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Overview This dream illustrates how to add switches to the Roller Coaster dream. These switches permit the path of the train to be controlled via DS. Depending on the configuration of the switch, the train will proceed down one or another set of tracks.

In order to understand how switches work, it is first worthwhile to review how the logic that controls how the train moves across the floor tiles.

The train's behavior is as follows:

1) Attempt to continue moving forward.
2) Attempt to turn right.
3) Attempt to turn left.
4) Derail.

Based around these simple rules, many different types of switches can be constructed. For each type, they can be rotated and flipped to match the topology required. The two most basic variations are illustrated below.

Non-Reversing Switches A non-reversing switch allows the train to continue in the direction it was proceeding in. This type of switch is similar to a traditional railway switch, but is somewhat more complex as it has no configurations that result in a derailment.

Figure 1 - A non-reversing switch in the "off" position

Figure 2 - A non-reversing switch in the "on" position

Reversing Switches A reversing switch behaves the same as a non-reversing switch while in the "off" position. However, in the "on" positional, instead of allowing the train to continue in the same direction, it reverses the direction of the train, sending it back down the other track.

Figure 3 - A reversing switch in the "off" position

Figure 4 - A reversing switch in the "on" position

Switches in Action The below diagrams illustrate how the reversing switches interact with trains traveling in the three different directions:

Figures 5 and 6 - A south-west heading train

Figures 7 and 8 - A north-east heading train

Figures 9 and 10 - A north-west heading train

The included dream uses reversing switches, as it allows the furre to control the direction of the train such that it can be operated in a loop. This illustrates the basic principle around several dream concepts, including mazes, where the furre must throw the correct combination of switches while traveling on the train.

Please send comments, questions, suggestions and requests to tafyrn@kasuria.com
Last Updated on: 2004-10-06