Torpedos

[ctwaterman]

Posting just to say: I am in awe of the erudition in this thread.

Im in awe of the word Erudition ????

[Laertes]

<derail>

Erudition n. Learning, knowledge. Usage: damocles showed great erudition in his knowledge of US tanks.

One of the many words in the world which sounds rude, but isn't, like mastication or fasces. Use responsibly and with great lols.

</derail>

[Darman]

Posting just to say: I am in awe of the erudition in this thread.

Im in awe of the word Erudition ????

I agree!  I had to look it up....

But I do agree that damocles post was quite impressive. 

If we decide to do anything with torpedo (or munitions in general) quality I think it must be connected to your research/tech in some way.  Perhaps you research a tech, then research a type and for the type its hit or miss for quality.  That will definitely lead to more paperwork though.  Especially for the mods if they are the only ones keeping track of quality. 

[ctwaterman]

No I dont think were going to be adding another layer of complexity and uncertainty to the game.

I mean who accept the poor countries wouldnt spend whatever ammount of money it takes to test both their shells and their torpedoes to insure they worked.

I mean even Italia would find an Old PDN hull to turn into a live target ship and shoot it up every decade or two...

[Darman]

I mean who accept the poor countries wouldnt spend whatever ammount of money it takes to test both their shells and their torpedoes to insure they worked.

Couldn't they just buy torpedoes/shells (or designs perhaps) from richer neighbors?  Didn't Krupp, Schneider, and Armstrong each (with varying degrees of success) sell armaments to lesser powers? 

[ctwaterman]

Yes and you would find the small poorer countries buying and just like OTL not testing or training or even properly maintaining the things like Wet Heater Torpedoes.

Live training exercises are just very expensive and using even a few live torpedoes on a target ship is something most nationions could not afford to do on a regular basis.   

Which as I pointed out is how Germany,  Great Britain, and the US all ended up with major torpedo problems at the start of WWII.

[Darman]

Yes and you would find the small poorer countries buying and just like OTL not testing or training or even properly maintaining the things like Wet Heater Torpedoes.

Which would be a serious mistake on their part.  If you're going to spend money buying equipment you can't build yourself its in your best interest to maintain it well, right? 

I do see it as potentially being less effective, to buy as opposed to build your own.  However, as it is we often end up buying equipment anyways. 

[Laertes]

ctwaterman makes a good point - all major nations in the Nverse would put the maximum effort and expense into making sure their munitions functioned. On the other hand, real life major powers evidently didn't (and I personally don't know why they didn't; building a huge gun and not making good shells for it seems a difficult budgetary decision to justify), and thus representing this might be a non-trivial game design problem.

I am personally in favour of more abstraction, rather than less. Easier bookkeeping, easier on the mods, and less room for metagaming.

[damocles]

ctwaterman makes a good point - all major nations in the Nverse would put the maximum effort and expense into making sure their munitions functioned. On the other hand, real life major powers evidently didn't (and I personally don't know why they didn't; building a huge gun and not making good shells for it seems a difficult budgetary decision to justify), and thus representing this might be a non-trivial game design problem.

I am personally in favour of more abstraction, rather than less. Easier bookkeeping, easier on the mods, and less room for metagaming.

We will say that the Country X has a weapon directorate.

Now Country X has something called a referent enemy, Country Y.

Country Y has a navy 1 and 1/2 times larger than Country X-especially in its line of battle ships.

What does country X do, especially if Country X plans to attack country Y?

Country X looks for a cheap offensive equalizer.

In the case of France versus the UK, it was the ironclad.

In the case of Japan versus the US, it was the torpedo armed aircraft.

In the case of the US versus everybody it was the heavy strategic bomber.

Only one of them got it right. (No, it wasn't the US.)

The US answer to the Japanese ship carried Long Lance and the Kate carried Type 93 was the Mark 37 (AAA) fire control system, the Wildcat fighter, the Ford ballistic  computer and a series of super-heavy artillery shells for the 6", 8", 12", 14", and 16" naval guns.        
   
That was a good technical defensive solution as it allowed an outnumbered American Navy to defeat the numerically and technically superior Japanese in 1942 and early 1943.

Lots of naval battles and defeats happened for Japan from May 1942 to May 1943. May 1943 to May 1944 there was no serious naval fighting? Nothing, as both sides sort of retired and fixed their discovered wartime problems.

For the Japanese this was their aircraft engines and machine guns, their lousy naval artillery, and their poor radios.

For the Americans this was catchup time to replace their early 1930s era cheap-made Curtiss Wright junk aircraft with the cluster of 1938 outstanding Douglas and Grumman designs.      

Someone figured out how to drop the Bliss Leavitt torpedo from PT boats and aircraft.

And the Mark XIV they fixed, sort of...

Then June 1944 comes and the retooled fleets, who think they fixed their discovered peacetime defects, fight.

Japanese aircraft armament now could hurt American aircraft. Their improved engines allowed their planes to keep pace with the faster Americans. This would be okay if the Japanese had fixed their real problem, which was pilot training. They didn't. Kill ratio was 10/1 in favor of the Americans who never bothered to fix the severe problems they had with their own aircraft armament (-even against the Germans). Why bother with guns when its the pilot who matters if the machines are anywhere near equal?

Japanese naval shell quality was never a problem, it was the design of their naval rifles. The Japanese were to show that no matter what they tried, once they departed from British practice (1908 series guns) they were just incompetent naval gun smiths. Return to first principles would pay dividends against the 1944 British, but not against the 1944 Americans-not in a gunfight-where American tracking parties zeroed in on your baseline track and straddled you within three salvos. (That is 90 seconds!)       

