Chapter 429 The General Assembly Dilemma

"The flange holes don't align! They're two millimeters off, the bolts can't pass through!"

Lin Jianguo's voice boomed down from above, carrying a fury that even a tin loudspeaker couldn't suppress. He Yuzhu threw down the blueprints in his hand and scrambled up the scaffolding in three quick steps. His feet clanged as he stepped on the steel pipes, the ladder wobbled a couple of times, and he grabbed the edge of a flange to steady himself—his fingertips didn't touch the coolness of metal, but rather a greasy, sticky rust-preventive paint that smeared all over his hands.

The forty-meter-long hull sections hung suspended in mid-air, swaying precariously, supported by two gantry cranes. The front section, transported from Dalian, and the midsection, made in Shanghai, faced each other, separated by a fist's width, with the bolt holes on the two flanges offset by a small margin. He Yuzhu took out calipers and inserted them, reading 2.3 millimeters. He put the calipers back in his pocket and ran his oil-stained finger along the flange.

"The boring machines in Dalian and Shanghai have different precision." Lin Jianguo squatted on the other side of the scaffolding, holding a handful of bolts. The bolt heads gleamed coldly in the sunlight. He inserted one of them into a misaligned hole—it got stuck halfway in. When he pulled it out, several white marks were left on the threads. "Out of 120 holes, 11 are out of tolerance. The spindle runout of the boring machine in Dalian is too large."

He Yuzhu didn't say anything, and jumped down from the scaffolding. His knees jolted as he landed, and he squatted down on the spread-out blueprints, tracing the flange's position with his finger. Ma Yuejin came over from the side and squatted down to his right, his work pants having two holes worn through at the knees.

"Dean He, let's use carbon nanotube bonding technology, and we won't need flange bolts anymore."

He Yuzhu looked up, didn't reply, and stared at Ma Yuejin for a few seconds. Ma Yuejin's eyelids twitched, but he didn't look away.

"You think this is like pasting cardboard boxes?" He Yuzhu's voice wasn't loud, but every word was heavy. "Two thousand tons of segments, something from the heavens, you think you can glue them together?"

Ma Yuejin's face flushed red. He pulled a crumpled piece of paper from his pocket, covered with densely written data. "Dean He, the antenna base of the Soyuz return capsule is glued on, and the ceramic-based antenna window is glued to the titanium alloy hull. It hasn't fallen off after decades of flight. The heat insulation tiles of the Space Shuttle are also glued on; tens of thousands of tiles, not a single one has fallen off. Our special adhesive for carbon nanotubes has an overlap length of 10 centimeters and a tensile shear strength of 35 MPa, which is 5 MPa higher than the base material. A one-meter-long sample broke under a 2,000-ton tensile test machine, breaking on the base material, but the adhesive layer was unharmed."

He Yuzhu took the paper and looked at it for a few seconds. The handwriting on the paper was messy, but the data was written very clearly. He returned the paper, stood up, and glanced at the misaligned flange again.

Have you done large-size testing?

"A one-meter-long sample is big enough. Any bigger and my tensile testing machine won't be able to pull it."

He Yuzhu turned to Lin Jianguo. "What do you think?"

Lin Jianguo came down from the scaffolding and dusted off his hands. "The adhesive bonding process looks good in the lab, but on-site, for a 40-meter-long flange, the adhesive layer thickness needs to be controlled to 0.2 millimeters, and it needs to be uniform and free of air bubbles. This is impossible to do by hand. If there is even one hollow spot, the entire weld will be a hidden danger."

Ma Yuejin interrupted, "No manual work. I designed an automatic glue applicator that runs along the flange track, uses a scraper to control the thickness, and a vacuum bag to pressurize and remove air bubbles. Curing can be done at room temperature; no oven is needed."

He Yuzhu neither nodded nor shook his head, glancing at his watch. 10:20 AM. The Dalian section had been hoisted since 7:00 AM, and not a single bolt had been tightened.

"Lin Jianguo, call Guangzhou and ask about their sectional flange deviation."

Lin Jianguo took out his walkie-talkie, walked to the dock, and shouted. He Yuzhu squatted back in front of the blueprints, and Ma Yuejin spread out the sketch of the glue applicator next to him, pointing to the crooked lines on it.

"The track runs along the outer ring of the flange, and the magnetic wheel is attracted to the side of the flange. The adhesive layer thickness sensor provides closed-loop control with an accuracy of ±0.03 millimeters."

"Magnetic wheel?" He Yuzhu looked up at him.

Ma Yuejin paused for a moment, then reached out and touched the flange. The surface of the carbon nanotube composite material was smooth, but not magnetic. He withdrew his hand and remained silent for two seconds. "Change to vacuum suction cups. Six suction cups will adhere to the outer surface of the flange, maintaining the vacuum level. I'll verify it tomorrow."

