Hump yard verses flat switching

[BaltACD]

5 years on and the same discussion.

[coborn35]

I've no experience in a hump yard, but where I work this is how it goes. Nothing coming in to us is blocked at all, all loose car railroading. On an average shift you can expect a crew to switch 200-400 cars. Lets say you have destinations of A-G.

A-C go on on the same train, and D-G go on the same train. When switching inbound trains, all cars for A,B,C go to the same track, and then D,E,F,G go to the same track. There are times you switch inbound cars directly onto an outbound train but that gets to be a little more advanced than needed here. So its time to build. Train one is made up of A-C and is blocked A then B then C. Lets say we are building a westbound train from the west end of the yard. Lets say we will use tracks 1-3 to build this train, with 1 being the primary track.. Since we are building a WB from the west end, you want the rear of your train going into your build track first, in this case Track 1. So, all of our C cars will go into Track 1. All the A cars will go to Track 2, and all the B cars will go to Track 3. Once you are done spreading, you double the cars over for correct blocking. In this case, Track 2 (B's) doubles over to Track 1. Then, Track 3 (A's) doubles over to Track 1. Therefore you have the train in the correct A-B-C blocking.  Rinse and repeat for D-G. Many different factors affect this such as REO, head end only cars, loaded tanks, and long/short cars. But this is how a flat switching yard that builds trains works in a nutshell.