Japanese radios now worked. Too bad that the trained cadre of electricians and radio operators who could maintain and use those excellent sets were dead at Iron Bottom Sound. Also too bad that it wasn't radio where the Japanese needed to do the work, it was radar.    

How did the Americans do?

Musashi, Yamato, another Japanese battleship whose name I cannot remember about a dozen Japanese cruisers, and a score of destroyers and five aircraft carriers were sunk by American torpedo armed planes carrying the poor stubby little Bliss Leavitt Mark 13 torpedo. I think that the little wet-heater accounted for more ships between June 1943 and June 1944 than any other aerial weapon in history, because I didn't include all the forty or so torpedoed Japanese ships sunk during the Truk raids (and there were at least another hundred attacks all across the Pacific). The Bliss Leavitt torpedo was the one 'good' quality American torpedo and had worked somewhat at Coral Sea. It was the 'poorly trained' (read wrongly trained) American pilots and not the torpedo that actually failed at Midway. A little weapon tweaking to correct a porpoise and broach problem during fast high drops (which is how you actually drop a torpedo and survive AAA) and a lot of pilot training fixed the early war 'poor torpedo performance' problems.  

The American subs ran riot in the Pacific from June 44 to June 45. They sank at least five (six?) aircraft carriers, one battleship at least four cruisers, almost forty destroyers and patrol boats. This Japanese debacle was accomplished with American torpedoes (Mark XIV and Mark XVIII) that can only be described as 'still simply awful'. Once again, the Japanese who had excellent torpedo-armed subs showed that it was the trained American crews, not the Japanese weapons that mattered.

The question is then what does this have to do with the underlined above?  

When you are in a depression, what do you spend the little tax money you get on?

Training-always training, the weapons have to wait.  

   

[ctwaterman]

*Chuckles* Sitting here wondering why I cant sleep but an interesting read.

I wouldnt call the American Fleets of 1942/43 quite out numbered and by the the Marrianas Turkey Shoot or lets say late 1943/ Early 1944 the Japanese Aircraft were completely outclassed by the Corsairs, Hell Cats, and P-38 Lightings they were being asked to face.  When you add in that the New Japanese Pilots joining the carrier force had 100 or so Hours of flight training when most of the US Pilots had over 500 well that  really really hurt the Japanese.

The Problems with Training before Weapons is a complex problem.   If your training and training and training on a weapon system that is outdated then you could have just lost your self the war.  And New Battle Ships and Carriers are long lead time Items.... any Capital Ship takes at least 2 years to build after you think you need it....

So when France Feel in 1940 the American Response with an even larger 2 Ocean Navy bill basically cornered Japan... by the Time of the US Oil and Steel Embargo Japan was faced with the fact that they had a slight material and training edge over the USN NOW mainly in Carriers, Carrier Aircraft and Aircrew experience.  But that by the End of 1942 early 1943 the US would begin putting into service the first of 16 New Battle Ships and Dozens of new Carriers.   Heck Roosevelt had even announced the desire to build 50,000 Aircraft a year in 1941....

So do you attack now and hope you can force a settlement before the enemy simply has more planes, and ships then you can ever realistically fight or do you surrender you national ambitions to form an Empire.....

We all know what the Japanese Choose... In then End they Choose Poorly.

[damocles]

*Chuckles* Sitting here wondering why I cant sleep but an interesting read.

I wouldnt call the American Fleets of 1942/43 quite out numbered and by the the Marrianas Turkey Shoot or lets say late 1943/ Early 1944 the Japanese Aircraft were completely outclassed by the Corsairs, Hell Cats, and P-38 Lightings they were being asked to face.  When you add in that the New Japanese Pilots joining the carrier force had 100 or so Hours of flight training when most of the US Pilots had over 500 well that  really really hurt the Japanese.

The ratios are these after December 7,1941 to May 1943) and are Pacific averages.
                         Japan                                          United States
Aircraft carriers        8                                                     4
Battleships              11 (10 once Mutsu blew up)                 7 (available)
Cruisers                 ~30->20 (they were whittled down)       18 (constant)  
Destroyers              120 (constant)                                  100->130 (increase)
Submarines             110-120 (increase)                     80-110 (increase)

The Japanese started the Pacific war with about 550 naval and 600 Army air force aircraft outside China and Japan. The Allies had 400 US naval, 60 British naval, and almost 1500 (mostly British) land-based aircraft on December 6, 1941. By Coral Sea the British were mostly wiped out. The US forces were 200 naval and 500 land-based (by that time mostly in Australia and New Guinea). Japanese levels were about constant.

After the New Guinea/Solomons fighting the Japanese strength  increased to about 1000 land based aircraft and remained naval constant.  
                 
It wasn't until mid 1944 that the pilot massacres set in.
==============================================================

Sources are

The First Team: Pacific Naval Air Combat from Pearl Harbor to Midway
http://www.amazon.com/First-Team-Pacific-Combat-Harbor/dp/0870211897
Shattered Sword
http://www.shatteredswordbook.com/
Hyperwar as always
http://www.ibiblio.org/hyperwar/PTO/index.html

The Problems with Training before Weapons is a complex problem.   If your training and training and training on a weapon system that is outdated then you could have just lost your self the war.  And New Battle Ships and Carriers are long lead time Items.... any Capital Ship takes at least 2 years to build after you think you need it....

