Comparisons of different nations' sub fleets

[Incubus]

Obviously the major differences between nations is that each had a different overall mission, which likely reflected their boats' design. However, it is interesting to compare them. As far as I am aware,

KM: Playing SH3, its exciting to be in a situation where the odds rapidly stack against you. KM's fleet seems doomed on the 'too little, too late'; not having enough boats when there was advantages, and not being able to win the tech race when aircraft were scouring the skies and DDs scouring the depths. In spite of this, U-boats seemed to have the best underwater performance of any nation, and their skippers definitely pushed the boats to their limits. Late war models (like the Electroboat) were awesome precursors to modern submarines- the use of a snorkel allowed for great underwater performance with minimal exposure.

USA: Obviously operating in the Pacific, their boats needed to be longer ranged. US and IJN's boats are huge compared to Germany's. The other thing I noticed is the number of tubes- compare a Type IX, with 4 bow and 2 stern tubes with many US classes boasting 6 bow and 4 stern tubes, not to mention 2 deck guns in some cases. Ive heard that as the war progressed, the surface armament of the boats actually increased. One thing I'm wondering, though, is if the IJN's lackluster ASW allowed US to get away with stuff Germany couldn't (big honkin boats that must have much slower dive times/maneuverability underwater). Their size and profile don't strike me as terribly stealthy (haven't heard of any antisonar/radar coatings in SH4 like the Germans get) and it makes me wonder what a spanking the US sub fleet would get against a more ASW-oriented nations like England.

IJN: Their fleet did surprisingly lackluster in merchant tonnage, why is that? Certainly their subs needed the same overall requirements US boats did (range, stamina) they were big, had lots of torpedoes, including an adapted version of the Type 93. Some of their boats also carried scout planes, which seemed pretty unique and sounds like it would have potential. However, with a number of exceptions (Yorktown, Indianapolis, etc) they seemed to have a marginal role in the IJN fleet. I find this hard to comprehend considering that in comparison, the US fleet sent a huge amount of steel to the bottom, and regardless of nation and skipper, all subs share inherent strengths/weaknesses.

Royal Navy: I know they had some subs and midgets, but I never really hear much about them. Granted, geography meant they didn't have much quarry (maybe in the Mediterranean?) but they were involved in the Pacific, too. How did their subs fare?

[tater]

The deck guns didn't matter much, they didn't really sink stuff bigger than trawlers with them.

As for the IJN subs, it was not their doctrine to attack supply. The raison d'etre for IJN cruising subs was to whittle down the US Fleet to improve the odds for the Combined Fleet in the "Decisive Battle" they sought.

Regarding Allied ASW, you must not forget INTELLIGENCE in the calculus. We did so very well vs axis submarines in large part because we knew where they were. It's not just the ASW technology, but putting the technology in the right place, and having an ASW doctrine that continues to prosecute the attack until they have some idea of the outcome.

If the japanese could have steered their shipping away from our subs, and put what ASW units they had on top of our submarines, the Fleet boats would ahve had a MUCH rougher time for less of a tonnage bag.

tater

[Packerton]

U boats suffered from the breaking of the Enigma code which allowed Merchant shipping to be redirected.

[bookworm_020]

The Japanese Subs didn't go after merchant in general as they considered warships to be the major goal, but when they did go after merchants they did extremly well. They did a good job on the Australian East coast after the miget sub attack on Sydney.

They did sink a Hospital ship of Queensland. That wasn't so good

[seafarer]

Things could have been very different for the German navy had Hitler not gone to war sooner then he had led his naval commanders to believe. In 1939, Donitz had been told by Hitler that he would not begin anything for 6 years, and that would be enough time to grow a U-Boat fleet of 300+ (mainly type VII's), and replace all of the aged type II's. Donitz planned on being able to keep 100 boats at sea at all times. As it was, Donitz went to war with only 57 boats (and only about 38 or so of those ready for war time service, including many type II's which were never designed for blue water operations).

