I'm the Dauphin in France

Chapter 1181 Warship Designer

Sane looked at the Crown Prince with a puzzled expression: "Iron shell? What do you plan to use it for?"

Joseph replied without hesitation, "Of course, it's used to stop artillery shells."

Sane smiled and shook his head without hesitation: "That's impossible, Your Highness. Even to defend against cannonballs fired from a distance, such as a 24-pound cannon from 500 meters away, you would need at least a 5-centimeter-thick iron plate."

He quickly did the mental calculations: "This would add more than 250 tons to a Tier IV battleship. You know, even though steam-powered warships have strong propulsion, such a heavy load would reduce their speed to below 9 knots, and would also severely affect the amount of coal and supplies they could carry."

He was being polite, but in reality, a fourth-class ship with a displacement of just over 1 tons would be almost impossible to sail if its outer armor took up a quarter of its weight.

Joseph nodded with some regret; it seemed that an "ironclad warship" was unlikely in the short term.

Moreover, 5 centimeters of armor is insufficient. He recalled that historically, the armor of the "Napoleon" was 10 to 12 centimeters, capable of withstanding direct fire from Russian 32-pound cannons. That was what truly made it combat-ready.

The main problem was that the steam engine's power was not high enough; otherwise, even the heaviest ship could be lifted by a powerful engine.

Sane comforted the Crown Prince, saying, "Your Highness, if you wish to enhance the ship's defensive capabilities, we can thicken the hull of the steam warship by another 4 centimeters; I mean, the oak hull."

Joseph sighed. The extra few centimeters of wood hull had almost no effect, at most enhancing defense against cannons weighing less than 12 pounds. But in battleship engagements, the main weapons were cannons weighing 24 pounds or more.

He then casually asked, "How much heavier will the new ship be compared to a regular fourth-class ship?"

“Approximately 25 tons, Your Highness.”

This little bit of weight is barely enough to make a difference...

"Wait a minute." Joseph suddenly stopped in his tracks. Who said that this little bit of weight couldn't be used? He thought of the iron ribs of the ship.

[Schematic diagram of a sailing warship's skeleton]

The basic structure of warships in this era consisted of first laying a thick keel, which served as the main support for the hull. Then, along the keel, a pair of curved ribs were installed every 0.7 to 1.5 meters, from bow to stern. The hull was supported by these ribs.

The current ship ribs are made of oak; replacing them with iron would significantly increase the warship's defensive capabilities.

If an enemy shell hits the iron ribs, it is almost impossible to penetrate them. Even the oak shell within a few centimeters in front of and behind the ribs will be multiplied in toughness due to the strong support.

In other words, nearly half of the ship's area will become a defense enhancement zone!
Joseph, too lazy to do the calculations himself, asked Sane directly, "If all the ribs on the ship were replaced with iron, how much weight would it add?"

The latter failed to respond instantly this time because the ribs were curved, and accurate calculations required the use of calculus.

Seven or eight minutes passed before Sane looked at the calculation results on his notebook and said, "Approximately 15 tons, Your Highness."

"In other words, it's completely within the acceptable range," Joseph said excitedly. "Then we'll replace all the ribs with iron. This will greatly enhance the warship's protection."

Sane paused for a moment, then immediately shook his head and said, "Your Highness, I'm afraid that's not feasible."

"Huh? Why?"

The chief designer patiently explained, “Your Highness, as you know, ironwork on ships is very prone to rust, especially the ribs, which are partially submerged in seawater—this is because ballast water is pumped into the hull when the ship is unloaded—which exacerbates the situation. “And since the ribs are load-bearing components, if even one-fifth of them rust, they will be unable to support the hull structure and may even cause severe deformation of the ship.”

"In fact, the Spanish used iron bolts to fix the ribs in order to strengthen the connection between the ribs and the keel. As a result, they had to replace all the bolts on their ships every three months. Later, they had to switch back to using wooden wedges to fix them."

The humidity at sea is very high, and the air contains salty moisture, making iron products very susceptible to extensive rusting.

Joseph immediately thought of stainless steel, but Namur Steel Works had only just produced manganese steel, and stainless steel was nowhere to be seen.

He recalled the various rust prevention methods of later generations and quickly found one that worked: "We can use sacrificial anodes to protect the iron ribs."

Sane blinked. "You mean, sacrifice... what?"

"The essence of metal rusting is the loss of electrons and oxidation..." Joseph stopped after saying only one sentence, "Mr. Cullen can explain the principle to you in detail."

"In practice, this involves adding a piece of zinc to the iron parts, or better yet, galvanizing them. This way, the zinc block will 'rust,' while the iron parts will remain as they are."

Well, explaining the "galvanic cell effect" is too complicated, mainly because people in this era didn't have much of a concept of electricity. If you told him that a metal more reactive than iron could donate electrons to protect iron from oxidation, he would probably listen as if he hadn't heard a word.

"Are you sure this is okay?"

“Of course, you can verify it yourself by doing the experiment,” Joseph said. “In the future, you just need to replace the anode periodically… ah, that is, replace the zinc block that is about to run out.”

Sane's eyes began to light up. He had heard so much about the Crown Prince's reputation in the academic field that he had no doubts at all; he was filled with ecstasy. As a ship design expert, he naturally knew the significance of replacing all the ribs of the ship with iron.

He immediately added, "Your Highness, if we can use a large amount of steel, we can also replace the 'rib beams' with iron to further increase the defensive density. This would probably add another five or six tons of weight."

The rib beams are the crossbeams between the ribs of a ship, and they can also withstand cannonballs.

Before Joseph could say anything, Sane slapped his thigh hard again: "Also, the rivets needed for copper plating on the bottom of the ship can be replaced with iron ones, which can reduce the rivet density by about 30%, thereby greatly improving the construction speed."

Joseph didn't quite understand: "What do you mean by rivet density?"

Sane hurriedly explained, “Your Highness, you previously ordered that the bottom of all warships be clad in copper, but because iron rivets are very prone to rusting, it was necessary to use brass rivets to secure the copper plating.”

"But as you know, brass is very soft, so in order to ensure that the brass sheet does not fall off, the only option is to increase the density of the rivets."

"But now that you have your rust prevention method, you can use strong iron rivets."

Joseph greatly admired the chief designer's ability to utilize new technologies, but then another question immediately came to mind:
"Wait, you mean that brass rivets are being used to secure the copper hull plating?"

"Yes, Your Highness."

"So what is the material of the copper sheet?"

"It's also brass, Your Highness."

(End of this chapter)