The answer is you need to do the research and prototype work. Then you improvise.

Can't build eight fast carriers? Then build eight fast oil tankers (or ocean liners) that you can plank over and turn into carriers.

Need a battleship killer in a hurry?  Research torpedoes and aircraft.  A plane takes ninety days. The torpedo had better work. Make sure you have a lot of trained pilots.

Build quick-build ships. Submarines and destroyers are expensive but lend themselves to two qualities that are desirable, they can use the same torpedoes as planes if the tubes match the weapon and they only take a year to build.

There was an argument that if the US had traded the Iowas in on equivalent monetary investment in subs that the Pacific War would have ended a year sooner.

Let's compare.

ship                      Iowa                            Gato    
Cost(millions)         $180                             $10            =18 subs
Crew (men)           2700                               88            =30 subs
Oil(tons)               4000(1 trip)                    200(1 trip)   =20 subs
sank ships/ship lost  0/0                              60/1            1 sub = >100 Iowas
 
Makes a lot of sense doesn't it? As a general rule (once one does this for all battleships versus all US subs) one US battleship actually = 20 US subs as per cost and one US sub = 10+ US battleships for total damage inflicted on enemy.  
                                         
The numbers are roughly 5/1 in favor of US subs when you compare to US aircraft carriers.

So when France fell in 1940 the American response with an even larger 2 Ocean Navy bill basically cornered Japan... by the Time of the US Oil and Steel Embargo Japan was faced with the fact that they had a slight material and training edge over the USN NOW mainly in Carriers, Carrier Aircraft and Aircrew experience.  But that by the End of 1942 early 1943 the US would begin putting into service the first of 16 New Battle Ships and Dozens of new Carriers.   Heck Roosevelt had even announced the desire to build 50,000 Aircraft a year in 1941....

A little economics analysis and you throw money into a 30 knot sustained combat speed 7000 ton 6" gun and torpedo armed cruiser prototype, a 25000 tonne carrier prototype, and the most advanced submarines, destroyers (frigates) and aircraft in small lots that you can build and afford. You develop  3"L50 and 2"L50 automatic anti-aircraft weapons, a 6"L50 dual purpose naval gun, a wet heater (or electric) 40 knot/10,000 yard/1 ton torpedo and the large fast carrier based plane to carry it and a decent carrier fighter to protect it and your carrier, as well as launch tubes to fire that torpedo from ships and subs and MTB boats.

You test that torpedo until you know for sure that it works and then you manufacture thousands not hundreds.

With other $1 Billion in scarce development money you develop radar and sonar and naval mines.

Then you cross your fingers as an American and pray that the Japanese do exactly what they did.  Because if they do, the money you saved on the choices listed above
-allows you to re-deck the Arizona with a bomb deck and put TDS blisterx on every battleship that was torpedoed at Pearl Harbor.
-replace the 5"L51 casemate and 5"L25  AAA guns on every Pacific battleship with 8 x  5"L38 twin mounts
-allows you to install CXAM or SCR on every battleship and carrier you own.    
-allows you to install torpedo tubes on every 8" gun cruiser you own.  

And then you go into a two ocean program in September 1940 knowing that it will be September 1942 when all those new ships work up and NOT September 1943.      

So do you attack now and hope you can force a settlement before the enemy simply has more planes, and ships then you can ever realistically fight or do you surrender you national ambitions to form an Empire.....

You stall, try for a Lindbergh Peace.

We all know what the Japanese Choose... In then End they Choose Poorly.

So did the Americans.

[Brockpaine]

It wasn't until mid 1944 that the pilot massacres set in.

That's something of a dishonest statement.  As Shattered Sword points out - which you yourself cited - the creme of the IJN naval aviators were wiped out over the course of the Solomons campaign, and that's really the point where the IJN's naval aviation died.  The battles of 1944 were only one-sided massacres because the USN had already torn out the throat of Japanese naval aviation.

Also, while you argue for building more subs instead of the Iowas, you might instead gain a similar rise in cost-benefit analysis by more effectively using your submarines as minelayers, rather than as raiders.  US submarines laid 658 mines to sink or damage 54 ships for no operational losses, and a significantly higher number of kills for the amounts of ordnance expended.  But I know you already know about the effectiveness of mine warfare, Damocles. ;)

[damocles]

It wasn't until mid 1944 that the pilot massacres set in.

That's something of a dishonest statement.  As Shattered Sword points out - which you yourself cited - the creme of the IJN naval aviators were wiped out over the course of the Solomons campaign, and that's really the point where the IJN's naval aviation died.  The battles of 1944 were only one-sided massacres because the USN had already torn out the throat of Japanese naval aviation.

Also, while you argue for building more subs instead of the Iowas, you might instead gain a similar rise in cost-benefit analysis by more effectively using your submarines as minelayers, rather than as raiders.  US submarines laid 658 mines to sink or damage 54 ships for no operational losses, and a significantly higher number of kills for the amounts of ordnance expended.  But I know you already know about the effectiveness of mine warfare, Damocles. ;)

1. The history shows that the collapse of Japanese pilot training came after September1944 when they ran out of tankers and imported fuel. That was when the Kamikazi decision was made.  