The Royal Navy operated a lot in Norwegian waters and the med (look up the famous 10th flotilla's actions there). In the pacific a major area of operations was the Malacca Straits (between Kuala Lampur and Sumatra). More so then any other submarine force, they did a lot of covert operations (landing agents and commando's, supplying resistance forces, and keeping Malta fighting and alive), and a lot of mine laying. They lost 74 submarines during the war, about half of them to inshore mines which reflects their main deployments to near shore waters. According to the Royal Navy Submarine museum web site, they sank "2 million tons of enemy shipping and fifty seven major war vessels, including thirty five enemy submarines, by gun and torpedo".

P.S. an excerpt from wikipedia's entry for HMS Torbay, who's commander, Lieutenant Commander Miers won the VC:

"Lieutenant Commander Anthony Cecil Chapel Miers DSO Royal Navy Whilst on patrol in HM Submarine Torbay off the Greek coast on the 4th March 1942.

Lieutenant Commander Miers sighted a northbound convoy of four troopships entering the South Corfu Channel and since they had been too far distant for him to attack initially, he decided to follow in the hope of catching them in Corfu Harbour. During the night 4/5 March, Torbay approached undetected up the channel and remained on the surface charging her battery. Unfortunately the convoy passed straight through the channel but on the morning of the 5th March, in glassy sea conditions, Miers successfully attacked two store ships present in the roadstead and then brought Torbay safely back to the open sea. The submarine endured 40 depth charges and had been in closely patrolled enemy waters for seventeen hours.[1]

Having sunk in the region of 50 ships, Torbay was reassigned to the Pacific Far East in early 1945"

[greyrider]

Originally Posted by seafarer

Things could have been very different for the German navy had Hitler not gone to war sooner then he had led his naval commanders to believe. In 1939, Donitz had been told by Hitler that he would not begin anything for 6 years, and that would be enough time to grow a U-Boat fleet of 300+ (mainly type VII's), and replace all of the aged type II's. Donitz planned on being able to keep 100 boats at sea at all times. As it was, Donitz went to war with only 57 boats (and only about 38 or so of those ready for war time service, including many type II's which were never designed for blue water operations).

The Royal Navy operated a lot in Norwegian waters and the med (look up the famous 10th flotilla's actions there). In the pacific a major area of operations was the Malacca Straits (between Kuala Lampur and Sumatra). More so then any other submarine force, they did a lot of covert operations (landing agents and commando's, supplying resistance forces, and keeping Malta fighting and alive), and a lot of mine laying. They lost 74 submarines during the war, about half of them to inshore mines which reflects their main deployments to near shore waters. According to the Royal Navy Submarine museum web site, they sank "2 million tons of enemy shipping and fifty seven major war vessels, including thirty five enemy submarines, by gun and torpedo".

P.S. an excerpt from wikipedia's entry for HMS Torbay, who's commander, Lieutenant Commander Miers won the VC:

interesting story,

well, the germans had a two year head start on war,as well as the british, over the united states, how much more of an advandage can you give them,
they were veterans, the united states was green, remember casserine and new guinea?
this below is one battle of s-38, at lingayen, early in the war.
she had other battles, including bombarding enemy installations on enemy held islands,
and the picking up and rescueing of 54 british sailors, from HMS electra.

