CORP - Automatic Block Signaling Demo

by Carsten S. Lundsten

This simulator demonstrates the Automatic Block Signaling (ABS) system found on the Central Oregon and Pacific Siskiyou Line in the late 90s. The ABS is a classic type found on former Southern Pacific single track lines. All signals are shown as lower quadrant semaphores though some were replaced with newer signal types over the years.

The line between Wilbur and Sutherlin is equivalent to the automatic block signaling system described here except that the "Distant" and "Overrun" signals are located as pairs, rather than staggered.

Sutherlin and Oakland are too close together for this signal arrangement to work. Instead the block between the sidings is overlapped by short approach track circuits along the sidings and the "Siding-Exit" signals are also the "Distant" signals for the next siding.

Click on the main track sections to set them free/occupied. Switches cannot be operated but an open switch is equivalent to its track circuit being occupied. Reload the page to reset the simulator.

The zoom in and zoom out buttons allow the line diagram to be enlarged, but then only covering 10 miles at a time. By clicking above the milepost numbers you can center the display on that milepost. The simulator will, however, only pan from MP578 to MP592 as this is the only section simulated so far.

This version unfortunately doesn't work in Internet Exploder. It works in Firefox. Other browsers I haven't tested. The first version of the simulator is still available if IE-users also want to have a go.