2. You can't lay submarine launched mines until you design and build them. The US did not develop a really good tube-launched self propelled mine until after the war. (same reason as the torpedo weapons-mistakes in tactics and manufacture.) Most of the mines the US used were laid by strategic bomber aircraft or fast mine-layer and did not affect Japanese operations in home waters until 1945. That was especially true of US submarines as you can see HOW* the USS Argonaut was wiped out. Other large US subs** had trouble approaching Japanese harbor entranced because while  Japanese open ocean ASW was a joke, their coastal defense setups made the Germans look like the rank naval amateurs they were.  

http://www.navweaps.com/Weapons/WAMUS_Mines.htm

* USS Argonaut.
http://www.navy.mil/navydata/cno/n87/history/pac-campaign.html
** US submarine losses.
http://www.history.navy.mil/library/online/sublosses/sublosses_intro.htm

RESULTS OF THE AMERICAN

PACIFIC SUBMARINE CAMPAIGN

OF WORLD WAR II

Michel Thomas Poirier
Commander, USN
30 Dec 1999

The year 2000 marks the centennial of the U.S. Submarine Force. Among the most extraordinary accomplishments of American submariners is the impressive victory of U.S. World War II Fleet Boats over the Japanese Navy and Merchant Marine. While many books have been written describing this victory, few understand to what degree the U.S. Submarine Force gutted Japanese industrial and military strength during the Second World War. Such details are contained in the post war U.S. Strategic Bombing Study of Japanese industry and in Mark Parillo's excellent Japanese Merchant Marine in World War II.

The U.S. Pacific Submarine campaign had three major accomplishments. First, Japanese merchant marine losses crippled the ability of Japanese industry to generate military power. Second, destruction of Japanese merchant marine and naval forces significantly reduced the Japanese ability to project power throughout the vast Pacific. Third, use of the submarine enabled the U.S. Navy to take the offensive in Japanese controlled waters and inflict disproportionate losses relative to the U.S. investment in submarines.(1)

We will review the effects of the U.S. submarine campaign on Japan including the effects on the four military pillars of Japanese power: her merchant marine, Navy, Army and air power. The implication for today's military, heavily dependent on logistics for power projection should not be forgotten. Today, even with the impressive and growing ability of the U.S. Navy to effect land warfare, sea control still remains job number one.

The U.S. Submarine Campaign in the Pacific: 1941-45

The Japanese attack on Pearl Harbor resulted in a significant loss of strength for the U.S. Navy and placed that Navy in a defensive posture. The only weapon system immediately available to take the war to the enemy was the U.S. Submarine Force. Indeed, FDR had decided prior to the start of the war that "unrestricted submarine warfare" would be undertaken in the event of hostilities with Japan.(2) Throughout the war, the growing U.S. submarine force was employed in attacks on Japanese merchant shipping as well as on Japanese fleet units when the opportunity presented itself. In both these tasks, the American submarine force was aided by magic- intelligence derived from broken Japanese codes.(3) The Japanese Navy, with Mahanian intellectual roots, prepared tardily and insufficiently for an onslaught not directly related to "decisive battle." The American Navy won a spectacular victory.

Editorial comment. Those ship kills were in the open ocean where US mines did not work in 1941-1944. That was torpedo terrain.  

The Japanese Merchant Marine lost 8.1 million tons of vessels during the war, with submarines accounting for 4.9 million tons (60%) of the losses.(4) Additionally, U.S. submarines sank 700,000 tons of naval ships (about 30% of the total lost) including 8 aircraft carriers, 1 battleship and 11 cruisers.(5) Of the total 288 U.S. submarines deployed throughout the war (including those stationed in the Atlantic), 52 submarines were lost with 48 destroyed in the war zones of the Pacific.(6) American submariners, who comprised only 1.6% of the Navy, suffered the highest loss rate in the U.S. Armed Forces, with 22% killed.

Editorial comment. The losses versus results were extraordinary when you consider a. defective torpedoes, b. meager open ocean Japanese ASW, and c., lack of US air cover. The thing you need to remember is that most of those US submarine kills were coastal.  

The American Pacific submarine campaign had substantial direct, indirect and second- order effects on the Japanese economy and the four bases of Japanese military power- Japanese airpower, the Army, the Imperial Japanese Navy and the merchant marine.(7) I will analyze the effects of the American guerre de course in each of these areas. It is important to note that the submarine was the predominant, but not the only, factor in the destruction of Japanese commerce and the ensuing damage to the Japanese economy. We cannot realistically look at the submarine campaign in complete isolation from other attacks against the Japanese transportation system.

Editorial comment, such as airpower. Battleship effect? Zero.

Loss of Shipping Impoverishes Japanese Industrial Strength

The Japanese merchant marine started the war with 6 million tons of shipping. The Japanese Army and Navy each requisitioned a part of the merchant marine to transport and supply their respective operating forces. The Japanese leadership believed they needed to retain 3 million tons of shipping in order to meet the industrial and civilian needs of the economy- although this estimate was probably too low.(8) Two important points need to be made in order to understand the effect of the war on the Japanese transportation system. First, Japan's industrial capacity was proportional to her ability to import needed material.(9) Secondly, due to the extensive drafting of merchant vessels for military needs as well as high losses from American attacks, Japan never achieved the minimum of 3 million tons of capacity required for industrial and civilian uses.(10)

Editorial comment, nor was the 1 million tons for overseas garrisons in the SE Pacific zone of operations deliverable. (Their ciewpoint.)

