Casey Durand's additional commentary: "What this is, is a very nice Jackson Tamper.  It appears to be set up so it can be used on switches as well as normal track.  It works by electric motors running a vibratory which vibrates the steel "fingers" that stick down.  These fingers are slid down beside the ties, at the tie ends, where they vibrate and squeeze down and then pinch under the tie.  All this motion displaces ballast underneath the ties."

Tom Hatfield's additional commentary, "Model 2400 Tamper. This one is used for switches, diamonds, small, quick jobs. This one does not have capability to line or level but can be equipped."