Chapter 230: Flat Glass Factory
The Five-Year Plan meeting, lasting a full day and night, finally concluded amid Ma Qianzhu's constant reminders of "Stay on topic, don't wander off." Various departments began implementation according to the general principles established at the meeting.
These principles were quite general—each department still had considerable discretion in specifics. The Planning Committee only issued near-term targets to be achieved. How to achieve them depended on coordination between departments. Documents between departments flew around on the OA system. Though there were quite a few capable people and also slackers among the transmigrators across various industries, no one had experience coordinating the operation of a massive industrial system. Naturally, there were many blunders, and some waste existed—frequently a project would reach the halfway point only to discover that supporting projects hadn't even started, forcing them to stop and wait. As Ma Qianzhu said: "We're learning how to run a planned economy. Paying some tuition is normal."
What Ma Qianzhu was looking at now was the glass factory expansion report.
The Light Industry Ministry's current-stage goals were mirrors and window glass. To manufacture these two products required flat glass production capability. Most transmigrators had read Verne's The Mysterious Island and knew that flat glass was first made by blowing an oblong glass bubble, then slowly rolling and shaping it, finally producing a cylindrical glass tube. The two ends would be removed with a diamond cutter, then cut lengthwise, reheated to soften, and spread open into a glass sheet that was rolled flat. This process was quite aptly called the manual blown-tube spreading method.
From the description alone, this method seemed easy to implement. However, when everyone tried to practice this process, they discovered that Verne had greatly understated the professional skill requirements—he'd probably copied it from a book too.
Starting in the early 19th century, this technique replaced the older, more laborious crown flat glass manufacturing method, but it still required glass craftsmen to have highly refined technical skills and strong judgment. The gathering worker had to properly estimate the amount of glass liquid needed to make the cylinder. After cutting and spreading, it had to produce a glass sheet of given size and thickness—if this wasn't a problem for transmigrators who just wanted to make products, then the blowing craftsman's technique was much harder: he had to constantly swing and rotate the molten glass to ensure the entire cylinder achieved uniform thickness and correct overall dimensions. Flat glass manufactured this way required five types of skilled workers: the gatherer, blower, positioner, cutter, and flattener. Finally, the glass sheet still needed grinding and polishing before becoming flat glass suitable for windows or mirrors.
The skills, techniques, and experience involved were simply beyond what amateur transmigrator glassmakers could master. Especially the blowing technique—in glass workshops of that era, these were the most experienced senior workers. Even the five people on Lincoln Island might not be able to do it.
The first four or five experiments failed without surprise. Either they couldn't make a cylinder at all, or the glass was uneven in thickness, or it shattered from stress before even being spread.
After repeated experiments, the mechanical people moonlighting as glassmakers finally produced one oddly-shaped, uneven glass sheet. Naturally, no one thought this thing could be sold, much less made into a mirror.
"Let's use the flat casting method," Wang Luobin said helplessly, looking at the many baskets of broken glass.
"You sure about this?" Ji Situi had some understanding of glass manufacturing. "This counts as industrial scale."
Wang Luobin sighed: "Industrial scale it is. We don't lack technology, but we lack skilled workers. We'll have to make up for technique with scale."
Cast flat glass, also called the "French flat glass casting system," began batch production in France in 1688. By 1760, French flat glass annual output had reached over 1,000 tons, the vast majority used for window glass and coach windows.
It was quite different from flat glass made by the manual blown-tube method. The advantage was the ability to produce much larger glass sizes—nearly three times larger than the blowing method. Worker skill requirements were also much lower. The disadvantage was very large fixed asset investment. If the previous spreading method was still cottage-style manufacturing, then the casting method was completely like a modern factory.
If not for the fact that the 17th-century Chinese market was completely blank for flat glass, investing in flat glass would have been hard to profit from. The English introduced it for the first time in 1691 and completely failed; the second introduction nearly went bankrupt due to cost and breakage rate problems.
"Alright." Ma Qianzhu knew approving this request meant increasing fixed asset expenditures. To pilot flat glass production, Bing Feng's glass factory expansion plan gave Ma Qianzhu quite a shock: Was this still that shed-style glass workshop? A large-span workshop with steel frame structure, containing one melting furnace and one sintering kiln inside the workshop, plus ten annealing kilns. Throughout the workshop, hundreds of meters of ceramic piping would collect waste heat from the kilns for comprehensive utilization.
"Isn't the scale too large?"
