Railroad Trains for the Soul: Locomotive Lights
We all know that every locomotive has front and rear headlights (with one or two beams) that must always be turned on during normal operation. In addition, there are many types of auxiliary lighting systems, some of which are mandatory or optional, to not only increase safety for civilians at railroad crossings but to also warn other trains. Some steam locomotives and early diesels have an oscillating mechanical light that moves in a figure-eight or elliptical pattern. The two notable types are the Mars light and the Pyle Gyralite. Because of the gyration of either light, this gives a distant perspective of a flickering bright-dim pattern until the train passes through the crossing.
Ditch lights (or crossing lights) are two separate fixtures that are mounted on the pilots of more modern locomotives. They were initially used in Canada and soon became mandated by that country. Although ditch lights were optional on some American railroads, the United States was the next country to require installation of them on both new and existing locomotives by 1997. Some recent locomotives, such as those on Norfolk Southern and Canadian National, have ditch lights on both the front and rear ends, ideal for added safety when in long-hood forward operation or switching duties. Interestingly, the British Columbia Railway was the only railroad to use not one but two pairs of ditch lights on many of its diesels. The top pair are mounted above the front porch while the bottom pair are below. The latter are referred to as “rock lights”, which provide additional illumination to the roadbed.
When the engineer blows the horn, the ditch lights can automatically flash in a back-and-forth pattern and continue to do so for generally 30 seconds after the horn is silenced. On western freight carriers (primarily Union Pacific and BNSF) as well as Canadian carriers, these lights typically stay lit, even when the horn is sounded. However, eastern operators such as CSX and Norfolk Southern prefer to make them flash at the command of the horn controls. The same thing is true for many North American passenger railroads, especially Amtrak. Even the Southern Pacific had some of its locomotives with flashing lights before its demise. Regardless of those methods, the virtually maintenance-free ditch lights are the most effective means of alerting people who are near the train tracks.
Other lighting systems are considered to be optional and are only requested by some railroads; in other words, some are normally intended for fire trucks and other emergency vehicles. Strobe lights can produce each flicker in less than one second. Amtrak used to have these on many of its locomotives, up to and including the GE P40DC GENESIS units. However, the agency eventually phased out the strobe lights, which were supplanted by the more reliable ditch lights. Some Burlington Northern locomotives also had strobes that are typically mounted on the pilot where the ditch lights would normally be.
Not all types of locomotive lights are necessarily colored white so here are several examples that are intended to be a different color. Marker lights are red to prevent approaching trains from colliding into another up ahead. A few freight railroads use marker lights, which must be illuminated when a locomotive is being operated as a helper at the rear of the train. They are also called “DPU lights” (particularly on Canadian National diesels), suggesting that they can be turned on to indicate that a unit is serving as a distributed power unit. While optional for freight duty, markers are essential for passenger locomotives if assigned to push at one end of the train. This is controlled by a cab car that is leading the other end.
Emergency lights are also colored red but can only turn on if an emergency brake application is initiated. They can be built in the form of a strobe light or a gyrating light. Notably, Amtrak used the former while some railroads, like the Southern Pacific, used the latter. Another type of non-white light is the beacon, which is colored amber. Although some beacons have a rotary mechanism, others contain separate bulbs that flash in sequence to create the circular motion. Perhaps the most complicated type ever used by the railroads were called classification lights. During the age of “timetable-and-train-order” systems, class lights were colored white and green to indicate a specific train. This is not directly related to safety but just a brief mention of it.
While some lighting systems are obsolete in today’s railroad industry, Metra actually has a lot of locomotives that are fitted with almost everything: headlights, ditch lights, marker lights, Gyralites (white and red), and beacon lights. Even some of the new Siemens SC-44 Chargers have two strobes and one emergency light mounted on the cab roof. Here are a few videos of some unique locomotive lights.
A Rio Grande F9 diesel with Mars light
A CSX GP40WH-2 (ex-MARC) with Gyralite and markers
A Southern Pacific AC4400CW with flashing ditch lights
A Metra F40PHM-2 with ditch lights and gyrating light
A Burlington Northern SD40-2 with pilot strobe lights
A VIA Rail P42DC with a spotlight above the main headlight
Sources