In order to minimize the amount of engineering required for on-site pouring of general railway bridges, Zhu Youxiao still took the method of asking for efficiency from machinery, Bo Jue was found by Zhu Youxiao again, Zhu Youxiao asked him to make an engineering mixer and cement tanker this time, mainly to increase the power of the pot camel machine, and then transport cement for use, which requires the use of a large number of tankers, and there is no such engineering vehicle yet, the characteristics of this tanker are not easy to stabilize, because it is loaded with fluid, This needs to be solved by Bo Jue's thinking, otherwise it is easy to have an accident.

The genius Bo Jue slightly lengthened the transmission shaft on the pot camel machine, and then used the gear to change the direction, and it was very simple to transform the mixer, but he encountered a problem in the transformation of the cement tanker, which was also a problem in later generations, otherwise there would be no accidents that often crushed people, what Bo Jue could do to reduce the center of gravity of the tanker, as much as possible to reduce the impact of shaking on the car body, he could not find any other way.

Improvised to solve these two problems, the following is about the Yellow River, the Yangtze River and other large rivers of the railway bridge problem, this problem is more troublesome, with cement on-site pouring is definitely not possible, the first problem is that Zhu Youxiao requires that the future must be able to pass large ships, the second is that it must be sturdy and durable, and can not often need to be repaired. This is a lesson that Zhu Youxiao has learned from later generations, and strict standards must be made in this era, and the construction of various bridges on large rivers in the future can only be higher than this standard and not lower than this standard.

The first railway bridge built in China on a large river is the Zhengzhou Yellow River Railway Bridge, with a total length of 3,015 meters, a total of 102 holes when completed, and 50 holes of semi-through-type steel truss girders with a span of 31.5 meters in the deep groove part, of which 26 holes are located at the north end, 24 holes are located at the south end, and the middle shoal part has 52 holes with a span of 21.5 meters on the upper bearing steel plate girder. The bridge foundation is made of cast steel pipe piles with an inner diameter of 30 cm, an outer diameter of 35 cm, and a spiral wing with a diameter of 120 cm at the lower end, but the soil is shallow, and the bridge pier is very scoured, relying on throwing a large number of stone pieces to protect it, and barely maintain the traffic. Due to the limitations of bridge construction technology and geographical conditions at that time, the depth of the bridge pier into the earth was only 30 meters, and the foundation was shallow. Probably due to a lack of investigation of the geology along the Yellow River, or due to the technology of bridge construction at the time, Belgian companies built the piers in silt rather than on rock, which made the bridge unstable and buried the trouble.

In the projection, the Yellow River railway bridge Zhu Youxiao also intends to build in the later Belgian company to build the railway bridge, the use of steel structure, referring to the parameters of the new bridge, as well as the speed of vehicle passing, the bridge must be thicker than the steel structure used by the Belgian company, and then the bridge pile must be very deep, that is, it must go deep under the rock layer, how much depth is needed, it depends on the ability of the Lei brothers, but it must be guaranteed to go deep below the rock layer, to resist the impact of the flood season of the Yellow River, This is the most basic criterion.

To ensure navigation, the problem is not big on the Yellow River, but it is a big problem on the Yangtze River, and the problem on the Yellow River is that the Yellow River is a hanging river, and its bottom is higher than the ground. Of course, the current era is not as exaggerated as the later generations, but this is a hidden danger, the reason why Zhu Youxiao wants to rearrange the Yellow River is to hope that the origin of this Chinese civilization will not become a harmful river, whether it is the middle and upper reaches of the water and soil protection measures, or the downstream diversion, flood storage area, the purpose is the same. Zhu Youxiao wants to turn the Yellow River into a navigable economic river, although the Yellow River does not have abundant water sources like the Yangtze River, but after the protection of water and soil in the middle and upper reaches, the ecological environment will become better, even if it is impossible to navigate the whole basin, it can also be navigable in sections, and navigable in the Henan section is very realistic. Therefore, the plan to build the Yellow River railway bridge this time must consider the issue of navigation.

