We know what snow does to rail operations, but what about pure cold weather (without the snow)?
I have read that cold affects the air brake system. Do railroads typically reduce the car counts in a train? What about rail? Does it contract much and what problems does that cause?
BTW…temps here in NW Indiana are forecast to be the coldest of the season for the next week with lows typically at or below zero and highs in the single digits or teens. Makes me glad I dont have to walk a 10,000 foot train looking for broken airhose at midnight.
Yes, most railroads will reduce car count in cold weather. They of course do not want to, but the alternative is having trains taking two or more hours just to charge the trainline sufficiently to do an air brake test. Additionally, even if the train does get out of the yard, if the engineer sets the air anywhere during the trip, you can just about bank on the brakeman having to walk the train for sticky brakes at the next detector.
Rail is also greatly affected. I know mudchicken could give you much more info, but I do know that pull-aparts become more quite common as the temperature drops. Many of the pull-aparts are so serious that it breaks the bond wire, and sometimes actually shears the angle-bar bolts.
This past Saturday the temp out here didn’t get about 0 degrees (air temperature) and there were several broken rails reported up and down the Morris sub (between Willmar, MN and Dilworth, MN. They also had regular track inspections all throughout the weekend due to the cold.
Because it takes longer for the brake pipe to charge in cold weather, train lengths are reduced.
Also, you can usually count of some borken rail during the first cold snap of the season. You have more problems with the rail, when the temperature changes rapidly.
I often hear dispatchers have trains pass slowly (10mph) over broken rails. I would assume that the broken rail is not necessarily broken with a void in the track, but cracked. Is this correct?
The scenario for the discovery of most broken rails…
Train operates through track segment and leaves a track circuit on in a segment after the train has passed. Existence of the track circuit is communicated to the Signal Dept and generally the M of W Department for inspection, and repair. Signal maintainer or track inspector takes 2 hours more or less to respond after the initial report of the track circuit. Three other trains have been operated through the track segment at restricted speed as they have either had to be given verbal permission to pass an Absolute Stop signal or have received a restricted proceed wayside intermediate signal entering the affected segment. Signal maintainer or track inspector finds broken rail and make determination as to the permissibility of continuing to pass trains over the broken rail until permanent repairs can be made.