Chapter Twenty-One: The Bucket Elevator

For security reasons, the Senators’ dormitories were located within the compound of the combined machining center. Furthermore, the equipment of the combined machining center had not yet been operated by naturalized citizen workers—operating this set of equipment required at least a high school mathematics foundation from the old world, and workers with at most a Type B diploma were not up to the task.

Zhan Wuya’s dormitory was a suite. Inside was a small bedroom, and outside was a living room that also served as a workshop, though it was more often used as a conference room. The Senators from the factory often discussed technical issues here. In the middle of the room was a large square table, surrounded by rattan chairs and benches. Against the wall was a fitter’s workbench with a vise fixed to it. There was also a locked tool cabinet containing his private tools.

After the six o’clock whistle blew, Zhan Wuya first checked the fire and safety conditions of the combined machining center workshop and the controlled goods warehouse, ensuring that the power had been cut off and all doors and windows were locked. This was a daily routine. As the Director of Manufacturing and the director of the General Machinery Plant, he held the keys to these two places and was directly responsible. Zhan Wuya knew that the risk of armed sabotage here was low; the biggest fear was a safety accident, especially a fire.

After ensuring everything was in order, he instructed his female apprentice to buy late-night snacks and drinks from the Senator’s canteen, preparing for a night of work to continue tackling the problem. The female apprentice was actually his maid. Zhan Wuya felt that since he lived at the factory long-term, it was useless to have a maid just for show, so he kept her as an apprentice. She wasn’t cut out for fitting, but she could handle a lathe.

Before everyone arrived, Zhan Wuya took a few damaged sections of the chain from the workshop to the workbench outside. He turned on the work lamp and carefully examined the fracture points of the chain, then looked at them with a magnifying glass for a while. He had a background in heat treatment. Although he didn’t understand metallography, his years of experience had given him some insight. After studying the fracture points for several minutes, he felt it was still a problem of material stress.

After a while, everyone arrived and examined the broken chain links over and over, discussing how to increase the strength of the chain. It should be said that this time, the General Machinery Plant was determined to master the production of industrial chains. Zhan Wuya personally handled the heat treatment, and a large heat treatment furnace was specially built. The steel from the Ministry of Metallurgical Industry was also the best product the steel plant could produce.

But the result was still not satisfactory. Everyone gathered around the pile of chains, examining them repeatedly and occasionally joining in the discussion. Liang Xin measured the chain links one by one with a vernier caliper, jotting down the data on a piece of paper. Sun Li checked each section of the chain for any flaws… Everyone was busy studying the chains in their hands from various angles. Before forming an opinion, there would be no discussion—even hypotheses had to be based on physical evidence. Zhan Wuya’s female apprentice refilled their tea and occasionally helped with lighting fires and emptying the full ashtrays.

By midnight, everyone finally reached a unified technical analysis conclusion: the chain was not subjected to uniform stress. The main cause of the problem was the manufacturing process.

The process flow for manufacturing chains at the General Machinery Plant was to first forge the blanks, then anneal them to relieve stress, then perform cutting and machining, then normalizing and surface treatment, and finally assembly.

“I just checked many sections of the chain, and the tolerances are not ideal, with some as large as ±0.7mm, and an average of ±0.5mm. The dimensional error is still relatively large. According to the GB standard, the limit tolerance for this size of chain link should not be greater than ±0.4mm. This shows that the pre-stress problem during the cutting process is more serious than we imagined,” Liang Xin said. “The accumulation of small tolerances caused a few sections of the chain to bear concentrated stress, eventually leading to fracture.”

Sun Li said, “I think we should do the heat treatment after machining. Even if it consumes a few more tools, it’s worth it. After all, we can always solve the tool problem in the future; it’s not a one-time consumable that we can’t replenish. Also, the forging should be done at the arsenal. The forging press there is larger than here. For such high-strength industrial chains, the larger the tonnage of the forging press, the better.”

“We can’t solve the problem of manufacturing super-hard tools for the lathes in a short time. I don’t know if we can get it done before the end of the first five-year plan,” Zhan Wuya said with a frown. Super-hard tools required alloy steel materials, especially rare metals like tungsten, cobalt, tantalum, and niobium—there was no sign of these things yet. And alloy steel tools had high requirements for metallurgy and processing technology. The super-hard tools used on the various machine tools in the Ministry of Machinery Industry now completely relied on the inventory of old-world products. Only in low-requirement cutting and machining did they use the factory’s self-made carbon steel tools.

Zhan Wuya considered it over and over. “This is indeed a reason, but the lathes all rely on good tools. We’re not just making a few chains now. I can’t rest assured to consume tools without regard for the consequences before we have a clear mass production of qualified super-hard tools. I think we should still start from controlling the tolerances, forging, and heat treatment. We’ll do another heat treatment after cutting to eliminate the stress.”

