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Young and frivolous, Mao Yisheng really experienced this idiom at this time, because he suddenly couldn't be frivolous and felt deep pressure.

The undersea tunnel is as simple as it is to be realized.

This plan that does not know the height of the sky has spread throughout the world, and the foreign technical circles have ridiculed the Chinese for not being able to measure themselves, and this is the source of pressure on Mao Yisheng, if it is just himself, he will fail if he fails, and he is just a disgrace, but now it is not just a person who loses himself, but a person who loses the country and the nation, and this person he Mao Yisheng cannot afford to lose.

Yang Zi's laboratory wants to give anything, money, materials, and equipment, and even rented a submarine to help survey the seabed terrain, so Mao Yisheng didn't do any work, at least he learned a lot of hydrological topography of the seabed, and sorted out thick data.

But the more so, the greater his pressure, in the seabed to build a tunnel, this is not on land, the first thing to solve is the huge water pressure on the seabed, although the depth of the Bohai Strait is shallow, but the deepest depth is more than 70 meters, this water depth is not a person can dive for a long time, this era no one directly participated in the construction, is unimaginable.

At present, the world's mainstream underwater tunnel construction methods mainly include excavation method and immersed pipe method, the British built an underwater tunnel on the Thames River, using the excavation method, and invented the shield method for the construction of this tunnel; The Americans favored the immersed tube method, which built a railway tunnel at the bottom of the Detroit River 30 years ago, and the Germans just built an underwater pedestrian tunnel in Berlin this year, using the same immersed tube method.

It should be said that the immersed tube method is a popular method at present, prefabricating a steel or steel-concrete structure, and then slowly putting it into the pre-dug seat at the bottom of the water, and then using a pump to drain the water is successful. Compared to the conventional excavation method, the workload of underwater operations is greatly reduced, so the efficiency is greatly improved.

However, the current immersed tube method is only applied on the river, and the longest is not more than one kilometer, and the submarine tunnel of the Bohai Sea is more than 100 kilometers, even if it can dig out the seat at the bottom of the sea, even if it can complete the installation, but it is very difficult to drain the seawater in the tunnel with the current technology, even if the water is drained, a tunnel more than 100 kilometers long, can it resist the water pressure, and the sealing tunnel of hundreds of kilometers, the ventilation problem is a technical problem, the Anglo-French tunnel conceived by engineers during the Napoleonic period, A huge chimney (ventilator) is installed on top of it that sticks vertically out of the water.

One technical problem after another weighed on Mao Yisheng's mind, making him feel for the first time that he was only too poor in mastery, and he was still a doctor of engineering.

But Mao Yisheng was not convinced, since the British could dig a tunnel on the Thames in 1825, there is no reason why the Chinese will not be able to build an undersea tunnel in 100 years, since the British engineer can invent the shield method, he Mao Yisheng must also design a new construction method.

Mao Yisheng first read a lot of other engineering and mechanical technologies by himself, and then began to seek the help of other scientists, he invited some technical experts to join his team, and used the funds provided by Yang Zi's laboratory to continue to do experiments, and constantly solve technical problems.

Inadvertently, Mao Yisheng formed a huge team, and even he didn't realize that under pressure, he actually explored a project engineering model, and the first application of this model in research and development should have been when the Americans were developing the atomic bomb.

Mao Yisheng has been busy experimenting for 27 years, and Siemens has also successfully tested the technology that Yang Chao needs.

There are not many new technologies, all of them are the accumulation of Siemens' mature technology in the electric railway, but the most advanced technology has been integrated.

High-horsepower electric locomotive is not a problem, Siemens has such a technology, Jinpu Road has been successfully operated, and through thousands of kilometers of Jinpu Road continuous improvement, heavy-duty electric locomotive technology has been quite mature, since it can carry heavy objects, there is no reason not to carry people, but need to run a little faster.

To run fast, Siemens' electric locomotive more than 20 years ago ran at a speed of 200 kilometers per hour, so speed is not a problem, the problem is stability, if in the case of high-speed driving, do not derail, do not overturn, this is a difficult problem.

Stability technology is not developed by Siemens, but by his cooperative enterprise, China Railway Corporation, the car runs steadily on the road, the most important thing is not the car, but the road, this is a common sense.

The answer given by the senior engineer team of the railway company is to build the railway with the highest standards, the railway track levelness adopts the world's strictest standards, and at the same time adopts seamless rail technology, the seamless rail is not absolutely seamless, but greatly reduces the gap between the tracks, under normal circumstances, the ordinary railway has a joint of about 40 meters, which greatly affects the stability of the railway, so the ordinary train always clangs when it runs. The seamless rail technology greatly lengthens the length of a single rail and greatly reduces the gaps, and the current technology can reach a joint of 120 meters.

