At breakaway the fireball was 280 yards across with a surface temperature of 2,300 degrees. Once it wasn't pushing the blast wave before it, the outer layer was reheated by the interior to reach a uniform temperature. As the fireball expanded and heated up again, a second flash began as the fireball started to release the large amount of thermal energy it contained. At 1.07 seconds after initiation, the fireball was 360 yards in diameter and had a surface temperature of 10,800° F, greater than the surface temperature of the Sun. So far it had radiated 22 percent of its thermal energy and the fireball started to rise rapidly, while its surface temperature and brightness begin to decline. However, it continued to expand until at 8 seconds after initiation it had reached its maximum size of 400 yards across and released 90 percent of its thermal content.
The cooling fireball continued to rise and expand, dragging trails of smoke and dust to form a strange and terrifying mushroom cloud, no longer glowing but still reddish in hue and reaching 30,000 feet into the stratosphere. As the cloud cooled, moisture condensed into water and the mushroom cloud turned white, forming an impressive, complex wrapping of layers of clouds.
In Duren, it blotted out the Sun and created near a field of near-darkness that tried to hide the devastation. At Ground Zero, a region 180 yards across had been fused into glass. Within 6,000 yards of Ground Zero a semi-continuous fire was raging. Dust and debris was falling from the sky over the devastated areas, along with a black rain produced when atmospheric moisture superheated by the explosion recondensed on the plentiful dust and smoke particles. The black rain lasted several hours but by then, it didn't matter any more. Duren was dead.
Blast and fire were the effects that could be seen but the third horseman of the nuclear apocalypse had already arrived in Duren; high energy gamma radiation and the particles from atoms altered within the warhead during detonation which damaged the cells of nearby living organisms. Snow-like particles of radioactive debris were falling across the ruined city, causing an acute burning sensation on exposed skin. Survivors outdoors were quickly incapacitated by large doses of radiation doing direct damage to the central nervous system, causing convulsions, coma, and death within minutes. Those inside lasted a little longer.
A new disease was being added to the medical dictionary - radiation sickness, the combined effects of internal and external hemorrhaging, immune system damage, diarrhea, nausea, vomiting, anorexia, ulcers, hair loss, sterility, miscarriages, thyroid gland damage, fever, and liver damage. Throughout the area all the trees, mammals, and birds were wiped out by the combined effects of blast, fire and radiation.
Of Duren’s 89,600 inhabitants, more than 60,000 had been killed within ten minutes of Christine releasing her device. The rest would be dead within a week.
Panzer-Grenadier Lehr Detachment 101, Hurtgenwald, near Duren, Germany
Major Johan Lup reflected that he had been tasked to evaluate and report on two alternative solutions to a tactical requirement. One was the right solution to the wrong problem, the other was the wrong solution to the right problem. There was a moral there somewhere. The tactical requirement was quite simple and very important. In Russia, the American Army had introduced armored personnel carriers for their infantry. Full enclosed, tracked vehicles armed with machine guns. They had replaced the old half tracks and given the American infantry a marked tactical edge. So, the Army wanted an equivalent.
Two companies had been asked to develop prototypes and deliver them to PGL-101 for evaluation. Henschel had used one of the big eight-wheeled armored cars as a basis, enlarging it, giving it a boxy body with firing ports for the men inside and a one-man turret with a MG-151 20 millimeter cannon at the back. The back of the vehicle dropped down to form a ramp that allowed quick evacuation of the vehicle. Beautifully, designed, beautifully engineered - but wheeled. And the requirement was for a tracked vehicle.
Porsche had offered a tracked APC. One day, Major Lup wanted to meet Ferdinand Porsche so he could perform a few well-chosen atrocities on his anatomy. The Porsche vehicle was almost three times the weight of the Henschel and was elaborate to the point of insanity. It had a ramp at the back as well, but the Porsche design opened upwards and was powered. No power, the ramp stayed closed. There were no firing ports for the men inside, but there were remote-controlled cannon mounts once designed for use on a defunct heavy fighter, the Me-210. Because the Porsche vehicle was so heavy, it had two engines and burned fuel at a prodigious rate.
Lup shuddered, perhaps they should give the Porsche design to Henschel and ask them to re-engineer it. He went into the command vehicle, a Henschel thankfully, and tried to marshal his thoughts for his written report. They'd spent most of the morning trying to extract the Porsche vehicle from a ditch; heavier than most tanks, this had proved hard. Relaxing in the dim light he tried to find suitable adjectives for the experience when suddenly the ground under the vehicle started rocking violently. An earthquake? Surely not, such things just didn't happen here. Then he suddenly realized the inside wasn't so dim any more. Bright, blinding blue-white light streaming in through every crack and opening in the vehicle.
Outside he could hear screaming, then the APC rocked as a hot blast hit it. The screaming was drowned out by a mighty roar, one that made the his teeth vibrate in his head. Over it all, the shaking went on and on. Lup hung on to the fittings of the APC, still getting battered by the metal edges and by equipment that was thrown loose by the shaking.
Finally, the rocking stopped and he ran outside. Towering above them, over the nearby town of Duren, was a huge cloud, mushroom-shaped, glowing red and orange and black, reached up, high, high above him. It had punched the clouds aside, creating strange abstract patterns in the sky around it. Lup shook himself away from the sight and went to his men. Two, a sergeant and an enlisted man were lying on the ground while their medic bandaged their eyes. The doc saw Lup and shook his head. “When the explosion happened, they were looking straight at, at that” gesturing at the cloud. His lips moved quietly but Lup could read the words. They'll never see anything again.
“Sergeant, get the men up, put the wounded in the Porsche. Whatever's happened over at Duren, it must be a disaster over there. We've got to get in and help. Form column behind me,” There were five vehicles, two Henschels, two Porsches and a command vehicle. Not a bad little command but not much if the scale of the disaster was anything like his fears.
Just before they pulled out. there was another flash, this time from the direction of Aachen. Much less bright that one, distance saw to that, and Lup noted how men immediately ducked into the shadows. Again, the ground rocked violently, followed a few seconds later by the airborne Shockwave. The gap was greater than before, the explosion must have been much further away. On the horizon, another mushroom cloud was growing. Before they got to Duren, there had been many such blasts and he'd counted more than a dozen of the evil, glowing mushrooms forming. Whatever was happening wasn't an accident.
From the hill overlooking the town, Duren looked like a disaster. There was no mistaking the scale of the catastrophe, the whole town looked yellowish in the smoke-filtered light that covered it. Fires had broken out across the city and were spreading fast. Even in the five minutes Lup could watch, the fires grew bigger and their smoke spread everywhere, dividing the city into two parts. In one, the sun was still shining brightly but behind the cloud on the other side, it was completely dark. About 60 or 70 percent of the sky was covered by the cloud and the other 30 percent was completely clear but the darkness was spreading over the city even as he watched.