Although the Rhein City's subway was completed a long time ago, it still requires some time before normal operations can begin because the current Rhein City is quite sparse, and there is essentially no need for a subway to alleviate traffic.

This results in the Rhein City's subway being completed earlier than Hungary's subway, but the official usage is much later. In fact, the subway in Rhein City was completed as early as 1896, and as for Ernst's mentioned completion time of the subway beneath the Rhein Palace, it's actually referring to the second line of Rhein City's subway.

After all, it involves the royal palace, so the design of the second line is more complex and the standards are higher. Additionally, the second line's section between the government and Rhein Palace has supporting shelters, temporary command centers, and other facilities, resulting in a larger project.

This also means that the only two subway lines in Rhein City currently are in a suspended state. The first line is a fully civilian line, traversing through the city center and the Southwest industrial and residential areas, while the second line is divided into two parts: one section for civilian use, and another for use by the East African Government and the royal family. Even the royal family's private line differs slightly from the East African Government line.

The two subway lines in Rhein City represent the current subway construction status in East Africa, such that even the economically most developed city, Dar es Salaam City, has not commenced construction.

After all, Dar es Salaam City has only about 700,000 people, whereas London had over 2 million when it built its subway in 1863, and now it has surpassed 4 million. Thus, Ernst believes the standard for subway construction should start at a city population of 2 million, but no city in East Africa reaches this standard.

Regarding the Hungary subway, it was a political project for Hungary to celebrate its 1,000-year anniversary of statehood, and Budapest's population had reached 2 million by 1896, meeting both economic and population demands for subway construction.

The reason why Budapest had such a large population is mainly due to its foundation, originally consisting of two cities: Buda and Pest, which merged into Budapest in 1873 and became the capital of Hungary, with its population already in the millions at the time.

With the industrial development of Austria-Hungary in recent years, Hungary being a plain area, facilitated the concentration of industry and population in Budapest.

In comparison, the Rhein City subway is purely a political creation. Given the current population scale of Rhein City, opening the subway for operation would be a total waste of resources.

Of course, Ernst believes that the construction of the Rhein subway is entirely sensible, as East Africa's aircraft have already taken off, and in future scenarios when cities face bombing during wartime, the subway will serve as a natural shelter. As the political center of East Africa, Rhein City must prepare early.

Obviously, foreign forces contemplating air raids on Rhein City face a challenging endeavor, given Rhein City's inland central location in East Africa, which requires considerable flight time from the coast.

...

At night, after Ernst and Constantine returned to the Rhein Palace, Ernst and his family began to familiarize themselves with the structure of Rhein Palace.

Naturally, Ernst was also a newcomer, so Thomas the steward introduced it to them.

"Here is the entrance to the Rhein Palace subway, constructed in the center room of the palace. Once you rotate the mechanism behind the bookshelf, a passage appears. Follow the stairs down, lift the gate here, and the power supply will begin to illuminate the lights."

Once Thomas closed the gate, the lights in the passage instantly lit up, and everyone followed the stairs downward.

"Actually, there are other passages in the Rhein Palace, even equipped with elevators, but elevators are inherently less reliable. Hence, it's best to choose traditional stairs during an escape," Thomas said earnestly.

Ernst didn't completely agree on this point, as stairways are undoubtedly more reliable than elevators, though not to the extent Thomas described, as though accidents easily occur.

After all, the elevator maintenance at Rhein Palace is very well done, with regular inspections, making failure virtually impossible, though it's prudent not to be too absolute.

An elevator was installed at the Sweet Palace in First Town, and more so at Rhein Palace, thereby requiring more maintenance work at Rhein Palace compared to Sweet Palace.

After walking for a while, they reached a flat area, though there were still stairs ahead.

"The Rhein Palace subway is located over 170 meters underground, so the stairs extend down in phases," said Thomas.

Finally reaching the bottom, an iron door appeared before everyone.

"This metal door serves as the first barrier separating the Rhein Palace subway from the palace, with a total of two such doors. The construction of this metal door alone took a lot of effort, requiring machinery for opening and closing."

While speaking, Thomas demonstrated by using a lever to operate the complex mechanical structure for opening and closing.

Thomas merely performed a simple demonstration to move the door a few centimeters, as they still needed to descend further, without closing the door prematurely.

After a while, they finally arrived at the location of the Rhein Palace subway, where a palatial subway station constructed beneath the palace lay in extravagant splendor.

According to Ernst, this subway station resembled those built during the Soviet era in Moscow from his previous life, thus he readily accepted the sights before him.

However, Constantine, Karina, and the princes and princesses of the Heixinggen Royal Family had different reactions, greatly awed by what seemed like constructing an underground palace below the Rhein Palace.

"This subway station and a few others won't appear on the Rhein City subway map. The Rhein subway has many secret lines, shelters, and areas generally closed to the public, such as the Rhein Palace subway station, which is typically unused unless the royal family encounters a major threat. These subway stations are always in readiness for any potential emergencies."

Such scenarios are unlikely to occur even within the next hundred years, given Ernst's arrangements, ensuring no foreign enemies can enter the Rhein Palace area, excluding nuclear wars. However, Ernst is confident East Africa will be the world's first nuclear-armed state in this timeline, assuring Rhein City's safety to the utmost unless a true madman desires mutual destruction with East Africa.

"Speaking of, I've never ridden a subway at my age. Can I give it a try?" Constantine interjected.

"Dad, we want to too!" Several youngsters echoed their grandfather's sentiment, showing keen interest in the subway.

After all, aside from East Africa, only the United Kingdom, Hungary, and the United States have subway constructions worldwide as of now.

The United States' first subway, completed after Hungary and East Africa, is the Boston subway built and opened in 1897.

Naturally, Ernst enthusiastically agreed to his father and children's requests, as he also wished to witness and experience the 19th-century subway.

Subsequently, following Ernst's orders, the staff activated the Rhein subway, traveling from the Rhein Palace station all the way to the Central Government building platform, a mere ten or so kilometers journey.

As for the experience, it can't be described as particularly great, as it didn't differ much from trains and resembled a tram more due to its electric power, driven by electricity supplied through tracks, unlike trams which rely on overhead antennas connecting to the power grid, the speed wasn't fast, plus the staff wasn't keen on driving at high speed.