Tamping track

So Spike, what makes rough track smooth again? A surface, line and dress. Huh?

A few short decades ago, gandy dancers did this work with lining bars, hand operated jacks and tamping bars or shovels. Today, workers (or more correctly, one worker) use a multifunction machine called a production tamper to level and line the track, then "tamp" (or compact) ballast under the ties to hold them in position. A production tamper uses lights, sensors and a servo circuit to detect deviations from profile (low spots in the track or lateral misalignment). Another function activates a jack to lift the track to the proper level and push it to one side or another until the sensors indicate that it is back in a straight line (or conforms to a predetermined curve). Confusing? Perhaps to most of us so instead check out these photos of a Jackson 6300 in action (followed by a ballast regulator to broom the extra ballast off of the track) and see the end result at the bottom. (Tip: if you click on the photo, you will be able to view a full screen version.)