Ancient Chinese bridges, in the classification of bridges, mainly beam bridges and arch bridges, as for suspension bridges, mostly exist between the two mountains, with the help of ropes or iron cables, the construction of bridges, mostly temporary to solve traffic problems, can not pass vehicles.

In ancient China, the beam bridge was also called the flat bridge, which was mostly built in the place where the water depth was not high, the flow rate was not fast, and the degree of navigation was not high, because it was relatively simple, and the technical difficulty was not high, it became the theme of most of the bridges.

Although it is said that the construction of a flat bridge is also not a problem for the Dinghai Navy, a flat bridge of more than 180 meters is really built, then the river will be cut off.

Even in the 21st century, it is necessary to isolate the water before the piers can be built, and at the same time, to ensure sufficient height, the piers must be built very large.

Even if the technology of cement and steel bars in the Northern Song Dynasty is not low, and the concrete has become very good through different proportions, but the large bridge piers are still a little difficult.

If the piers can't be built very high, then the girder bridge is cut off from the waterway, and some slightly larger fleets will not be able to pass, only some small sail boards, or fishing boats and the like.

Water transportation played an important role in the entire territory of the Northern Song Dynasty, and even a small river could not be cut off casually.

Although the Dinghai Navy began to build a railway, the water transportation of the Northern Song Dynasty could not be broken, and if it was broken, there would be a big problem, which was the key to maintaining the existence of the entire Northern Song Dynasty at present.

The Northern Song Dynasty itself has the conditions for water transportation, and its own Beijing-Hangzhou Grand Canal, as long as it operates slightly, can increase the navigation capacity, not to mention the Yangtze River.

This world-class natural waterway, Nanjing can pass 30,000 tons, to Wuhan can pass 10,000 tons, but unfortunately, this natural waterway, blocked by a bridge, later generations of many proposals, to blow up the Nanjing Bridge.

It's a pity, if it's just a Nanjing Bridge, it's blown up, and if it's blown up, I don't know how many such bridges have been built, once they are blown up, the cost is too great, and this is also a world-class golden waterway, and the surrounding area is also the richest area in China, but such a waterway is wasted.

Although the waterways of the Northern Song Dynasty were not as developed as the Yangtze River in later generations, the channel from Yingtian to Bianliang was not so important except for one Bianhe River, which was more critical, but Zhao Xin would not have the idea of what to do.

When the railway is not dense enough to replace river transportation, arch bridges are probably the only option.

Of course, there is another option, that is, the suspension bridge, especially the cable-stayed suspension bridge, this kind of bridge, the technical difficulty is higher, and even some mechanical and material science requirements, compared with the beam bridge and arch bridge, much higher, basically impossible to choose, unless the mechanics and materials science enter a new height, some later more in-depth formulas have also been pushed out.

In ancient China, the technology of building bridges was quite developed, especially the arch bridge, which survived to the 21st century, the most famous Zhaozhou Bridge, his aperture was as high as 37 meters, creating a historical miracle.

The span of the Zhaozhou Bridge is more than a few tens of meters, and it should not be a problem for materials such as cement, but in order to ensure efficiency, once it exceeds 40 meters, it must be porous.

This longest, 180-meter-long bridge, is the use of porous shape, on both sides of a small arch bridge of about 15 meters, in the middle of a large arch bridge, will produce a certain slope, but will be filled and some other ways, adjustments, will let the railway pass smoothly.

In ancient China, the construction technology of arch bridges has been quite skilled and perfect, similar to arch bridges, the key is the joint, similar to the bridge pier, but higher than the general bridge pier.

River water, especially natural river water, is always shallow on both sides and deep in the middle.

This kind of river water, in general, extends to the entire riverbed during the high season, and in autumn and winter, during the dry season, or during the freezing season, the sides are actually dry.

This greatly solves the problem, you know, with the current technical level of the navy, it is really difficult to dig a sealing groove in the river and build a bridge pier.

Perhaps, the strength of cement and steel has been reached, but the balance of strength is not easy to calculate, how much depth must be reached, how much water flow must be resisted, so as to make the bridge stable, these need to be accumulated and calculated for a long time to obtain.

Now, the dry water on both sides is dry, except for a little more sand, it is similar to the construction on the land, in this case, if there is any problem, the excavation construction is good.

If there is anything you don't understand about mechanics, then increase the accommodating degree, when the bearing capacity of this force exceeds a lot, even if there are some small problems, it will not affect the overall situation.

Even, in terms of construction, when efficiency is compared with quality, it is even more relative to efficiency.

In this way, the efficiency is relatively high, and it also saves the construction period, and the navy, if there is not so much time, it will take a few years to build a century-old project.

With the busyness and development of the railway, at most a few decades, it will inevitably be re-covered.

In the history of the development of railways, from steam locomotives, to diesel locomotives, to electric locomotives, almost every locomotive has been separated by decades, or even close to a hundred years.

However, this traditional, fixed method of climbing the technology tree does not exist in Dinghai, as long as the technology is developed and the train is upgraded, it can be carried out immediately.

It is still the most traditional, horse-drawn method of running trains, but with the development of technology, as soon as the sealing material is found, the steam locomotive can be immediately put on the horse, and then the diesel locomotive.

Although the current steam locomotive still has no clue, as long as the sealing problem is solved, it will not be a problem at all to build this.

Ordinary steam trains can still use the original railways and pass through the original bridges, but when it reaches the level of internal combustion engines, it is impossible to use the original railways and bridges.

After the appearance of diesel locomotives, huge diesel locomotives will bring heavy weight, and when the time comes, the weight of the rails will increase to 35, or even 45 kilograms, and when the time comes, these bridges will definitely not be able to withstand the pressure brought by such a strength train, in this case, this bridge will not be able to support the weight of the railway behind.

