Thanks both, didn't know about the harvesting of cuttings and embankments.
Still exploring the various aspects of provender traffic. Further from the Horse Department instructions:
"Immediately upon receipt of a supply of empty provender, the Station Agent must shoot as much of it in the Bin accommodation will admit of, pack up the empty sacks and forward them to the Provender stores [...] Provender sacks must not be lent, or used for any other purposes."
I wonder how the sacks were returned. Possibly with the provender wagons, depending on whether those wagons were to be returned directly. The Q1s yes, but also the Opens?