“So you think Townsend is going to blow up these Tainter gates?” Briggs asked. “Heck, why not just blow the dam itself?”
“The dam is concrete, probably thirty feet thick. How much dynamite would it take to blow that wall?”
“Probably ten thousand pounds of TNT.”
“It would probably take a lot less trouble and explosives to duplicate the 1995 accident and blow those struts on the Tainter gates,” Patrick said. “That forensic report they downloaded from the Internet spelled out exactly where they could set the charges to dislodge those gates. And if more than two or three of those floodgates let loose, with a nearly full dam it would cause a massive flood downstream. Christ, it could wipe out a half-dozen towns along the river and inundate most of downtown Sacramento. The lake is near capacity right now from all the rains and runoff.”
“But I still don’t get it,” Briggs said. “Why do all this? Is he just plain crazy?”
“I don’t know,” Patrick replied. “But we’ve got to stop him first.”
“You ever think about the possibility that this might be a trap?” Hal asked. “What if he planted that information on the computer so you’d find it and chase him out there? What if this is another diversion?”
“We’ve got nothing else to go on, Hal,” Patrick said. He put on the suit helmet, activated the BERP system, then clicked open the radio commlink: “Drop me off at the top of the dam,” he said to the pilot over their command channel. “Then get as close as you can to the face of the top of the dam. Watch out for power lines.”
“We’ve got the power lines on radar,” the pilot reported. The MV-22 used a millimeter-wave radar that could detect power lines as small as a half-inch in diameter in time for the pilots to steer over or under them.
The big aircraft settled into a hover just ten feet above Folsom Dam Road atop the huge concrete dam. Patrick, fully suited up, jumped out of the right-side cargo door. He could see the level of the lake on the northeast side of the dam-it was just a foot from the top, 465 feet above mean sea level. No doubt about it: If the dam let go, it would create a monumental disaster for miles downstream on either side of the American River.
Patrick landed on the road, climbed over the guardrail, and jumped down onto a catwalk. The catwalk ran across the top of the spillways, eight steep concrete chutes that plunged 340 feet down into the American River gorge. All the spillways appeared dry, with no more than small rivulets of water running down the steep faces. That meant that the entire discharge from the lake was being diverted to the hydroelectric turbine chutes to make electricity.
Right below the catwalk were the tops of the eight Tainter gates. The Tainter gates were huge curved steel doors fifty feet high and forty-two feet wide, with support struts in the middle that attached the gates to trunnion pins on each side; the pins were mounted on the concrete supports on both sides of the spillway. Each gate had two large chains, resembling huge bicycle chains, that lifted the gates when necessary and allowed water to flow down over the spillway to relieve hydrostatic pressure from the reservoir side of the dam.
From the catwalk, Patrick could look down the back of the Tainter gates at the chains, using the infrared scanner visor on his helmet. Everything looked normal. He ran down the catwalk and inspected the top of each gate. Still nothing. “I don’t see anything yet,” Patrick radioed to the MV-22. “You guys see anything?”
“Not yet,” Briggs replied. The pilots were using the infrared scanner in the nose turret to scan the face of the dam. “We’re getting as close as we can, but those transmission lines will keep us at least two hundred feet from the dam. We’ll see if we can slip in between the lines and the dam, but it’ll be tight. We’ve got dam inspectors and National Guard on the way to secure the dam. Their ETA is about fifteen minutes.”
“Copy,” Patrick answered. “I’m going to have to go down the face of these gates, Hal. The way they’re designed, blowing the chains would prevent the gates from opening.”
“Roger that,” Hal acknowledged. He was rereading the computer printout as the MV-22 began to maneuver over the transmission lines. “According to this forensic report you got off the computer, when that gate let loose back in 1995, it was friction from one of the trunnion hinge pins on the sides of the gate that caused the strut braces to buckle. The braces hold the gate against the spillway opening. Once they bent, the water pressure and the weight of the gate just pushed the gate out. Check the struts on each gate. If I was going to blow anything, that’s where I’d set the charges.”
“Copy,” Patrick said. He looked over the edge of the catwalk. There was another catwalk forty feet below him, at the same level as the trunnion pins on which the Tainter gates pivoted. Patrick considered trying to jump down to the lower catwalk, but if he missed, it was a three-hundred-foot fall down the face of the dam to the river below. “Hal, come back to the top of the dam and pick me up,” Patrick radioed. “It’s too far to jump to the lower catwalk.”
“On the way,” Hal replied.
Patrick hit the thrusters and jumped easily to the road above. He saw the MV-22 climb and start toward him, maneuvering easily over the transmission lines. With remarkable speed and agility for a bird its size, the huge tilt-rotor aircraft moved smoothly toward the road.
Then a streak of fire arced across the sky from the lower catwalk and plowed directly into the right engine. The engine disintegrated, a shaft of fire blowing downward from the right rotor as burning fuel streamed out and was caught in the rotor wash. The MV-22 dipped down below the rim of the dam. Patrick heard the left engine spool up to full military power, and the bird veered right, missing the lower catwalk by just a few feet.
“Will!” Patrick screamed into his helmet radio to the pilot. “Pull up!”
“We got it! We got it!” one of the pilots radioed back-Patrick couldn’t tell who it was because the voice was so high and squeaky. But it didn’t look as if he had control. As he watched, the aircraft slipped to the right, barely missing the power lines across the gorge in front of the dam, and dropped.
But the MV-22 had a crossover transmission system that allowed power from one engine to drive both rotors, and as it fell down into the gorge, power was coming up on both rotors. What started as a barely controlled crash quickly turned into a powered glide. It was still going down but the pilot was back in control. Just in time, the pilot pulled back on the control stick and flared the aircraft as it hit the water a few yards from the rocky shoreline. It skittered across the rocks, spun around facing upstream as the dead right-engine nacelle struck the water, and came to rest on the edge of the shore, with the right wing and right-engine nacelle dipping into the American River.
“We’re okay! We’re okay!” Hal radioed. “We’re evacuating the aircraft!”
Patrick’s relief gave way to a rage that rose up out of his chest and flooded his brain with hatred. He was past thought or calculation-he reacted. He used his helmet’s infrared scanner to pinpoint the location of the terrorists on the lower catwalk-one of them was still holding the red-hot rocket launcher so spotting them was easy-and he hit his thrusters. He bounded over the railing on the road and soared out into space, aiming for the terrorists in the darkness nearly a hundred feet below.
His aim was perfect. He landed on his chest and face right on top of the guy holding the spent rocket-launcher tube. He went down hard, but so did Patrick, who then crashed over onto the catwalk. The electrical surges coursing through the suit startled him with their force. Screaming in the effort to clear his head, he reached up to grab the handrail of the cat-walk…