Empire Builder on Time!!

Amtrak Unlimited Discussion Forum

Help Support Amtrak Unlimited Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Status
Not open for further replies.

montana mike

Conductor
Joined
Apr 21, 2012
Messages
1,520
Location
Whitefish, Montana
For the first time in what must be more than 6 months it looks like the EB (#8) will arrive in Chicago --ON TIME-today!! Hurrah. All of the EBs, both east and west bound were, in a snapshot at midday today either on or very close to schedule. Maybe I am dreaming and will wake up, but it was truly heartening to see that this train, which used to be Amtrak's flagship, on time route, may have turned over a new leaf, at least for a moment.

I know the track construction is pretty much wrapped up for the season, but perhaps BNSF has changed some of its freight scheduling to help--or is this just dumb luck?
 
Since I am riding it next month with a fairly tight connection in Chicago, I have been following its on-time performance. It's improved in the last week, usually being "only" around 60-90 minutes late. Hopefully it is a trend and it will no longer be soooo late on a regular basis.

Of course, yesterday, it was 3 hours late, so who knows? But you're right, 8(13) is doing better than any 8 has done in a long time.
 
A lot of the lost time on the Empire Builder is due to the heat. Once the weather changes and the temperature drops to winter temps, the speed restrictions are lifted. Therefore, you will arrive at your destination on time, barring track work and mishaps along the way. It was explained to us on our trip on the EB in August, that the tracks on that route are built on perma frost, and when the outside temperature reaches a certain level, they have to go slower to prevent the tracks from buckling due to the melting perma frost.

Hope this makes sense.
 
It has still been consistently and significantly late even since the weather cooled off, though not quite as bad as midsummer. So heat is not the sole reason.

There is no permafrost on the Empire Builder route. You have to go further north, like up to Churchill, Manitoba, for that. The person who told you that was either pulling your leg or didn't know the actual reason why the rail might "buckle" with heat themselves. The reason for the speed restrictions are sun kinks in welded rail. Since it isn't jointed, there isn't any room for the rail to expand due to heat. This is controlled by a good ballasting of the roadbed, locking in the ties, and the rail being heated to an optimum temperature for the climate when it is laid (that temp is higher in AZ than it is in ND). If it gets really hot, you increase the change of sun kinks (buckling) so they put speed restrictions on.

The opposite problem happens in winter when the rail contracts. This can cause the rail to break instead of kink. Which is why the temp of the rail is when it laid is so important. You have problems on either extreme.
 
Who ever said that the track was built on perma frost does not know what they are talking about. The reason that there are heat related speed restrictions is due to the possiblity that the rail could expand so much because of the heat and the track could go out of gauge and derail the train. About 22 years ago almost all of the Empire Builder derail due to a sun kink just west of Saco Montana which is 20 miles east of Malta Montana.
 
It has still been consistently and significantly late even since the weather cooled off, though not quite as bad as midsummer. So heat is not the sole reason.

There is no permafrost on the Empire Builder route. You have to go further north, like up to Churchill, Manitoba, for that. The person who told you that was either pulling your leg or didn't know the actual reason why the rail might "buckle" with heat themselves. The reason for the speed restrictions are sun kinks in welded rail. Since it isn't jointed, there isn't any room for the rail to expand due to heat. This is controlled by a good ballasting of the roadbed, locking in the ties, and the rail being heated to an optimum temperature for the climate when it is laid (that temp is higher in AZ than it is in ND). If it gets really hot, you increase the change of sun kinks (buckling) so they put speed restrictions on.

The opposite problem happens in winter when the rail contracts. This can cause the rail to break instead of kink. Which is why the temp of the rail is when it laid is so important. You have problems on either extreme.
Welded rail neither expands nor contracts. In experiences tensile or compressive internal forces. The general concept is to set the rail so that the stress is zero at a temperature near the high end of the temperature range. This temperature is called the zero stress temperature. Simply put, tensile force, that is what you have when the temperature is low, is usually less of an issue than compressive forces, that is what you have when the temperature is high. Think of the difference between pulling and pushing a rubber band. If you pull it is straight. If you push, well, obviously it sags.

A low temperature failure is a pull apart, usually near a weld, or at a place where there is some form of internal defect in the steel. If this happens on signaled track, you know before you get to it.

A high temperature failure is a buckle in the track. If you have a small one, the lateral pushes from a train going over it will make it larger, and with much of any speed derail the train. High temperature buckles are prevented by having good ties well embedded in the ballast and having good ballast shoulders in conjunction with a zero stress temperature as high as practical for the location.

The key for this temperature is the location. That is why a 100 degree temperature in the Southwest desert or the Gulf Coast is not the problem it would be in Montana and the Dakotas. You set a higher zero stress temperature in these normally hot areas than you would in the normally cold northern plains.

Some spokesperson for an agency that will remain nameless to protect the guilts said, "The rails get soft at high temperatures." NO IT DOES NOT.
 
Last edited by a moderator:
Status
Not open for further replies.
Back
Top