CN recently retrofitted an RDC (Rail Diesel Car) as a track inspection car. It can do inspections at up to 60 mph and detect cracks in rail joint bars as small as 1 mm. It is CN 15016 (RailPictures photo by Michael Quagliano).
Wendell Lemon reported it is visiting the Maritimes as train 482. It should be on the Newcastle (ex-NBEC) subdivision today and Thursday.
EDIT: The RDC arrived in Campbellton at 8 PM Wednesday.