Losses of merchant vessels combined with the indirect loss of a portion of the merchant marine fleet due to convoying significantly reduced Japanese economic strength. Imports of 16 key materials fell from 20 million tons in 1941 to 10 million tons in 1944 and 2.7 million tons in the first 6 months of 1945.(11) The specifics were impressive:

"Bauxite imports fell off 88% just between the summer and fall of 1944 (E. c., aircraft). In 1945, pig iron imports plunged 89%, pulp 90%, raw cotton and wool 91%, fats and oils 92%, iron ore 95%, soda and cement 96%, lumber 98%, fodder 99%, and not one ounce of sugar or raw rubber reached Japan."(12)

Editorial comment Sugar you need for fermentation.... for explosives as well as for fuel.

Moreover, the reduction in imports of raw materials mirrored problems importing food. During 1944, average caloric intake fell 12% below the minimum daily requirement for the non-farming population.(13) The enormous drop in importation of raw materials resulted in a significant drop in Japanese industrial production. In fact, the Japanese mobilization committee stated in a late 1944 report: "Shipping lost or damaged since the beginning of the war amounts to two and one half times newly constructed shipping and formed the chief cause of the constant impoverishment of national strength."(14)

The Japanese pilot trainee received a special diet. I wonder why?

Submarine attacks on the oil flow to Japan were a second critical factor in destroying Japanese military potential. Japanese oil imports fell from 1.75 million barrels per month in August 1943 to 360,000 barrels per month in July 1944. In October 1944, imports fell even more due to high losses around the Philippine battlefields.(15) After September 1943, the ratio of petroleum successfully shipped from the southern regions that reached Japan never exceeded 28%, and during the last 15 months of the war the ratio only averaged 9%.(16) These losses are especially impressive when one considers that the Japanese Navy alone required 1.6 million barrels monthly to operate.(17) Much anecdotal evidence describes Japan's often desperate responses to the American guerre de course. For example, in early 1945, the Japanese Navy loaded crude oil barrels on battleships to import home, while at the same time the nation experimented with producing gasoline from potatoes.(18)
Editorial comment. That was how Haruna was killed. She carried aviation gas, no fuel oil. Did you know that? Why was that?

The loss of raw materials and petroleum and inability to transport items to the front lines lay at the heart of Japan's weakening ability to maintain effective military strength. Munitions Minister Toyoda said as much when interrogated after the war: "the shipping shortage and the scarcity of oil were the two main factors that assumed utmost importance in Japan's war efforts."(19) We will now look at the specific effects of the drop in industrial production and inability to transport goods on Japanese airpower, naval and merchant marine shipbuilding and the army.

Editorial comment: open ocean submarine torpedo kills. Non salvageable non recoverable in deep water.

Effects on Japanese Airpower

Aircraft production was strongly affected by the war against Japanese sea lines of communication (SLOCs) due to the lack of raw materials. By April 1944, aircraft engine production had fallen to "critical" levels.(20) The Japanese significantly reduced aircraft engine testing due to lack of aviation gas: from about 8 hours and 5 flights for each engine in 1941 to 2 hours of testing on 10% of the engines built at war's end.(21) The reduction of bauxite imports by 500,000 tons from Indonesia and Malaysia resulted in a 70% drop in aluminum production in 1944.(22) As a result, by the end of 1944, 80% of every plane was made from aluminum pilings, which significantly reduced aircraft quality.(23) By the spring of 1945, the Japanese fabricated major parts of aircraft from wood and they actively planned to construct entire aircraft out of wood.(24)

Editorial comment: no planes means no training, same effect as for fuel.

The war against Japanese SLOCs resulted in significant indirect effects on Japanese air strength. In fact, the reduction in Japan's air power strength was not so much due to the reduction of aircraft quality or production but due to the reduction in pilot quality. Fuel shortages substantially reduced pilot training.(25) In 1944, the great Japanese naval aviator Fuchida complained about the "inadequate training" aviators received prior to attachment to an operational unit.(26) Moreover, once Japanese pilots reached operational units, their training opportunities often did not improve. For example, prior to the Battle of the Philippine Sea, Admiral Toyoda stationed his carriers at Tawitawi near the Borneo oil supplies due to the effective submarine campaign against Japanese tankers. U.S. commanders vectored submarines into the area. Alerted to the danger, the Japanese commander refused to sortie for training- with the result that what little skills his undertrained pilots possessed atrophied.(27) The resulting Japanese aerial defeat became known as the Marinas Turkey Shoot.

Editorial comment: note the dates?

An additional indirect effect of the war against Japanese transportation should be noted. Inadequate numbers of merchants and fear of additional losses resulted in the use of barges and small boats to ferry supplies in the empire's combat zones. As a consequence, the Japanese undersupplied forward-deployed units, including ground based aviation units. As an example, one air staff officer noted "a 75% drop in aircraft serviceability in New Guinea from such causes [loss of shipping] and blamed the loss of aerial supremacy over that strategic island on transport shortages."(28)
Editorial comment That set of causes was far more important than the  loss of Japanese veterans which is a myth.

