[ARC5] Locomotives

[Roy Morgan]

On Dec 19, 2012, at 10:46 PM, D C _Mac_ Macdonald wrote:

> Added weight on the rails for any locomotive means
> that heavier train weights can be moved.

Right on.

>  Friction
> coefficient of steel wheels on steel rails..  .25.
>  This means that the maximum weight
> that can be moved .. is 25% of the weight of the loco.

Actually, the maximum PULLING force would be a quarter of the weight  
of the locomotive.  I'd expect the force needed to get a freight car  
going would be a small fraction of the weight of the thing.

Rail yard workers used to use a long handled prying device to get a  
freight car started in motion. It was stuck under a wheel and the  
various lever actions provided mechanical advantage enough to roll a  
loaded car a short distance.

Roy

Roy Morgan
k1lky at earthlink.net
K1LKY Since 1958 - Keep 'em Glowing!