That night, she headed for Lingayen Gulf. On the morning of 22 December, she entered the gulf; and,
at 0645, she sighted an enemy convoy escorted by two destroyers. At 0710, she fired four torpedoes—all misses.
As she reloaded, the enemy destroyers closed in. Three depth charges exploded close to her. At 0758, she fired two
torpedoes at an anchored enemy cargoman. Less than a minute later, the 5445-ton Hayo Maru blew up. The enemy destroyers
again closed the submarine. Depth charges went off close aboard. From 0804 to 0930, the S-boat ran silent, using evasive
tactics. At 0930, she grounded at 80 feet, then coasted up the bank to 57 feet. The destroyers, joined by small boats,
continued the search through the day. At 2130, the hunted submarine began efforts to clear by backing. During the maneuvering,
her port propeller was damaged; but, by 2201, she was free and underway for the Hundred Islands area on the western side of the gulf.
S-38 remained there through 23 December and on 24 December, moved to the southern section of the gulf where she closed a formation of
six large auxiliaries just prior to 1130. Her presence however, was discovered. At 1152, a depth charge exploded on her port side. She
went deeper. Between 1206 and 1208, eight more exploded around her. At 1209, she stopped all motors and sank to the bottom in 180 feet
of water. The depth charging continued, but the explosions were more distant. At 1230, the submarine began to move again. At 1245, the enemy
hunters again located her and resumed depth charging. S-38 again settled to the bottom. The depth charging continued until after 1300. The search
continued until after 1800.
At 1842, the submarine got underway, heading back to the Hundred Islands area. At 2235, she surfaced to recharge her batteries. Five minutes
later, her after battery exploded. At 2304, she went ahead on her starboard engine, making her way out of Lingayen Gulf.
Soon after 0200 on 25 December, she sighted two enemy destroyers, but remained undetected. At 0346, however, she sighted a third, which sighted
her. S-38 submerged. The destroyer closed the submarine's last surface position and, at 0350, commenced depth charging. From then until after 0900,
the submarine evaded the destroyer, using her one quiet propeller. She then grounded on a steep bank at 85 feet. For the next two hours, the
destroyer circled. S-38 slid down to 200 feet, used her motor to bring herself up, then repeated the maneuver. The destroyer moved off and, at 1235,
the S-boat got underway for Manila. An hour later, she grounded, but only briefly; and, at 2145 on 26 December she entered the outer minefield at the
entrance to Manila Bay.

[Packerton]

Wow and I thought British Sub hunters were persistant.

[Ducimus]

Originally Posted by Incubus

USA: Obviously operating in the Pacific, their boats needed to be longer ranged. US and IJN's boats are huge compared to Germany's. The other thing I noticed is the number of tubes- compare a Type IX, with 4 bow and 2 stern tubes with many US classes boasting 6 bow and 4 stern tubes, not to mention 2 deck guns in some cases. Ive heard that as the war progressed, the surface armament of the boats actually increased. One thing I'm wondering, though, is if the IJN's lackluster ASW allowed US to get away with stuff Germany couldn't (big honkin boats that must have much slower dive times/maneuverability underwater). Their size and profile don't strike me as terribly stealthy (haven't heard of any antisonar/radar coatings in SH4 like the Germans get) and it makes me wonder what a spanking the US sub fleet would get against a more ASW-oriented nations like England.

If you compare dimensions, you'll find a typical US fleet boat, isn't that much different then a type9D2. From accounts ive read, for a US fleet boat, a dive time of 40 seconds was what was minimally accepted for a combat boat, with a 35 second dive time the true goal.

As for maximum depth, im unsure. Nobody really knows much about the 9D2's and information on how deep type 9s were pushed is also sketchy. But its a safe bet that they were probably, on the average, deeper then a gato because of all the external hull openings in the way of torpedo tubes. (although for a balao, im sure it could dive deeper then a type 9) Of course on the other hand, what better way to store torpedos, then in a tube? A us fleet boat, carried, as many torpedos (if not just 1 more fish), then a type 9, without the need for external stores.

The biggest advantage US fleet boats enjoyed (aside from ULTRA), was in their electronics. Depth charge plotters, thermal layer bathospheres, and radar were far more advanced then the germans, at a much earlier point in the war.

[jdkbph]

Originally Posted by Incubus

<snipity> it makes me wonder what a spanking the US sub fleet would get against a more ASW-oriented nations like England.

Hmmm. No bias here....


But to address your points...

I think you more or less covered it yourself, right up front...

Originally Posted by Incubus

<snipity snip snip> Obviously the major differences between nations is that each had a different overall mission, which likely reflected their boats' design.

Dingdingdingdingdingding!

But then you went on to ignore the point for the most part.

It is indeed all about horses for courses. The designs of the boats were firmly rooted in the doctrine espoused by that particular navy... typically developed during the period between the wars.

The Germans, despite an early prediliction toward and investment in the philosophies of A T Mahan, embraced Guerre de Course as a viable strategy, and built a Navy (including a submarine force) geared toward that type of activity. Entirely understandable given their 'tween wars circumstance and the constraints they were forced to operate under.


The USN viewed the submarine as a direct extension of the fleet... hence "fleet boat". The 21 knot top speed and 10000 nm range was not a coincidence. They had to be big... capable of extended operations (think "war plan orange") in a tropical environment. Meeting these requirements obviously had a profound effect on the basic design of the boat.

