The Imperial Japanese Navy after Midway

This week, courtesy UltimaRatioRegis, is a look at the IJN post Midway. After suffering grievous losses in ships, sailors and airmen at Midway, the IJN was still far from finished.-for the moment.  For while Midway had turned the tide, that razor’s edge could cut the other way given the reed-thin status of the US fleet. So, what would the Japanese, led by their revered flag, Admiral Isoruko Yamamoto, the architect of the victory at Pearl Harbor, what would they do next? What *could* they do next? – SJS

On the eve of the epic fleet clash at Midway in early June, 1942, the Imperial Japanese Navy had very nearly driven the US and her Allies from the seas. The US Pacific Fleet battle line sat in the oily mud of Pearl Harbor, or was in drydocks stateside for repair of bomb and torpedo damage. The collection of gallant but obsolete warships that comprised the Asiatic Squadron had been hunted down and sunk, or chased to Australia, in the months following December 7th. Fleet carrier Saratoga (CV-3) had yet to return from Bremerton, where she was being repaired due to torpedo damage suffered in January, and getting a major refit which replaced her 8” guns with much more useful DP 5”-38 twin mounts . Yorktown (CV-5) was undergoing extensive repairs at Pearl Harbor from two bomb hits suffered at Coral Sea, in which Saratoga’s sister Lexington (CV-2) had been sunk.

It was clear, however, the US Pacific would not go without a fight. The stubborn bravery of Admiral Hart’s Asiatic Fleet against truly hopeless odds, Jimmy Doolittle’s carrier-launched raid on Tokyo, surprisingly effective US carrier raids on Japanese outposts (including Tulagi), and the blunting of the Japanese stab for Port Moresby at Coral Sea, all signaled that the US Pacific Fleet remained a dangerous force with remarkable fighting spirit.

The Battle of Midway was a catastrophic defeat for the Japanese, suffered at the hands of an inferior American force. It was a disaster from which the IJN would never fully recover. The sinking of four fleet carriers, a heavy cruiser, and loss of nearly 250 aircraft manned by veteran pilots could never be made good by the Japanese industrial base or her aviation training pipeline. US losses, carrier Yorktown, destroyer Hammann (DD-412), and 100 aircraft, were serious but temporary, and were offset once Saratoga returned to action, and the new Buchanan (DD-484) joined the Pacific Fleet in mid-June 1942.

Despite the disaster at Midway, however, the Japanese Navy held significant advantages over the US Pacific Fleet in nearly all categories in mid-1942. The IJN still badly outnumbered the US in aircraft carriers, (Shokaku rejoined the fleet after repair of damage at Coral Sea), and trumped the United States Pacific Fleet in battleships, heavy cruisers, light cruisers, and destroyers. The only warship type in which the US Pacific Fleet held an advantage over the Japanese was in submarines .

That disparity was more than simply numerical. Japan’s Navy was superbly trained and equipped, excellent in gunnery, and led by experienced and aggressive commanders. The Japanese held a decided advantage in warship and aircraft design, and fielded the finest and most lethal torpedo in the world’s arsenals. Their captains and crews were also highly trained in night surface combat.

Japan’s heavy cruisers, beginning with the four-ship Takao-class through the pair of Tones, were built in the 1930s well in excess of treaty limitations, and proved to be fast, powerful units, more than a match for American and Allied heavy cruisers of the same period. The excellent Fubuki-class destroyers and their successors were among the most heavily-armed of their types in the world until the US Fletcher-class began entering service in 1942. Follow-on classes of Japanese destroyers suffered weight issues (as did US designs) but overall were superb ships, much-respected by their opponents.

The heavy cruisers and destroyers, as well as Japan’s light cruisers, carried the deadly 24-inch Type 93 “Long Lance” torpedo. With a half-ton warhead and a range more than three times that of the American 21” Mark 14 torpedo, the Long Lance struck mortal fear into US ship captains, particularly at night. The Japanese were able time and again to inflict frightful damage to US units as the latter attempted to close range for a gun duel.

By contrast, problems with the US Mark 14 torpedoes, most notably the exploder, magnetic detonator, and depth-regulation, frustrated American submarine and PT skippers throughout the first two years of war. These defects thwarted what might have been several devastating attacks on Japanese carriers and capital warships.

In the air, the vaunted A6M2 “Zero” fighter had nearly swept the handfuls of obsolescent Allied aircraft from the skies of the western Pacific in the weeks following Pearl Harbor. By July of 1942, it was only the skill of US Navy pilots in exploiting the strengths of the stubby Grumman F4F Wildcat which offset the Zero’s considerable edge in climb and maneuverability, and prevented defeat in what would otherwise have been a short and unequal fight.

The Nakajima B5N2 “Kate” torpedo bomber was the most advanced aircraft of its type in the world in 1939, and in 1942 was still far superior to the vulnerable, lumbering Douglas Devastator that had met with such disaster at Midway and was in the process of being withdrawn from service. In addition, the Aichi D3A “Val” dive bomber was at least a match for the Douglas SBD Dauntless, and one of the few Japanese aircraft sturdy enough to absorb punishment and survive.

Perhaps the biggest advantage the Imperial Japanese Navy held over the US Pacific Fleet in the summer of 1942 was that of training for night surface combat. The emphasis on seeking and winning night combat, like that of torpedo technology and employment, was born of necessity. The provisions of the Washington Naval Treaty ensured that the Japanese Fleet would be at a significant disadvantage in the Jutland-style fleet actions anticipated by both sides in the event of war between the US and Japan. Therefore, the IJN sought to master a doctrine that would largely negate the US advantage in numbers of ships and weight of broadside. Night tactics were the answer. Great emphasis on individual and squadron formation and maneuver procedures, communications, night gunnery, use of flares and searchlights, resulted in the skills of fighting a night surface engagement being raised to a near-art form . Conversely, the US Pacific Fleet, not wanting to squander its numerical and power advantage, emphasized a doctrine that looked to avoid night combat.

Even after Midway, the Imperial Japanese Navy remained a most formidable opponent. But the eastern horizon was growing increasingly dark. The United States Navy was expanding with lightning speed. US shipyards and factories had revved into high gear. New aircraft designs were entering service or mass production that outclassed any Japanese machines. And by August 1942, the following warships were on the ways or awaiting completion in American shipyards :

• Six Fleet Carriers

• Eight Light Carriers

• Twenty-two Escort Carriers

• Five Battleships

• Four Heavy Cruisers

• Nine Light Cruisers

• One hundred thirteen Destroyers

• Twenty-nine Submarines

Yamamoto’s “sleeping giant”, was awakening. The Japanese had tipped the hourglass at Pearl Harbor. By August of 1942, the sand that measured the Japanese Navy’s pre-eminence in the Pacific had all but run out. The coming clash in the Solomons represented the last real chance for the Imperial Japanese Navy to inflict a strategic defeat upon the US Pacific Fleet.