Effects on the Japanese Navy

The submarine offensive gravely weakened a second pillar of Japanese power: the Imperial Japanese Navy (IJN). As previously discussed, 30% of total Japanese Navy losses were caused by U.S. submarines. Submarines played another important role in reducing IJN capabilities. Damage to ships, caused in part by submarines, significantly increased ship repair time in Japanese shipyards, thereby reducing opportunities for new construction. The Japanese Navy spent 12% of its construction budget on ship repairs in 1943 and 1944; the figure increased to 34% in 1945.(29) Additionally, the submarine campaign had two important second order effects on the Japanese Navy. First, the necessity to build merchant ships to replace losses resulted in a reduction of potential naval construction. Private shipyards devoted to naval construction fell from 44% of the total in 1942 to 30% in 1943.(30) Secondly, the requirement to build escort ships and naval transports (also to replace merchant losses) reduced the potential to build more powerful combatants. As a result, while the IJN used 14% of its construction budget for escorts and transports in 1941, the percentage shot up to 54.3% in 1944.(31) More astonishing, the need for escorts and merchants was so grave, that after 1943, the Japanese Navy started construction on no ship bigger than a destroyer!(32) Finally, the American stranglehold on imports, in this case, iron ore, proved fatal to any long term ability to build adequate numbers of warships to replace losses.(33) By September 1944, the Japanese had so little steel that naval construction fell precipitously.(34)

Editorial comment: open ocean submarine torpedo kills. Non salvageable non recoverable in deep water.

Effects on the Japanese Merchant Marine

In addition to the direct loss of merchant hulls already described, the Japanese suffered an important indirect effect of submarine warfare caused by the loss of efficiency due to convoying. The entire merchant marine (including that shipping throughout the empire that was not convoyed) had a loss of "carrying efficiency" of 8% between January 1942 and January 1944 with a further reduction of 21% by 1945.(35) However, on the critical line between Singapore and Japan, efficiency declined by 45% between May 1943 and May 1944, with further substantial declines later.(36) Not only did Japan have too few ships, but their ships took longer and longer throughout the war to carry badly needed cargoes the same distances.(37)

Editorial comment: carriage losses per trip means loss of opportunity to make the tools of offense.

In response to American attacks, the Japanese attempted to increase construction of merchants to replace losses. The Japanese used 7% of their total steel production on merchants in 1941 but 46% in 1945. (No tanks) (38) Despite their best efforts, the import crisis hit merchant construction hard. Of note, concentrated submarine attacks on tankers resulted in the Japanese augmenting construction of the vital petroleum carriers at the expense of general-purpose ships. In the fall of 1944, lack of steel forced significant cutbacks on production.(39) Despite considerable efforts, Japan never succeeded in building more than 45% of her losses. In the words of the Strategic Bombing Study, the Japanese "didn't have the production potential to surpass wartime shipping losses."(40) The inability to protect merchants and replace losses could only result in disaster for such a nation so dependent on imports for survival.

Editorial comment: every loss at sea was lost forever.. The machine tools in a bombed factory could be cleaned off and moved. Mined ships were salvaged. Torpedoed ships (deep water) were not.  

Effects on the Japanese Army

The breakdown of the Japanese merchant marine placed grievous logistical constraints on the ability of the Japanese Empire to supply her army deployed throughout the Central and Southern Pacific. Japanese logistical problems first became apparent in 1942 during the Guadalcanal campaign, when an overstrained logistical system and relentless U.S. air attacks resulted in frontline Japanese units receiving only 10% of the supplies comparable American units received.(41) U.S. submarines attacks directly affected the ability of the Japanese to move troops and supplies into important combat zones. For example, concentrated submarine attacks on shipping delivering the experienced 32nd and 35th Infantry divisions to the New Guinea theater resulted in the Japanese convoy disembarking the surviving troops over 500 miles from their destination. As a consequence, the Japanese barged ineffectual penny packets of troops to combat McArthur's forces in Biak and Hollandia.(42) In another case, U.S. submarines destroyed 6 transports loaded with troops destined to boost the defenses of the Marinas before the U.S. invasion of those islands, and sank ships loaded with vital concrete and wire needed for the islands' fortification.(43) The rate of successful delivery of military supplies to front line units averaged 96% in 1942, declining to 83% in 1943, 67% in 1944 and 51% in 1945.(44) These statistics fail to capture the extraordinary indirect effects of both U.S. submarine and air attacks on Japanese merchants as the Japanese had to resort to carrying much of their supplies within the combat zones by slow, inefficient means such as barges, fishing boats and the like. These direct and indirect effects of U.S. attacks clearly impacted Japanese army units. Throughout the war, munitions deliveries were 15% below front line needs, and 33 to 50% of all food sent to the front was lost due to attack or spoilage.(45) Accounts from front line units depict significant efforts to make up for lack of food deliveries by gardening, fishing, or bartering with natives with sporadic accounts of cannibalism in especially poorly supplied areas like New Guinea.(46)

Editorial comment: open ocean submarine torpedo kills. Non salvageable non recoverable in deep water.

Misplaced Resources and Strategic Immobility

Several important second order and indirect effects must be noted in the U.S. submarine campaign. First, the Japanese used a portion of their submarine force to supply bypassed units. Indeed, the Japanese army and navy each built significant numbers of submarines designed for the express purpose of carrying cargo.(47) Not only were scarce resources wasted in this way, but Japanese submarines that could have been used to attack the extended American logistics train were not properly employed. Another important combined direct and indirect effect of the U.S. campaign against the Emperor's lines of communication was strategic immobility. The inadequacy of total lift and reliance on barges in theater meant large number of Japanese troops could not be quickly moved around the empire. U.S. sea and airpower usually prevented the Japanese from reinforcing islands under attack or removing defeated troops from an island under assault. Therefore, the Japanese could not exploit their advantage of interior lines of communication to move and supply adequate numbers of troops to defeat any of the three major Allied lines of advance in the Pacific theater.

