Translations:AY Honors/Model Railroad/Answer Key/48/en
Oval
The simplest layout for a model railroad and the starting point for most designs. In this design, two straightaway segments are connected by a semi-circle at each end. This is also the only layout which can easily be created with sectional track without the use of a manufacturer-specific design. Curved sectional track is sold by radii (half the distance across the semi-circle) and a box of such track sections will almost always create exactly half a circle. The two straightaway sections will usually utilize multiple pieces of sectional straight track, as desired by the modeler.
Figure-Eight
The second most common beginner's layout. This layout is best accomplished by purchasing it as a single set or following a manufacturer's layout design using their sectional track. The intersection in the center of the layout can either be accomplished by a piece of crossover track, or by elevating one track over the other. In the latter case, a set of piers or risers will be needed to raise the track at an appropriate rate.
Twice-Around
A modification of the figure-eight, in which one end-loop is contained within the other. The crossover here is not at 90° like in the basic figure-eight example and can be accomplished by using a alternately angled crossover piece or by using elevated track to pass one track over the other. The twice-around layout design allows the train to run continuously for longer than the simple oval before reaching its starting point.
Point-to-Point
This design does not allow a train to run continuously indefinitely, as you might imagine most plans would allow. However, this is the design that most closely resembles real-life railroad operation, since real-life railroads run across country, not in loops or circles. You can construct more elaborate yards at each end in order to enjoy the complexities of real-world operation.
Out-and-Back
This design approximates real-world operation, as each train must make a journey before it returns to the yard from which it originated. Although real freight never returns to its origin the same way it left, this arrangement does allows you to concentrate your time and resources on one yard instead of the two required in a Point-to-Point design (above).
Loop-to-Loop
This design diverges from realistic operation, but does allow the operator to interact with a continuous-running train. A yard can be added in the middle of the layout to simulate freight coming in from each direction. When modeling with two-rail scales, such as HO and smaller, special wiring will be required to insulate each loop from the rest of the line and allow the direction to be reversed on the mainline.
Dog Bone
This design is similar to the loop-to-loop design, but allows for continuous running without intervention from an operator. In addition, the two tracks running side-by-side simulate the double-track lines often seen in real life.
Twisted Dog Bone
This design is adds additional length to the mainline featured in the basic dog-bone design (above). Keeping one or both of the end-loops out of sight allows this layout to very realistically simulate the long distance running of a real railroad.
