Eric Flint: Grantville Gazette Volume 24

"I asked that too, after I started at the plant. Each new generator at the plant gets a number, in order. When they built the plant back in the 1920's, over seventy years before the Ring of Fire, it was a much smaller place, with two units, numbers one and two. They were only a few megawatts each. Then they enlarged the place in the 1930's and 1940's and put in two new units, three and four. Those two might have added up to fifty or a hundred megawatts, and once they were working, they scrapped one and two. Now, the hall that used to hold one and two is the plant machine shop. After World War II, fifty years before the Ring of Fire, they replaced Units Three and Four with Unit Five. That's about two hundred megawatts. The space where Units Three and Four used to be is where we're building our new units."

"What's a megawatt?" I asked, befuddled. "Are they like the kilovolts I heard talk of this morning?"

"Yes and no," he said, launching into a confusing description of the difference between force and power. I must have looked baffled, because he gave up halfway through, took a sip of his drink, and started over. "Think about a mill," he finally said. "You can measure the power it takes to turn the millstone in watts, or you can measure it by how many horses it takes to turn the wheel. One horsepower is about 750 watts. Anyway, two mills might need the exact same amount of power, but one could get that power from a high wheel with just a trickle of water, while the other gets it from a low wheel in a broad stream. You can think of volts as the height of the fall."

He paused to pick the olive out of his glass and pop it into his mouth. "Ah, these Italian olives are pretty good."

All I had left in my glass were two cubes of ice and an olive, so I imitated him. I don't eat olives very often, but it did seem better after soaking in my gin martini.

"Earlier, you said you'd had lots of trouble with accidents," I said, after spitting the olive pit into my glass. "And then you said you expected lots of accidents. Why?"

He sighed. "We're in way over our heads, that's why. Nobody in Grantville has ever built a steam engine bigger than a few horsepower, and now we need to build an engine with a thousand horsepower. Andy Frystack has built little engines, and he's a good machinist. The people at the power plant know steam, but not piston engines.

"Then, think about the size we need. The engines I've tracked down that put out a thousand horsepower all run over a hundred tons of iron, and we want 14 of the things. That's a lot of iron. Even if we can get the iron, who around here can cast pieces that big?

"Accidents? We've had castings break. Bad foundry work is the obvious explanation. We've had steel bolts snap. We might have made a mistake guessing the force they could handle. We've had bearings fail for lack of oil. We're used to automatic oiling systems, we probably didn't oil them enough. We've been lucky, so far. Not too many pipes have burst, and nobody's been killed, but we've come very close to catastrophe.

"Before you go inside that plant, I want to make sure you understand that it's a dangerous place."

"I got a lecture on the danger of electricity when I visited this morning." I said.

"It's more than that," Scott said. "We're working with chunks of iron that weigh a ton or more. Chunks of stone, too, for the engine foundations. Be careful what you walk under. Steam pipes are hot. We work with superheated steam at four hundred pounds of pressure per square inch. That's a high enough pressure that it is like working with gunpowder. Steam pipes can explode like bombs, and the cylinder of a steam engine can shoot a piston just as well as a cannon can shoot a cannonball."

Scott Hilton met me at the power plant the next morning and led me into the building. "This is the hall they made for Units Three and Four," he said, as I gawked at the scene. "Now, we've built Unit Six at the far end, and we're building Units Seven, Eight and Nine."

The room was huge, filling perhaps a quarter of the whole power plant. Huge windows along the south and west walls spread a soft light through the room. The place reminded me of a cathedral, except for huge machinery and construction toward the east end and a work crew digging a pit toward the middle.

Scott led me to the construction area. A crew of masons were at work there, filling a newly dug pit with stonework. Scott's explanation mostly went over my head. "This is the foundation for Unit Eight," he said. "Parts of it stand up high to hold the cylinders, but we need access to the steam and condensate pipes, and of course, there's the pit for the generator and flywheel."

While we watched the masons, a huge door at the west end opened to admit a four-horse team hauling a heavy freight wagon.

"Ah," Scott said. "They're delivering a stone for Unit Eight. Watch."

At first I didn't notice, but there was great bridge spanning the width of the room and it was moving toward the freight wagon. As a huge hook lowered from the bridge, I realized that it was a crane. When it reached the wagon, the teamsters hung their load from it, a single large stone.

"How much does the stone weigh?" I asked.

"About two tons, solid quartzite," Scott said. "It's quarried from the ring wall north of Schwarzburg, less than a mile from here, all downhill for the heavy stones. The little stones go to that new warehouse they're building in town, we keep the big ones."

As he spoke, the crane silently carried the stone toward the awaiting masons and lowered it onto a bed of fresh mortar.

"What's all that stuff," I asked, pointing to piles of ironwork stacked along the wall beyond the masons.

"Parts. We're getting parts from foundries and forges scattered all over. Some workshops are better at little castings, other can do big ones. Some forges do wrought iron, some can give us the little steel parts we need. When the parts come in, we line them up over there until we're ready to use them. Let's look at Unit Seven. There, we're starting to put things together."

He led me to the narrow space between Units Six and Seven. Six was a huge version of the machine I'd seen in Scott's basement, churning away at double-time and making a quiet pop-pop noise as it worked. About half of the big iron pieces of Seven were in place, with a group of men hard at work on one of the big pieces.

"They're turning the low-pressure cylinder right now," Scott said.

"Turning?" I asked. "Looks like it's not moving at all."

"Boring, I should say," Scott said. "See, they've run a boring bar down the middle of the cylinder, between those cast iron centers attached across each ends. There's an electric motor turning the boring bar, and there's a tool on the bar that goes round and round scraping the inside of the cylinder to be exactly thirteen and a half inches radius, as close as we can make it. It's not that different from boring a cannon, but a whole lot bigger around."

Turning to look at Unit Six, I could see similarities to the engine I'd seen the night before, but there were differences. "On your little engine, the valve and the cylinder were right together on the same side of the big wheel, but here, they're on opposite sides."

Scott looked baffled, and then chuckled. "No, my little engine at home has just one cylinder. Here, we have two cylinders, and each has its own valve system. The thirteen inch one on the far side is the high pressure cylinder, the twenty-seven inch one on the near side is the low pressure cylinder."

He must have seen the baffled look on my face. "It's a compound engine. That means we use the steam twice. The high pressure steam is four hundred pounds per square inch. We get half the work out of the steam dropping the pressure to seventy-five PSI, that's pounds per square inch. The low pressure cylinder gets the other half of the work, dropping the pressure to near zero."