How Superb Recon in the South Pacific Helped to Win WWII

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September 21, 2020 Topic: History Region: Oceania Blog Brand: The Reboot Tags: HistoryWorld War IIPacific WarIntelligencePBY

How Superb Recon in the South Pacific Helped to Win WWII

The Australian coastwatcher organization and the American “Black Cat” PBY Catalina flying boat squadrons made substantial contributions to minimizing Allied losses and ensuring that Japanese losses were ruinously high.

The Japanese force assembled off the south end of Bougainville. There were 61 ships there, including six cruisers, 33 destroyers, 17 transports, one large cargo liner, and many smaller vessels; another force of two battleships and escorts was also involved.

Signal intelligence warned of their coming, and the watchers on Bougainville spotted them on November 10, 1943. The coastwatchers and the Black Cats kept tabs on this force as it advanced down the Slot. There was a running fight all the way to the shore of Guadalcanal. Henderson Field was in the fight all day with planes shuttling from the field to the convoy and back again.

Both sides lost naval vessels. The U.S. Navy lost more vessels, but the Japanese lost more tonnage, including two irreplaceable battleships. The Japanese also lost 11 of their transports, and much of the Hiroshima Division drowned. Japanese destroyers picked up about 5,000 shocked, demoralized men without most of their uniforms and none of their weapons and equipment. Three of the transports were beached, and another, already on fire, attempted to beach. All the ships were taken under fire by Marine artillery and essentially destroyed.

This was really the end of Japanese hopes to hold Guadalcanal. A few weeks later, the evacuation began. For the rest of the campaign, the Allies would be moving north through the island chain.

The coastwatchers and the Black Cats, working in concert, played an important part in keeping Allied casualties disproportionately low. Both groups provided vital intelligence. Both inflicted significant casualties, the Cats directly and the coastwatchers by calling in aircraft. And, finally, both were directly involved in search and rescue.

Granted, Black Cats and coastwatchers were not the only reason Japanese losses were so hugely disproportionate to those of the Allies. Signal intelligence complemented the coastwatchers’ input, and cultural factors made the Japanese more willing to take losses; against Westerners, their infantry tactics were insanely aggressive.

The Allied leaders also consistently made good use of the mobility their naval and air strength gave them. The strategy of bypassing Japanese bases and giving the Japanese the choice of expensive evacuations or having their forces wither on the vine was used repeatedly.

Also, Japanese action on Guadalcanal seemed to suggest that if the Allies could build a perimeter on a major island the Japanese could be expected to take heavy casualties trying to break through it and drive them off. An effective Allied response involved limited attacks and choking off the enemy’s supplies. Eventually the Japanese would give up and withdraw. That strategy was used on Vella Lavella, New Georgia, and Bougainville. The Japanese never developed an effective counter to it.

Instead, Japanese leaders regularly put their troops in positions where they were nearly impossible to supply. As Emperor Hirohito put it, “I am tired of hearing that the troops fought heroically and then starved to death.”

Operation Shoestring gives lie to the myth that the Allies simply used their industrial power to bludgeon their way across the Pacific. But the main significance of the Solomon Islands campaign is the aforementioned change in the relative power of the Allies and their Japanese adversaries during that campaign.

Perhaps that change was least obvious on the ground. The Imperial Japanese Army began the war in the Pacific with around 50 battle-ready divisions. The Solomons campaign and the simultaneous fighting in the islands to the west whittled that down considerably. By late 1943, the building of a chain of air bases around Rabaul was complete; the Allies isolated it and took the troops there off the board, obviating the need for a bloody invasion.

Two Japanese divisions, two separate brigades, a tank regiment, a huge force of artillery, and a large number of service troops totaling about 100,000 men were trapped there and spent the rest of the war trying to grow enough vegetables to survive.

In and on the water the change in relative strength was more pronounced. Japan could not begin to replace the major fleet units it lost. Destroyers took less time to build than capital ships, and up to this point in the war 40 new Japanese destroyers joined its fleet—the same number they lost by the end of the campaign.

America lost the same number of destroyers but commissioned 200 new ones during that period. Moreover, using submarines and bombers to run supplies to Guadalcanal and destroyers to get critical parts and personnel to Rabaul removed them from the Japanese order of battle just as if they had been destroyed.

