Chapter 383: Chapter 381: Shield Tunneling Machine
In fact, building a shield machine is not as difficult as many might think, because the world’s first shield machine was born in the late 18th century, two hundred years ago. It relied on manual digging, and compared to today’s large mechanized shield machines, it didn’t have many high-tech components.
Though early shield machines were structurally simple with no high-tech elements, they are the ancestors of today’s modern shield machines and their principles are derived from them.
Chen Xin wants to build a shield machine himself. Unless he starts from scratch with a novel design approach, he cannot bypass the foundational principles laid over two hundred years ago.
The principle of a shield machine is not complex. The main idea is that while the tunneling machine is advancing, it constructs a "shield" to protect the tunnel and prevent collapses — it excavates and repairs simultaneously.
Of course, with technological advancements, today’s shield machines still follow the same principle, but some large or mega shield machines no longer need to build the "shield" during excavation. They can directly construct the tunnel as they dig, which is convenient and fast.
The basic principle of shield machines comes from a marine organism — the shipworm, which continually digs into wood and secretes mucus during digging to protect the surrounding wood from being corroded, swollen, and damaged by seawater.
Thus, for Chen Xin, who doesn’t need a conventional shield machine, he merely needs a machine that can quickly excavate through snow and hold the tunnel open without collapsing until the pipe installation is completed.
And these two points are really not difficult to achieve.
Snow is not solid ice blocks; it has some hardness but is much easier to excavate compared to soil. The internal texture of snow is uniform, and doesn’t pose complex structural issues, so there’s no need to worry about encountering rock layers or other complex geological structures during excavation.
As for the second point, it’s even easier to resolve. Given the current temperature, simply apply a bit of heat to the tunnel walls during excavation, allowing the snow on the tunnel walls to melt and quickly refreeze, forming an ice shell to support and protect the tunnel from collapsing.
After all, it’s just snow, not some complex geological structure. A layer of ice shell support is already sufficient.
With these two key points clarified, making a functional shield machine might be beyond a primary school student but should be manageable by a technically skilled secondary school student.
A cylindrical main structure with a blade or drill bit made of relatively hard metal at the front, surrounded by a ring of electric heating wires for melting snow and internal insulation, would basically complete the task and meet construction needs.
Beyond this, it’s just about optimizing the internal mechanical structure and adding some auxiliary functions.
For example, the front blade or drill bit could be manually rotated or could have an electric motor added for mechanical power. The excavated snow could be manually transported or mechanically conveyed, and if Chen Xin is willing to invest effort, he could make the entire shield machine fully automated, making it capable of self-excavation and completing the entire construction once placed into the snow.
Chen Xin hesitated a bit, pondering the size of the equipment he should build.
Creating a large one and directly digging a tunnel so workers could enter and lay pipes is a simple and straightforward approach. This method doesn’t require the machine to be overly complex or advanced; as long as it can excavate quickly, it will suffice.
However, in this case, the construction speed wouldn’t be high, because constructing a large machine means the excavation face is also relatively large, thereby multiplying the amount of snow removal work, extending the construction period.
As for creating a small one, or just one as wide as the pipe itself, to excavate while laying the pipe, this is undoubtedly much more convenient.
The only drawback is, creating a small shield machine would vastly increase the technical content.
After weighing the pros and cons, Chen Xin decided to choose the smaller shield machine.
After all, for him, enhancing the technical content is the simplest task.
With multifunctional mechanical arms, crafting such a shield machine is not a difficult task. He needed only to cut a section of pipe, install a drill bit for excavation on one end, connect an internal pipe for extracting snow slush, and finally attach an electric motor and power source to complete it.
Although this device is completed and ready to start working, before officially utilizing it for tunneling operations, Chen Xin needs to make slight upgrades.
For instance, equipping it with a microcomputer to allow remote control or pre-programmed automatic operation is quite essential.
Chen Xin even considered installing a 3D printer to print the pipeline directly during excavation, eliminating the need for laying the pipeline itself.
However, after contemplating for a while, Chen Xin decided against this and opted only to add remote control to the small shield machine he built, ensuring the ability to remotely control its forward, backward, and stop functions.
The finally assembled shield machine resembles a bullet, with a hollow drill bit at the front cutting through snow with its curved blade, then extracting cut snow through an inner pipeline to ensure the drill bit advances smoothly.
Aside from the pipeline, there is also a ring of heating elements behind the drill bit to heat the snow surrounding the shield machine, allowing the snow to melt and refreeze in low temperatures, forming an ice shell to stabilize the tunnel.
The entire shield machine is powered by a small motor installed by Chen Xin, which drives the drill bit and tread wheels at the bottom for forward propulsion, with power supplied by a small battery.
After assembling the shield machine, Chen Xin took it to a nearby snowy area for a test, and the results were very promising.
The drill bit advanced quickly through the snow. Chen Xin let it drill for just about three to five minutes, and it had advanced about two meters. At this rate, it’s estimated that within an hour, it could tunnel 20-40 meters, which is considerably faster than manual excavation.
Seeing the effectiveness of his shield machine, Chen Xin felt satisfied and prepared for workers to start construction.
But it was then that a worker raised a question with Chen Xin; though the shield machine could rapidly tunnel, how would the pipeline be inserted into the tunnel?
The shield machine’s diameter is only a few centimeters wider than the pipe itself; inserting the pipe straight into the drilled tunnel is not an issue, but this pipeline isn’t just a straight line; there are bends in it.