Sure enough, Huang Dezhang practiced it himself.

In less than three days, he found a blacksmith, a carpenter, etc. and carried out some operations.

The emperor was also quite happy and rushed over to join in for a fun.

Now it seemed like poking a hornet's nest. Several princes and princesses, led by the eldest princess Li Weier, rushed over and watched with novelty on their faces.

Seeing this, the emperor did not drive him away, so he asked them to visit together.

Huang Dezhang did not care about his identity as a prefect and personally conducted research on the situation. He was covered in dust and did not dislike the mess.

"Your Majesty, let's not mention the carriage for now, but the wooden tracks are to be discussed."

Huang Dezhang frowned, looked more serious, and said to the emperor: "When I lifted the wooden track, I felt that it would be cheaper to dig a concave rut and let the carriage go along the rut."

People living in rural areas may notice that after the rain, it is much easier to walk along the ruts. By the same token, dig out ruts on the ground and let the rear car follow along, which is similar to the wooden tracks.

When the emperor heard this, he thought it was a good idea. He should not be restrained from his thoughts, and it would be great to try it out.

So, the craftsmen dug up the ruts and took about a mile to make the carriage gallop.

Sure enough, the speed of the carriage was faster than that.

Huang Dezhang was happy in his expression.

"What's wrong!"

The emperor was also happy, but then he frowned and said, "You are flat, which is naturally convenient, but if it is a slope, it is afraid it is not more difficult to run than flat ground?"

The rut has less resistance on the flat ground, but when the wheels get on the slope, the wheels fall into the rut, so naturally there is a greater resistance and it is even more difficult to run. Junior high school physics.

"This--" Huang Dezhang immediately experimented. Sure enough, the carriage was downhill and flat, and the speed was faster than the price, but it was quite difficult to go uphill.

The wheels scratch the ruts from time to time, and they are suddenly tilted, making it very easy to run out.

Now, the children looked at it very seriously.

When the car is fast, they clapped their hands and cheered, and when the car is slow, they are weak.

Such a novel experience is something that has never been seen in books, which makes them extremely curious.

“The disadvantage of ruts is obvious!”

Huang Dezhang said helplessly: "The ground is slippery and soft, and it is not feasible. Only hard ground, like a stone road, can it be feasible."

Therefore, the ruts were directly abandoned.

This was the case with the ancient Greeks, who chiseled ruts on the ground paved with stone slabs. This was fine if it was a short distance. The territory of hundreds of miles and the length was absolutely unbearable.

Moreover, ruts have no advantage in uphill, and they have become useless.

Since that's the case, Huang Dezhang was no longer confused and started using the wooden tracks directly.

And the wood used in wood tracks has become the key.

However, the wood selection of wood tracks is also very particular.

If camphor wood is too soft, it is prone to cracking and deforming.

The shirt wood has stable compressive resistance and is not easily worm-eaten, but it has a light weight and is not suitable for serving as a wooden rail.

Pine wood has stable corrosion resistance and compressive resistance, is not easily worm-eaten, and the wood is light in weight and does not easily deform, making it an ideal material.

Pine is very suitable.

So, Huang Dezhang thought about it for a moment and had the idea of ​​pine wood.

Moreover, another major advantage of pine wood is that it is widely distributed throughout the country, making it very convenient to log, and the cost is very low, and it can be replaced at any time.

"Each section of pine wood is one meter long, and two pieces are worth three hundred."

Huang Dezhang picked up the abacus and started to calculate it. He paved a mile of land, which was twenty pieces, and it took almost twenty-six knots.

During the Tang Dynasty, the size standard was the double steps of Emperor Taizong of Tang Li Shimin (one step each with one foot) and it was called "step", and it was stipulated that 300 steps were one mile. One "step" was one foot. In the Tang Dynasty, the ruler was now 0.\n303 meters, and one mile was 454.\n2 meters.

Of course, this is just a material fee, and nothing is calculated by labor.

But if we estimate that one mile and thirty stakes will be at least 3,000 mile.

The distance between the two rails is about five feet, which is 1.5 meters. All wooden rails must be at this distance.

But if it was difficult in other places, the Ordnance Department had long had a ruler, a ruler of one foot, a tenth of an inch, a tenth of an inch, a tenth of a cent, a slight difference.

So, the distance is good, but the difficulties come again.

What if it is fixed in this way? Will the carriage not loosen when it is running?

It is spread directly on the ground, and it will loosen when it shakes, and it is used for rivets.

Therefore, at the emperor's suggestion, sleepers were laid below, and wooden nails were no longer used, that is, "monomerectile dynamite".

In response, Huang Dezhang raised objections: "Your Majesty, iron nails are too expensive and will be loose for a long time. If you use mortise and tenon, it will be cheaper."

When Li Jia saw the carpenters skillfully using mortise and tenon, he felt relieved and recognized it in his heart.

At this moment, I am sure that it is not as good as mortise and tenon, and the cost and structure are not as good as.

In today's era, iron nails are not mass-produced by machines now. They must be forged one by one by one by the blacksmith. Although the forging process is not complicated, the forging cycle is very long.

Moreover, it is basically giant iron nails, used with wooden nails.

Even Emperor Yang of Sui, who was extremely extravagant and wanted to be famous in history, was not willing to use a large number of iron nails. He just used them on a dragon bed, and did not just nail them into the wood with a hammer. Instead, he dug a hole in the wood in advance and then embedded the iron nails in it.

After the sleeper, wooden nails were added, and the inlay was hit and inlaid, the one-mile-long wooden track was successful.

The top is raised, and the wheels of the carriage are just indented, and the two are covered and fit, just like the current train tracks.

The carriage started running, thrilling, and the speed was faster than the rut lane due to the draught reduction.

The crowd cheered.

Huang Dezhang frowned, and looked at the rapid friction and the deformed tracks, he couldn't help but touch them, pinch them again, and said, "Your Majesty, the wooden tracks do not have iron sheets. Even hardwoods like pine wood are difficult to carry in large quantities."

"If this happens, it will be worn out in less than ten days."

"In addition, the axle needs to be made of iron, otherwise it will be worn out in one day when running like this."

To put it bluntly, the biggest loss of a wooden rail car is on the wooden rails and the axles.

The axles don't matter, but the iron used is difficult to measure, and the iron output today is definitely difficult to meet.

More importantly, even if you are satisfied, you will be able to wrap the wooden rails with iron sheets, and there is no way to be safe.

You should know that even before the New China, iron has always been a strategic resource, and put on the road, isn’t it a crime?

When we get here, everything gets stuck.

In the final analysis, it is still a matter of money loss.
Chapter completed!