AD Track Example

The Importance of an A/D Track

A common trend when designing an L-gauge layout is to attempt to pack as much track as possible into a space. We all like to show our trains, and, unlike buildings or scenery, we need track space to do so. Often we set up our railway yards as display areas, where visitors to our layouts can see the scope and variety of our creations. This works well until we get to our favorite part, moving the trains.

A standard ladder yard design works great as a display case. Trains are lined up in long even rows, waiting for their turn to run out onto the mainline. A problem arises, however, when you want to build up a new train consist from cars parked in the yard, especially if they are not already in the order needed. In order to shuffle cars around, it’s usually necessary to pull something out onto the mainline, where it could obstruct, or “foul”, the train that is running on that track.

Enter the A/D track. By adding a single Arrival/Departure track to our yards, we can eliminate fouling the main. The A/D track is a simple siding that sits between the mainline and the yard. This track can be used as an area to build up and then stage trains until they are ready to go. Cars can be shuffled around without interfering with any trains that are running around the layout. When it’s time to swap trains, the switches on both ends of the siding are thrown. The train on the mainline comes into the siding (the Arrival) while the train in the siding goes out onto the main (the Departure). The arriving train can then be broken down, if necessary, and shuffled back into the yard.

For small layouts with only one or two trains, an Arrival/Departure track may not be necessary. For larger layouts with busy mainlines, however, an A/D track can really help improve operations, keeping the mainline running while work is being done in the yard. For visitors to the layout, there is no break in the action, and for operators, there is more fun and less “Hand of God” shuffling of cars. Adding an A/D track is one small step in moving from “LEGO Display” to “Model Railroad”.

AD Track Example
Arrival and Departure Track Example

4 thoughts on “The Importance of an A/D Track”

  1. This is slightly off topic, but with the Yard/Ladder configuration that you have here, do you notice trains either getting derailed or following the next switch when they go into the “parking” spots? With my controller, I have all of the switches controllable and I will park trains very often (every 30 minutes when I’m controlling it) and I’ve noticed that the wheels will catch the next switch if there is a curve piece right in front of it. My “design rules” now include a straight piece between the “front” of the switch and any curve piece. This includes the main lines as well as the train yard, but the affect on the train yard has a bigger impact.

    Also, thanks for explaining what the A/D siding is for. I had noticed it in a few layouts.

    1. I have noticed that occasionally, especially if I’m using rolling stock with trucks that don’t swivel well. When I design layouts for public shows, I generally try to add a straight before each switch as well.

  2. Definitely important, and something I’ve noticed would help with layouts I’ve run on. In grad school I took a whole class on yard design, and A/D tracks (and entire arrival or departure yards) were one of the big things. Being able to assemble trains would make shunting in the yard more fun as well, as Glenn and I know!

  3. This is a really great topic, and a direction in layout building that really changes the way we get to interact with our models.

    As for putting a straight in front of a switch, yeah, PennLUG often does that when we have multiple switches in line, although we are working to eliminate as much of that as possible with modified (gasp) yard ladder tracks.

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