A derail (as opposed to a derailment) is a device on a railroad track designed to intentionally derail a railroad car, in order to prevent worse harm. There are various types of derails, including the type that in the UK are called "catch points" and are permanent parts of the track. The pair of industrial sidings known as the "
House Tracks" (a name deriving from the days when Fernley had a train station at this site) have catch-point-style permanent derail switches at both ends of each siding. These are intended to prevent a railroad car that rolls away from rolling onto the adjacent main line. The derail switches divert the car away from the main line. (You can see the main line in the photo below easily because Union Pacific recently re-ballasted it, and the fresh light-colored ballast is very visible.) Fixing a derailed car would be better than having a train come along at speed and collide with the car fouling the main.
The derail switches here have a large letter D on the switch stand. You can tell that they are in the open (will derail a car moving through the switch) if the D is visible as you move toward the switch while on the track. When closed (not derailing) the D faces away from the track.
On last Friday evening, Lisa observed that one of the derail switches on our siding was not set correctly.
The switch on the right is in the open (derailing) position, as it should be when the tracks are not being worked. The switch on the left is in the closed (not derailing) position, which is bad because there are cars on this track, and should one of them roll away, it might be able to build up enough momentum to roll onto the main line, although it would have to roll through two other switches set against it (the switch between the two house tracks and the mainline switch that leads to both house tracks) and up a slight incline to do so. Also, the cars on the siding should have their hand brakes set, although if the crew forgot to reset the derail, one wonders if they remembered to set the hand brakes.
I would have opened this derail switch, but the last crew to work the yard had (correctly) locked the switch. They just forgot to reopen it when they finished their work. We're trying to decide whether we should call Union Pacific (it's their tracks and their main line, even though the house tracks are leased to BNSF for their trackage-rights operation) and tell them about this. At the very least, if I'm able to do so when the "little BN" switch job comes out to work the track, I think I should walk out there and ask them what we should do if we see a closed derail like this, as it seems like a potentially dangerous situation.
Mind you, the cars currently parked on this track look like they are carrying natural gas, so we're screwed no matter what: either they derail and potentially explode, or they roll onto the main line and definitely explode when hit by a train unable to stop in time. But a low-speed single derailed car is less likely to break open and leak explosive unodorized natural gas.