“They’re tweels. They’re the robots that stretch and size the glass. A good bit of our operation is automated. More every year. Imagine by the time I retire most everything’ll be done by robots.”
In spite of himself, Hoffman was growing interested. Like many men, he easily became fascinated with machines that carried out automated functions. He could easily stand and watch by the hour as a machine carried out human, sometimes superhuman, tasks.
He became aware of a marked drop in temperature.
“Not as hot, is it?” Culpepper sensed his relief. “This is the annealing process. We relieve the stress on the glass by lowering the temperature gradually. The glass is cooling. But,” he added quickly, as he saw Hoffman approach the emerging thin, smooth glass, “you wouldn’t want to touch it yet. Still quite warm.”
Hoffman, hands now inserted in trousers pockets to avoid further temptation, stepped away from the glass.
A series of revolving cylinders conveyed the glass rapidly forward to a point where it was cut for the first time. The process was, again, automated. Two cutters, acting in tandem, were propelled alternately across the breadth of the glass. “Primary cutters,” said Culpepper. “Looks real simple, but actually they’re a little monument to engineering. Looks like they’re cutting on a bias. But what they’re actually doing is compensating for the movement of the glass through here.”
Hoffman initially found the cutting process engaging. Once again, he was drawn by the automation. Now, informed of this special technological achievement, he became engrossed in the operation. Gradually, he became aware he was standing directly in the path of one of the cutters. As the razor-edged blade raced repeatedly across the glass’s surface, each time it stopped abruptly and automatically, only inches from his navel. He looked at Culpepper with a challenging grin.
The manager correctly interpreted Hoffman’s smile. “Never fails. The blade’ll always stop at that precise point. Every bit of automated equipment we’ve got in the plant is monitored by fail-safe devices.” His smile exuded confidence.
Maybe, thought Hoffman. But he wasn’t convinced. As fascinating as he invariably found automation, he also firmly believed nothing was fail-safe. As long as humans were involved, and the thing was made up of parts, and Murphy’s Law remained ubiquitous, machinery would find ways to fail.
Hoffman could not identify what was making him edgy, but he could not deny the feeling. The incredible heat of the blast furnace; this automated cutter, which, were it to break loose from its arm, undoubtedly would kill him—everything seemed to contribute to his sense of nervous foreboding.
The group moved along the production line.
“These are the cord wood cutters,” Culpepper pointed. “Now the glass’s in rectangular shape. It’ll be cut one more time into the desired windshield size further on down the line. See? Some of the glass has already been broken or damaged. Well, these guys,” he indicated workers wearing heavy gloves and positioned on either side of the conveyor, “pull off all the spoiled glass and just let it drop down there, where another conveyor going in the opposite direction takes the glass back to the beginning where the cullet becomes part of the batch all over again.”
The glass that survived all this cutting and jostling was carefully removed from the conveyor system by workmen, again heavily gloved, who stacked the glass in wooden brackets. The brackets were then manually loaded on dollies and transported to the next stage of the operation.
“And here,” continued Culpepper, as the group reached a rather congested area, “is where the glass is shaped into the windshield.” Sensing Hoffman’s interest, Culpepper let the machines do the talking for a few minutes.
Ingenious, thought Hoffman. Untouched by human hand. A robot with four arms extending from its control box, the arms bent downward where suction cups replaced hands . . . hands that picked up the bracket glass, a single pane at a time, then swung it to another machine. The robot then positioned the glass carefully and precisely on the table of another robot. The well-oiled “finger” of the second robot, armed with a glass cutter, traced the shape of a windshield on the glass. The outside rim fell off, and a perfect windshield would be delivered to the next worker in the chain.
Yes, Hoffman had to agree, in time this entire operation might well be totally automated.
“Like a mother picking up a baby,” commented Culpepper, having allowed time for Hoffman to become mesmerized by the robots. “Its sensors establish the limits of how far it moves the glass, and then it counts the pulses before laying the sucker down right on the exact spot. Amazing, ain’t it?”
The two men were by no means alone in the fascination with the robots. The eyes of the entire entourage were riveted to the process.
Something was wrong. Culpepper sensed it rather than reasoned it. His right arm shot out, catching Hoffman on the shoulder, knocking him to the floor.
Instead of delivering the glass in its usual herky-jerky fashion, the robot’s arms swung in a smooth, forceful, fast arc, passing through the space just vacated by Hoffman, and stopping only when it smashed into a nearby pillar.
Culpepper bent to the visibly shaken Hoffman and helped him to his feet.
The robots ground to a halt. Someone had cut the power. But Culpepper seemed the only one interested in Frank Hoffman. The technicians and engineers were absorbed in their machine, trying to figure out what had caused a fail-safe device to fail . . . and only incidentally, come within a hair’s-breadth of killing a man.
“What we’ve got is a bad case of axis runaway,” stated a tall, laconic Bill Kelly, the glass plant’s chief engineer.
“Could you explain that a little more fully?” asked one of the two black Detroit police officers who had responded to the call.
The officers, Kelly, Culpepper, and Hoffman stood near a work table in the plant manager’s office.
Kelly nodded. “The robot is programmed to make suction contact with the glass, raise it from the bracket, and move it to the cutting machine, counting the pulses on the way. At the exact count of the exact number of pulses, it lowers the glass to the cutter. Instead of moving on its axis to the count of pulses, it lost its programming entirely.
“In layman’s language, all hell broke loose.”
The officer suppressed a smile. “And can you tell us how this could happen?”
Kelly nodded again. “Y’see, the type of material used for this silicone chip is a metal oxide semiconductor. We know it as just MOS. And, y’see, if an external, static-type current is applied over the MOS, it’ll fail—in a completely unpredictable way.” He looked from one officer to the other to make certain each understood.
“So,” the officer said, as he finished writing on his notepad, “this ‘external, static-type current’ could come about accidentally? Or would someone have to bring it about intentionally?”
“No; it could happen accidentally.”
“Could you think of any way in which this ‘axis runaway’ might be deliberately caused?”
Again Kelly nodded. “Sure. Somebody could enter a sequence in the computer programming the robot’s probe—or arm—to run away and break its sequence.”
“I see. But if someone were to enter such a sequence in the computer, an expert like yourself would be able to find it?”
“No,” Kelly scratched his chin, “. . . not necessarily. Anybody who could program a switched sequence like that could also program the computer to erase the sequence from its memory.”
“Just like that?”
“Just like that. A couple of numbers would do it.”
“I’ll have to bow to your expertise,” said the officer, “and admit that it’s possible for someone to program this robot runaway and also to erase the memory of this programming from the computer. But if Mr. Hoffman were the targeted victim, how would the programmer know the precise moment when Mr. Hoffman would be standing in the exact spot where he could be hit?”