Thanks for posting, that's a piece of equipment I never would have seen or even knew existed living in Central Calif., as most of the trackage around here doesn't seem to get the groth of plants and trees like your picture shows.
I was intrigued by the apparatus on the Right side of the small loco a I first thought it was some sort of a ballast spreader then I realized that the two things that looked like hand holds are actually guides to allow the unit to be positioned around small trees or bushes too large for the heavy duty weed trimmer and chop them off with is large sheers.