It is known that the doctrine to the IJN Submarine commander are very strict in choosing their target. They tend not to attack on merchant ships and alike. They event restricting number of torpedo use against type of warships.
Does this really effect on the result of the war. As for Kriegmarine, they do nothing but sinking allied merchants, and yet, Germans was defeated as well.
Cheers
The failure to strike at Allied merchant shipping is one of the main strategic reasons Japan didn’t do as well as it should have in the war, and lost whatever chance it had of holding onto some of its conquests which was the whole reason it went to war.
… many argue that the Japanese submarine force would have been better used against merchant ships, patrolling Allied shipping lanes instead of lurking outside naval bases. Bagnasco credits the Japanese submarine fleet with sinking 184 merchant ships of 907,000 GRT. This figure is far less than achieved by the Germans (2,840 ships of 14.3 million GRT), the Americans (1,079 ships of 4.65 million tons), and the British (493 ships of 1.52 million tons). It seems reasonable that an all-out blitz of the American west coast, the Panama Canal, and the approaches to Hawaii, New Zealand, Australia and India would have caused the Allies more difficulty than did the naval deprivations that were actually achieved. Losing a significant number of merchant ships, and also needing to spread meager defenses even more thinly along two coasts, would surely have had some substantial consequences for the United States in 1942.
http://www.combinedfleet.com/ss.htm
Japan had an outstanding submarine fleet http://www.combinedfleet.com/ss.htm
and, typically for Japan in WWII, used it very badly in a long term strategic sense.
The merchant tonnage sunk by Japan’s entire submarine fleet in the whole war is about the same as that that sunk or captured just by nine of Germany’s nine commerce raiders (auxiliary cruisers based on merchant ships http://www.geocities.com/pentagon/2833/kriegsmarine/raider/raider.html ), independently of the huge tonnage sunk by the U boats, in a couple of years.
American submarines sunk about one third of the IJN’s warships and two thirds of its merchant fleet, which crippled Japan. They would have sunk a lot more if they’d had a serviceable torpedo in the early years of the war.
The measure of the inefficiency in the way the IJN subs were used is that Allied merchant ships sailed across much of the Pacific without naval escort, and without great risk. Compare that with the North Atlantic.
America was building merchant ships much, much faster than Japan could sink them. As the war progressed America’s production increased while its rate of sinking Japanese merchant ships also increased.
By the fall of 1942, the production rate of the Liberty Ships had far exceeded the expectations of the Maritime Commission with an average construction period of 70 days. In September, Henry Kaiser’s Portland, Oregon yard set a record by completing the Joseph N. Teal in a mere 10 days. The Liberty ship ROBERT E. PEARY was built in a West Coast shipyard in the world’s record time of one week flat. By 1944, the average time to build a ship was 42 days.
http://www.globalsecurity.org/military/systems/ship/liberty-ships-production.htm
Meanwhile, Japan was losing merchant ships a lot faster than it could build them, which became progressive worse as the war went on. The end was inevitable for a nation which had virtually nothing in natural resources and needed to ship just about everything in to supply its industry. By mid-1945 the USN was sailing up and down the coast of Japan and pretty much controlled the seas around it. Exactly what Hitler intended for Britain, and a very effective means of bringing an enemy to its knees. Maybe it would have succeeded if Japan hadn’t attacked and brought America into the war.
Another consequence was that Japan couldn’t supply its military outposts with its declining merchant tonnage, so it started using subs as transports, which was just plain stupid. The result was that huge numbers of often starving Japanese troops were marooned in the island chain, notably in New Guinea and surrounding islands where by 1944 the main activity of many Japanese troops was tending their vegetable gardens so they could exist at a subsistence level. Conversely, the Allied troops were relatively very well supplied.
Bearing in mind that the whole purposes of Japan’s southern expansion were to acquire natural resources such as rubber and oil and minerals which Japan lacked and to build a trade bloc with those countries for Japan’s sole benefit, it was, as with so much else Japan did, stunningly stupid not to ensure that it actually had a merchant fleet which could bring those resources back to Japan. Japan was militarily excellent in short term tactics and strategy and incredibly stupid in long term strategy.
The reasons for Japan’s strategic failures stem largely from the same source as its other strategic failures: a curious blend of modernity and medievalism, producing notions about warrior spirit (in a way a militarily corrupted version of chi) being able to overcome adversity and focusing on warrior conflict. Hence the focus on attacking warships rather than merchant ships, because it was beneath a warrior to attack a merchant ship. Pity they didn’t apply the same principle to civilians in occupied countries, but that’s the WWII Japanese mentality for you.
