There are at times one or so Unit Train on the layout.
Coal Car Unit Train
I have a coal mine so coal cars are needed and are shipped in a unit train. So I started collecting 3 or 4 dumping coal cars, so I can load them at my coal mine loading station and unload them into one of those Lionel coal bin/trays.
Oil Tank car Unit Train
I have 3 or 4 oil tank cars, chemical tank cars, gondolas, boxcars, flat cars, log cars, milk cars, cattle cars, etc. to make unit trains for each type car.
Below is an example of one, a tank car Unit Train.
Unit train of Milk cars
Auto loader Unit Train
Pictured below are 4 auto loaders operating as a unit train. I have to be careful with these when using heaver metal cars as they are top heavy on curves. I picked up a box of red metal 57 Chevy convertibles but plastic ones are better for auto loaders
So you can see unit trains add interest and fun to the layout and operation.
Charlie