Editorial comment: With only forty boats per sortie cycle, if you tied them up as mine-layers you don't have anything out there to blockade the oceans where the Japanese could cover with artillery and aircraft. The submarine is an open ocean blockade weapon.

Disproportionate Costs Imposed on Japanese

I have attempted to roughly calculate costs of each side's effort in order to determine whether the U.S. campaign was "efficient." The cost of merchant ships and warships lost to U.S. submarine attack were calculated using actual Japanese prices and added to the cost of all Japanese ASW frigates and corvettes (but not fleet destroyers or ASW aircraft).(48) Using U.S. Navy figures I calculated the cost of the entire fleet of 288 U.S. submarines that served or were built during the war (regardless of whether they served in the Pacific). The result is impressive although not surprising: the Japanese spent at least 42 times more on anti-submarine warfare and in losses attributed to submarines than the U.S. spent on her Submarine Force. When one considers the fact that the Japanese economy was only 8.9% of the size of the U.S. economy in 1937, the submarine campaign was clearly both an extraordinarily cost efficient and effective means to employ U.S. forces against Japan.(49) Regardless of the cost effectiveness of the U.S. submarine campaign, the military effects were stunningly clear. Fully a year before the end of the war, and before the extensive bombing of mainland Japan, the war against Japanese lines of communication resulted in decisive impact on the Japanese war economy and on the Japanese military logistical system.


Editorial comment: open ocean submarine warfare with defective weapons., Imagine if we had Italian torpedoes.

Why Should We Care?

We can draw several important lessons from the U.S. submarine campaign. First, Japan was a vulnerable opponent who required the use of the sea to import raw materials and to project military forces far from the homeland. Similarly, the U.S. must project power overseas and, like our allies, depends significantly on sea trade for both resources and essential industrial products. Second, the U.S. Pacific submarine campaign, much like the German U-boat campaign of World War II, incurred disproportionate costs on the side conducting ASW; there is every reason to believe the same would be true today.(50) Third, the indirect and second order effects of these campaigns were virtually as important as the direct costs. In the case of Japan, the U.S. submarine campaign substantially reduced Japanese war production, and, ultimately, significantly reduced the Japanese ability to implement their preferred defensive strategy. As a result, the submarine campaign proved itself as an efficient way to wage war against a competitor that must supply its forces over long distances by sea.

It is interesting to contemplate to what degree the United States is vulnerable today to a campaign by a committed regional power or peer competitor against our sea lines of communications. Within the U.S. Navy today, one hears some discussion on the possible impact of submarine attacks against our Battlegroups, but few consider the impact a campaign against our vulnerable sealift train might have. Since America remains dependent today on sealift to project military power, an opponent might well assess this vulnerability worth exploiting.

1 The German World War II campaign also resulted in disproportionate investment in ASW capabilities by the Allies (at least ten times the German investment in submarines) and placed significant logistical limitations on Allied strategy. See "Sea Control and Regional Warfare" by the same author in the July '93 Proceedings)

2 Janet Manson, Diplomatic Ramifications of Unrestricted Submarine Warfare (New York, Greenwood Press, 1990), pp. 154-158.

3 C. Blair, Silent Victory (Philadelphia, J.B. Lippencott and Co., 1975, p. xvi

4 U.S. Strategic Bombing Survey, The War Against Japanese Transportation (Washington, D.C., U.S. Government Printing Office, 1947), p. 47.

5 Joint Army-Navy Assessment Committee, Japanese Naval and Merchant Shipping Losses during World War II (Washington, D.C., U.S. Government Printing Office, 1947), p. vii.

6 Theodore Roscoe, U.S. Submarine Operations in World War II (Annapolis, U.S. Naval Institute Press, 1949), pp. 493, 853.

7 An example of submarine induced direct costs is loss of enemy merchants or warships; example of indirect costs are loss of part of the effective merchant fleet due to convoying; example of second order costs is the cost of additional escorts built to combat submarines.

8 Mark Parillo, The Japanese Merchant Marine in World War II (Annapolis, U.S. Naval Institute Press, 1993), p. 75.

9 Strategic Bombing Survey, Japanese Transportation, pp. 60, 108-109. This study indicates there was a number of factors that were important, but that in most industries, industrial output was directly linked to imports of primary materials.

10 Parillo, Merchant Marine, pp. 75-78.

11 Strategic Bombing Survey, Japanese Transportation, p. 4.

12 Parillo, Merchant Marine, p. 207.

13 Ibid., p. 218.

14 Strategic Bombing Survey, Japanese Transportation, p. 48.

15 Parillo, Merchant Marine, p. 215.

16 Ibid., p. 215.

17 Mark Parillo, "The Imperial Japanese Navy in World War II," in Reevaluating Major Naval Combatants of World War II (New York, Greenwood Press, 1990), p. 64.

18 W.J. Holmes, Undersea Victory: The Influence of Submarine Operations on the War in the Pacific (Garden City, N.Y., Doubleday, 1966), p. 425. C. Blair, op. cite., p. 792.

19 Parrillo, Merchant Marine, p. 46.

20 Strategic Bombing Survey, Japanese Transportation, p. 110

21 Parrillo, Merchant Marine, p. 213.

22 Ibid., pp. 109-110.

23 Ibid., p. 113.

24 Ibid., p. 112.

25 Parillo, Merchant Marine, p. 213.

26 J. Belote, Titans of the Seas (New York, Harper and Row, 1975), p. 280.

27 Potter, op. cite., p. 326.

28 Parillo, Merchant Marine, p. 212.

29 U.S. Strategic Bombing Survey, Japanese Naval Construction (Washington, D.C., U.S. Government Printing Office, 1946, p. 4.

