Model Railroading > Speaking of helpers------

One day I decided to test locomotive position in a train for the highest traction rate.

I loaded down two Atlas GP-7's until they could not pull the train up the long 2 % grade and two curves on my layout.  I marked the location of the stall and then moved one engine to the rear of the train. and attacked the hill again.  No problem.  They pulled the train with ease up the hill.  I then started adding more cars to the point where the train stalled again.  It took the  addition of 5 cars to stall it on the hill.  I did not try putting the 2nd engine in the middle of the train.

As a practical matter I don't add any helpers to the rear of a train.  I normally put enough power on the front.

Putting the locomotive on the rear works because it takes some of the curve bind out of the equation. I think the most ideal situation would be to have each locomotive 1/4 of the train in from each end so that they are both pulling 1/4 and pushing 1/4 of the train at the same time, minimizing the curve bind.
 

Ted Curphey
Ontario, OR

funnelfan Wrote:
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> Putting the locomotive on the rear works because
> it takes some of the curve bind out of the
> equation. I think the most ideal situation would
> be to have each locomotive 1/4 of the train in
> from each end so that they are both pulling 1/4
> and pushing 1/4 of the train at the same time,
> minimizing the curve bind.
>  

You mean kinda like CP does with their 1 x 1 x 1 x 1 DPU placements.