The so-called sailing ship is to add mechanical power to the sailing ship so that it can not be limited by wind force and direction. Generally speaking, the sea is windy, and the demand for mechanical power is not so strong. However, in inland waterway shipping, because the inland wind is small, there is a great demand for power other than wind power.

Previously, Marin had discussed this problem with Leonardo da Vinci, and had described the general principles of a sailing ship, and then left it alone. Later, Marin also instructed Leonardo da Vinci to develop a single-cylinder watt steam engine and a single-cylinder diesel engine.

However, both types of machinery are very problematic when they come on board. First of all, the Watt steam engine, because it was the original version, it was very slow and inefficient. Leonardo da Vinci loaded it onto the boat for experimentation, and it only ran three or four knots of speed, which was not as fast as a sailboat.

The worst thing is that this original version of the Watt steam engine is very bulky and requires a lot of space. For example, installing a 200-ton ship with a Watt steam engine will not only increase its speed to a limited extent. Moreover, the Watt steam engine and boiler and coal storage room took up a third of the ship's space, which was very uneconomical. Even, because the steam engine and boiler are relatively heavy, it also slows down the sails to drive the speed of the ship.

All in all, this original version of the steam engine, which could be used to pump water, to power ships and even trains, required great improvements before it could be practical. This was also true during the Industrial Revolution. Watt developed the Watt steam engine in 1785, but it was not until 1803 that Fulton's Claremont got off to a good start.

But the Clermont also has a low speed, only 9 kilometers per hour, which is 4.85 knots. Then, after several decades of improvement, it was not until the mid-19th century that the steam engine was added to the steam engine to replace the pure sailboat.

Leonardo da Vinci is here, although he has Marin's guidance. But Marin was also half-baked, he had only learned the principle of the Watt steam engine in middle school, and did not understand the principle of the two-cylinder steam engine on the train or even the three-cylinder steam engine on the ship. Otherwise, he would have been able to bring the Beihai Kingdom into the steam age in one step.

However, from the memory of the broken walk-behind tractor at home when he was a child, Marin also asked Leonardo da Vinci and the craftsmen to restore a 12-horsepower single-cylinder diesel engine.

But this single-cylinder diesel engine is more problematic because it requires more parts, the speed is faster, and the manufacturing requirements of this diesel engine are extremely high. Diesel engines are made according to the standards of making stupid steam engines...... Therefore, at the beginning, the batch of 12 horsepower single-cylinder diesel engines had a lot of problems, and they lay down at every turn...... Sometimes, the time to repair the diesel engine is more than the normal operation time of the diesel engine......

Then, Marin didn't care about the mechanical things and went about his own business......

But Leonardo da Vinci did not give up, he divided dozens of mechanical college students under his command into two groups according to their personal hobbies, one group specialized in the improvement of single-cylinder steam engines, and the other group was led by him himself, specializing in the perfection of 12-horsepower single-cylinder diesel engines......

In addition, Leonardo da Vinci also remembered the description of the "river boat" that Marin told him, which is to hang a single-cylinder diesel engine on the stern of the river boat, as a hang-up engine, to drive the boat to run on the river.

Therefore, in the days that followed, Leonardo da Vinci personally led the team to improve the 12-horsepower single-cylinder diesel engine, which greatly reduced its problems. At the same time, we are also studying how to turn a single-cylinder diesel engine into a marine hang-up.

During this period, Leonardo da Vinci also asked Marin about the propeller, and Marin didn't care, and drew a propeller pattern for him according to the blade pattern of the electric fan, and asked him to find someone to process it himself. Of course, this pattern is not nonsense. Because, the fan blades of this electric fan used by Marin in his previous life are said to be made in the style of simulating the propeller of a submarine. At the time, it wasn't a publicity stunt. Marin then memorized the style of the electric fan, and then gradually forgot about it. But after crossing over, his memory became stronger, and many forgotten memories were "sorted out" by him.

While drawing the propeller pattern for Leonardo da Vinci, Marin also drew him a schematic diagram of a speedboat driven by an idle machine in later generations.

Marin didn't care about it, he thought it was an inspiration to Leonardo da Vinci. Leonardo da Vinci was very concerned about this matter, and when optimizing the single-cylinder diesel engine, he was also experimenting with installing the single-cylinder diesel engine as a hang-up on a river boat.

After some improvements, Da Vinci found that because the speed was faster and the power was stronger, the diesel engine was far more worn out than the steam engine. Therefore, while standardizing the manufacturing process, the space for adding oil is designed in the parts of the diesel engine that are easy to wear and tear, so as to reduce wear as much as possible.

Then, Leonardo da Vinci enlisted chemistry students to help him extract a high-temperature resistant mineral lubricant from a pile of asphalt that had been refined into gasoline and diesel for the lubrication of diesel engines.

There is also the problem of overheating, the diesel engine is very fast, and it can rev hundreds of revolutions per minute. Even with the use of lubricating oil, frictional heat generation, combined with the compression of diesel fuel, produced very high temperatures, which required practical cooling.

But that's not a big deal. Because, Marin pointed out their diesel engine structure, there is a water-cooled box, which can cool the fuselage more fully. Moreover, the cooling of the fuselage should not be paid too much attention, and the body must be guaranteed to have a certain temperature, otherwise it is difficult to achieve the conditions of diesel combustion......

After a long period of optimization and modification, the 12 hp single-cylinder diesel engine can finally run for a long time without problems. At this time, Leonardo da Vinci began to try to install single-cylinder diesel engines, which had few problems, into river boats, to make what Marin called "speedboats......

It was not difficult to load the diesel engine on the ship, and Leonardo da Vinci quickly got it right. However, it is more difficult to turn the diesel engine in one hand along with the propeller system in order to change direction, as Marin said. Because, later generations of speedboats generally used light diesel engines, rather than bulky diesel engines.

Leonardo da Vinci tried many times and found that a diesel engine weighing hundreds of pounds was really difficult to turn easily. Even if it turns, it needs to be very forceful......

In desperation, Leonardo da Vinci later changed his method to fix the diesel engine and propeller. As for the steering, he also set up two linked rudder blades on both sides of the stern, connected by a long rod. When you need to change direction, you can directly hold the long rod to adjust the direction of the rudder blade......

After many experiments, Leonardo da Vinci finally came up with what Marin described as a "speedboat". This "speedboat" is indeed fast, at least, as it seems to people of this era. Because, he didn't rely on other power, only the power of a single-cylinder diesel engine, and actually ran out of 7 knots of "high speed......

But when Leonardo da Vinci triumphantly showed the "high-speed" diesel engine "speedboat" to Marin, Marin's expression was very strange...... Nima, 7 knots also dare to call high-speed?