Chapter 670 (2/2)

Around 1750, the British began to use copper to cover the bottom of ships to prevent the adhesion of insects and aquatic plants.

In 1761, the British Royal Navy cruiser ”alarm bell” laid copper sheet on the whole bottom of the ship, and then cruised out to sea. After two years, it came back for inspection and found that the protection effect was excellent, and no foreign matter was found on the bottom of the ship.

However, new problems appeared very quickly. The copper coating on the bottom of the ship began to peel off after a few years. The reason was that the iron nail fixing the copper coating gradually corroded due to electrolysis and finally broke.

Later, after many years of experiments, scientists finally found a solution. In 1786, the Royal Navy began to use copper zinc alloy nails instead of iron nails to fix the copper skin on the bottom of the ship, which solved this problem.

Especially with the outbreak of the war of independence, France, Spain and the Netherlands declared war on Britain one after another. The Royal Navy is faced with severe challenges. The fleet is going to sea more and more frequently and for a longer time. It is an extravagant hope to clean the bottom of the ship regularly. So the British Admiralty decided to cover the bottoms of all warships with copper. By 1781, all the main ships, cruisers and auxiliary ships of the Royal Navy had been equipped with copper bottoms, becoming the first ”copper bottomed” fleet in the world.

The warships with copper bottoms not only reduced the trouble of cleaning the bottom, but also brought an unexpected benefit to the British, that is, the speed of warships with copper bottoms has been greatly improved.

In the era of sailing, in order to achieve higher speed, warship builders will try their best to improve the hull line. France is leading the trend in this respect, and a large number of designers proficient in the so-called ”hydrodynamic principle” have emerged.

French warships are famous for their graceful and smooth lines, but their speed advantage is not obvious compared with British warships. The French naval generals could not understand it, and they could only blame the poor construction quality of their warships. This is actually a misunderstanding of the scientific community in the 18th century.

In the sailing age, the speed was usually less than ten knots. At this speed, the maximum resistance of warships came from the friction between the hull surface and the water, not from the lines. Because of the smooth bottom surface, the resistance of the bronze bottom warship is far less than that of the ordinary warship, so when the Royal Navy warship is equipped with copper bottom, the speed is often inexplicably fast.

This accident was quite confusing to the experts of the Navy Department, and the generals who only cared about the actual combat performance were naturally overjoyed.

Later, the French and Spaniards also got the news of ”copper bottom”. Although they could not figure out why warships with copper bottom could get higher speed, it did not prevent them from learning from the British and providing copper bottom for their warships.

It was only last year that Noel's Atlantic horn had just completed the preparation of copper bottoms, while the seahorse, another class III windsurfing battleship in the sub fleet, also had copper bottoms.

As for the three armed merchant ships, it was naturally impossible to provide copper bottoms. But it has nothing to do with Noel, who is now ready to give up the three Spanish armed merchant ships.

There are many factors to make such a decision. The most important one is that Noel thinks he must escape from the sky and send back the news of the emergence of such strange ships in the new continent of North America and the kind of artillery that can hit more than 10 kilometers. That's what Noel thinks is the most important thing.

It's a pity that Noel, who is trying to escape, suddenly finds that even though his two ships have soared to nearly 11 knots, those strange ships behind are still rapidly narrowing the distance.

Even half an hour didn't work, and the sea sounded like thunder again