The System 21® Guideway and Vehicle Interfaces



 Figure 1

 Figure 2


Figures 1 & 2 depict the vehicle-to-guideway mechanical interface to both the upper and lower rails. Two of these suspension interfaces occur per vehicle, with 18-foot wheelbase separation on the 28-foot long vehicle. Primary suspension elements consist of an outrigger attachment to the upper rail, a main drive wheel/gearing/motor configuration riding along the lower rail, and a load leveling suspension unit. The dual-flanged, 26-inch diameter main drive wheels have a concave profile to operate with the specially crowned rail head.

The outrigger is unique to System 21, with its primary functions being to carry tension loads to prevent vehicle overturning, and to serve as a mount and conduit for a contact shoe used to draw DC power from the guideway-mounted contact rail. The interface between the outrigger and the top rail is shown in Figure 3. The outrigger surrounds the upper rail head to provide a guide for the outrigger rollers. Each outrigger has four rollers above the web of the rail, and four below. An "in-line skate" mounting arrangement for the rollers, a configuration of interconnected hydraulic cylinders, and a cam track mounting of the outrigger to the carbody allows the outrigger suspension to conform to guideway transitions through curves, switches and stations.

Figure 3