"Ahh Fifteen zhang ...... Where to find such a big whole ingredient! "Wen Lao Er completely made Hong Tao stunned, fifteen zhang is more than forty meters long, if you want to make a more than forty meters long keel, you need a sixty-meter-high tree, pinch the two ends to the middle. Are there any trees in the world that are more than 60 meters tall? Anyway, Wen Lao Er has never seen it.

"Hey, hey, the keel doesn't have to be a whole root, it can be spliced, I will, when this ship is built, how about we slowly try to splice the keel?" Hong Tao didn't know what level of shipbuilding technology in the Song Dynasty was, but they probably didn't know how to splice the keel, or the ships of the Song Dynasty didn't pay much attention to the strength of the keel and hull. Because at this time, there is no high-intensity long-distance demand, and there is no high-intensity naval battle, and there is naturally no one to study things that are not in demand.

Hong Tao carefully observed the keel structure of the Tan family's row of boats and Luo Youde's bird boat, and came to the conclusion that the overall strength of the Song Dynasty's ships was not enough, which was also a technical limitation that they could not sail far. Take Luo Youde's bird boat as an example, a large ship nearly 25 meters long and a displacement of nearly 150 tons, but the size of the main keel is very small, only about 20 centimeters square of a pine wood, no ribs, only 8 whole bilge partitions and two auxiliary keels.

This structure is like a cage, and the force is almost large everywhere, and the force is evenly distributed, so that the space inside the hull is relatively large, which is conducive to loading more things. But it has a fatal drawback, that is, the redundancy is insufficient, once one side is too forced, it will click and fall apart, and there is no chance to repair.

In addition, at this time, the Song Dynasty ships relied too much on the ship board to bear the torsion and pull of the whole ship, a bit like the body load-bearing cars of later generations, without girders, relying on the body iron sheet as a bone and as a leather. The advantage of this design is that the body is light and economical, but the disadvantage is also obvious, that is, the body is not strong enough to withstand too strong bumps and twists. Therefore, the real off-road level vehicles are all non-load-bearing chassis, and the body is just a shell sitting on the girder, and the girder becomes the stressed element.

However, the design ideas of the Song Dynasty's sea ships were very much in line with the current navigation needs, and there was no strong naval state around the Great Song Dynasty, and there was no urgent need to sail to the farther seas. The vast majority of people think that the southern countries have reached the edge of the sky, and since this kind of ship can pass, what is the use of bothering to study more expensive, more difficult to build, and stronger ships? With that money and time, it is better to build two more lucky ships, Guangzhou ships, and bird ships to run transportation.

But Hong Tao can't think like this, he now wants to wake everyone up, let them pay more attention to the ocean, and can't do without it, and then rely on their understanding of the sea to always stand one step ahead, and then use this advantage to ask for everything they need and want. Others can be lazy, he can't, the leader has to run fast, not to mention that he is not really ahead yet.

The technique of splicing wooden keels comes from the Puyol brothers, who went with him to salvage shipwrecks in their previous lives. This pair of old men has studied the Spanish Golden Fleet thoroughly, not only knowing the history of the fleet, but also the construction of Spanish galleons. When everyone was resting on the Mouse Superman, Hong Tao talked to the old man about shipbuilding, and at that time Hong Tao thought that the keel of ancient shipbuilding was a whole big log, and if he wanted to build a big ship, he had to find a big tree first, and he was laughed at by the Puyol brothers.

After the 15th century, European shipbuilding technology developed by leaps and bounds, and although the Crusades did not succeed in the end, they allowed ships from northern European countries to enter the Mediterranean. As a result, these countries in southern Europe looked at it, hey, your ship is not the same as ours, so let's talk about it. After a while, the shipbuilding techniques of the Norwegians and Swedes in northern Europe were fused with the shipbuilding techniques of France, Italy, and Greece in southern Europe, and with some things stolen from the Arabs, the Venetians were the first to build a larger sailing ship that was more suitable for long-distance voyages. At this time, the keel problem, which originally limited the size of the ship, was solved.

The Europeans used an oblique tenon structure, coupled with the three-layer composite method of the outer keel and the inner keel, and successfully turned a whole sailboat keel into a state of three-stage joint, and the degree of solidity was not lost at all, but it was much stronger. In this way, the sailing ship was no longer limited by the keel timber problem, and the European galleon became bigger and more perverted, and slowly went farther and stronger, gradually dominating the sea, and then began the colonial period when they grabbed resources from all over the world.

