Steve’s Western Pacific Layout
Chubb System



Across the top you can see the  Detector Cards. They are the ones with the blue circle and white tags beneath. One for each block. They detect current flow and tell the computer something is in this section of track. This is also reported on the Dispatchers board as a yellow occupancy light. This information is also used for block assignment.   

The Cab Relay Cards  are the green boards with the black relays and green circles.

There is one of these cards for each block..  There are 7 relays on each card, one for each throttle (Cab). The red leds show which cab is connected to that block at any given time. When you or the computer assigns a block to your cab, this is where it happens. As the train moves from block to block along the railroad, the computer assigns the appropriate blocks, based on availability and direction of travel.  


The horizontal board with the black rectangles is for switch machine control. There is one chip for every mainline turnout on the railroad that is controlled by the Dispatcher. These make it so the Tortoise switch machines can be thrown by an input from the Dispatcher board.


The cards with yellow, green and white wires are digital input and output cards. An input is when a switch or button is pushed, an output is the action to carry out that command. The first board is the serial board, all the information from and to this area is packed and sent to the computer for processing on a 3 wire cable!


The area to the left and behind the wood post is the signal board. This is where the commands from the Dispatcher for a specific signal designation are implemented.


This component board is repeated at Niles in a parallel configuration. This is because we also feed the Dispatchers board from that location, which doubles the I/O boards needed. There is also a smaller version located in Salt Lake. All this is managed with an old 386 computer. All the boards were assembled and tested on site.