My Shipyard

- I-690 Class Submarine -

# Ship Version

After the attack of Bright Waters Harbor realized by the Sun Empire, the high-rank officers of the Imperial Sun Navy started the research for the development of a peculiar class of vessels that supposedly should be strongest since it would be a mix of the two greatest major threats the Sun Empire considered: aviation and submarines. The I-690 (Fukakami Type) class of submarine aircraft carriers was, however, developed only after a series of studies on the jet engines that were used on the aircraft of the submarine, giving the class a great performance in battle, only three submarines of the class were built, they are I-690 Fukakami, I-691 Sango and I-692 Shinkai.

In comparison to the I-400, the I-690 was considerably larger which allowed a much greater aircraft capacity for the class. The I-690 Fukakami usually held seven Taifū model 6 jet planes which were slightly faster than the Taifū model 4 used aboard Kamikaze, having a pair of two extra light guns in the wings to help the lone nose gun, an enhanced engine that was as potent as the one of the Taifū but smaller allowing a larger fuel capacity for larger operations ranges. There was one more plane to totalize eight, a Taifū model 6 suicidal modification used for emergencies, in which the engine was more powerful to allow higher speeds, the guns were removed together with the fuel tank reduced for a single trip to give space for a 1300 Kg bomb in the nose. Meanwhile, the I-691 Sango and the I-692 Shinkai had aboard aircraft more suitable for bomber operations since the intention was for the three submarines to always work together. Both the Shinkai and the Sango had four planes each, that were Ihyō model 2 jet seaplane bombers equipped with two forward-fixed guns and a rear one while each was capable of reaching a top speed of 815 km/h without afterburn, 873 km/h with it and carrying either a 900 kg bomb, two 275 kg bombs, a 533 mm Kataka aerial modification torpedo or even four depth charges. The aircraft of the three submarines, however, were all launched by a steam catapult that allowed take off with high speeds. The bombers were all the four already in the catapult, it was just needed to open the hangar for them to launch. In the Fukakami, however, only four Taifūs were on the rail while the other four would need to wait to be launched.

The class didn't have only good aircraft aboard but was also quite peculiar in certain aspects. The sub was capable of reaching the same depths as the U2 class of submarines but could stay underwater for much longer thanks to the oxygen capacity and battery efficiency and potency. The hangar had a door to open behind and in the front and a railing could be seen inside the hangar and could be extended to connect with the railing positioned outside the submarine. Two single 10 cm guns and two triple mounts of Kaze 25 mm AA guns were inside the hangar on this railing as they could be taken outside to fight, locking in place on the railing, an attempt to decrease the drag underwater. The sub was also equipped with active and passive sonars and lastly two 690 mm torpedo tubes together with four 533 mm on the front and a single 533 mm on the rear.

The submarine, of course, had considerable disadvantages that could be quite easily be used against her. Firstly, despite the effort to lower drag, the equipment quality, weight and size aboard the I-690 slowed the submarine to 18 knots surfaced and 6.3 knots submerged, which could be worse were the guns kept outside the submarine. The greatest disadvantage was the lockers that keep the guns in place... They are quite troublesome to open and that could delay the process of submerging if were the guns locked outside to fight vessels nearby.

It was requested an appearance scheme to make the submarines unique if the weapons and aircraft aboard weren't unique enough for them. However, the use of statues on the submarine or structural changes was forbidden to not increase drag, so only paint was used. The submarines were covered in dark blue color that fades to black as it gets to the bottom. On the blackest area of the submarine was painted a few corals with more vibrant dark blue and green-ish details, but the greatest thing was the long black snake dragon painted on it, with details of shining red and wearing an armor along the body as well as a samurai helmet. He's the god of the depths, Fukakami, believed to be the provider of fortunes for the sailor. There's also a belief that this god is helping Rome Empire in the submarine development.