From the steam engine to the internal combustion engine, in fact, it has not been a long time, in 1794, Watt improved the steam engine, so that the original steam engine was only a theory and scattered use, became the basis of the industrial revolution, but five years later, that is, in 1799, the French put forward the blueprint of the internal combustion engine.

However, from theory to reality, the road is very long, the first usable internal combustion engine appeared in 1860, and after 30 years, it was gradually improved, and the internal combustion engine began to walk on the stage of history.

With a history of more than 100 years, the replacement in the middle is like moisturizing things silently, but for the Dingjun, this does not exist.

From the establishment of the Dinghai Navy to the present, a huge city with a scale of one million, the Dinghai Navy has only gone through one year, as for the steam engine, it is not impossible, but it is not impossible to find suitable materials.

In fact, similar sealing materials have been found in the card system, but it is more difficult to synthesize, the cost is high, and even if it is embodied in the card system, it is expensive.

At present, in terms of the development of the navy, the current manpower, animal power and water conservancy are enough, and there is no need to climb for the time being.

Zhao Xin plans to spend 5 to 10 years gradually into the field of steam engines, promote the progress of steam engines, and at the same time, will not let go of the internal combustion engine.

In fact, from the invention of the internal combustion engine, it was only a few years after the improvement of the steam engine, but at that time, not much was known about combustible gases such as oil, and the first experiments were also done using kerosene.

In the era of cracking liquefied petroleum gas, only kerosene was profitable, and the rest was incidental, but in the field of internal combustion engines, gasoline and diesel eventually came out on top and became the dominant combustible gas.

The development of the internal combustion engine is slow, the material is on the one hand, and the lack of a large amount of combustible gas is also a key, but now, the Dingjun can carry out a small attempt to crack the oil, in this case, the research and development of the internal combustion engine is not a problem, and even unceremoniously said, as long as the key problem of materials is solved, from the steam engine to the internal combustion engine, it is just a theoretical problem, this theory, for Zhao Xin, is it difficult?

Even if Zhao Xin is studying liberal arts and studying history, but how is he also a doctor, or a relatively good doctor, in daily life, he also drives, usually inside, there are also contacts, four-stroke, two-stroke, spark plugs, cylinders, gears, these things, or understand, although not comprehensive, as long as there are these as the basis, according to this research can be, and gasoline and diesel, the two most widely used combustible gases in later generations, will also be included in the internal combustion engine, When the time comes, the pace of development will be even faster.

It is conservatively estimated that it will not take 10 years to transition from horse-drawn trains to steam locomotives, and as for steam trains to diesel locomotives, it may not even take 10 years.

That is to say, the current construction of these railways, at most is 15 to 20 years of life, which is obviously different from the development of history, it is to recognize this, Zhao Xin's made this decision, taking into account the speed of the premise, appropriate release of quality.

This liberalization is not to make some tofu scum projects, but similar to some projects that have been around for a hundred years or even a thousand years, there is still no need.

The reason why Zhaozhou Bridge is great is not only that it is the longest single-hole arch bridge in the world, but also that it has stood for 1,400 years.

However, this 1400-year-old standing is built on the construction period of up to 11 years, a span of 37 meters, the total length of the bridge is only fifty or sixty meters, a simple construction team in later generations, can carry out construction, and even build up the effect will be better, but the use of reinforced concrete these bridges, dare to say that they will be able to stand for a thousand years.

It is simply impossible, the process cannot be reached, and in fact, it is not necessary.

Anything, as long as it is in the early stage of birth, must be developing rapidly, not to mention, with Zhao Xin, a traverser and such a golden finger as having a card system, it is just an overall operation, accompanied by various systems of the Dinghai Navy, and after it is completed, it will be like a blowout.

Knowing that there will be better ones in the future, or even better ones in a short time, it is impossible not to build them, it is impossible not to build a railway in order to wait for the steam engine, it is impossible to build a relatively high-end or advanced railway because the internal combustion engine is going to appear, in case a specification problem is not up to standard, and the previous investment is not all wasted.

On the basis of the existing one, even if it is only a five- and ten-year service life, it needs to be built, and it needs to be built with big highlights.

The railway for the entire Northern Song Dynasty, and even the promotion of the Ding Navy is huge, to put it bluntly, for the market share, as well as the use of various resources, it is definitely very high, in this case

With railways and without railways, there is absolutely no difference between the development of the Ding Navy, and with the railways, at least, for a long period of time, the development of the Ding Navy will not have any worries.

At present, the entire Dinghai Navy has a limited area, and it is not easy to concentrate so many people in such a small area, but after that, as long as you are a little prepared, there is no problem in taking some offshore islands, and Taiwan is definitely one of the very good choices.

Although there are records in history, it is isolated overseas, even if it is an island that was opened by Soochow during the Three Kingdoms period, but since the Three Kingdoms, there are not many records in almost every historical period.

In ancient times with limited technology, the ocean is always unpredictable, a large-scale storm, not to mention the ancient sea ships, even if it is modern, there is no way to avoid it, the awe of the sea, except for those islands near the sea, a little farther away, is basically separated from the mainland.

But this island is very good, not far from the mainland, the entire Taiwan Strait, the narrowest place is 135 kilometers, the widest, but only 150 kilometers, this is not very long, the same location, he radiates the entire south, the south of the Northern Song Dynasty has developed, it is a rich land, some handicraft workshops have also appeared, easy to radiate, the most important thing is that his territory is big enough.

A fixed navy, a few hundred square kilometers of land, for a city is enough, for an industrial base is not enough, Taiwan, although most of the mountainous areas, but there are also a lot of plains, the most important thing is that the total area of more than 60,000 square kilometers, such a place, is simply the most perfect industrial base.