In my post from yesterday, I presented the first draft of the diagram that operators of my layout will use to help them determine which cars are moved to and from each car spot. That post generated a question about the purpose of the spots and the commodities, so I’ll start to answer that with a description of how the plant manages the production of energy. I’ve added some colour to the diagram to help clarify things and to give some indication of how the plant operates.
It takes a great deal of energy to make paper, and the International Paper plant at North Tonawanda had its own powerhouse fueled by coal. During peak production times, the plant consumed as much as 150 tons of coal per day. That amounts to average flow of two to three hopper cars daily, depending on the size of freight car being used. I don’t have all of the details of how coal was delivered and unloaded at the plant I’m modelling, but I’m making some informed guesses to come up with something plausible.
I do know that coal was stockpiled at the edge of the property near the warehouse/shipping area, so that’s what I’ve modelled. There was also a 100 ton silo at the powerhouse, so in my estimation, they would make sure the silo is always more than half full to ensure there are no interruptions in power supply. The powerhouse is shown in red in the diagram. The stockpile is adjacent to the “coal track” at the bottom right.
The stockpile of coal assures that fluctuations in the supply of coal can be managed. Coal can arrive at the stockpile in quantities larger than the daily consumption for a number of operating sessions, and there also needn’t be any delivery of coal for a few “days.” This allows for a great deal of variation in the flow of traffic. The plant also uses a hopper to shuttle the coal from the stockpile to the powerhouse. To accomplish this, they’re sure to keep one empty hopper car captive at all times, and the crew switching the plant might be assigned the task of shuttling a load or two between the bulk storage and the powerhouse. It’s also possible that some coal loads went directly into the powerhouse at the time they were delivered to the plant, though I imagine that would have happened less frequently than coal being delivered to the stockpile. Coal hoppers can be spotted at 27, 28, or 29. The unloader is at spot 29. The powerhouse is at spot 21.
I’ll put together a description of the other spots in a future post.