Just saw a BNSF mixed train go past here in Fargo/Moorhead with a few open hoppers that had small solar panels on the side. Cabling was visible running from the panels to the underside of the cars. The hoppers looked to be loaded with gravel, but I couldn't be sure. Of course, they were gone before the camera was in hand. Anybody have any idea what they might be?
A guess based on what I learned riding the Austin Steam Train last month... The Austin Western railroad has a scale track which weighs every car on the rock trains that go through. (Each car is weighed empty on the way in, and weighed loaded on the way out, for accounting and safety purposes.) Each car has a transponder that communicates with the scale track so that the scale track knows which car it is weighing at any given moment, regardless of whether they have been re-ordered in the train or any such thing. Those solar panels may simply provide power to the transponders (probably via charging a battery). Just a guess, it may be a different but similar application.
A lot of MOW ballast hoppers are being equipped with GPS systems and automatic gates, and the solar panels you saw may have been power for such a system. The cars can be programmed to dump at pre-set locations based upon GPS coordinates.
As info, the AAR standard AEI transponders are passive radio tags... i.e, they don't require batteries. There are tags that utilize batteries, they are primarily used on ISO containers, the non-replacable batteries in them last over ten years.
THe dump system is powered by the solar panals, this way you do not need air or hand power to dump a car. I am not sure how many BNSF has but I have seen several 40-50 car trains of these at the same time. Kevin
A couple of these were involved in a derailment in Tulsa. http://www.rrpicturearchives.net/showPicture.aspx?id=1629956 Thanks Erik Edmonds for the photos.
I have seen some open hoppers like this in the Roseville yard from time to time. Never seen them full, but the dust on them looked like gravel or ballast. They have a tent or a shaped set of solar pannels on the ril of the end of the car. I assumed it was for charging a battery used to open and close the hatches in locations that didn't have power handy... that is why I though they might be ballast cars.
Those are them! The cars in that derailment pic are exactly what I saw, mystery solved. Funny thing is - I saw them later in the day from the other side of the tracks. Short train pulled by two 4 axle locos, maybe 15 cars or so. Again, no camera (I was also driving, so maybe best that I didn't try to take a picture...) Thanks for the replies, all!