The flattest rails, the fewest joints, the stability is naturally greatly improved, after Siemens specially built 2 kilometers to achieve half a year of test of the line, the current operation is stable, but it has not been tested on a longer line.

Yang Chao promised Siemens to renovate the old line for testing at a distance of nearly 40 kilometers between Lijin County and Dongying.

Dongying is the first big city in Wudingfu, much more prosperous than Fucheng, and even Lijin near Dongying is now developing much more prosperous than Wudingfucheng, three years after the great prosperity began after the war, Dongying and other big cities have finally reached the limit, land prices, manpower has increased significantly, and Lijin, the nearest city to Dongying, has become the best choice for transferring Dongying industry.

After several years of development, there is a large number of textile industry in Lijin County, the suburbs have formed an industrial zone, and the road construction between Lijin and Dongying is very good, the freight is basically taken by road, the freight rate is very low, which is less than 40 kilometers of short-distance transportation, flexible car transportation, has an absolute advantage, the railway can not compete at all.

The development of highways has made the electrified railways of the past dilapidated, in disrepair, and only maintained by passenger transport, not only can not be self-financed, and even the normal operation of the two can not be done, so last year Wuding Mansion decided to give up this place, if not Yang Chao took over, the roadbed here will be stripped off, and then sold to some industrial enterprises to build factories.

Yang Chao asked Siemens to renovate this broken railway, the first is as an experiment, the second is not to affect the transportation between the two places, and the third is not to re-acquire land, the land price here has risen to a sky-high price in recent years, although it is not as big as the bubble in the United States, but it is also a headache price.

Of course, in addition to not having to demolish and relocate, it is more difficult to renovate this railway than to build a new one, and the roadbed of the old railway even has to be stripped off and rebuilt according to the latest technology, and the roadbed of the old railway cannot ensure the stability of the new railway.

Fortunately, the distance is short, and Siemens believes that it can be completed in one year, and then enter the experimental stage, and if there are no problems in the trial, it can be rolled out the year after next at the latest.

Yang Chao attached great importance to the construction of the railway, and found that Lijin County was indeed much more prosperous than before, he stood outside the city and could not see the city wall, the city wall was not demolished, many Chinese laws learn from the United States, and the United States inherited from the United Kingdom, the Anglo-American system, and even the entire Western civilization, attaches great importance to historical relics, and it is impossible to have so many ancient relics if you do not pay attention to it, so no one dares to demolish the city wall, but the surrounding high-rise buildings are too high, and there are too many, covering the city wall.

Yang Chao is still quite satisfied with the development of Lijin County, this is not how clever the officials of Lijin County are, it is purely a market choice, they just do a good job in infrastructure and system construction, and prosperity is brought about by economic development.

Lijin is not even the best development, the best city in recent years is Jiaozhou, Qingdao has been unable to accommodate too large industrial enterprises, so it is natural to develop outward, although many old enterprises have not moved out, but the first choice of the new factory is not Qingdao, but the nearest Jiaozhou.

For example, the second phase of Yangzi Automobile factory was chosen to be placed in Jiaozhou, Yangzi Automobile set up a factory in Jiaozhou, which can easily use Qingdao's metal processing industry, and purchase parts from Qingdao for assembly, and then go to sea through Qingdao for finished products, because of this geographical advantage, Jiaozhou, which was sucked by Qingdao's black hole effect in the past, has finally benefited, and has become a medium-sized city with a population of 200,000 in recent years.

Relying on the development of Qingdao is not only Jiaozhou, Jimo also got a piece of the pie, but the people of Jimo are not very welcome to Qingdao's industry, at the beginning of Qingdao Germans came to Jimo to buy land, the landlords near Jimo County proudly said that a piece of land will not be given to the Germans, because when the Jiaoji Railway was built, the German soldiers killed people in Jimo, and it was these big landlords who blocked the Germans from building the railway.

Therefore, the first few new factories settled in Jiaozhou, and industry is a kind of thing, there is an agglomeration effect, for example, a street initially appeared a few electronic stores, and finally it is likely to develop into an electronic street, the earliest factories settled in Jiaozhou, the result attracted the later related factories, Jiaozhou naturally snowballed up, there is industry and money, Jiaozhou itself built a road to Qingdao, which offset the Jiaoji Railway first through Jimo and then through Jiaozhou distance disadvantage.

Of course, Jimo is not without any gains, after all, Qingdao's German industry is now less than half, national capital is dominant, many factories that seem to work in large numbers of Germans, the owners behind are Chinese, probably Shanghai bankers who rarely come to the factory.

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