Diesel Battleship Yamato: German-Japanese Honeymoon

Phase 01 - Honeymoon with Germany

The battleship Yamato, which was decided to be built in real life under the design A140/F5, was originally planned to have diesel engines installed in half of her powerplant.

Diesel engines are said to be slightly heavier and take up more floor space compared to steam turbines, but they have significantly better fuel efficiency. In the Yamato's era, it seems that they had about 30% better fuel efficiency. In the case of the Yamato, this would mean that she wouldn't need to carry around 1.000 tons of fuel. Additionally, a substantial reduction in crew members, smaller smokestacks, and exhaust vents would also provide advantages in terms of defense. Moreover, by using diesel engines, the vital parts could be made smaller, and the overall length of the ship could be shortened. On paper, it appeared to be all advantages, something that technology enthusiasts would want to build.

However, during that time in Japan, there were significant technological hurdles to overcome, and, regrettably, the installation of diesel engines had to be abandoned. One of the reasons was the challenge of integrating two different types of engines on a single ship, along with disadvantages in terms of operation, maintenance, and repairs.

Nevertheless, in this world, I would like to see a world where the technical challenges are overcome, and a Yamato with diesel engines is built, creating a timeline where it exists.

As far as I know, I have never seen a fictional alternate history world where the Yamato was built according to the final plan. For that reason alone, I wanted to explore it someday. However, just that wouldn't be enough, so I'd like to tamper with history as well, as usual.

So, I want to rewrite history based on the premise that the relationship between Germany, which had the highest diesel engine manufacturing technology in the world at the time, and Japan was deep. By doing this, I hope to slightly accelerate Japan's development and create a slightly better version of the war than in reality.

However, if we make Japan's relationship with Germany closer than in reality during World War II, Japan might have to be involved in the war from the beginning. It would also change its relationships with other countries. I would like to explore these aspects as well.

Simply creating a Yamato with diesel engines would only involve introducing the ship and would be a rather shallow exploration of the parallel world. Instead, it might become the central theme to follow the history of a world where "Germany and Japan had a long-lasting close relationship."

I probably want to see the situation where Japan gets deeply involved in the war starting from the outbreak of World War II.

Nonetheless, Isoroku Yamamoto will have quite a tough role to play. After all, he assumed the position of Commander-in-Chief of the Combined Fleet just before the outbreak of World War II (September 1, 1939). Probably, Yamamoto won't have time to consider the attack on Pearl Harbor, among other things! (lol)

Before I begin, I want to mention that, like commercially available alternate history novels, there may be differences between the title and the content of this exploration. Essentially, I will be examining the scenario where Japan entered the war in September 1939, delving into the "time crime" within the context of Japan and Germany's close relationship. The Diesel Battleship Yamato is merely one of the most impactful weapons that could have emerged in that parallel world.

Perhaps it won't playa significant role at all, but I hope you'll understand and forgive that possibility.

- Katsumi Fusō