TG:Logic/Designations/Yard design

First and foremost, http://www.housatonicrr.com/yard_des.html. That page is dedicated to the railroad modeller, but we can understand the parts of a yard and how they work together from there.

To summarize the info in that article:


 * The main line is not normally a part of a yard (unless extremely lightly-used branch).
 * The lead track is the most important one in the yard.
 * Arrival/departure tracks are the preferred way to get complete trains in and out of a yard.
 * If using cabooses, you need somewhere to store them.
 * There must be at least one runaround somewhere, aside from the built-in ones using sorting tracks on both sides.
 * Overcrowded yards are very very bad.

Use of a yard usually involves breaking long trains by running them into the lead and then into the sorting tracks, chopping off into smaller bits that have internal cohesion, and the opposite action of taking smaller bits and building them into long trains.