30 Strategic Bombing Survey, Merchant Shipping, p. 3.

31 Strategic Bombing Survey, Naval Construction, pp. 9-10.

32 Ibid., p. 3.

33 Strategic Bombing Survey, Japanese Transportation, pp. 4, 21. Iron Ore imports fell from 6.3 million tons in 1941 to 2.2 million in 1944 and 341,000 in 1945. As a result, steel deliveries to naval shipyards in 1944 were 58% of that delivered in 1941.

34 Strategic Bombing Survey, Naval Construction, pp. iv, 11-12.

35 The Japanese calculated merchant marine efficency by a factor called Kakoritsu. Kakoritsu is computed by dividing actual cargo carried (in metric) tons in a given time period by the cargo carrying capacity of ship's in use during that period in that particular service.

36 Strategic Bombing Survey, Japanese Transportation, p. 51.

37 The delays were caused by the need to await sufficient merchants and escorts to form convoys and by the Japanese tactic of running some convoys near the coast- which lengthened the distances that needed to be traveled.

38 Strategic Bombing Survey, Merchant Shipping, p. 32.

39 Ibid., p. 3.

40 Ibid., p. 3.

41 Parillo, Merchant Marine, p. 211.

42 Ibid., pp. 139-141.

43 Ibid., pp. 1-5, 211.

44 Ibid., p. 211.

45 Ibid., p. 211.

46 Ibid., pp. 213-215. Only 3% of deaths on New Guinea were due to combat. Some Japanese opted for suicide rather than the slow starvation that caused so many deaths.

47 Ibid., p. 175.

48 The U.S. Strategic Bombing Survey includes cost data on Japanese ships (although the relative exchange rate between the U.S. and Japan must be estimated).

49 B.R. Mitchell, International Historical Statistics, Africa and Asia. (New York, New York University Press, 1982), p. 761. U.S. Data from: World Almanac of 1940, op. cite., pp. 559, 604.

50 In my July 1993 article I make the case that the Germans submarine campaign placed significant logistical constraints on the Allies even after the Germans had lost the U-Boat war; furthermore, the Allies required a disproportionate resource investment to defeat the German U-boats. British forces used many platforms and over 200 ASW weapons with no successful hits against a single unlocated Argentine submarine during the 1983 Falklands war.

http://www.fleetsubmarine.com/ss-166.html[/email]

Last editorial comment. I am an expert on the US Pacific War.

My statements may be fact-based opinion, but they are not false in the slightest.

Those are very similar to the the same views held by the United States Navy.    

And yes BP landmines is something I have unfortunate experience with.  

[P3D]

And which Nverse nation would have inadequate testing before accepting a new weapon?

But one can run a lot of tests and arrive at wrong conclusion, if the initial test criteria are faulty - as the RN had learned after Jutland, and the US Army with the 76mm tank gun.

As for the 76mm gun, it worked too. It was the 75 that you mean and in a curious way that is also very misunderstood when it is called a failure.

I meant the 76mm gun. I recall from somewhere that the ammo tests were done at perpendicular penetration, and the shells had subpar performance against sloped armor - APCBC had the same performance as  the 7,5cm KwK 40 L/43 (with 40m/s less MV), which degraded worse as the impact angle increased.

http://www.freeweb.hu/gva/weapons/german_guns5.html
http://www.freeweb.hu/gva/weapons/usa_guns5.html

And 91mm@30* won't penetrate Panther's upper front hull, 80mm@55*. HVAP could penetrate, but those rounds were available August '44 in limited quantity.

McNair, TDs and 76mm Shermans...

Indeed, the 76mm Sherman was available, but no one wanted it, armored commanders (like Abrams) and the Tank Board included. 75mm can deal with the Pz IV, has better HE, and the occasional Tiger can be dealt with like in Tunisia. Their new heavy tank with fancy sloped armor should not be a big problem either.
However, Panther was not a heavy tank but a mass-produced "MBT". So field commanders got their wish with 75mm armed Shermans, and the 76mm armed tanks were sitting in warehouses in the UK.

A gigantic (45 page) thread on Tanknet on this topic, might take a few hours to read:
http://208.84.116.223/forums/index.php?showtopic=32156&st=0

[ctwaterman]

My statements may be fact-based opinion, but they are not false in the slightest.

Hey Play Nice we are all expressing Opinions here even Commander Poirier is simply using Statistics and Facts to support his arguement.

Ok that being said... I will hopefully not have my 2 pages of replys eaten by the computer this time.  So I will try to be Brief... ;D ::)

I have always been a suporter of a Balanced Fleet Option.   A Dozen or even 2 Dozen subs cannot replace a battle ship in all circumstances.   They cannot provide AAA defense to a Carrier, nor can it provide Naval Gunfire Support to an Amphibious landing.  I also doubt you would find enough volunteers among the crew of One Iowa class BB to man 20 Subs...????   To many people do not like boats that sink or really really tight confined spaces.

In addition Japanese failures in the Radar Department really hampered their Convoy and ASW escorts.

So given my choice and realizing that without Radar a sub can only see a very very small circle around itself and with Radar that circle only increase slightly then I want to Have Destroyers, Subs, Cruisers, Battle Ships and Carriers... all have their uses and an all Sub force or all Destroyer force is unbalanced and has limitations.

Charles