to change to CWR? Sounds like the old clicky-clack rail would be better in temperature extreme regions. Are there other benefits that outway the temperature problems? Just curious.
 
MrFSS said:
What was the reason to change to CWR?  Sounds like the old clicky-clack rail would be better in temperature extreme regions.  Are there other benefits that outway the temperature problems?  Just curious.
Lower maintenance costs.

Even though the installation of CWR requires some tender loving care and you have to be careful in temperature extremes, the day-to-day maintenance of well constructed CWR is much, much lower than jointed rail. Today’s heavy trains just beat the track structure to death and CWR stands up much better to that abuse than jointed rail.
 
CWR also rides much more better than stick rail, perfect example the New England Central. After coming off the NECR onto CSX the Vermonter is much smoother in CSX's CWR vs. NECR's Stick Rail (both railroads have a MSP of 60 for comparison purposes).
 
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