The IJN view was similar to the USN, but while the USN adapted to the SLOC denial (strategic supply line interdiction) role, the IJN more or less maintained the fleet boat concept through-out (with some nuisance type stuff thrown in here and there).

The Brits I'm not altogether familiar with... but from what I do know of them, they seem to have employed their boats mainly in a tactical or ops support role.

These differences required different points of emphasis in boat design. The only notable thing that stands out in my mind is that fact that the USN alone was able to successfully adapt to a completely different role than the one it was designed for - on the fly (as it were) - using the same hardware.

As to comparisons between the boats?... I hope the above makes it clear that intellectual exercises like role swapping (plugging USN boats into the German situation, or vice versa), much less head to head comparisons (For the honor of the services! Type VII vs Gato - torpedoes and deck guns at dawn) are pretty much a waste of time.

The only real method of comparison, IMHO, is to make an evaluation of how well the boats performed in their intended and actual roles, while dealing with the conditions they found themselves operating in and the forces they found themselves operating against. Realistically though, this may be as much a measure of pre-war naval planning and leadership as it is a measure of technical design. As such, adaptibility (see my comments RE USN designs above) is a critical factor in gauging relative success.

So with that, the question becomes, which of the submarine services fared best in carrying out their assigned mission during the war?

Very simply:

The KM attempted to strangle the Brits via blockade and knock them out of the war. They came close, but ultimately failed.

The IJN tried to pare down the US battlefleet prior to "The Decisive Engagement" (ala Hipper's BC squadrons vs the RN in 1914 and 1915). This strategy they carried through to the end of the war in the form of Kaiten.

The USN, on the other hand, from Dec 41 onward, set out to interdict Japan's strategic supply lines and destroy their seaborne logistics infrastructure, and they did just that. Overwhelming success.

The Brits? Again, I apologize for not knowing more about them... but it seems that their direct combat contributions were not what one might call "of profound impact".

So which side had the best subs?


JD

Has anyone else here read Cryptonomicon by Neal Stephenson? That was a very interesting piece of fiction set in both WWII and modern day. lots of naval stuff and the war in general (particularly the pacific theatre)

[scrag]

At the start of the war US and Japan envisioned submarines acting as long range scouts. The US termed there boats as "Fleet Boats". When the Balloon went up and bulk of the American Fleet was OOA for the first year it forced a change of tactics - this also lead to a mindset change and a more dangerous operating profile - the rest is now history but essentially the book was being re-written by the like of Dealy, Morton and Ramage.... They did loosley adapt some of the U Boat Tactics but the single biggest factor in US operational success was likely Radar. This allowed the US Subs to see A/C sooner, to conduct approaches in a number of poor conditions and to even communicate with other US Subs with the Radar (read "Clear the Bridge" by Okane)

Conversely the IJN used the submarines or better stated squandered them by forcing them to resupply troops, Scout for US Warships, to essentially severly limit there use against any Allied Shipping (the exception here would be the operations by IBoats in the Indian Ocean, which enjoyed some success) and finally to serve as Kaitan platforms. I Boats also continually fell victum to Radar and were frequently sunk (eventually the US learned how to fire the guns and use the radar as Fire Control radar). The Japanese ASW forces erroneous believed that US Subs operated at a shallower depth and so the US Boats were able to safely evade deep. IJN Subs did have a superior torpedo just stupid tactics. Why - as great of an Admiral that Yamamoto was he was a Carrier/BB Admiral and by comparisson we have Nimitz???? A Submarineer.

The Germans - masters at some craft but frankly amazing stupid in others (lack of radar or any means to detect it even after sufficent evidence was accumulated to prove conclusively it existed) Enigma compromise, insufficent numbers of boats. etc The dive times were very quick by western standards but again the threat was all around where as the Pacific not so much.

[Rockin Robbins]

@incubus

Are you German? Seems like you have a bit of pro-U-Boat prejudice going there. Or it could be a wealth of information on U-Boats vs a much less complete data set on American boats. That can have the same result.

