1st Layout. Questions on cab control.

[bigjdad9]

I am building a 4X8 HO scale layout. I plan on using 2 mrc cabs wired to 8 blocks. If I wire the layout using commen rail system will I be able to run one train forward and the other in reverse at the same time? I have a pretty good knowledge of DC electicity and it seems to me that it would have a short when the polarity would change on one of the cab. If you can't, why would someone want to use commen rail if you can't reverse a train on a spure/yard while another train runs the main line?

[Eastern Roads]

Nice to see you here on TWP, Big Dad! I hope I can answer your question. I use two MRC Control Master 20's, and a Tech 4 using one common rail, and what I have are two mainlines with a yard in between the two. I have it controlled so I can run a switcher back and forth while trains run on the main.
So to answer your question, in a word, "yes". You just need to use some DPDT switches to make it go. We have a modeler here on the site named HOScalemodeler 1967 who is a guru with DC wiring who could answer just about anything.

Please show us your layout as you go along, and don't be shy in asking away! There are no dumb questions here! Everyone has to start somewhere! Hope you enjoy your stay at TWP!

[bigjdad9]

If my power pack is ratted at max output 20DCVA, what is a volt amp and how does in compere to AC current amperage? (DPDT toggle switches all seem to be ratted in alternating current)