 American ships were becoming more numerous and, more importantly, more capable. Take one narrow facet of naval power: the ability to locate one’s enemy at night and engage it effectively. Japan’s training program for night lookouts was unequaled and its equipment was first rate.

In a night fight between surface ships, the Japanese could open fire first and fire more accurately than comparable U.S. units. They could usually hit more effectively because the Long Lance torpedo was more accurate and longer ranged that the American equivalent. The Long Lance remained a formidable weapon, better than even improved versions of American torpedoes.

Radar reversed the balance in night combat. American ships could usually see farther than the Japanese, and the fall of their shells was controlled by the increasingly available SG radar. As Captain Hanima of the destroyer Amagiriput it, “U.S. forces were using radar and we were powerless to prevent them from approaching … guns blazing.”

With the deployment of radar-equipped aircraft, Americans could now see even farther at night, and aircraft could alert American vessels to the location of Japanese ships well over the horizon. The improvement was so pronounced that had it happened earlier the pattern of daytime American control of waters around Guadalcanal and Japanese control at night might not have developed.

The change was most pronounced in the air. The Japanese air arm was strained even before the beginning of the Solomons campaign. At Midway the Japanese had lost four aircraft carriers. The incursion into the Indian Ocean and attacks on British installations on Ceylon cost Admiral Chuichi Nagumo’s air groups more pilots. The Battle of the Coral Sea had cost the Japanese an aircraft carrier, including pilots and the nonflying members of the air groups, and rendered still another carrier combat ineffective since it, too, had lost most of its pilots.

Whatever the total losses in Japanese bombers were in those first raids on Guadalcanal, it is clear that the rate of loss was unsustainable. After two days of raids there was a pause in the air activity while additional aircraft were flown in. On several occasions the air groups were temporarily stripped from the Combined Fleet, Japan’s main striking force. It, too, was gravely weakened. This was especially serious since training a pilot to be carrier qualified was so difficult. The last time the Japanese deployed carrier planes to Rabaul, they sent 173 aircraft of which only 53 returned.

By one account the Japanese lost 1,467 fighters and 1,199 torpedo and dive bombers during the campaign. Most of the aircrews were lost, too. It is fair to say Japan squandered its air assets by making so many long-range raids into the teeth of an effective American air defense.

As Japanese air power shriveled, American air power became increasingly dominant. At the beginning of the campaign, aircraft were sinking about one tenth of the Japanese supplies shipped; by the end, it was up to 25 percent. During October 1943 alone, Allied aircraft carried out about 5,600 sorties.

The Japanese policy of keeping an airman in combat until he was killed hurt their air arm gravely. American fighter pilots were in combat for a limited period of time. In the Army Air Forces, it was a certain number of missions. Navy squadrons were regularly broken up, and the surviving flyers were usually posted back stateside. There they were used to impart their experience to fledgling pilots. Not so the Japanese. The splendidly chosen and trained airmen were replaced by less qualified pilots.

As a result, when American forces assaulted the Caroline Islands a few months after the Solomons campaign, the combined Japanese fleet could not sortie. The same thing happened when MacArthur’s forces breached the Bismarck barrier farther west.

A few months later came the next attack in the Central Pacific and the Battle of the Philippine Sea. By this time American flyers who had been flying for two years before being assigned to a carrier air group were facing Japanese flyers whose training had been for three to six months and were stale from more months sitting idly in harbor.

The Americans were flying a new generation of aircraft with substantially better performance than the F4F, while Japanese industry had been unable to produce significant numbers of their planned followup to the Zero. The Americans calledthe Battle of the Philippine Sea the Great Marianas Turkey Shoot.

From the beginning of the conflict, Japan’s only hope of winning in the Pacific was to make the cost in Allied lives so high that the Allies would accept a negotiated peace. Dumbos and coastwatchers were among the factors that helped keep the Allies’ human cost relatively low. Poor choices on where to fight and hyper-agressive infantry tactics resulted in high Japanese casualties. Clear strategic thinking by the Allies combined with innovative weapons and tactics also contributed to Japans horrendous casualties.