Sub Corner 34: Why Doctrine Application Matters (the Type-A Submarine)


I’m back!

Also, it’s like, totally not my birthday or anything. I mean, my historical counterpart was laid down a week ago, but today’s the day where line-art of me could be found for the first time!

*Reads notes* Yeah, I know I’m apparently due for a “major” world/setting update, but it’s my birthday, so, eh, setting updates can wait. Let’s talk submarines.

Today I think we should consider a weapon system that’s pretty much used only by the Japanese: the “midget” submarine. It’s not to say that the rest of the world didn’t think of it, but the Japanese were the only ones that put it into practice.

How well did it work? Welllllllllll… Funny you’d ask. Honestly, from start to finish, I’d like to put forth the proposition that Japan’s approach to submarines have always been a bit biased in perspective. To understand this, we need to first understand what role submarines were meant to play in Japan’s “decisive battle” doctrine.

“Well, Tau-tau, that’s easy,” you say. “Japanese submarines are meant to be auxiliaries designed to wear down the opponent until such time where a decisive battle can be engaged.”

You’d be right, mostly. If we’re to look at the second edition of the Principles for the Defense of Imperial Japan, you’ll find that this document in 1928 already called for exactly just that. Only, well, in this case it specifically called for a multitude of “small” submarine units, preferably launched from surface motherships.

… Yeah. Small. Like I said, while the Japanese did indeed create other (what we’d soon be calling cruiser submarines) types of submarines, this idea, uh,  of small group (and obviously to the uncultured western barbarians like us, elite) submarines will launch in a gracefully coordinated swarm to destroy the much bigger, likely well-armed and armored, American warship.

Is this sounding familiar? Does this sound uncomfortably similar to the whole “mind over matter” or “spirit over bullets” stuff that formed an integral part of the Japanese “warrior” ethos?

Because that’s exactly what this is. The origins for this in particular originates (Ha!) from a naval officer who was a torpedo boat captain in the Russo-Japanese War, going all the way back to 1931. In this proposal, Captain Yokou proposes to create a “hand-picked” “elite” force of “man-torpedo riders,” where each man would bravely sortie towards the enemy riding a torpedo launched from a “mother torpedo” which would be then launched by a submarine.

If you’re wondering how’s the guy riding the torpedo supposed to come back, well, that part was less important. What was important, however, is that this sorta thing really tickled the fancy of the guy in charge of torpedo development (aka, the head of the torpedo section, a Captain Kishimoto). Basically, doing some back of the envelope math, they successfully convinced the IJN that if allowed to develop properly, Japanese submarines can launch dozens of these submarines firing hundreds of torpedoes (manned or unmanned), which can devastate the enemy before the fleets even clash.

(I should point out here, in the spirit of fairness, that the specific midget submarine that we’re currently talking about is not intended to be a suicide craft. The latter Kaitens are. However, as an American, when I am going over these materials, I noticed a consistent theme of near-suicidal bravery, where bravery and spirit is emphasized pretty much above everything else. Just thought I’d raise my voice.

Does it really matter if Yamamoto told them to come back alive if none of the men – quoting the survivor from the Pearl Harbor attack – expected to do so? You’d find it hard to find the same sentiment in say, Sherman or Cromwell crews.)

Anyways, so, this program starts up in 1932, and trudges along for several years. Progress was made pretty well, and for the industry base that Japan’s got, we’d even say that progress was very good. The issue, in my opinion, is a complete breakdown of – you guessed it, practical application as a result of doctrinal dissonance.

Let’s think about what a small sized submarine like this is supposed to do. Doctrine calls for these things as offensive weapons, so ideally you’d want a midget submarine that carried good armaments and went pretty fast so you can intercept the incoming enemy ships. This, by the way, is pretty much what the Type-A midget submarine was built to do. However, if you go fast you sacrifice things like maneuverability and stealth.

… So if you were going to be attacking a stationary target (e.g. moored ships in a harbor), what good is that high-speed profile going to do for you? Not much, right?

