I live near a clay pit, which has a spur track that connects to a main train line. Once or twice a week, they bring out their little locomotive hauling a few train cars worth of clay to the main line. Along their short (approx. 1/4 mile or so) spur track, there is a switch on the track with a bright yellow sign that says “Derail,” which stays in the derail position whenever they are not using the track. This was just put there recently, and I can’t imagine there would be other trains using their spur trak. Why the derail switch?
If you are talking about a thing like a set of points that can shunt a runaway train off the rails and onto gravel to stop it, then I shall hazard a WAG.
It might be that the ‘main’ railway (I assume there is one since you describe this as a spur) plan on using this spur as a derail point for runaways. I.e. if a train on the main line runs away, shunt it down the spur line where it will safely derail without blocking the main line.
I would suggest you ask someone who works there
Another WAG: It could also be a safety to keep the clay train off the main track except when it’s supposed to be there. If the clay train is shunting cars back and forth, or is parked at the top of a grade, it could get loose and accidentally run onto the main line.
You could distinguish between this WAG and slaphead’s by noticing which way the switch is aimed, if there’s a difference. The best way, though, is to ask somebody who knows.
The switch is designed to derail going into the clay pit as opposed to heading to the main track. I neglected to mention that this spur track happens to connect to the track in which the Graniteville chlorine spill took place back in January. This occured only four or five miles down the main line from where this spur track is located.
My WAG is the best one so far. My existence is validated!
Don’t ask anyone who actually knows, in case my fragile ego is crushed when the truth becomes known.
Railroader (and a railfan, too) here…
Derails are quite common and are used for a variety of reasons. The guess about runaways is one, though rare. More often, derails are simply a way to protect the mainline from unauthorized movements. In the case of this spur, my impression was that the clay pit owns its own switch engine and brings its own cars to be interchanged on the main. In that case, the Class I rail line (Union Pacific, BNSF, CSX, etc.) would place a derail to protect their main from that little switcher.
In other cases, derails are placed on the ends of passing sidings where trains are “parked” for extended periods of time (generally occuring when the yards are at capacity and trains are stacked) so that there is an extra safety measure when leaving said trains unattended.
Temporary derails are placed on the track (sometimes at a turnout (switch) but sometimes not) to protect gandy dancers working on the line, as well. These are simply clipped/bolted to one railhead and have an attached DERAIL sign. This is, in effect, the last line of defense for the workers. There should be no movement through the area anyway, as the dispatcher wouldn’t allow it. However, human error happens, and the track gang wants and deserves every measure of safety.
BTH
The clay pit does indeed have it’s own engine, and typically brings 4-5 loads of clay out at a time once or twice a week. There is a sidetrack on the main line where the cars sit for a while sometimes. I was wondering if the Graniteville accident had anything to do with the new switch, since it has only been there for a month or two. I don’t know anyone who works there to ask, but I appreciate all the input.