An extension of this was the notion of the decisive battle, flowing from the crushing defeat inflicted on the Russians at Tsushima in 1905, in which the IJN would defeat the USN and gain control of the Pacific, which produced Midway where Yamamoto intended to crush the USN for good. This thinking demonstrated just how out of touch much of the Japanese leadership was in not appreciating America’s industrial and military capacity and the nature of its people, although Yamamoto understood it very well and was in the minority who foresaw the dangers in attacking America. The decisive battle notion also governed the approach to each major naval conflict, with the aim of bringing overwhelming force to bear to crush the enemy.
Torpedoes were actually much more significant on surface ships than submarines in Japanese naval doctrine. There’s an excellent summary here of the doctrine and how it failed in practice to achieve the intended results. http://www.navweaps.com/index_tech/tech-067.htm
Japan’s superb Long Lance torpedoes came with their own disadvantage, because the oxygen propulsion system made them much more dangerous to the vessel carrying them if there was a fire.
Thank you RS,… quite informative,… however it seems IJN Subs fleet are not as great as they look,. most of them dont have radar??,… and to some,. their technology was quite outdated,…
yet as per your explanation,. i stil can’t concure that part of unsuccesful performace was partly due to Submarine doctrine on choosing their target,. as it is clearly stated,. US could produce more ships than anything else,.
Cheers
I don’t have references to hand, but I expect that Google can produce the relative tonnages etc of the combatants during the war.
The relative maximum industrial capacity and merchant shipping tonnage of Japan and the US meant that Japan was doomed to lose before it even started the war with America.
The Pacific war was essentially a sea war, and a war won by whoever could transport the most troops and materiel by sea across the vast sea miles between land posts.
Some Japanese, like Yamamoto, understood that. Too many others, imbued with an arrogant spirit they thought could overcome just about everything, didn’t. As Yamamoto said before Pearl Harbor, (can’t recall his exact words but this was the sense) Japan would have a great run for about six months, but after that it would lose its advantage. He was right.
Merchant tonnage was the heart of the Pacific war.
Have a look at a map and look at the relative distances between the US west coast and everywhere America had to fight in the Pacific and the initial bases which had to be supplied in Australia. Compare that with the distances Japan had to cover to ship resources back to Japan from S.E. Asia and the NEI. Then look at the map of Japanese occupied and attacked territory and work out the shipping needed to sustain it, particularly in 1942 when Guadalcanal and Papua New Guinea were absorbing big tonnages in supplying the advancing Japanese troops.
Even when Japan was at its zenith in the first half of 1942, it lacked the tonnage to land and sustain an invasion force in Australia, regardless of the fact that it didn’t have the troops.
To understand the failures in Japanese conduct of the war, one needs to grasp that the IJA and IJN were essentially separate entities without any of the unifying overall command that the allied forces had, regardless of the turf wars the various Allied services fought between each other.
The IJA had its own air force, while the IJN had its own air force and ground troops. Not so different from the US at the time with the US Army and USAAF and the USN with carriers and the USMC, but the US forces were ultimately under a joint command which was lacking in the Japanese system where the IJA and IJN in many respects ran their own wars. The representation and power of the army and navy at government level in Japan was much greater and more influential than in the US or Western nations where the politicians had ultimate control and could pursue national rather than service interests.
Competition between the IJA and IJN allowed a fractured approach to war and gaining its spoils. The IJN was largely locked out of the IJA benefits gained in China before Pearl Harbor, but the Pacific war offered it the opportunity to redress the balance.
The proposed invasion of Australia, together with the decision to occupy Papua New Guinea which was only a potential target in the original war plans, were, chronologically, Japan’s first two big mistakes, apart from starting the war. The third big one was attacking Guadalcanal.
There was heated conflict between the IJA and IJN in Tokyo in February 1942 when the IJN wanted to invade Australia and the IJA didn’t. The compromise was an advance to the Solomons and Fiji, to try to isolate Australia from American supplies by sea. From a Japanese submarine viewpoint, it was a crucial point in the war, as was the use of subs as supply vessels, as revealed by this post-war interrogation
Q. Why were not submarines used more to oppose our advance through the PACIFIC?
A. The main reason was the lack of submarines. Many were used in the SOLOMONS Operation. It was also very important for them to supply even isolated and ineffective bases because the Army, which was also a partner in the planning, would have refused to send additional strength to the South PACIFIC if the Navy had left men to starve. The exact use of submarines was the point of much discussion at headquarters, but we were forced to let them be used for supply, actually, because of the shortage of warships and supply ships of all types. While opinion and advice were handed down freely from General Headquarters the decision as to use of submarines was made by Combined Fleet Headquarters. Another point was that this use of submarines as supply weapons fitted in with out overall strategic planning for fighting delaying actions on all islands.
