Chapter 71: Water and Power (Part 1)

The locomobile had originally been destined for the main city district, but its considerable drawbacks—the clouds of flying ash, the thunderous noise, and the boiler's insatiable thirst for water—ultimately relegated it to the hydroelectric zone instead. The thermal power station, distribution room, and substation were all built on deliberately raised foundations to protect against flooding.

For all its advantages to the transmigrators, the locomobile devoured fuel at an alarming rate. Worse still, boilers demanded soft water, and shipping distilled water from the ships proved far too extravagant. Natural water worked best when collected as rain; river water could serve, though it ideally required softening treatment. Luo Duo claimed he could produce tannin extract for this purpose, but the raw materials were nowhere to be found on short notice. In the end, it was Wang Luobin who offered a solution drawn from rural practicality: boiled water would suffice.

Boiling water for such a behemoth seemed almost absurd. Yet there they were, a row of stoves dug into the riverbank, every pot unloaded from the ships pressed into service. Flames roared and steam billowed skyward in a spectacle that might have been impressive if it weren't so ridiculous. The transmigrators threw themselves into cutting grass and felling trees until mountains of fuel rose along the shore.

"Why not just use the diesel generators?" Wen Desi surveyed the scene without enthusiasm. To his mind, this was pure waste—time squandered, labor frittered away. Yes, the locomobile avoided oil consumption, but the sheer expenditure of human effort hardly made it economical.

High-powered locomobiles required hardened ground beneath them. Not just the foundation itself, but the entire city district needed proper groundwork—especially the planned simple-housing residential area and the main streets. The transmigrators lacked bricks, but concrete was another matter. Cement and rebar had been shipped over in quantity, and at Bairren Rapids, stone was unlimited. This had always been Lingao's quarry, historically supplying not just the county but its neighbors as well.

When the transmigrators arrived, the masons had fled, but they left behind considerable quantities of dressed stone. The quarry also held ample crushed rock, and the riverbed provided sand that needed only sifting. Cement and mixers came from Bopu, where Wu Kuangming had established an electric sawmill that conveniently produced lumber in various sizes. Wooden forms were quickly manufactured and delivered.

Once they had hardened the locomobile power station's foundation, the Building Group pushed forward with the hydroelectric project. Boiling water daily for the boiler was simply not sustainable, and as Committee offices, residential areas, and new industrial zones were relocated and established, power demand would surge far beyond current output.

The Energy Group's plan designated the Bairren Rapids Hydroelectric Station as their priority project. Complete design drawings existed, but after consulting with the Building Group, everyone agreed that full implementation exceeded their current capabilities by a wide margin.

The historical Bairren Rapids Hydroelectric Station—begun after Spring Festival 1967 and completed by late 1968—had boasted a dam ninety-four meters long and seven and a half meters high, complete with matching gates, culverts, channels, aqueducts, and pipes. Even in twentieth-century Lingao, this had required a countywide effort: more than three hundred cadres mobilized, over a hundred hydroelectric engineers, hundreds of workers conscripted from across the county. They had even summoned two hundred fishing-village women from the Touzui, Huanglong, and Kunshe communes specifically to carry stones. The total came to sixty-four thousand work-days, fifty-one thousand eight hundred cubic meters of earthwork, over five thousand cubic meters of masonry, and six hundred thirty cubic meters of concrete.

For the transmigrators, these figures were astronomical. The complete drawings were shelved, and they settled on a simpler design: a channel-diversion power station with a two-hundred-kilowatt generator.

The plan called for excavating an intake channel upstream of Bairren Rapids' nine-level cascade. Channel width and depth were calculated from flow rate and gradient—fortunately, standard tables existed for such computations. Final specifications settled on a bottom width of one and a half meters with a water depth of one meter.

The intake channel would feed into a pressure forebay: a pool connecting the channel to the penstock. This structure comprised an anterior chamber, trash rack, gate, inlet chamber, spillway, and sediment outlet. Crucial to the entire operation, the forebay would settle sediment and block floating debris before it could enter and damage the turbines. With multiple units, it would also distribute water flow—but its primary function was regulating the volume of water entering the turbines.

