Rail grinder RG309 is in New Brunswick. Wendell Lemon reported it went down the Sussex subdivision from Moncton late this morning. Jeremy MacPherson reported it in Petitcodiac around 2 PM, and Wendell reported it returned to Moncton late in the afternoon. Perhaps it will venture farther toward Saint John tomorrow. When it is not grinding, it travels at track speed.
RG309 is Loram's rail grinder machine. It grinds the tops of rails down to a specified profile to enable better, more reliable operation of trains. RG309 is not capable of doing switches and crossings, so another machine will follow up to do those. Photos of RG309
David Othen has a nice video showing a rail grinder at work in the Halifax area, in his DVD Trains in Nova Scotia Volume 2. I own this and I recommend it.