Let's give the Germans this much. They originated and executed the first workable strategy for actually winning a war using submarines: strangle the enemy by denying him supplies. They evolved this strategy into a highly efficient, but unnecessarily fragile procedure. The fragility of their procedure resulted in their defeat. Unfortunately, the fragile parts of their strategy were key items, without which they could have no success at all. Once broken, they were reduced to an ocean of rats, scurrying for cover that no longer existed. I realize that is a pretty provocative statement so lets analyze it a bit.

The basis of U-Boat strategy was organized around the radio and the Enigma machine. The German mind tends to be very rules and systems oriented.

An American race driver traveled to a German racing school. The instructor walked his pupils around the track, pointing out the precise line they were to take. Then they took their cars around the track, following the instructor in these precise lines. Video taping the session made possible critiqueing (sp) of possible deviations from the perfect line. Then when on full-speed runs the American changed lines, resulting in an even faster lap. The German instructor took exception to this, asking why he came to be instructed in the proper way to race if he was not willing to follow instructions. The instructor had forgotten the purpose of the instruction was to teach the students to drive faster. He was so wrapped up in his "perfect procedure" he could no longer see the process or the result.

The exact same thing happened to the German submarine program in WWII. Early on, they decided that while at sea, triangulation would not be a problem because there were not enough listeners close enough to refine U-Boat positions to the point of danger. Rather than analyze U-Boat sinkings throughout the war to determine the truth of their assumption, they blithely chatted on the radio as if they were in a private conversation. And without the radio, they did not have a method to coordinate attacks anyway, as the U-Boat system was highly centralized, relying on coordination from base.

The U-Boats relied on a hole in the middle of the Atlantic, where they were safe from overflying aircraft and could transmit in comparitive safety. When the hole was plugged, their initiative was lost.

The worst hole in German strategy was their Enigma machine, supposedly unbreakable, but broken by the Czechs early in the war. They migrated to Britain, where a reasonable system was made to decode Enigma messages, but it was the Americans who produced huge decoding "bombs" which actually allowed the Allies to read the message before its intended recipient could. The Germans were so confident that the Enigma was unbreakable they instituted no monitoring systems to test its security.

German boats were similarly hampered by "securely confined within the box" thinking. In spite of repeated air attacks from nowhere, it never occurred to the brass that radar could be involved until way too late. Radar was too large to put in an aircraft, so the captains were wrong. German subs were denied active radar as well, although in a convoy situation where the Allies were ready, it is debatable how much advantage that would have given them. At least it would have leveled the playing field a little.

So the German story is a Shakespearean tragedy. Their strengths, strong code system, central coordination allowing wolfpack attacks and advanced convoy tracking, incredibly disciplined and well-trained personnel, and indominable spirit were the very weakness which resulted in their defeat. Had they eliminated these weaknesses, they would have been throwing away the very tools up which their early success depended.

Once the Americans organized their jeep carrier task forces, it was game over for the German submarine in the Atlantic. All that was necessary was to locate a boat once, draw the circle of death representing its max submerged range, cover that circle completely until sighting the sub again, draw a new circle, and tighten the noose until the sub was killed. The battle of the Atlantic was over.

It depended on several abilities not posessed by the Japanese:

Air superiority, more like sole air presence. The circle had to be covered like a blanket so any reemergence of the sub would not allow a battery recharge. The Japanese never had unchallenged air superiority.

Manufacturing capapbility to make a fleet of jeep carriers. The Japanese never demonstrated any ability to replace losses of naval fleet at any time during the war. They were in actuality defeated before the first bomb dropped on Pearl Harbor. They had no idea that during the height of German success in the Atlantic, America was building cargo ships faster than the U-Boats could sink them. There were not many months were losses exceeded production during the battle of the Atlantic.

Trained pilots able to execute the plan. The Japanese were always losing pilots quicker than they could train them. This was the major reason that toward the end of the war they used 2,000 Zeros for kamikaze missions. The pilots could barely fly the planes. They had no capacity at all to fight them. So they settled for dying in them. That would have happened anyway.

Yike! This is getting long. Advantages of the American boats:

Four engines, resulting in faster speeds than U-Boats and higher reliability. Radar. Nothing needs to be said there. Size, resulting in greater range and better sea-keeping abilities.

