"Stop." The pull halted and the heavy vehicleswayed just a foot above the churn in the waters. Alec waited a minuteuntil the tractor quite swinging and then ordered, "Let's go down."
* * * * *
Number One crane began paying out cable and the tractor and menslipped beneath the surface of the turbulent waters.
Surging, silt-laden water rushed upwards past the sides of the heavycab and swirled around Troy and Alec. Both were clamped into the seatby a steel mesh belt and the waters tore and whipped at them. Despitethe six-ton mass of the tractor, both men could feel it quiver againstthe thrust of the waters rushing and breaking against itsundersurfaces. Although both had turned on their powerful suit lights,the lamps made only a dim glow in the surging waters. When the tractorhad dropped some thirty feet, it was Troy who yelled "Hold it!"
The downward motion stopped.
"Let's get back against the wall," Troy yelled over the roar of thetorrent. "Those pumps are pretty well to the center of the bore and Idon't want to come down on top of one of them, even the bad one. Moveback!"
On shore, both cranes began inching up stream.
In the thundering bore, the tractor bumped against the wall of thehole. "Hold it," Troy shouted. The carriers stopped. "Take 'er down."
Again the massive vehicle descended into the depths. The roaringbecame louder with every foot and the constantly dinning noise rattledthe earphones of the crane and carrier operators. Hall stood on thebank, his eyes glued to the thread of cable vanishing beneath thewaters.
The tractor was bumping against the wall with more violence and theengineers could feel it tip and sway as the turbulence increased frombelow.
"I think we're too close to Number Two pump," Alec yelled. "Let's geta little more offshore." On the far bank, Number Two crane beganhauling the pulley towards him.
The undersurface bobbing lessened. "That's good, Number Two," Alecshouted. The downward motion continued.
As suddenly as it began, the turbulence almost ceased and the sounddiminished in the black, watery hole. The big nuclear pumps stoodthirty feet high with their great jets at the top. The tractor haddescended blow the level of the jet thrust. At the same instant, therewas a forward motion and the tractor began to sweep toward thedownstream wall of the bore.
"Drop us, fast," Alec commanded. "We're being sucked."
Number One crane operator slammed his release button and the tractorfell with a jarring crash to the floor of the catch basin. On thefloor, its mass held it in place against the drag of the three hugepumps and the natural flow of the water.
The water was clearer and their lights penetrated a few feet into theblack-green hell around them.
"You see it?" Alec asked his partner.
"Not a thing," Troy replied, "but we can't be more than a few feetfrom it. It's got to be somewhere in front of us and I think a littleto my side. The suction drag doesn't seem quite so heavy over here."
"Number One," Alec instructed, "give us a fast one-foot lift and dropit immediately. The current will move us."
The operator took up the slack in the cable and then gave a shortburst of upwards pull and slammed the release. The tractor lifted andwas carried forward about five feet before it slammed down again andstopped.
"There it is," Troy yelled, aiming his light to the right front of thetractor. The beam picked out the massive casing of Number Four pump."Let's get in close." On instructions from the submerged engineersboth cranes lifted and hauled briefly. The tract slammed into the bulkof the disabled pump. Troy and Alec played their lights over theplate.
"This is the bottom plate," Alec said. "It's tipped all right. Got toease around to one side."
Again the cranes dragged and lifted and the massive tractor scrapedalong the bottom plate of the overturned pump. Suddenly the vehiclewhipped forward. "Drop it," Troy yelled, and the carrier smashed tothe basin floor.
They were alongside the main outlet tube, now tilted downwards on anangle towards the floor of the basin. Below them and under thecurvature of the tube was the pile housing. The explosive had to beplaced at the point where the pile housing, the pump base and theoutlet tub met.
Currents of water still swirled around them and tugged at the two men.But it had much less force than during the downward descent. Alecunclamped the seat belt, then slammed his magnetic clamp suit bootsagainst the outer plates of the carrier. His suit buoyancy dragged himinto an awkward crouching position and he swayed and fought againstboth the upwards lift and the current swirl.
