Lights

While not positive, these look like "starting" or "conductor" lights that once hung in Union Station. The metal bracket was screwed into the bracket above the track to indicate when the train had permission to leave.

One light is set by mechanical forces. Before passengers board, workmen are inspecting the train, checking cables between cars, the buzzer system connected to the engine, marker lights are burning on the rear and the brakes. Only after all workmen are off the train, the chief workman calls K Tower, the station's nerve center, and says "Everybody in the clear on 178. Give the train one light." K Tower pushes a button and one light illuminates.

Passengers board the train. However, the conductor doesn't know when the last passenger has walked through the gate. Only the gate usher knows. The gate usher announces the train and stations and checks tickets.

After the last passenger walks through the gate, (s)he will push a button that illuminates the second light. That tells the conductor the last passenger is on the way to the train. The usher calls passenger services that the train is "on the light." The usher on the platform calls passenger services after the train begins to move out of the station. Passenger services will enter the train's departure into Amtrak's reservation system. This updates the train's status on the website.

MARC trains don't have an usher so MARC trains can leave on one light.

Lights are on BOTH sides so the conductor can see the lights if (s)he is standing at the front or rear of the train.