Want to use Rheostats or resistor bridge to reduce voltage to certain blocks on layout

[Anonymous]

wow 30 x 50 thats huge. Got any pics? Sorry i dont know anything about Rheostats, just say the huge layout and was wondering if you got pics. Dont worry there are some smart guys and gals here who will answer this. ...thanks

[cruikshank]

I need to slow down trains in a 3 rail lionel conventional control public / club layout.  We are running multiple trains using stop and trigger tracks.  There are some down grade areas where the trains just run too fast.  We want this when on view to the public be a hands off layout.  I need to isolate some blocks and through rheostats, or a resistor bridge taps decrease the voltage to these blocks, while maintaining it on the others.  Using Lionel 135 or 180 watt powerhouse bricks what value and wattage resistors / rheostats should I use, and where best to buy?  Thanks,  Dave