Is there any precedent for non ballasting of mainlines. I am new to Model RR.
How are yards supported. Just dirt and gravel on top[?]
Most railroads ballasted their main lines to a much higher degree than sidings, branch lines, and yards. Engine facilities in the days of steam usually used cinders from the locomotives as ballast in yards and service facilities. An abandoned Southern Pacific line here in SE Arizona was ballasted with copper smelter slag.
Welcome, tdnmor1.
None that I have ever seen, both in the real world and on layouts. Unless the ties are anchored well, the rails would creep around in an attempt to escape flange pressure, especially on curves. So, ya gotta ballast, at least with something unmoving.
Yards, on the other hand, though still ballasted, do not have raised beds like main lines do. The rails are closer to the land surface, but still anchored to keep them put.
The dirt and gravel does not go on top, as you last said, but rather lies up against, and between, the ties. Usually, the tie tops are cleared of as much ballast as possible because it would represent a waste of time and money to have ballast literally lying around doing no good. Why incur the costs to have it on top of the ties? The more that is placed where needed, the less you have to ship from quarries.
This is a very good forum to get questions answered if you are new, but some of our longer-in-the-tooth people have hockey socks full of skill and the skookum layouts to prove it. Ask away.
By the way, the numbers of stars, though dazzling, does not correlate tightly with skill or experience, just the number of times the person has responded to a thread or initiated one.
im using a med grade ,for my mine lines ,and a mix of med.to fine in the yards seems to look real ,its just what you think looks best,dont rush ! take your time ,
carl.