When station load increased and turbine flow demand rose, the forebay reservoir could supplement any shortfall from the channel, preventing water-level drops that might suck air into the penstock and reduce output. Conversely, when load suddenly dropped or upstream flooding occurred, excess channel flow could be discharged through the spillway, protecting the structures from damage.

The channel gate controlled flow and cutoff from its position in the forebay's inlet chamber. Given the station's modest scale, wood would suffice. Wang Luobin, drawing again on his rural observations, recommended a curved wooden gate that had been popular during a certain period—operated with pulley systems and hand-cranked windlasses for opening, closing by gravity alone. Simple in structure and quick to operate, it was highly convenient.

The penstock presented a far greater challenge. As the component creating the pressure head to drive the turbines, it had to withstand not only the normal head pressure but also the water-hammer pressure that resulted from sudden flow stoppage when closing turbine guide vanes or gates. Without sufficient strength, the penstock would crack.

Modern small-to-medium stations typically used steel or reinforced-concrete pipe, but large-diameter steel pipe was unavailable. Reinforced-concrete pipe could be manufactured, yet it consumed too much rebar and cement—materials they could not yet produce themselves and which were desperately needed elsewhere. Someone proposed ceramic pipe, but its tensile strength was poor; it would crack under ten meters of head and was suitable only for low-head stations. Such large ceramic pieces had never been made, and Lingao probably lacked potters capable of firing them. Besides, the transmigrators had not yet found a pottery kiln—or even a brick kiln.

After considerable deliberation, Wang Luobin proposed wooden pipe. Constructed from planks four to six centimeters thick, joined together and secured with iron hoops, wooden pipe proved stronger than concrete and could handle heads up to one hundred meters—compared to concrete pipe's fifty-meter limit. With proper care, it could last ten to twenty years.

Lumber was relatively easy to come by. Logging had not stopped for a single day. Though they lacked proper drying equipment, Wu Kuangming built a makeshift kiln that slow-smoked wood with brush and leaves. Efficiency was low and drying uneven, but it provided enough usable lumber for their purposes.

The real problem was that joining planks into pipe was essentially barrel-making—a craft nearly lost even in their own time, let alone for pipes of such large diameter. After several failures, someone finally used CAD modeling to decompose the standard dimensions for every plank. The lumber team examined the drawings with their millimeter-precise measurements and detailed angles, laughing bitterly. We don't have CNC saws.

But with actual numbers, experimentation finally had direction. Following the drawings through several more days of trial and error, they at last assembled the first pipe: four meters long with a diameter of 0.7 meters, secured with iron hoops. Simple water testing revealed that joint strength remained insufficient. For the second attempt, they added more hoops and used thicker planks. After this version passed testing, the sawmill produced thirty-two meters of wooden penstock, with twelve meters held in reserve as backup. This foresight proved necessary when two pipes were damaged during construction. Pipe joints were sealed with cement mortar, and the penstock's support piers and anchor blocks were built from stone masonry with cement mortar.

At the penstock's base stood the powerhouse. Its foundation demanded exacting standards, so they spared no expense, using crushed-stone mortar concrete and incorporating various stone bars of unknown original purpose that had been left at the quarry.

Though Mei Wan and his Building Engineering Group had never constructed a hydroelectric station before, the rural-designed power-station equipment came with detailed, easy-to-understand manuals. A group with rich engineering experience studied these carefully, combining the written instructions with memories of stations they had seen over the years. Figuring out the construction methods proved less difficult than anticipated. Excavating earthwork and channels, building the powerhouse, erecting power poles—all lay well within their capabilities. The channel was earthen; other structures used cement-mortar stone masonry.

Some rocky sections proved difficult to excavate, but air compressors and pneumatic hammers overcame these obstacles. The Committee had allocated ammonium nitrate and diesel for blasting if needed, but Mei Wan thought it best to minimize the use of such heavy measures. None of them had any blasting experience.

Wang Luobin had spent years living and working in rural Guangxi, where he had grown intimately familiar with agricultural infrastructure like small hydropower. He had been coordinating the recent projects and now made a tour of the site. Near the hydroelectric station, he spotted a group of people gathered together, apparently in the midst of an argument. Moving closer, he recognized members of the Building Group and crew. Group Leader Mei Wan stood on one side; on the other, vaguely familiar, was Zhuo Tianmin—the same man who had proposed the simple-road approach during highway construction.

(End of Chapter)