He Yuzhu stood up and walked towards the workers' shed. Inside, sitting on either side of a long table were Lao Zheng, the chief engineer of the Jiangnan plant; Sun Demao, the quality control chief of the Dalian plant; and Chen Guoqiang, the newly arrived process engineer from the Guangzhou plant. Lin Jianguo ran back from the slipway and slammed a data sheet on the table.

"The maximum deviation of the Guangzhou segment flange is 1.8 millimeters, with the direction between 6 o'clock and 9 o'clock. The deviation distribution of the three flanges is different: Dalian's is deviated from 11 o'clock to 2 o'clock, Shanghai's from 4 o'clock to 8 o'clock, and Guangzhou's from 6 o'clock to 9 o'clock." Lin Jianguo marked the deviation area on the schematic diagram of the three flanges with a red pen. "If we rotate the Dalian segment 180 degrees, so that its deviation direction is opposite to that of the Shanghai segment, and then use adhesive bonding to incorporate the remaining deviation, the three segments can be aligned."

Old Zheng looked up at He Yuzhu. "Dean He, the Soviets used glue to attach the antenna base to their spacecraft; those are small parts. A forty-meter section of the hull, from bow to stern, is entirely glued together. Who would dare sign off on that?"

"I'll sign." He Yuzhu slammed Ma Yuejin's sketch onto the table. "Tomorrow, Ma Yuejin will conduct the vacuum suction cup adsorption test, Lin Jianguo will prepare the adhesive bonding process documents, and Lao Zheng will prepare the flange surface cleaning equipment. The complete plan will be ready on Thursday, and construction will begin on Friday. The keel must be joined by the end of the month."

Sun Demao raised his hand. "Dean He, the Dalian section was hoisted and lowered, and the anti-rust oil on the flange surface needs to be cleaned thoroughly. We've never done ultrasonic and plasma activation before."

Lin Jianguo opened his notebook. "Acetone degreasing, ultrasonic cleaning for twenty minutes, and plasma treatment to activate the surface. We've verified this process in the lab; it increases the strength of the lap joints by forty percent."

Chen Guoqiang pointed to Ma Yuejin's sketch. "Engineer Ma, where does the power cable for the vacuum suction cup of the glue applicator go?"

Ma Yuejin grabbed a piece of paper and redrawn. "The cable hangs on the trolley of the gantry crane and moves with the glue applicator. The glue applicator travels forty meters in one circle, and the cable is forty-five meters long, which is enough."

Old Zheng stood up, walked to the door of the work shed, and stood there for a long time, staring at the section on the slipway that hadn't yet been matched. He turned around, his face crinkling with wrinkles. "Director He, I've been in shipbuilding for thirty years, and this is the first time I've seen a ship glued together. This isn't a ship, it's a spaceship. I don't understand spaceships either. You sign here, and I'll get to work."

He Yuzhu slammed his hand on the table. "It's settled then. Tomorrow, Ma Yuejin will conduct the verification, Lin Jianguo will prepare the documents, and Lao Zheng will prepare the equipment. Meeting adjourned."

The workers gradually left the shed. He Yuzhu stood alone at the entrance, watching the searchlights on the slipway light up one by one. It was getting dark, and the Guangzhou section hadn't arrived at the dock yet. He took out his walkie-talkie.

"Lin Jianguo, what time will the Guangzhou segment dock?"

"Around 8 p.m., the tide level is not high enough, we'll wait for the tide to come in."

He Yuzhu tucked the walkie-talkie back into his belt and walked towards the dock. A river breeze blew by, carrying the smells of diesel fuel and rust. Several workers squatted beside the mooring bollards, smoking, their cigarette butts glowing and dimming in the twilight. Seeing He Yuzhu approaching, they stood up and stubbed out their cigarettes on the soles of their shoes.

"Captain, are you here to take over the Guangzhou section?" He Yuzhu asked one of the workers.

The worker nodded and pointed to the river. "The tugboat just passed the Wusongkou; it'll be another two hours."

He Yuzhu squatted by the dock, watching the river water lap against the embankment. A layer of oil film floated on the gray-black water, shimmering with iridescent colors under the lights. He recalled the look on Ma Yuejin's face when he paused for a moment before changing his mind after saying "vacuum suction cup," and the resolute determination of Lao Zheng when he said, "You sign, I'll do the work."

At 8:10 PM, the sound of a tugboat's engine came from the river. A searchlight swept across the area, and a flat-deck barge slowly approached the shore. On its deck lay a massive 40-meter-long section, its gray-black carbon nanotube shell gleaming dimly under the lights. The barge struck the dock's rubber fender with a dull thud, shaking the ground. Workers rushed over to secure the mooring lines, wrapping them three times around the bollards and pulling them taut.

He Yuzhu stood up and dusted off his knees. The Guangzhou section had arrived. Flange measurements tomorrow, plan finalized on Thursday, construction on Friday. The day the keel is joined won't be far off.

He turned and walked toward the parking lot. The old jeep's headlights illuminated the road ahead, while the searchlights on the dock went out one by one behind him. In the rearview mirror, the newly arrived section lay quietly on the barge, like an unopened gift.

The road ahead is long, but the direction is right.