"It's not large. This factory's annual output is only about 200-300 tons," Wang Luobin said from the side. "This is an integrated enterprise—much more economical than the previous simple small glass factory. Especially in waste heat utilization and material flow, front-end processes like material sintering can also be completed in one step."
"Ten annealing kilns? That's too many. There's only one melting furnace and one sintering kiln?"
"Flat glass annealing takes ten days. Ten annealing kilns is the absolute minimum. Otherwise continuous production can't be guaranteed."
"Alright." Ma Qianzhu knew it was better not to argue on professional matters.
The glass factory expansion project began in earnest. The casting method required at least one set of pulley hoists in the workshop to lift and move crucibles of glass liquid, plus the large number of glass kilns inside meant the workshop needed excellent ventilation. So this workshop's clearance height exceeded 6 meters. To accommodate 12 kilns, the workshop's span was also quite large.
Bing Feng completely abandoned the original simple brick-column wood-beam structure in favor of portal steel frame construction—this was his specialty after all.
Using portal steel frame construction not only shortened construction time but also provided fire protection—much safer than wooden trusses in a glass factory full of fire kilns everywhere.
"You want such long steel trusses, but our rolling mill isn't in place yet," Ji Wusheng was a bit worried. "We haven't done any trial rolling either. First time probably won't work."
"No problem—these can be made from wrought iron or cast iron."
"Wrought iron? You mean malleable iron?"
"Right. To simplify completely, use cast iron. Not just the trusses—many load-bearing parts and columns I'm also planning to cast from pig iron. Steel structures have many advantages, especially for people like us who are doing Great Leap Forward-style industrialization."
Though the columns still used brick as usual, to strengthen structural integrity, cast iron columns were built into the interior. The entire workshop had an A-frame roof, with rows of large windows on the exterior walls near the roof for ventilation and heat dissipation. Combined with the large amount of pipe racks to be laid inside the workshop, the rendering already looked quite similar to old-style workshops commonly seen in another timeline.
Ji Wusheng considered: "I really haven't done anything this large, but we can try."
"This isn't even that large." Wang Luobin brought over a roll of drawings. "You also need to cast this thing."
The drawing showed something like a large ping-pong table with a heavy frame underneath. Ji Wusheng looked at the marked dimensions and was shocked—the dimensions were staggering: 3 meters long, 2 meters wide, 150mm thick.
"All cast iron?"
"At least the tabletop needs to be cast iron. Can you use other materials for the frame?"
"A cast iron plate this size definitely can't be supported without steel. At minimum, reinforced concrete or even stone would work."
"This iron plate can't be fixed—it needs to roll. So it must have a frame."
"Damn, this is really exciting." Ji Wusheng cursed, but felt quite satisfied inside—without coming to this other timeline, he wouldn't have this kind of experience even working his whole life in a steel mill. He quickly calculated: the entire table plus frame would weigh 8 tons.
"What's this big iron table for?" Xiao Bailang was sketching out the structure of the future massive casting on paper—he was responsible for designing and making the sand mold.
Wang Luobin explained: "Molten glass liquid is poured on top of this. Then spread flat on it."
"Can't other materials work? 8 tons of pig iron!" Xiao Bailang was then shocked by the sand mold volume he'd calculated. "And this much molding sand and charcoal powder!"
"Iron's not a problem—pig iron inventory is already over 200 tons. Another shipload is coming soon." Ji Wusheng studied the drawings from every angle. Barring surprises, this was the largest casting they'd ever made, and probably the largest for years to come. Though the Industry and Energy Committee had plenty of experts, most were from mechanical backgrounds, with only superficial knowledge of casting—he felt somewhat hesitant.
"Let's try. Everything has a first time." Wang Luobin encouraged.
"Fine, we'll try. But Boss, you need to approve us building two or three more large cupola furnaces." Ji Wusheng's reasoning was solid: currently they had only one cupola, producing at most 1.5 tons of molten iron per heat. Though the 8-ton iron table could be cast in sections, no single section could be completed with just one heat of iron.
"This really is labor-intensive and expensive." Ma Qianzhu felt more heartache the more he looked. Though with his knowledge he understood this was a necessary technical upgrade. To build industry, you had to be willing to invest in basic industries. Expanding the steel mill's scale a bit wasn't bad, and making this big table now would give the transmigrators experience casting large components in the future.
"Alright, I approve." Ma Qianzhu signed the project sheet.
(End of Chapter)