p.144 http://sun-wais.oit.unc.edu/hyperwar/AAF/USSBS/IJO/IJO-34.html
The result was that the Japanese got bogged down on land and sea in trying to acquire the Solomons etc and put too much of their tonnage and naval resources into that, when they should have left it alone and put their naval resources into cutting the sea routes for merchant shipping, which in turn would have required the US either to divert naval forces to convoy protection or abandon Australia. One consequence of abandoning Australia would be the loss of the Australian naval bases for the USN on Australia’s Pacific and Indian ocean coasts and in Darwin in the north, thus restricting USN and US merchant navy activity to bases in Hawaii and the US west coast, with much longer steaming times and fuel consumption to the western and south western Pacific where the Japanese held their land bases.
That would have meant that MacArthur’s strike from Australia could never have happened, so PNG, the NEI, and the Philippines would have remained in Japanese hands.
The US would have been limited to a mid-Pacific thrust to the west from Hawaii while Japan held air and naval bases on land in its front, while the major Japanese naval base at Truk threatened its southern flank whereas the naval forces at Truk were moved away in 1944 under pressure of both USN attacks on Truk and land advances by the Allies to the south west which threatened to isolate it.
The USN might have acquired the Marianas by a mid-Pacific thrust and been able to use Tinian as the launch for the A bombs, but it’s highly debatable that being nuked without the approaching American roll up through Japanese occupied territories would have had the same effect.
Similarly, the A bombs would have been a lot less effective if Japan hadn’t been brought to its knees by the USN strangling its imports by destroying its merchant navy and blockading its sea approaches.
The Papua New Guinea fiasco sucked in a ridiculous amount of Japanese resources and troops from the start to the end of the war, to no real strategic purpose. http://ajrp.awm.gov.au/ajrp/remember.nsf/pages/NT00002FAA
So, rather than taking an intelligent national approach to matters, such as trying to strangle Australia and deny it as a base to America in 1942 by attacking trade routes to Australia, the IJN was allowed to waste its considerable resources on Guadalcanal and PNG to establish the first defeats of the Japanese on land (Milne Bay, Kokoda, Buna/ Gona / Sanananda, Guadalcanal) by the end of 1942 – early 1943 along with the draw in the Coral Sea as part of that general thrust. That was the beginning of the end for Japan, and its failure to use its sub force aggressively and against merchant shipping then and subsequently just hastened that end.
You did mention about Yammamoto,… now,. he was one of the key positions of IJN,. and he did reliazed the strategic important of logistic capabilities of his country, he should then (my assumption), also recognize the important of supply line of US forces in the pacific theatre.
why he (or other like the one in my Avatar) were not useing their influnce to change the doctrine of IJN Submarines fleet then? do you have any idea or source perhaps?
say… you’re australian?
Cheers
Essentially it was because the Japanese were focused on decisive battles in all engagements, so that subs were the reconnaissance screen and to be used to sink enemy warships. The focus on subs supporting battles between warships meant that there was not much place for subs in attacking merchant shipping.
Compare that with the American approach and results. http://www.navy.mil/navydata/cno/n87/history/pac-campaign.html
Good references for further info in bibliography here
http://ajrp.awm.gov.au/ajrp/AJRP2.nsf/5c2a7f65120f209aca256b6d0020a228/225b90b97196e29bca256a1d00130203?OpenDocument
Yamamoto didn’t necessarily agree with Japan’s strategy in the war, but once unable to persuade others to a different view he carried out his orders to the best of his ability. He’d served as a naval attache in the US and knew and understood America much, much better than most of his contemporaries in Japan. He recognised America’s industrial capacity and the threat it posed to Japan in a long war, but he wasn’t the one who made the decision to go to war with America. He was opposed to any steps that might bring America into the war, but he was outnumbered.
Yes, I’m Australian, but don’t tell anyone else or they’ll be jealous. 
The Americans began “unrestricted” warfare against Japanese shipping and followed the logic that Everyone followed everywhere- deny the enemy supplies and equipment, ie., hit the merchants. It was proven to work everywhere.
If the Japanese believed that destroying combat ships was the way to weaken the enemy they were obviously wrong. They made the wrong decision that’s all.