And the construction structure of this keel, the Puyol brothers not only have pictures and truths, but also experiments to prove it. After encountering Hong Tao's bar, the two brothers went into battle in person and used a 14-inch square log to demonstrate to Hong Tao how to connect three sections. The results of this test made Hong Tao speechless, after this kind of oblique falcon splicing keel does not lose its sturdiness, in a sense, it is stronger and more economical. Because you can choose better quality wood to splic, you don't have to put up with some imperfections on the whole big log. Originally, it could not be used as a large ship keel, but now as long as the quality and thickness are enough, it can become a part of the keel, and the cost is plummeting.

Such a fun thing, Hong Tao had to try it himself, so he himself tried this oblique falcon splicing method. To tell the truth, although Hong Tao didn't have a long time to do anything, his hands-on ability really didn't say, he only failed once, and he didn't consult the Puyol brothers.

In addition, Hong Tao also has a skill, that is, he is curious about all the things he is curious about and he likes, and he will not forget them after learning them, and he can remember them for a lifetime, but serious things are not so easy to remember, and he will forget them the next day, or even turn his head. With this experiment and the successful experience of his own hands, the oblique falcon splicing method has become a part of his memory, and he will never forget it as long as he lives.

So why not use this approach in the construction of the Explorer and the second new ship? It's very simple, Hong Tao is not very at ease with Wen Lao Er and Wen Lao Da's family, just like that nautical chart, he will only teach the people around him little by little, and slowly try whether the people around him are reliable and whether they can have the same heart as themselves through the touchstone of time, and then they will be taught. These technologies are things that can change an era, in case of a Tuofei person, it will make it very uncomfortable, technology diffusion is supported by Hong Tao, but it has a premise, that is, you must have the ability to control your own destiny before you can proliferate.

"Listen to your ...... Add! "Wen Lao Er let Hong Tao's waves of new technologies completely eat to death, and if you want your children to learn, then you can't object, you have to do it if you grit your teeth and die in distress. Outsiders don't understand the importance of keel splicing, as a shipwright, Wen Lao Er knows very well what kind of situation it will be to be able to use short wood to splice a whole keel? That means that he and his children will no longer have to worry about finding a suitable keel wood in the future, and the cost and difficulty of shipbuilding will plummet.

"It wasn't enough to wrap the ribs, I wondered why the planks of the bow had been torn apart by the waves, because they were so thin and long that glue and nails alone were not enough to fit them on. My suggestion is to thicken and shorten the bow plank, and thicken the hull board. Hong Tao felt that it was not very cost-effective to use a keel splicing method to replace a consent encryption rib, and then put forward a request that made Wen Lao Er grit his teeth.

"How thick?" Since Wen Lao Er has already taken a step back, he doesn't care about taking another step back.

"6 inches!" Hong Tao was afraid that he would not be able to express himself clearly, so he picked up a rib of wood and compared it.

"The ribs are only 6 inches thick, and the planks are 6 inches?" Wen Lao Er still couldn't hold back, and had to prepare to start raising the bar with Hong Tao again.

"Thicken the ribs to 8 inches, but you can reduce the number of partitions to two, so you don't waste too much wood, don't you think?" Hong Tao was also afraid that Wen Lao Er would be in a hurry, so he also took a small step back.

"Reducing the transom what if the boat leaks?" Wen Lao Er is not only distressed about the wood, he is also very responsible. The partition plate is the water barrier, and reducing the water barrier is equivalent to reducing the number of water barriers, and such a ship believes that the sinking resistance is insufficient.

"You see, our ribs are more than twice as heavy as before, and the planks are twice as thick as before, and if we get so many partitions, the ship will be too heavy to run. A good ship must take into account the parameters of solidity, seaworthiness, speed and flexibility, and no aspect can be too lacking, nor does it need to be too prominent in any place, which will sacrifice the performance of other aspects. ”

PS: Clicks, Collections, Recommended Tickets! Sanjiang ticket threw it to Hong Papi hard...... I don't know if there are any book friends who don't know how to vote for Sanjiang, I write out the method of voting for Sanjiang here, and the collective method is as follows: 1. The computer opens the starting point website, clicks on Sanjiang, and enters the Sanjiang homepage (mobile phone users please use their mobile phones to search for Baidu on their mobile phones: starting point Sanjiang, pull to the bottom after entering, click on the computer version), after entering the lower right corner of the Sanjiang Dafeng push, you can see a Sanjiang ticket to receive a few words, click to receive, after receiving it, you can pull the web page to the bottom, and see that there is a voting label behind "Southern Song Dynasty does not cough". and click Vote. 2. The use time of Sanjiang ticket is from 14:00 in the afternoon to 14:00 in the afternoon of the next day, each account can only vote once in this 24 hours, and it is invalid when it is outdated, so please vote directly for "Southern Song Dynasty No Cough" after receiving it, this vote can not be accumulated, one vote a day for one account, as long as it is an account that consumes more than 1 yuan, you can vote. I hope that book friends will work hard and vote for Sanjiang.