Crazy cheap deployment, but I don't think those panels will stand up to it very well. The vibration is bad enough, but metal fragments are the real threat, I suspect. I've been in a few rail yards, and vehicles that habitually get parked close to rails that are in active service have paint damage from tiny metal chips flying off the rails and wheels. Unless they have some kind of replaceable clear shield, those panels will not just get dirty, they'll get slowly sandblasted till not much light is actually reaching the photovoltaic panel.