In the future navigation problems, Zhu Youxiao asked the Lei brothers to search for the hydrological data of the Yellow River and the Yangtze River in detail, investigate the highest water level in the history of the Yellow River and the Yangtze River, and determine the height of the railway bridge according to the highest water level. However, there is one point, when the flood forms the flood peak, it is not suitable for boating, this point must be taken into account, the railway bridge design of the Yellow River is not too high, as long as it exceeds the maximum water level of nine zhang, the height of the relative Yangtze River has to exceed fifteen zhang, after all, the water source of the Yangtze River is abundant, and the 10,000-ton freighter of later generations can only arrive in Nanjing, which is just an eternal criticism, so Zhu Youxiao let the height of the Lei brothers design is the clearance height, so that in this standard, the flood period can also pass the 10,000-ton giant ship, A 50,000-ton freighter in the flat water period can also pass, but the difficulty of construction has increased a lot, and Zhu Youxiao doesn't care about this, anyway, there is no shortage of money now, and the financial resources can fully support it, but the technology needs to be studied.

Later, the Lei brothers adopted a very interesting way of construction, when building a railway bridge over the Yellow River, because the water volume of the Yellow River is limited, the Yellow River was divided into two trenches during the dry season, and when one side was constructed, the other side was watered, and after the construction was completed, the water was crossed from the other side, which greatly facilitated the construction. The pier adopts the method of drilling, Lei Zhensheng transports the steam engine to the river, uses the mechanical way to drill, the root of the pier is deeply driven into the rock layer below three zhang deep, in order to better ensure stability, the bottom part of the root is also made a horizontal hole one zhang deep in four directions, the way of gear steering, the hole is drilled with a drill bit, and the reinforced concrete is poured, this method exhausts great strength, but in order to ensure the stability of the pier, some are at the extreme.

A total of 100 such piers were built on the Yellow River, and there are such special piers in the mainstream section of the river, and as for the piers on both sides, there is no need to spend so much effort. The abutments on both sides are also made of cement and steel, and the foundation is also up to five feet of rock formation, so even when the Yellow River flood peak arrives, the abutment cannot be shaken. Zhu Youxiao also asked Lei Zhensheng to take into account the relationship between the Yellow River and the flood, and all the bridge piers are made of sharp-angled steel castings on the surface of the water, so that even the largest ice blocks will be crushed, and there will be no ice blockage.

It is much more difficult to build bridge piers on the Yangtze River than on the Yellow River, because the dry period of the Yangtze River is too short, and can only be operated in the water, but in this era, the difficulty of water operation can be imagined, whether it is diving equipment, or underwater operation machinery, there is no such thing as never before, for which Lei Zhensheng tried his best to figure out the construction method, but due to the restrictions of the times, many later generations of construction methods Lei Zhensheng is unexpected. Zhu Youxiao has seen the construction of bridge piers, but it is also on the general river, like the construction of bridge piers on the Yangtze River, I am afraid that only the professional construction team can see, but in the construction scene on the large river, Zhu Youxiao has also seen, first make a sealed cofferdam cage into the water, and drain the water in it after sinking (the water will continue to seep, and the water should be pumped all the time during the construction), and the construction in the cage. Lay the foundation, under the steel cage, inject cement, and remove the cofferdam cage after the cement of the pier base is solidified, and continue the construction above, this method is more time-consuming and laborious, but it is also the best construction method, Zhu Youxiao can only explain it to the Lei brothers.

The construction plan for building the railway bridge was solved under the guidance of Zhu Youxiao, but this is a long process, it is much slower than the construction of the railway, so when the railway has not started, it has to start in advance, Lei Zhensheng took the initiative to undertake the task of building the railway bridge, let Lei Zhenzhou repair the railway, and the two began different division of labor.

Whether it is the Beijing-Guangzhou line or the Beijing-Shanghai line, Zhu Youxiao chose to avoid the mountains and try to build tunnels. There is a Dayao Mountain Tunnel on the Beijing-Guangzhou Line in the later world, and Zhu Youxiao deliberately chose to avoid it this time, mainly because the construction is too difficult, and it is easy to collapse with the current technology, and the other reason is that it may cause environmental damage, such as the dark river in the mountain range, which may affect the natural water environment of a place.

The railway system in the design is very large, the construction of the railway is a long process, it may take decades or hundreds of years, in addition to the Beijing-Guangzhou line, Beijing-Shanghai line, Longhai line, these trunk lines, but also around the main line to build a railway network, only the formation of a network of railway traffic, in order to play the greatest economic benefits, which is proved in practice in later generations, so Zhu Youxiao needs a special railway management department, the Lei brothers became the largest organization under the Ministry of Industry of the Ming Dynasty - the director of the Railway Bureau, At its peak, he had nearly a million employees.