And the new material that Jiang Tian said is now in Li Yuanji's hands, in fact, when he got this thing, Li Yuanji knew what this thing was.

Rubber! Or to put it more bluntly, this improved rubber can be called industrial rubber.

Add some kaolin to the rubber, which can withstand a maximum temperature of more than 200 degrees, and this tolerance range has basically met the temperature requirements of the steam engine cylinder, and the next thing to consider is friction and wear.

In later generations, the solution was lubricating oil.

However, there is no lubricating oil now, so it can only be replaced by something else, although it is not effective, but in the face of the huge benefits brought by the train, even if it is worth changing the lubricating oil every time you run.

The train was moving quickly, and the concrete-laden carriages behind it were a little smaller than the huge front of the locomotive.

The current carriage is still a carriage for horses, and although it is as wide as the front of the locomotive, it is less than five meters long, which is only half the length of the planned train carriage.

So twenty carriages are actually equivalent to the weight of ten carriages.

But even so, the benefits of the train cannot be ignored, these carriages are specially modified, the main components are made of steel, the whole car up and down, only the board is made of wood, but the board is still carried by steel.

After a period of accumulation, the train actually pressurizes the boiler, and the method is very simple, fill it with coal one by one, and then wait for the temperature to rise.

The only regret is the lack of monitoring equipment, which means that the operator has no way of knowing the temperature of the furnace and whether the pressure in the boiler is enough to keep the train running.

And there is no accurate standard, which means that all this can only be manipulated by human power, to put it bluntly, it is to look at the feeling.

The burner is easy to say, you can directly see the fire inside, as long as you keep it up, but the boiler can be troublesome.

If the heat is heated for a long time without releasing heat, it will inevitably lead to a sharp increase in the pressure inside the boiler, and the most dangerous situation is naturally the tragedy of the boiler explosion.

This is very unpleasant, and I don't want to be so convenient in the future, after the pressure in the boiler reaches the safe upper limit, the pressure will be automatically released to ensure that the boiler is always in a safe state.

However, this is only a probabilistic event after all, and as long as it is manipulated properly, there is basically no danger from happening.

And Lao Xu's explanation for this problem is to constantly test and determine whether the pressure in the cabin is enough to support the operation of the train through the burning time.

And long before Li Yuanji and the others came, Lao Xu and they were already preparing, so now, when the train started to start, he had actually completed the preliminary preparations, and this process was half an hour, that is, an hour.

Don't think that an hour is a long time, put a pot of water on the gas stove and try to see how long it will boil, and the boiler has such a large volume, and it can be boiled in an hour with the help of coke.

Of course, coke will not be used in normal operation, it is a rare commodity, it is used to smelt steel, like a guy with rough skin and thick flesh, the general coal can be burned, if there is an emergency, chop some firewood can also be started, but time and power can not be completely released.

"This ......" the ministers watched as the train moved slowly like a snail, and it made a clattering sound, and at first they didn't care, but as time went on, the speed of the train became faster and faster, and after reaching a speed, it gradually stabilized.

This speed is not even comparable to the speed of the war horse's charge, but at this time, the ministers' hearts no longer have the idea of contempt.

Lao Xu had already said that this train had been running for a day yesterday, and Li Yuanji had more or less mentioned it to them, so they also knew that although the speed of the train was not as good as that of the charging war horse, the benefits were too great.

For example, the pull he can provide is far greater than that of a war horse, and in addition, he has to eat coal, water, and as long as there are rails, he can even run to the finish line without stopping.

This is the most terrifying part, and it is also the reason why these ministers no longer dare to despise the speed of the train after seeing it with their own eyes.

They are not some rookies who have never seen the world, and through the speed of the train in front of them, they can even easily judge that if this train runs to Luozhou, I am afraid that one day will be enough.

And one day, what does it mean?

Both commercial and military significance are incredible, if in the future the railway can lead to every state capital in the Tang Dynasty, then what does it mean for the imperial court? Even in the farthest place of Datang, half a month is enough for reinforcements to arrive.

And what is the difference between reinforcements rushing to the battlefield by train and recuperating their strength? There won't be much marching fatigue at all.

