[NOTE: This is a repost of Tracking the Light from Friday October 2, 2026. The original post suffered from a variety of unexplained presentation glitches. Hopefully these have been resolved and you will see a sequence of four photos to demonstrate the signal sequence at TOME interlocking.]

TOME is the interlocking on Norfolk Southern’s Port Road Branch at Port Deposit, Maryland. As discussed in Wednesday’s Tracking the Light post, we had been anticipating the progress of Norfolk Southern’s 596-unit coal train, which had been delayed as a result of a false reading by the high-and-wide detector near Port Deposit.

Once the train was under way again, we drove to the signal bridge at TOME, which displayed a yellow-over-flashing-green aspect—“Approach Limited.” This means proceed, approaching the next signal at Limited speed—defined as 40 mph for freight trains and 45 mph for passenger trains.

My goal was to capture the train with this signal aspect. This is a nearly impossible challenge in a single still photograph. So, I made this series of images, in which one of the images shows yellow-over-dark. It’s not perfect, but it conveys the spirit of the scene.

In the final image, the leading locomotive has shunted the circuit, and the signal has dropped to red-over-red, its most restrictive aspect.

Tracking the Light examines railroad night photography!