Hill apex length

The critical issue is transition at the apex.  You don't want a sharp transition from the ascending grade to level track.  The problem isn't roller pickup, it is loss of traction. 

 

On steam locomotives, traction tires are typically installed on the rear drivers only or on the front and rear drivers.  The drivers in the middle have no tires.  If the transition out of your grade is too sharp, the outside drivers will lose contact with the rails (loco supported by middle drivers only) and traction will be lost. 

 

Smooth transitions are generally easier to achieve with long track sections like Gargraves that can be screwed down so that a single section of track spans the transition point.  It is more difficult but not impossible with sectional track.  Transitions are also easier with gentle grades than with steep ones.  What % is your grade?

 

Thanks It's ab 3.5%. Most all locos on it will have magne traction. I read someone uses WS

 

2% inclines for transition. I have 27 profile tubular btw.

jay;

A rounded apex is better than a peak, and the more rounded the better.

Another problem with a "peaked" transition is the pilot on many steam locomotives will hit the middle track causing a potential short. It can also put an extra drag on the locomotive.

Make level section at least as long as your longest piece of equipment for best results