Charles, turntables only turn engines. If you have the space, you can turn a full train through a Wye, but it’s a 3-point process; go through one leg of the Wye, then back through the other leg, then go forward in the opposite direction. You can just turn an engine through a Wye too, but you then need to be able to runaround to the other end of the train to go in the opposite direction. If you don’t care what direction the engine faces, you can use a runaround to go in the opposite direction. It doesn’t work too work well with steam engines and train with a caboose.
For example, in my design you can park a train on the inner oval, then runaround to the rear and pull the train in the opposite direction. In Jan’s, you can do the same thing with any of the sidings.
