On the California Zephyr route out of Denver up the Front Range of the Rockies, there is a windbreak at the Big 10 curve. More info and pictures can be found here. At this location there are often high winds that sweep down out of the mountains and have in the past blown high profile cars off the tracks (no passenger cars have been blown off, but high-profile autoracks have. Amtrak's Superliners would be susceptible to this because they are tall and also relatively light for a railcar.) The railroad decided to create a windbreak by laying a track and placing about 2 dozen loaded hoppers on the inside of the curve. The siding was disconnected from the main, the hoppers were welded to the rails, and then painted an earth tone to blend in with the surroundings. Map view here. Additional pictures here here.