Some of the last remaining Color Position Lights (CPLs) along CSX’s Indiana Subdivision (formerly the Baltimore & Ohio Railroad Indiana Subdivision) are being replaced in Indiana.
While documenting scenes from an abandoned brick plant and bridge near Medora (milepost 105.4), I took time to photograph and record these soon-to-be-retired signals. CSX crews were nearby, actively working on the new replacements, making it clear this would likely be my last chance to capture the CPLs in situ.


The Color Position Light was a signal type unique to the Baltimore & Ohio Railroad. Designed to mimic the positioning of an upper quadrant semaphore, the CPLs differed from the Pennsylvania Railroad’s Position Lights by incorporating both color and position in their aspects. This redundancy added a layer of safety, as the signal remained interpretable even if one lamp failed.
Frank Patenall developed the CPL around 1925, designing it while the Pennsylvania Position Light signal was being created.
The CPL signal at Medora features a main signal head and a marker lamp above it. This configuration allows the signal to display a clear aspect (Rule 281), elevating it from a slow-speed signal. Without the marker lamp, a green signal on the main head would indicate a slow-approach slow aspect (Rule 287A).
Further west, at Sparksville (milepost 110.6), two additional CPLs await replacement. Both are equipped with marker lamps.











This rail line appeared to be on the verge of obsolescence for a time. Freight traffic had dwindled to just two through trains per week after CSX rerouted much of its traffic to a former Conrail line to St. Louis. The route has been without scheduled passenger service since 1971, and rusted sidings and signals suggested decline. There was speculation that the line might eventually be abandoned and converted into a rail trail.
However, in the early 21st century, CSX invested in significant track rehabilitation efforts. These included replacing thousands of railroad ties, rail upgrades, and now, the modernization of its signal system.
This line has a long history. Originally constructed by the Ohio and Mississippi Railroad, it was completed in 1857. In 1893, it came under the control of the Baltimore and Ohio Southwestern Railroad, providing the B&O with a vital connection to St. Louis, Missouri. The Southwestern was formally absorbed into the B&O in 1900.
Financial control of the B&O passed to the Chesapeake & Ohio Railway in 1963, and by 1973, it had become part of the Chessie System. In 1980, the Chessie System merged with Seaboard Coast Line Industries to form CSX Corporation. The B&O ceased to exist as a corporate entity in 1987 when it was fully merged into CSX Transportation (CSXT).