JeffPo's Classification Lamp Page
Last update: 10/28/15
Here you see a classification lamp made by the Pyle National company. The lamp is about 10 inches tall, not including the handle. A pair of these lamps would go on the front of the locomotive and the color would indicate the status of that particular train (which I'll explain in detail below). The lamp is marked on top with PYLE-NATIONAL and the symbol for the company, the letter P superimposed on the letter N.
The lamp has two white/clear lenses. The lenses are situated 90 degrees from each other, with one that would point straight ahead and the other would point to the side. In this image you can see the mounting bracket and a lever to the right of the lens.
There is also a second lever on the other side of the lamp, but both levers do the same thing. They worked a mechanism inside that would rotate two green glass disks between the light source and the clear lenses, thus changing the output color from white to green.
Here's an inside view of the lamp. You can see the two green glass disks that are operated by the levers. Either lever will turn both disks, as it's all connected. You'll also notice that the lamp has two mounting brackets. That was so it could be used on either side of the engine, left or right. The lamp also has an on/off switch on the outside for switching the light on or off.
Here you see the lamp lit with the white signal showing. This would mean that the train is an "extra", which I'll explain below.
Here you see the lamp lit with the green glass disks rotated to shine with a green signal. This would mean that the train has more than one section, which I'll also explain below.
How Classification Lamps Were Used
Image of Western Maryland Scenic Railroad engine (found on the Internet). Note the two lit white classification lamps on top, at about the 10:30 and 2:30 o'clock positions.
Back in the day before radios and such, trains ran on tightly structured schedules in which any unknown deviation could be dangerous in that two trains could find themselves on the same section of track at the same time. Classification lamps were lights located on the front of steam locomotives that indicated what class that locomotive was operating under, which was very important to the dispatchers and other workers at the various depots and train stations. The dispatcher had to keep track of where any given train was on the line. The train classes were regular schedule, a train that had more than one section, or an unscheduled "extra".
Unlit or Dark Classification Lamps
Regularly scheduled trains, both passenger and freight were assigned numbers and ran on schedule. Scheduled trains displayed unlit classification lamps (i.e. dark) and the number boards of the lead engine would display the train number. Note the train number is the schedule number, not the actual engine number (which didn’t change). So under normal scheduled conditions, the classification lamps remained off.
Lit or White Classification Lamps
Unscheduled trains were considered “extra” trains. If a train was operating as an extra train, it would display a lit classification lamp (i.e. white or clear light), and the number boards of the lead engine would have an X and the engine number. So if engine number 1218 of the Norfolk & Western line was operating as a lead engine on an “extra” train (i.e. unscheduled), the number board was read “X1218) and it would be displaying white (i.e. lit) classification lamps.
Lit Green Classification Lamps
Scheduled trains could be of varying lengths as the traffic dictated. If business was particularly heavy, a given passenger or freight train might have too many cars for one train so the “train” would be split into two or more ‘sections’. So let’s say the Southern Railway passenger train number 20 had to be split into three train sections because it was the holiday season. If a train had one or more other sections following it, it would display green lit classification lamps. The number board for the locomotive of the first section would be “20-1”, and it would display lit green classification lamps. The number board for the locomotive of the second section would be “20-2”, and it would also display lit green classification lamps. The number board for the locomotive of the third and final section would be “20-3”, and it would display unlit dark classification lamps. The unlit classification lamps of the last section would indicate that there were no more sections of train number 20 following.
Here's an image of a steam engine at a museum, where you can see classification lamps mounted to the left and right of the headlight. The red lamps at the bottom, on the left and right, were used as rear marker lamps if the locomotive was traveling in reverse. Image credit goes to Robert David Grant at http://www.rgusrail.com.
NOTE: Thanks and credit to Red Beard the Railroad Raider for providing information on how these lamps were used.