As per a thread on the NWP site they are empty petroleum coke (https://en.wikipedia.org/wiki/Petroleum_coke) cars. They've been in storage on the NWP for over a year, mostly up at Windsor until moved to the Burdel siding around April. Would be interesting to know reporting marks on the car, as there is another set of pressure differentiated covered hoppers stored on the S&S Shortline Leasting operation on the north end of the old Nevada Northern in Shafter, Nevada. They aren't related in any way to NWP freight operations, just extra revenue they are earning by storing the covered hoppers at a time they aren't being needed by their owner for anything else.

At present NWP does haul inbound feed for several feed mills in Petaluma, plus supplies for the Lagunitas brewery. Lagunitas has been wanting a spur directly into their facility that so far they have been unable to work with SMART to get one installed, so they are unloading cars a short distance north of their plant. NWP will apparently use the north end of the Burdell siding to stash loaded grain cars if they happen to have more on hand than what will fit in the unloading spurs, but otherwise they will get the empty cars off the property.

Jeff Moore
Elko, NV