Amtrak Train Speed

[Cricketer]

Actually this isn't about the fastest trains (no contest in the US, and I don't want this topic to become an argument over high speed rail). It's not about average, or indeed high speed on level track. What I'm interested in is speed for passenger trains on US mountain grades.

I assume train go more slowly up and down grades. What I'd like to know is why. Is it is because:

1. There simply isn't enough horsepower to get the train up at speed?

2. Curvature on many grades is such as to prevent speedy running?

3. The Amtrak trains are delayed by slow moving freight trains?

4. Track capacity on grades is so tight that all trains need to go at approximaltey the same speed, so a passenger train slows down to avoid taking up extra paths up the mountain.

Historical examples welcome.

 

 

[MILW205]

#2 for sure is an impediment.

As far as #1, it's an issue of optimizing motive power.  If the mountainous track was straight (which it almost never is), you could theoretically put, say, 5-6 (or whatever) engines on the Amtrak train instead of the usual 1-3 engines and enable the train to go up the mountain at a fast speed.  But, the incremental engines that you've put on the train for the mountain portion are nevertheless unneeded on the level areas of the route, and would therefore be wasted most of the time. 

 

 

[al-in-chgo]

#2 for sure is an impediment.

As far as #1, it's an issue of optimizing motive power.  If the mountainous track was straight (which it almost never is), you could theoretically put, say, 5-6 (or whatever) engines on the Amtrak train instead of the usual 1-3 engines and enable the train to go up the mountain at a fast speed.  But, the incremental engines that you've put on the train for the mountain portion are nevertheless unneeded on the level areas of the route, and would therefore be wasted most of the time. 

 

 

There was a brief feature on the "ABC Evening News" a couple of weeks ago, about America's [dearth of] high-speed trains.  The engineer on Accela noted, as he slowed to 80 to take a curve, that his train would surely jump the track if it tried to achieve top speed of 150 mph there. 

Things want to go in the direction they were just going (inertia), the same reason why you would approach a curvy road at a much lower rate of speed in your car than on a straight road (any excess horsepower on any gradients on the curvy road are probably not a factor for your car that would keep it from "making the grade"). 

 

[DMUinCT]

  Try "Ruling Grade",  The HP needed to move a train of a givin weight up the steepest hill on the line at the lowest acceptable speed.  

  Steepest Hill depends on a given railroad's track.  Lowest acceptable Speed may be 20 mph for a Freight, might be 50 mph for a Passenger train.   Might want to use fewer locomotives and a Helper for the hill.