Sentoku Type Submarine

Users:
Imperial Japanese Navy

Built: 1943-1945
In Commission: 1944-1945

Until the Ethan Allen Class ballistic missile Submarine was built, the Sentoku type submarines was the largest class ever contstructed. Not only having a world traveling reach with its range, but the ability to launch dive bombers as well. It would be the only submarine ever built to launch combat aircraft. It is considered the strategic predecessor to ballistic missile submarines, and though their wartime contribution was limited their design was no less remarkable.

The I-400 was originally built for the purpose of attacking American shorelines. Three Aichi M6A Seiran dive bombers would be carried within a tubular hanger on the deck. In the early war the submarine had a devastating potential, with the ability to deploy aircraft against unsuspecting targets.

Those plans alongside a planned attack on the panama canal would ultimately not come to fruition. Though the early war went well for Japan, it quickly started to shift against them. Despite being forced on the defensive they still held out hope that a strike from the three I-400 class submarines built could turn the war around for them.

Their most ambitious and deadly plan being the use of the submarines and their planes to drop biological weapon on the west coast of the United States in an operation codenamed 'Operation Cherry Blossoms at Night'. It would fortunately not come to fruition before Japan Surrendered.

The I-400's were soon captured and studied by the United States. Soon after they would be destroyed to keep them and their technology out of Soviet hands.

Though the design was advanced, it had several problems which marred its performance. A small rudder made it difficult to maneuver on the surface. It also had a very slow dive time, which could make it vulnerable in a bad spot. It's safe depth was also only around 80% of its length, which could be dangerous if the sub needed to dive quickly at a steep pitch. The offset conning tower also had effects on underwater performance, requiring an angle of rudder to keep the sub running straight while also making the sub turn slower in one direction than the other.

The submarine would ultimately see little action before the war's end, but even if they weren't likely to win the war the I-400 would likely have proved a uniquely effective naval asset if given the chance.

Source(s)

Wikipedia
Operation Stormbook
War History Online

Features:

• Fully functioning bow planes and rudder
• Simulated Ballast Control
• Deployable Dive Bomber (bomb included)
• Full set of Deck guns
• Near 1:1 scale

Instructions:
Submarine Operation
1)Pitch for bow planes (used for pitch and depth control)
2)Roll for Rudder (used for steering)
3)VTOL for ballast control (used for depth control)
4)VTOL up+AG8 for surface running (locks ballast up and frees VTOL for guns)

Gun Operation
1)AG3 for 14cm 11th Year Type naval gun
2)AG4 for Type 96 25mm autocannons
3)VTOL and Trim for aiming

Aircraft Launch and Operation
1)AG1 to open hatch.
2)AG2 to deploy aircraft, wait a moment for launch. Don't deploy below surface.
3)Normal aircraft controls for flight
4)Switch to Air to Ground mode and press FireWeapon to drop bomb.
5)Be careful and use airbrakes (B) when landing. Water only.

At request of Nerfenthusiast and Jerba, here is the I-400! Sorry I didn't use your mechanism Nerf, you should keep it in mind though as it could be useful for you in the future, and thanks for the idea anyway! The Hull here is SOOOO much better than the U boat. Never again will I try to use rotated fuselages, the results are just better and easier to do better when they're not angled.

Overall the Submarine part of went smooth and easy! Though Adding an aircraft has not and I've ultimately given up on adding more than one. It works though! Though I will say I've learned never to set any parts to zero weight and drag on a deployed plane, it leads to some nasty glitches. I considered adding deck railing, but the part count was getting high so I skipped on that. Hope you all like it!