"How much cement is loaded in a car?" Fang Xuanling couldn't help asking, this was not the first time he had seen a train, but it was the first time he had seen a train running so fast, the last time he saw it, the train was lying in the warehouse and did not move.

"Each carriage is loaded with 100 bags of cement, and the carriage weighs about 100 stones." Jiang Tian hurriedly talked about the situation in the carriage.

"What about the maximum load?" Fang Xuanling continued to ask, the body weighed a hundred stones, this weight was obviously a little unacceptable, and it only carried a hundred stones of goods on it, which was completely disproportionate.

"This has not been tested, and this kind of carriage is not a supporting carriage, and the formal carriage after that is about the size of two carriages, with a dead weight of more than 200 stones, and all made of steel, it is expected that the maximum load of a carriage should be more than 800 stones." Jiang Tian continued.

A five-meter-long carriage is only loaded with 100 bags of cement, and when you look closer, it is actually only two floors on it, and there are still many places to continue loading.

Lao Xu has been following Li Yuanji, watching the situation of the train, constantly introducing, and for the current speed, Lao Xu's explanation is that this is not the highest speed.

However, the pressure inside the boiler has reached a certain level, and it is necessary to continue to accumulate power, and then it can slowly increase the speed.

"Stop, test the maximum load!" Li Yuanji gave the order without hesitation.

It doesn't make sense to test how many carriages can be pulled, and the carriage weighs 100 stones, but only pulls 100 stones of goods on it, which is obviously not cost-effective and does not meet psychological expectations.

What Li Yuanji is most eager to know and what he wants to know the most is how much weight this kind of front can pull.

As far as the current known situation is that the weight of the twenty carriages is 2,000 stones, plus the goods of 2,000 stones, there is no problem in pulling the weight of 4,000 stones, and there is no sense of effort, which makes Li Yuanji have a strong interest in it.

Soon, the train stopped, and the army who had been waiting on the side dropped their weapons and quickly loaded the train with a bag of cement on their backs.

The advantage of using cement to test is that cement has now formed an industry standard, a bag of cement is a stone weight, and for this kind of test, you can save a lot of unnecessary trouble, for example, you only need to remember how many bags are loaded, and you know how much the carriage loads.

And this time it didn't increase a little bit like the first time, and the load of each carriage directly increased to 300 stones.

And the exponential increase in weight, even if the locomotive is a machine, not a horse, can be directly observed with the naked eye.

The most intuitive response is that the train starts slower and the process of speeding up is slower.

This time, it took twice as long as the speed of the train to stabilize, and similarly, the train stabilized a little slower than before, and the hourglass was used to monitor the time to calculate the difference between the speed of the two.

In the end, it was concluded that this time it was a quarter slower than before.

So, Li Yuanji waved his hand and continued to increase the weight, and the weight of each carriage directly increased to 500 stones.

And this is almost the maximum load of this train, the speed is more than half of the first time, and the time to speed up is also doubled, and even Li Yuanji has a feeling that the speed of this train is only about twenty miles.

However, this result is perfectly acceptable.

Twenty carriages weigh 2,000 koku, plus 10,000 koku of cargo, and the weight of 12,000 koku can still travel at such a speed, which is already a very good result.

And it should also be taken into account that the carriage used now is not a regular carriage, the more wheels, the more friction, in other words, the power will dissipate faster, and after the adoption of the new carriage, the speed is bound to increase.

For a dynasty that started from scratch, being able to do this, what else is Li Yuanji dissatisfied with?

He is very satisfied, but satisfaction does not mean satisfaction, he does not hide his satisfaction, but at the same time he also puts forward higher requirements for Lao Xu and them: "Continue to test, the test in the field is somewhat limited, and then you can choose a section of the area for road testing, in addition, you must continue to carry out technical research, and this time the main focus is on two aspects, for the temperature monitoring inside the boiler to ensure that the occupants know when they can drive, when measures must be taken to ensure safety, The other is to upgrade the boiler to make a better performing boiler possible. ”

Li Yuanji doesn't know anything about boilers, but it doesn't prevent him from knowing the power of steam trains, and he looks at boilers.

But then again, Lao Xu was able to make such a powerful boiler, which was even faster than in the early days of the Republic of China, and Li Yuanji was still quite surprised.