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Senior Engineer Li Jiang ran the midnight to noon shift at Three Gorges Dam on the Yangtze River. Li was proud of his job and proud of his country's achievement. The dam was the world's largest power station, generating almost a hundred terawatt-hours of electricity every year, a symbol to the world of China's engineering superiority. When Li was on duty he was in charge, responsible for the operation of the dam and the safety of millions of his countrymen.
The reservoir behind the dam stretched for more than four hundred miles. The dam itself was almost six hundred feet high. Power was generated by thirty-two enormous turbines. Li spent most of his working hours in front of a bank of computer monitors and watching the big board that dominated the main control room. He monitored the operation of the locks that allowed shipping to navigate the dam, the condition of the turbines, the amount of water flowing through the floodgates, the amount of electricity being produced, and more. The board and computer screens provided an instant picture of the health of the dam.
The main control room was spotlessly clean. Li sat at a long wooden work table lacquered in red. The main board formed a semicircular wall at the front of the room. The symmetrical layout of multiple graphic displays, switches and lights would have mesmerized any sufferer of OCD.
Li didn't have OCD, but he did have an almost obsessive attention to detail and a nearly photographic memory. He was finely attuned to the pulse of the dam, to the daily rhythms of the massive structure. For Li, the dam was like a living entity and he was like a physician assigned to monitor his patient's health. Mostly, things took care of themselves, as long as the proper maintenance was applied.
If the dam was a living entity, the beating heart resided in the turbines. Part of Li's job was to make sure the turbines operated properly. Everything was controlled by the computers. With a touch of a key, Li could alter the performance of the giant engines. Whatever he did, it was important that the generators turned in harmony with one another.
Harmony was one of the fundamental virtues in Chinese thinking. It applied to human relations and it applied to the working of a complex system like the dam. Without harmony, there was discord. Discord was unwelcome, especially between machines that stood six times the height of a man.
The first sign of trouble appeared on monitor two. Li adjusted his glasses and peered at the screen. Turbine four on the north side was showing anomalies. He called another engineer over.
"Zhang, take a look at this."
Zhang was an experienced engineer who'd been working at the dam almost as long as Li. He was a round faced man with a rounded belly. He reminded Li of a Buddha, though no one would ever say Zhang was enlightened. The two men were friends, and often talked over beers at the local café.
Zhang looked at the monitor. "That isn't right. The speed is fluctuating. What could be causing that?"
"Worn bearings, perhaps?" Li said.
He called up the maintenance schedule on turbine four.
"The bearings were replaced two months ago. There shouldn't be a problem."
"See if you can get it to stabilize," Zhang said.
Li entered a string of commands on his keyboard. On the monitor screen, the oscillation disappeared.
"Looks like you got it," Zhang said.
"Yes, but we have to find out what caused it."
A red light began flashing on the main board. Both men looked up. As they watched, two more lights started flashing.
Zhang looked at the monitors. "Turbines two, three, and nine are all showing anomalies. Their speed is fluctuating."
The lights in the control room flickered. More turbines began displaying speed variations. Red lights started to flash all over the board.
Li's fingers sped over his keyboard, entering commands. There was no visible response on his monitors. Somewhere under his feet, he felt a mild vibration.
"I'm going to shut them down," Li said. "Inform central power authority."
"They're not going to like it," Zhang said.
"They'll like it a lot less if those turbines self-destruct."
Li entered more commands. There was no effect. He felt the first touch of panic.
"I can't shut them down," he said. "Nothing happens."
Zhang pointed at one of the monitors. "The spillway gates. They're all opening. This can't be happening!"
Three Gorges had been designed to withstand a tactical nuclear strike. The sheer size of the dam almost guaranteed its survival in the event of war. But like any man-made structure, it had a potential weakness. In this case, that weakness was the underwater spillway design of the dam.
There was always a risk of cavitation when water moved at high speed through a spillway. Cavitation occurred when vacuum pockets appeared in fast-moving water. When the pockets collapsed, they had an explosive effect. The resulting shock waves would vibrate through the structure of the dam and the rock foundation upon which it was built. Severe cavitation created the potential for catastrophic collapse.
It was bad enough that the spillways suddenly opened. It was worse that the out-of-control turbines were sending erratic vibrations through the structure.
The vibration under Li's feet became more noticeable. A pencil on his worktable rolled off onto the floor. The dam was beginning to shake. Li looked at the big board. Everywhere, lights were flashing red.
The two men looked at each other.
"Sound the alarm," Zhang said.
"Yes."
A red metal box painted with yellow stripes was bolted on the corner of the worktable. Li ran for it, flipped the lid open, and pressed a large, red button set inside. On top of the dam, a siren began to sound, screaming a warning to head for higher ground.
A mile down the valley below the dam, Wang Kuo was enjoying the early morning coolness of the day, working the rich, black earth in his small plot. In the old man's hands was a hoe that had belonged to his grandfather. Wang's family had always lived here in the valley. There had always been the land and the bounty it provided. Somehow the family had managed to retain their small plot, even during the difficult years of the revolution and the chaos that followed,
The wailing sound of the warning siren split the still morning air. Wang lifted his head to look. The dam stretched like a great wall across the river and the valley, a towering triumph of engineering.
Why are they sounding the siren? Surely, it's a test.
Wang stared in disbelief as cracks began to appear across the face of the dam. Water trickled from the cracks, leaving dark trails across the grey-white surface. A sudden gout of water shot outward, followed by chunks of concrete crashing into the river below.
Wang stood rooted to the ground, unable to tear his eyes away from the disaster unfolding before him. As he watched, the central part of the dam broke apart in a tumbling cascade of twisted steel and shattered concrete. A wall of water six hundred feet high burst through the gap, a white capped, snarling, tidal wave of death. The wave swept toward him with the roar of a great beast.
Wang clutched the hoe to his chest. He had enough time to think of his grandchildren, before the water smashed into him.