DSNNRR Track Maintenance

Looked out my window and here was the Durango Silvertonb Narrow Gauge Railroad working on the road bed. This piece of business is a PT-12 by Harsco. I believe that it goes along using lasers for measurement and then lifting the rail and ties, then regrades the ballast under the ties, and then nestled them back into the ballast.  All the time keeping the rails at a constant elevation or slant.  Noisy bugger but fun to watch.