"Let's go," he said.
* * * * *
A hundred and seventeen feet above them, Hall and the crane operatorscould hear the hollow clang of the magneboots as the two engineersinched their way back alongside the tractor to a spot where thetractor hull touched the pump housing. Alec cut one foot loose fromthe vertical side of the tractor and slammed it against the pump baseand then quickly shifted the other foot and began forcing his way downunder the curve of the tube. Troy followed.
In the shelter of the base and tube, the current no longer pulled atthem and it was only the suit buoyancy to battle. It took them threeminutes to struggle their way to the juncture point. Alec wedgedhimself in with his back against the housing above him and carefullybegan unwinding the explosive belt he was wearing.
With his feet clamped on the vertical wall of the pump housing andknees locked in a skier's stance, Troy handed over the first of themagnetic clamps. Alec took it and carefully clamped the end of theplastic explosive belt against the pile housing. They worked slowlybut steadily until the entire band of explosive was in place along afive-foot arc of the housing.
During the entire operation, neither man spoke and on shore, thelisteners could hear only the heavy breathing of the pair and anoccasional muffled sound of a clamp going into place.
When the plastic was locked down, Troy carefully unclipped a timerfused from his belt and handed it across. He spoke for the first timesince they left the tractor. "It's set for seven minutes." In thewavering light of the murky waters, he saw Alec glance up at him andthen gingerly insert the fuse into the explosive.
"Get moving," Alec ordered. Troy started inching his way back along thepump housing wall. Alec waited until Troy moved into the gloom and almostout of sight, then flipped the water-tight switch that activated the fuse.The device was armed. In seven minutes, if the pile didn't go criticalbefore then, the charge would detonate--whether they were back on thesurface or not.
He shoved himself free of the pile housing and followed Troy backalong the wall of the base. At the hull of the tractor, he made thefoot-at-a-time crossover and again fought suit and current to get backto the cab. The seconds ticked off into the first minute and into thesecond. Ahead, Troy had reached the aperture of the cab door andreached in to grasp the end of the steel safety belt. He hauledhimself into the seat and looked back for Alec.
The other engineer had just reached the cab. He swung a leg over thesill and at that moment, a surge of current whipped his suit. Hetwisted, grabbed for a handhold and missed and shot up towards thesurface. In that same instant, Troy shot up out of the seat, holdingthe end of the belt in one hand and grabbing for Alec's ankle withthe other. He caught it and clutched. "Up, fast," he screamed.
The tractor snapped up under them and threw both men against the seat.Alec seized a control handle and hauled himself into the seat as thevehicle surged upwards. Under full power, it was whipping towards thesurface and now, the water pressure was holding them down. The timerpassed the four-minute mark when the six-ton carrier burst out of thewater in a geyser of spray. The cable whipped and almost threw themfrom the cab. Then there was a spine-snapping side jerk as the NumberOne crane operator began smoking the cable pulling them to the shore.
Thirty seconds later the tractor slammed to the ground. Hall and thecrane carrier driver were waiting. They reached in and jerked the twoengineers from the seat and half carried them to the rear of themassive crane carrier. The ope
rator had already leaped from his caband was lying prone, face down on the ground.
Troy and Alec, together with Hall and the driver, stretched outalongside each other in the dubious shelter of the carrier and waited.
The seconds ticked off. A minute later, a small geyser of water shotup a few feet from the surface of the water and seconds later theyheard a slight rumble. Then there was only the sound of theirbreathing and the rush of water in the river.
Hall jumped up first while the others were still scrambling to theirfeet. He raced to the radio after a hasty look at the river.
"Monitor," he called, "what's the story?"
"They got it, boss," monitor answered. "The pile is dead. You've gotsome hot material in the water but it's dissipating