If you and I can spend five minutes thinking and realizing that it didn’t make sense, so did the Japanese 70 years earlier. The IJN did their own internal assessment and found out that the Type-A was basically a scene out of the Pentagon Wars. Demanding superior capabilities is directly contradictory to the demand that these things be made lightweight. These boats were horrendously not suited for seaworthiness. Any attempts to stabilize or to improve stability resulted in staggeringly large increases in physical size, which runs contrary to the demand that these things be stealthy. These submarines can’t really dive very well, and attacking on the open ocean was “very, very difficult.” Also, do you know what happens when you get a high speed submarine? It makes a LOT of noise, and can’t go very far. Again, if you want a stealthy “ninja” type of ambush attacker, you would want attributes precisley in the opposite side.

To top things off, these things are about as well armored as my bathtub and their machinery broke down if you looked at it funny. Early war, the vast majority of crew time was spent on maintaining the submarine, with some implicitly understanding that they’ll probably only get one shot at most with these things. There are no redundancies. Everything was more or less manual. In short, being inside one was a horrible experience.

Oh, but you know what they did have in every design? A 300-pound self-destruct device, because the IJN were deathly afraid of the Americans getting their hands on one of these secret weapons.

(By the late 1930s there was growing demand from the less optimistic (or realistic) echelons of IJN high command for considerations of coastal and homeland defense,exemplified by Adm. Shigeyoshi Inoue’s essay detailing the necessity of land (and naval) based aircraft and submarines as an integral part of Japan’s defense.

Naturally, the idea of a midget submarine was enticing. Here again I’d like to point out that the idea was very innovative. It could have worked out pretty well, but it didn’t.)

Don’t get me wrong. The guys that had to man these things – especially at the start of the war – were the absolute best of the IJN. But, in my opinion, the war machine they went off to fight the “evil Americans” were just weren’t very good. To top it off, Japan had no time to adapt, no docks to build more, and no resources to adapt, so in effect these men were sent off on their first combat mission with the entire deck stacked against them.

Since the existence of the midget subs were kept a secret even to the other members of the Navy (to say nothing of the army; sidenote, that’s why they’re called Type-A. If you asked your average IJN sailor what these things are in 1940 they’d tell you they’re supposed to be towed targets for Japanese subs to shoot at), I can understand why they were sent off as they did. This program has been running for nearly nine years with pretty much nothing to show for it other than prototypes. Consider the timeframe and development of the Type 93 Torpedo (less than four years to mass production) or the A6M Zero (less than three years) and the results they were delivering, I think it’s reasonable to see why they wanted to make the midget submarine’s entrance as grand and as flashy as possible.

Not to mention, Japan’s got this weird obsession with keeping secret super prototype weapons to be used for some kinda decapitation one shot master kill strike or whatever it is that they call it. Postwar documents show that some aspects of naval planners genuinely believed that this Pearl Harbor thing was going to clean up the American navy, and so they were going to go all out.

Yeah, so, to nobody’s surprise, the launch wasn’t smooth. Some of the submarines had issues with their machinery, torpedos had to be refitted, parts were missing, oil and water leaks abound. Despite all these issues, they went ahead with it anyways. I personally take very little stock in the post-war accounts of “Admiral so and so agonized horribly” because in the end, the decision (a poor one at that!) was made. 

How many of these did they end up launching?


The results I’m going to call disastrous. First of all we weren’t caught napping. We had some suspicions that there may be attempts to sabotage our ships, so US naval assets were definitely up and about. Remember what I was telling you about how these things were basically not particularly seaworthy?

Yeah. One of our minelayers saw the periscope of the super-ultra-hyper stealthy submarine, and alerted the nearby USS Ward, a WW1 era ancient DD on ASW patrol. When USS Ward wandered over, her captain noticed again, a periscope that was tailing one of our ships. Hmm…

With some help from our aerial patrols courtesy of the PBY, in what would be the first shots fired in the war, an American WW1 destroyer built in 1918 with a bunch of green recruits straight out of basic (as in, this was their first time on an actual boat) sank Japan’s supposed ultra-secret weapon filled with the best men the IJN could muster.

One was damaged and abandoned before any torpedos can be fired. One was definitely sunk, though due to what people are still arguing. One attacked a US auxiliary ship, then decided to surface and attack a US DD (with predictable results), the last one had the honor of giving the US the first Japanese PoW after his sub ran aground TWICE and the scuttling charges failed to sink the sub for some reason.

The amount of damage done to the Americans? Negligible.