The discussion on the specific process and solutions continued until the early morning. Everyone dispersed after having a late-night snack.

The next morning, the manufacturing of the chains began anew. After the chain blanks were manufactured, they were transported to the Bopu Arsenal and forged on the arsenal’s large forging press—this was the largest tonnage forging press owned by the Transmigration Group. All of the Transmigration Group’s large equipment, heavy artillery, and ship keels were forged here.

After forging, the chains were transported back to the factory, annealed in the heat treatment furnace, and then subjected to cutting and processing. However, after cutting, they were subjected to another tempering heat treatment to eliminate the pre-stress generated during processing, followed by normalizing and surface treatment. Finally, threads were added, and they were assembled into seamless chain links.

“Take it for inspection,” Zhan Wuya said, looking at the completed section of chain. “Do a tensile test.”

“I’ll supervise it,” Sun Li said.

“Good, be strict! This is our own business, not fooling a customer.”

“Of course,” Sun Li said. “Let’s go, to the test site!”

Several naturalized citizen technicians who had been following and learning on the side responded, picked up the chain, and walked out. The female apprentice handed Zhan Wuya a large enamel mug of tea and a towel. Zhan Wuya drank half a cup in one gulp and wiped his sweat. He instructed the female apprentice to get a few bottles of salt soda for everyone.

“And bring two more packs of cigarettes!”

Several Senators squatted at the entrance of the heat treatment workshop, smoking and waiting for the test results—no smoking in the workshop was a rule set by Zhan Wuya. The female apprentice quickly brought over a few small stools. Although the work was mainly done by the naturalized citizen workers, the Senators had supervised almost every step, working for two days and two nights straight. Everyone’s eyes were red.

In a short while, Sun Li returned with a smile on his face. “Done! Success!”

Everyone stood up with a whoosh. Zhan Wuya was a little excited and asked again, “How was the test?”

“We did a tensile test according to the actual working conditions of the bucket elevator, and it passed completely. It only broke when we added a load of 120%,” Sun Li said. “I think we can do a full machine test of the bucket elevator right away!”

“Good, good. Once this test is passed, we’ll quickly compile the process manual and start mass production,” Zhan Wuya was very excited. Mining chains were a urgently needed product now—large-scale mining development almost all required mining chains. With the foundation for manufacturing high-strength mining chains, the production of chains for many industrial equipment in the future would be overcome.

After the second test was successful, the General Machinery Plant made improvements to the bucket elevator. First, a ratchet mechanism was added as an anti-reversal device. The biggest忌讳for a bucket elevator is a power outage. During the lifting process, one side is the ascending buckets full of material, and the other side is the descending empty buckets after unloading. After a power outage, the elevator will inevitably reverse due to gravity. The material will be unloaded into the bottom of the bucket elevator as the buckets reverse until it is full and stuck. Since the reversal is an accelerating motion, it can easily tear off the buckets, causing equipment damage.

Modern bucket elevators are all sealed—the purpose is to reduce the dust generated during the lifting and unloading of materials. For the sake of saving materials, the General Machinery Plant had initially omitted this outer casing when designing the elevator. But during the test, everyone felt it was better to install it—after all, a sheet metal casing would not consume much material, but it could significantly reduce dust pollution. The occupational diseases caused by industrial dust were something that the medical science of Lin’gao in this era could do nothing about. Besides, the dust from iron ore was also iron ore. A little bit adds up, and it can be sintered and used to make steel.

But after installing the sheet metal casing, a new problem arose. During the trial run, it was found that after sealing, it was difficult to feed and unload the material into the buckets. The buckets were not full, and they were not empty. Everyone quickly went to the technical archives to find the design drawings. A comparison of the two revealed that the director of the sheet metal workshop responsible for manufacturing the elevator’s sealed casing, a certain Senator, had omitted the suction pipes and vents at the head and bottom of the elevator to save trouble.

The sealed casing was well-made and reliably sealed, but it created a pressure difference during the unloading and feeding of the material, forming a negative pressure condition inside the sealed casing. This caused the loading and unloading to be not smooth. The vents made the internal pressure of the elevator basically equal to the external pressure, while the function of the suction port was to prevent dust from overflowing from the vents through suction, avoiding waste and cleaning the environment.

“A lesson, comrades, this is a profound lesson,” Zhan Wuya could not openly reprimand a Senator, but he still couldn’t help but use this as a typical example in the work meeting. “The design of an industrial equipment, a process method, is the direct embodiment of years of accumulated experience and lessons in industrial society. It is not something that can be changed at will by anyone! This kind of unrigorous attitude will cause accidents in industrial production!”