Warship of Great Power

The speed is not enough to gather power, which is applicable to any means of transportation. For example, on an aircraft, there is a saying: as long as the engine is strong, a brick can fly into the sky!

Therefore, for a reborn Qin Tao, who has decades of experience in ship design, it is definitely quite simple to increase the speed of this speedboat with a displacement of about ten tons.

The target customer is the customs inspection, and they require the speed of the ship to be as fast as possible, so what else is there to say?

Especially the speedboat in front of me will use an external engine, so it will be even simpler. If one is not enough, two engines will be installed. If two engines are not enough, three engines will be installed. It is simple and easy.

The smuggling boats at sea, needless to say three, are the ones that maximize this layout. Qin Tao has seen all of them with six external engines.

There are two arrangements for the engine of a ship. Large ships are arranged inside the hull and drive the propeller at the tail through the drive shaft. If the power of one engine is not enough, two or even four engines may be used. It can not only drive different propellers, but also work together online.

Small boats don’t need to be so troublesome. Just put the engine, drive shaft, and propeller together and put them at the stern. When needed, flip the device down to provide power. When you arrive at the dock, flip the device back. Avoid long-term immersion in water to cause loss.

In the past, Mingzhou Shipyard produced fishing boats, at least with a displacement of hundreds of tons, so the engine was inside the hull. What is being built now is a speedboat, using blueprints purchased from island countries, and a plan with an external engine.

For the workers of the Mingzhou Shipyard, this is the first time they have come into contact with this power output method. It is okay to follow suit, but it is impossible for them to innovate.

However, in the eyes of Qin Tao, a traveler, it was a piece of cake.

"Power? Change to a high-power engine? Our factory has no funds to purchase a new engine. If we used a domestic engine at that time, we could save a lot of money. However, Director Song insisted on purchasing engines from island countries." What a waste of money!" Zhao Changshui sighed again.

At this time, Qin Tao pointed to the Yamaha F100 external engine at the tail of the speedboat and said, "How many engines like this have we imported?"

"I bought ten units in total, five were used on the ship, and five were kept in the warehouse. When I bought them, ten units could be given the wholesale price, and one was 95,000. These engines alone cost nearly a hundred Wan!"

"That's right, the factory ran out of money at that time. The big liar Song mortgaged the assets of the factory to the bank and borrowed money from the bank. Now, the customs don't want these ships. Seeing that the repayment date is coming, the bank wants to seize us. If the big liar Song doesn't run away, the big guy must beat him up to vent his anger!"

Everyone became angry again.

Qin Tao nodded: "Well, that's easy to say, take out the engine in the warehouse, and put two engines on the back of this speedboat!"

What? Everyone was stunned.

"For a ship with a displacement of 10 tons, two 100-horsepower engines drive together, that is 200 horsepower. Now, are you afraid that the customs will be dissatisfied?" Qin Tao said

Qin Baoshan frowned there: "Isn't that appropriate?"

"Why isn't it suitable? It's not difficult at all to modify an engine pylon." Qin Tao was a little curious.

"One engine weighs more than 100 kilograms at least, and two engines weigh more than 200 kilograms. In this way, the center of gravity of the ship will change, the bow will be upturned, and high-speed navigation will be unstable."

When Qin Baoshan heard his father say this, he almost gave him a thumbs up.

Although Dad has a high school education, the level of teaching in the 1950s and 1960s was really not good. Five years of primary school, two years of junior high school, and two years of high school, how much knowledge can one learn? Not to mention that Dad only went to the first year of high school, and in the second year of high school, he entered the shipyard.

At that time, schools were run in accordance with the spirit of the "May 7th" directive: when schools were opened, students not only had to study literature, but also to study engineering, agriculture, and military... So, even if high school education was popularized, but the level of education...

Dad is a special case. He loves to learn and use his brain. Otherwise, he would not have made his mark after entering the shipyard, worked hard for decades, and became the director of the factory.

Now, Qin Tao said that he wanted to install two engines, and his father immediately brought up the risk of such an installation.

"Yeah, of course the bow of the ship will be upturned. In fact, we just need to make the bow up so that we can speed up." Qin Tao said: "According to specific calculations, a 100-horsepower engine can drive less than 100 horsepower. Tons of ships should be able to run up to 30 knots, but the existing speedboat tests are not optimistic, why is that?"

"High resistance?" Qin Baoshan's eyes sparkled.

Aluminum is replaced by steel, and the weight of the ship increases. Therefore, if the Yamaha marine engine originally designed to be placed at the stern can lift the bow by three degrees, it cannot be lifted at one time now. The contact area between the ship and the water surface is large, so it can run. The resistance also becomes larger. This is why current speedboats cannot reach the design speed.

If a ship wants to speed up, it is facing a very complicated problem of hydrodynamics. To put it simply, when the speed is low, the resistance is proportional to the speed. After the speed exceeds 20 knots, the resistance is the square of the speed. Proportional, at thirty knots, the resistance will be proportional to the cube of the speed. Therefore, the required power will also increase geometrically.

If no other changes are made, even a 100-horsepower engine can drive the speedboat to a speed of 30 knots, and a 200-horsepower engine can only drive the boat to a speed of 40 knots at most. To design indicators, other changes have to be made.

The weight of the two engines pries up the bow of the ship, so that the area in contact with the water surface is reduced, greatly reducing the resistance, and allowing the ship to increase to a predetermined speed.

"Will the ship be unstable?" Qin Baoshan was full of worries again.

"Unstable? How is it possible? The weight of the hull is increased by replacing aluminum with steel, so the stability should be better. If converted according to the ratio, the three engines are pressed at the back, and it has just reached the degree of inclination of the aluminum hull." Qin Tao said: "So, don't worry, it's absolutely safe."

While talking, someone has already pushed the engine out with a small cart.

Qin Tao directed a few workers to work quickly, dismantled the original engine, replaced the position of the bracket, welded the second bracket, and installed the engine, all within an hour.

"There is no champagne for a grand launching ceremony." Qin Tao said, "Let's try it like this!"

The berth is very simple, there are two rails under the speedboat, and everyone can push the speedboat directly, and the speedboat can be sent into the water.

With a splash, the water splashed, and Qin Tao couldn't wait to jump into the cockpit: "I'll try it!"