Lower Illinois Association of Railroaders


The above photo is a screenshot of the prototype CAD in use at the UP Harriman Dispatch Center in Omaha, NE. Thanks to Rodney Black for letting me use this screenshot.

This is the current CAD board for the Flora layout. It is still under construction, but usable. White track lines mean a clear section of track. Tick marks along the track are block boundaries. The red dots below the track lines are signal masts. Their state can either be "held" (red), or "cleared" (green). the dispatcher would click on the blue arrow next to that signal to request the system to clear a route for a train up to the next signal. The system will grant the request only if it's safe to do so. Once a route is cleared, no other route can be requested that could interfere with the first route. Clearing a route also locks all powered turnouts on that route.

To throw a turnout, the dispatch simply clicks on that switch. the switch will toggle thrown or closed, only if there is no route lined, and the switch is not occupied by a train.

If a manual turnout along the main line is opened, it will trigger all red signals at both ends of that block until that switch is restored to its normal position.

If a powered turnout along the main line is taken off power and thrown manuall