After coming to the shipyard, Zhao Yu called Yang Hanlin first and learned that Wang Kaiyuan had gone to other places and would not come back until two days.

Bai Zhizhan was not idle, and accompanied by the reception staff arranged by the shipyard, he went to visit the main warships that had entered the outfitting stage.

As for Zhao Yu, he is a busy man, but there are several warships for which he is directly responsible, and there are several in the design stage, which must be completed as soon as possible, so that the construction can start after the slipway of the shipyard is vacated, otherwise it will be delayed for several months, so it is impossible to act as a full-time guide for the war.

What interested Bai Zhizhan was not the second batch of large aircraft carriers of the "Provincial" class, but the supporting large cruisers.

The attitude towards large cruisers was always contradictory to the Reich Navy, or rather, several times.

Initially, many admirals, including the White Stop, felt the need to build large cruisers, that is, fast battleships were too expensive, and if they were built in a one-to-one ratio with the fleet carriers, it would inevitably crowd out a lot of funds, which would lead to a decrease in the number of aircraft carriers.

It would make sense to replace them with large cruisers, which cost much less.

At the time of design, to be precise, at the stage of project review, the Imperial Navy realized that the large cruiser was not as rosy as it seemed.

The point is, the cost is not low enough to replace a fast battleship.

The reason is also very simple, the power system of large cruisers has not shrunk, and the purchase price cannot be reduced at all, and the supporting main guns are redesigned, plus the number of purchases will not be much, and the supporting ammunition has to be purchased separately, and the actual cost is not low.

On a warship, the power system and the weapon system are the two parts with the highest proportion.

In the case of fast battleships, the power system accounts for about a quarter of the cost, and the weapon system accounts for a fifth, which is almost half of the total.

On the contrary, armor is not so expensive, after all, the empire's steel production capacity has always been in a state of surplus.

The power system has not shrunk, the key lies in the tactical indicators proposed by the Navy, that is, the need to have a speed that exceeds or at least the same as that of a heavy cruiser.

Large cruisers already have more power system requirements than fast battleships.

This is a very serious problem, if I have anything to say.

The speed indicators of the fast battleships designed and built by the Imperial Navy before the outbreak of the Great War were set according to the escort of aircraft carriers.

Take the "Xuhai" class as an example, the minimum requirement is 30 knots, and the highest is only 32 knots.

After entering the construction stage, the navy also made a compromise because of financial problems.

Only 4 hours of continuous sailing at the top speed is required, so the safety honor of the powertrain can be improved, and the maximum speed can be achieved by overloading.

In this way, the rated maximum output power of the power system can be reduced somewhat, thereby greatly reducing the cost.

It's no wonder, it was before the Great War.

Not to mention fast battleships, even more important fleet carriers must live within their means. If you can't get the funds, or if the funds are not enough, no matter how good the battleship is, you can only stay on the design drawings. What's more, there were 4 upgraded fast battleships before the "Asahimi" class.

Obviously, this approach simply did not work on large cruisers.

An air raid lasts a few hours at most, while a chase battle over the ocean often lasts for days.

At the beginning of the design of large cruisers, in fact, they were designed to suppress heavy cruisers and annihilate them in the open ocean, not to provide cover for aircraft carriers on a full-time basis.

Before the outbreak of the war, the navies of all major powers, including the Imperial Navy, had begun work on the design and construction of post-treaty heavy cruisers. The most representative ones are the "Ligen" class, which was built only 2 ships by the Narrow Navy, and the "Baltimore" class, which was built in large quantities by the Nuland Navy.

Although the Imperial Navy also had a project to design and build post-treaty heavy cruisers, the navy knew that it was not heavy cruisers that could suppress heavy cruisers, but large cruisers equipped with larger guns, faster speed, and thicker armor.

If anything, it is actually a battlecruiser of the new era.

The difference is that large cruisers are aimed at heavy cruisers, and do not require the ability to fight side by side with fast battleships, that is, they do not require the firepower to deal with fast battleships, and the tonnage originally used for firepower is used to enhance speed and endurance.

Obviously, among the main performance indicators of large cruisers, the most important is speed.

From the very beginning, the Imperial Navy required large cruisers to have a speed not lower than that of heavy cruisers in service, preferably more than 1 knot to 2 knots.

Obviously, this is not a low requirement at all.

Of the known heavy cruisers in service, the highest speed was 34 knots, and the lowest was 32 knots.

In order for a large cruiser with a displacement of 25,000 tons to reach a speed of more than 32 knots, the required propulsion power will not be lower than that of a fast battleship with a displacement of 35,000 tons and a speed of 30 knots. If it reaches 35 knots, then the propulsion power required is increased by about 40%.

Although after the trouble, the Imperial Navy lowered the requirements and set the maximum speed at 33 knots, but the calculation results given by the design unit were still very amazing, and the output power of the power system needed to reach 150,000 horsepower, which was 20,000 horsepower more than the "Xuhai" class, which was still in the design stage at that time.

This alone will increase the cost by 10%.

In the end, the Imperial Navy once again bowed to reality and decided to use the power system of the "Asahimi" class directly and accept the maximum speed of 32 knots under these conditions.

However, by the time the "Asahi" class was built, it benefited from technological advances, such as the advent of ultra-high-pressure boilers, and the output of its power system had been increased to 150,000 horsepower.

However, even so, the purchase price of the power system remains high, and the production of large marine boilers has not been substantially increased. After satisfying aircraft carriers and battleships, it is also necessary to consider fleet tankers and combat support ships, and finally large cruisers.

All in all, the power system became the number one factor affecting the cost of a large cruiser.

Of course, the same goes for weapon systems.

According to the original concept, the main gun was available in two calibers, 250 mm and 300 mm, and the design unit also gave different configurations. The cheapest option is four twin 240 mm guns, and the most expensive one is three triple 300 mm guns.

The choice of these two calibers is just a matter of habit, or it can be used for reference, so as to reduce the difficulty of development and manufacturing.

It's just that no matter which set of solutions, there is no way around a difficult problem.

After all the former dreadnoughts were decommissioned, the Imperial Navy did not use 240 mm and 300 mm shells, and even the supporting ammunition was destroyed.

Fortunately, this problem was perfectly solved in the later period, that is, the use of 280 mm naval guns imported and produced from the Horman Empire, and even the production line of artillery shells was purchased directly from the Horman.

Because the 280 mm shells were not capable of dealing with battleships, they were more than enough to deal with cruisers, and the Imperial Navy was willing to provide the production technology of armor-piercing shells in exchange for the advanced technology mastered by the Imperial Navy, so the Imperial Navy did not make any effort to design new armor-piercing shells.

It can be seen that before the outbreak of the Great War, only the Imperial Navy repeated the trade-off of large cruisers several times.

When a big war breaks out, it will be even more hesitant.