“We’re gonna make it,” Edwards said, gunning the tank down the streambed of the Little Tennessee River, the water flying up on either side. “I guess that armor is tougher than they thought.”
“Maybe,” said Major Porter, “if…”
What the conditions were Edwards wasn’t going to find out because as the major spoke the world went white.
The magazine for the SheVa guns was the heaviest armored container ever designed. The inner layer was simple steel, four layers of hardened case steel coated with “supersteel,” a recent development that increased the surface hardness of steel almost fourfold. Outside that were two layers of “honeycomb” armor made of tungsten and synthetic sapphire. The outermost section was multiple layers of ablative explosive plates. These had been found to disrupt Posleen plasma guns, to an extent.
In addition there were four sections that were designed to “control” the explosion and “blow out” if a round went off. And there were internal baffles designed to direct the majority of the explosion away from surrounding rounds. In that way it was felt that the explosion could be reduced to at most one or two rounds. Better a minor cataclysm than a major one.
The Posleen had determined that most tanks placed their engines at the front and rear. And since their orders were to keep pounding until the gun stopped and was burning, they had pounded over four hundred plasma blasts into the rear compartment. There was only so much that even the strongest armor could take.
The round that actually penetrated had one last defense to make it through. But at the end it cut through the thin shell of depleted uranium surrounding the antimatter core with relative ease. The antimatter then did what antimatter does when it comes into contact with regular matter. Explode. Spectacularly.
The accidentally targeted round was only equivalent to 10 kilotons and the engineers were relatively sure that a single round exploding would be controlled by the container. At the most, if it was on the outer rack it would blow out and only be a nuisance to any unit within, say, a mile of the gun. A major nuisance to them, but if you weren’t too close or, say, directly behind the gun, you might survive.
In this case, however, the round was on the inner rack, where there were no available blow-out panels. In addition the plasma rounds worming their way into the gun’s vitals had shattered most of the internal compartmentalization, for whatever good it might have done. So when the round went off it set off all the remaining rounds racked in the magazine.
The gun had fired twice and had one round loaded. So there were only five rounds to blow. But they went in a ripple sequence that was effectively instantaneous. And both the nature of the containment vessel and the damage that it had sustained combined to cause a near optimum explosion.
The fireball was noticeable from as far away as Asheville and the overpressure wave from it reached out to swallow the corps, huddled as it was in a valley.
Damage from nuclear weapons comes from three primary sources: overpressure, heat and radiation. Overpressure is generally referred to as the “shockwave” and is analogous to the effects of a tornado; when the high pressure of the “event” hits a structure, it collapses from the difference in pressure inside and outside its walls. Windows shatter inward, doors collapse and so do walls and ceilings. Combine this with hurricane force winds and close to the center of the blast, everything in its path is destroyed.
The second major cause of damage is from thermal effects. The intense heat of a nuclear, or in this case antimatter, explosion releases an enormous amount of infrared radiation. Any human, or Posleen, in direct view of the fireball, and within a limited distance, could be expected to sustain first-, second- or even third-degree burns. Due to the nature of the fireball, and the momentary containment by the walls of the magazine, thermal damage was minimized.
The third major category of injury was radiation. With antimatter explosions, there was a hard wave of gamma rays, but they were effective only at a limited distance. Like a neutron bomb, hydrogen-antihydrogen conversions gave lots of heat and “power,” but very little lingering radiation. This gamma pulse, however, was quite extraordinary.
It was the gamma pulse, as much as anything, which doomed Major Porter and his driver. They were dead before they even knew it, their bodies ravaged by high energy particles that caused massive systems failure as their nerve cells suddenly discovered nothing worked and the proteins in their musculature changed into a non-functional form. But it wouldn’t have mattered all that much because they were well within the ten psi overpressure zone. The blast wave picked up the seventy-two-ton tank like a sheet of paper and tumbled it into the air.
However, Major Porter was not the only being in the immediate area of effect. Even closer to the explosion were the tenaral of Pacalostal. The explosion tore apart the lightly armored tenar, sending all forty of them into instantaneous oblivion as it washed out over them and the embattled corps.
The shockwave swept over the tertiary defenses and the barracks of the human corps in less than a second, shattering buildings, collapsing bunkers and filling in the few redug trenches. The overpressure wave was still well above five psi when it hit the former school and collapsed the charming brick buildings in less than a second, scattering the bricks and wood of its structure down the hill and into the valley beyond.
The motorpool at the base was still within the worst effects of the overpressure wave, but the major damage was to the buildings as walls and windows shattered inward. Many of the Humvees and trucks in the motorpool had had their windows blasted out; but, by and large, the overpressure wave left them intact and they were shielded from the worst of the blast by the intervening hills.
The heat from the blast did not cause any flash fires outside the immediate vicinity of the SheVa, but the trees on the surrounding hills were tossed aside like matchsticks and those further out were stripped of their leaves.
Further to the west the explosion washed over the remnants of the corps and division artillery, detonating the remaining ordnance and killing most of the surviving artillerymen. The explosion also caught most of the remaining tenaral, however, tumbling them into ruin on the ground.
The human defense of Rabun Gap had been effectively gutted. The majority of its fighting forces were either under assault at the Wall or already dead from the SheVa detonation. The way north was open.
Well, almost.
Papa O’Neal whistled as he walked back to the house. He’d been whistling or humming Van Morrison’s “Moondance” just about all morning and Cally was just about sick of it.
“You’re awful smug today, Gramps,” she said. She was feeling edgy from the artillery; it had started up midmorning and had been hammering solidly ever since. From the amount and duration they were hammering a major attack although only recently had the Wall guns started to sound.
“I’m just in a fine mood, young lady,” he answered.
“Yeah, I suppose you would be,” she said with a malicious chuckle.
“And what’s that supposed to mean?” he said carefully.
Cally set down the knife she had been slicing with and wiped her hands. Reaching under the table she pulled out a Betamax tape and waved it in the air.
“You do recall that the entire house is wired for video,” she said, darting for the door.