what is this train?

The R&N has hauled a train of 4 black gondola cars filled with scrub brush followed by 20-30 orange box cars labled "MR" along the C&S a few times in Dec. Does anyone know what the deal is with this train...what it's for and who owns those cars? The boxcars are in pretty beat up shape.

Back when I was there, those were storage cars and spent their time up at Pittston, I had heard awhile back that they were supposed to find a new home somewhere else on the railroad, the boxcars were rumored to be going to the Swatara branch but that may have changed.

The cars are storage cars that are being re-worked in Cressona Yard for return to service. The Gondola Cars have already left the property.