Care of the crew: air conditioning and ventilation systems, crew comfort, excellent food all resulted in a better fighting capability. Never discount the fighting advantage of a crew that is well taken care of.

Technical superiority: The American TDC/PK was a impressive enough, but the agility of American boats resulted from a vastly superior ballasting system. The German "crew forward" was replaced by a trim ballast tank system, which allowed compensation for unequal weight trim in the boat, supplementing the dive planes in controlling dive angles. 45 seconds to periscope depth was not slow by German standards, and American boats beat that when they had to. For such a huge boat, the American Fleet Submarine was plenty maneuverable.

Better tactics: This was a gift from the Germans. Americans quickly realized that the original strategy of the fleet boat was in the garbage when we lost an effective surface fleet at Pearl Harbor. So we anayzed the German sub tactics, immediately identifying their Achilles heel and seeking to eliminate it. Therefore, American boats kept strict radio silence unless absolutely necessary. Information flowed outward unhindered: everyone knew where the base was, but possible radio triangulation of American subs was guarded against. When they did transmit, the transmissions were very short and consise, not giving time for an accurate enough triangulation to endanger the sub unless the receivers were very close. Although the American brass was every bit as procedure imprisoned as the German sub command, American skippers were amazingly innovative in how they violated those procedures to produce results. The lack of discipline among American skippers contributed to their success.

Innovation: The American strategy was one of reacting quickly to opportunity and continual self-analysis for weaknesses. When Morton succeeded in his "down the throat" sinking of a Japanese destroyer (a desparation move) the technique was spread throughout the fleet very quickly. After a certain date in 1944 (date available at ussubvetsofwwii.org) American strategy shifted to making Jap destroyers primary targets and merchies secondary ones. The Germans never did that. They would not have succeeded if they did, as the entire purpose of the U-Boat fleet was rendered impotent by the manufacturing capacity of the United States.

All this seems so obvious in retrospect, but we have to remember that it was not obvious at the time, either to the Allies or Axis. Both considered the war winnable and loseable. All the facts were not in, and managers did what managers always do: make decisions based on incorrect and incomplete information, because if you wait long enough for the information to be correct and complete, it is no longer useful. You are then reading a history book reciting the reasons you lost. How many fail to make the move that wins because they are afraid to make the mistake that results in defeat? Both sides can look back with satisfaction that this did not happen.

[tater]

^^^^ Excellent post.

<S>

tater

[Incubus]

Excellent post! I am more familiar with the U-boats than American boats because I played SH3 for quite a while, used the mods, and used the Type VII and Type IX extensively. I learned how to turn the boat into an agent of terror against my enemies, and even through '44 make it a haunting specter that may yet rise up and snatch an unwary merchant beneath the depths.

One reason I wasn't familiar on American boats is because I just got this game, and history-wise I think submarine skippers were under-credited. I'm surprised the Japanese didn't respect/fear them more- they could strike anywhere in the pacific, and the Japanese didn't have degree of naval intelligence the Allies did to hunt them down and kill them.

I like your explanation on why different nations did/didn't do certain things. I suppose if the Germany's rigidity is what hurt its submarine force, Japan's doomed hers.

Radio silence and working independently definitely makes the submarine an unpredictable weapon (and since attacking in a submarine is all about having the initiative) but what about the overall sucess of German wolf pack tactics? Were there coordinated submarine attacks in the Pacific?

Finally, just to drive home the effectiveness of American boats, I read that in something like 2-3 separate incidents, an American submarine sank a Japanese submarine! Granted it was happening on the surface, but still- I would think in a sub vs sub battle the playing field would be a little more even (maybe they used radar to find the Japanese boat?)

[AirborneTD]

US subs sank 23 Japanese subs during the war. The Japanese lost 134 subs from all causes. The USS Batfish sank 3 subs in four days. (Feb 45).

The US began using wolfpacks sometime in mid/late 43. They were typically made up of 3 boats with sometimes 4 or 5.

Unfortunately, some sub commands did not restrict radio silence early on, and it resulted in losses. Jimmy Fife, commanding at Brisbane, lost 4 subs in over 2 months as a result (most likely) of excessive radio chatter--Grampus, Triton, Argonaut and Amberjack.