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Switch and Switch Machine The switch, an LTV Aerospace-developed system for which a patent was granted, is a fast-acting guideway switch that can divert a vehicle to a siding, to another line, or can permit it to proceed in a direct line. It consists of both a movable part and a fixed entrapping rail attached to the top of the parapet wall. Depending on the position of the movable section, entrapping wheels on the vehicle cause the vehicle to be steered in the proper direction. The Typical Guideway Switch Operation illustration shows the two switch positions and the behavior of the vehicle as it is steered through or to the right or left. The vehicles cannot split the switch because the vehicle is entrapped all the way through the switch area. The switch actuator, or switch machine, is a standard railroad actuator that has been in service on the nation's railroads for many years and is a fail-safe device. This machine was originally located in the center of the guideway, as shown, for esthetic reasons. The Airport later moved it to the outside of the parapet wall for easier maintenance. The selection of this critical item off the shelf saved a great amount of time and development cost. The new-concept switch and the selection of off-the-shelf switch machines were significant contributors to the success of the program. Airtrans: Program Background |