Originally Posted by supton
Originally Posted by A_Harman
Originally Posted by atikovi
Originally Posted by eljefino
When you think about it train engines don't have a marvelous amount of traction with their steel-on-steel wheels on rails.
The slop in the connections between cars helps the whole mess get rolling. That way they're only accelerating one car at a time from a dead stop.
Electric motors make their maximum torque at zero rpm. Don't know if a gas powered truck could do that. Maybe torque converter would stall the engine before it started moving.
The Road and Track article explains why this is not a unique feat to the electric F150. The extremely low rolling resistance of steel wheels on steel rails makes it possible. Most current pickup trucks can generate the necessary tractive effort to move the train. R&T calculates that it only takes 1875 lbs of force to move the train. My Dodge has a tire rolling radius of 1.33 ft, so it would require ~2500 ft*lbs of torque at the wheel to generate the necessary tractive effort. Overall gear reduction in my truck is 21:1 in first gear, so the engine would only need to put out 120 ft*lbs of torque to move the train. No problem. Isn't gearing wonderful?
Very interesting. I could buy it.
Now just how much does it need when puling some hillls?
This is where it gets hairy. If it was on a 1% grade, the additional force required to move the train would be calculated by:
Grade Resistance = Vehicle weight * sin(arctan(grade %)) = 1,250,000 * sin(arctan(.01)) = 1,250,000 * sin(.573) = 12500 lbs, or almost 7 times the rolling resistance alone.