Big railroads couldn't run today without two-way radios. Typical communications include dispatcher's instructions arranging meets and granting authority to move, train crews announcing stations and signals, and talking defect detectors. This is great for the railfan. A scanning radio receiver (scanner for short) allows listening in on the action.
The dispatchers for both NS and CSX relay their messages by several repeater stations along their routes which are fed by microwave, fiber optic cable, or special telephone lines. Typically dispatchers clearly identify who they are (division wise) and who they are calling (train number or engine number). Going from train to dispatcher, NS crews call on a special frequency which is always monitored by the dispatcher. CSX crews request a link to the dispatcher by transmitting a tone (sounds like a touch-tone). The link request is good if a raucous buzz is heard. The dispatcher will answer shortly.
Both NS and CSX locomotive crews announce signal indications on the radio. Typically the transmission includes train number, engine number, direction, milepost (or station) and signal indication. Sometimes this gets reduced to "Clear Signal!". At least you know something's out there. Defect detectors on CSX may give location by name or milepost. Some give axle count, length, and speed, or any combination thereof. NS's detectors just give milepost and a "no defect" message if everything's okay.
The dispatcher's base stations are powerful and have high antennas. This combination insures they can be heard over a wide area. A locomotive's radio is a bit weaker and therefore has a more limited range. Defect detectors have low-power radios and have an even more restricted range. How far away you can hear a transmission depends on several things. Generally you can expect to hear the dispatchers from 10-20 miles away, trains about 10, and defect detectors about 5. Hilly or mountainous terrain will reduce the range further.
These frequencies are used by Norfork Southern and CSX between Atlanta and Chattanooga. The "AAR Channel" are numbers used by most railroads to identify channel numbers.
Frequency |
AAR Channel |
Use |
|
161.370 |
84 |
CSX road |
|
161.520 |
94 |
CSX Dispatcher |
|
160.440 |
22 |
CSX Local / yard |
|
160.950 |
56 |
NS Road, train to dispatcher |
|
160.245 |
09 |
NS dispatcher to train |
|
|