What went wrong? Pretty much everything. There are entire books written on the subject. The first and foremost is applying a ship designed to engage enemy vessels on the open water with limited endurance and having it fight in pretty much the worst condition possible. The stress of individual martial superiority and quality over quantity meant that the IJN submariners sortied sort of in a disorganized fashion, with no thought as to coordination (the fact that each one thought he was gonna sink a battleship – PoW no. 1 specifically wanted to get the USS Pennsylvania told us that much) or how best to utilize their weapon on hand.

Curiously, these issues were NOT addressed. If you search the combat records of these things, you’ll find that pretty much they were (for some reason) used mostly in harbor attacks, which they were eminently unsuited for. To add insult to injury, IJN high command were obviously aware of the issue, but did very little to resolve them.

Again, this is not to say that the idea was bad, or that the men were bad. Miniature or small submarines would be excellently suited for defending Japan’s coastal islands, and could have been both cost-effective and capable –

– if they were built to do just that. As it stands, the IJN instead built these things as a part of that decisive battle fantasy. “Misuse” would be putting it lightly.

I’ll get around to comparing submarine doctrine during the war at some point, and what you’ll soon come to realize: this is a very consistent theme with how the IJN used their submarines. They had capable men, and decent boats. They just … didn’t really use them well.

Now, in our own setting, I think it’s safe to say that you can see what we’re doing right. Again, we largely have Mike to thank, and part of the reason for why he ends up being promoted to the overall commander (as well as technically being Pacific’s “protagonist” – the TTK stand-in, if you will) is for his attentive consideration for how subgirls are meant to be used.

The Abyssal, for what it’s worth, appears to be predominantly a surface-based force. However, it’s worth mentioning that every single Abyssal encountered have some ability to enter the water (duh, I mean, it’s not like the Abyssals magically drown below the waves), which provides subgirls a unique challenge, since we’re underwater combat specialists.

How best to leverage our strengths? Ironically, in large-scale engagements (which is what STEC plans meticulously for – the upcoming “invasion”), our role is a bit similar to the Japanese application of attrition, but is probably more aptly described as “opportunistic predation” (which is more along the lines of the historical US or German doctrine, come to think of it).

Namely, subgirls are authorized to engage at will, on any target, so long as it kills. There’s very little “lone-wolfing” here, and each subgirl is working with others in her squadron to amplify her killing potential. Following STEC’s own doctrine of engaging at maximum distances, subgirls are more or less expected to harass as much as possible, and withdrawing rapidly to stronger STEC force concentrations should the Abyssals decide to engage.

Remember, unlike our real-life analogues, shipgirls can swim. For stealthy operations, we can use “stealth”-optimal equipment, or simply turn our machinery off. Now, naturally, an Abyssal can sort of “sense” shipgirls intuitively in the same way as we can “sense” them, but that’s why we’re (or wil be) putting decoys into action, and before those come into play, in these “major” engagements subgirls are deployed in coordination and support of other shipgirls.

Again, you can see that the English and Japanese shipgirl services both do this a lot differently. I chalk it up to the class-ist and hierarchical nature of their respective cultures, where operations tend to be built around “key” assets – e.g. formations and concentrations of shipgirls designed to overwhelm the Abyssal formation. The English I suspect do this because they have a lot more area to cover and a lot more bureaucracy, and the Japanese I think largely have very lopsided support for shipgirls almost entirely based on personal performance. So, it makes sense then that non-STEC affiliated English and Japanese subgirls tend to tag along as scouts and peripheral firepower, with less clearly defined roles.

So, I think the best way I can describe this difference is that in these large-scale engagements (decisive, if you want to call it), The English and Japanese shipgirl services are more likely to send out specialized shipgirl divisions alongside their “spearheads,” whereas STEC is less likely to move without a “combined arms” sort of approach.

This isn’t to say that for instance, the subgirls can’t sortie on their own and do just as well. We do that quite a bit on our own in other sorts of engagements. I am, however, simply talking about the “big” thing in which STEC arguably prepares for – the sort of catastrophic, potentially world-ending engagements where the Abyssals expend considerable effort to try to take us out in a single blow.

Make sense? Good. I’m off to loot fruit off of my own cake before the others do. See ya next time!