Engineers of Victory

by Paul Kennedy

  When MacArthur at last fulfilled his promise “I shall return” and marched ashore through the shallow waters for photographic effect in October 1944, he gripped the news editors’ attention. But that photo op was possible only because the Seabees had skillfully operated the pontoon barges and causeway units that brought the army—and the photographers—ashore in the first place. Very soon, 37,000 men of the Naval Construction Force were spread across the Philippines, building the main fleet bases, submarine bases, airfields, repair facilities, roads, housing, and hospitals for the gigantic military force that would then leap northward to Japan itself.50

  The invasion leap did not happen, for Hiroshima and Nagasaki brought the war to a close much more swiftly than most planners expected. The instrument of victory was a B-29 carrying the first atomic bomb, which took off on August 5 on its fateful overnight flight from one of the Tinian airstrips, so recently laid out by the Seabees, so recently captured by the marines, and in turn protected by the fast carriers. The symbiosis is remarkable.

  The Seabees didn’t just build things; they fought and took casualties again and again. During the marines’ troubled assault on Tarawa, these engineers had to figure out, under heavy fire, how to get landing craft, and then tanks, across low-lying coral reefs. The Seabees took casualties in so many battles simply because they had to be in the second wave that stormed the beaches, at Guadalcanal, Sicily, Anzio, Saipan, Normandy, and elsewhere. But this of course was Moreell’s original point: they were fighters as well as construction workers, because before one could dismantle an enemy’s coastal blocks and barbed wire, one might have to kill the soldiers lurking behind them. In the Pacific theater alone, the Seabees earned more than 2,000 Purple Hearts; they lost around 200 men in combat, and significantly more in dangerous construction jobs. Their stamina was remarkable. Fifteen hours after the marines had wiped out the remaining Japanese garrison at Tarawa, the bomb-cratered airfield was working again.

  When the Marshalls were taken in February 1944, the coconut-fringed Majuro atoll was converted into a major fleet base with all facilities (including a U.S. Navy officers’ club), while nearby Kwajalein was converted into a gigantic airfield and repair center, with far fewer creature comforts (for the army officers). The Carolines were the logical next step, because they had a superb position for supply lines to the intended invasion of the Philippines. By September 1944, the Seabees were constructing facilities there, including Pelelieu, which had been fought over so hard, as well as on the island of Morotai, which was MacArthur’s key stepping-stone between northwest New Guinea and the southern Philippines.

  The crown jewels of the Western Pacific, that is, the Marianas, had been taken a couple of months earlier. The Seabees’ role at Guam, Saipan, and Taipan in June and July 1944 was possibly their greatest during the war. Guam was important symbolically—the first American territory recovered from the enemy—and Saipan was to be turned into another huge naval base for the U.S. Pacific Fleet as well as an air base. Tinian, however, was the main prize. Though it was small, it was also relatively flat and low-lying, more like a massive wheat field in East Anglia than the spiny highlands of New Guinea or even the nearby jagged cliffs of Saipan. It had airfields already built on it, and space for more.

  Tinian’s chief problem—at least as viewed by the invasion forces—was the difficulty of access. One could come ashore at the best beaches, at Tinian Town itself, but that was where the Japanese had the fiercest defenses. To the north were the improperly named White 1 and White 2 beaches, which were tiny in width and guarded by low coral cliffs. There was, for example, only room for a maximum of eight LVTs at a time, compared with the ninety-six in each wave at Saipan, so the chances of being either stranded on the coral (as at Tarawa) or blown apart in a narrow funnel of a beach were significant. Yet the invasion, on July 24, 1944, turned out to be surprisingly easy, with far fewer casualties than at Saipan and Guam. The Americans put 15,000 men on White 1 and White 2 that day, about the same time as the Red Army reached the Vistula, Bradley broke out in Normandy, and Mark Clark’s armies started pushing north of Rome. The Axis defenses were all crumbling at the same time; imperial overstretch, a sort of collective geopolitical “metal fatigue” (as the engineer Moreell might have thought of it), had set in.

  Tinian was another superb example of how to do amphibious warfare. American forces staged a major but phony landing effort at the more predictable target of Tinian Town, together with a big naval bombardment, and as with the Normandy operation, deception paid a big reward. Japanese attention, like Hitler’s and Jodl’s, went to the wrong place. Then the marines came ashore, one company at a time, through the narrows of the White beaches; a whole regiment was on land within three hours, and with complete surprise. But all this only happened because the Seabees had devised and then operated special movable ramps that could get the fighting troops and their equipment over the outlying reefs.51

  That was only the beginning. The major work was the construction of the airfields that would allow the systematic destruction of Japan’s war capacities. Within a few weeks of the capture of the Marianas, the air bases—that is, tarmac runways built on foundations of ground-up coral, plus the wiring, control towers, Quonset huts, perimeter fences, engineering sheds, and radar stations—were being built. In all, the Seabees built five major air bases on the Marianas: one on Guam, one on Saipan, and no fewer than three on Tinian. Each of those five bases had a four-group wing capacity for the incoming B-29s. Tinian therefore could contain twelve groups. The Superfortresses began to arrive in mid- to late October 1944, while the Seabees were still expanding the base facilities. As noted above, the first raid against Tokyo, by 111 B-29s, was flown on November 24, 1944, out of the Marianas. From this time onward, endless streams of high-flying B-29s, glinting brilliantly as the Pacific sunshine reflected off their silver bodies, headed north to punish the enemy.

  The Silent Service

  The fifth piece in the Pacific tool kit was the U.S. submarine service, whose history is much less well known than that of the marines and the B-29s, partly because by definition the submarines were far less visible. American submarines in the Pacific War were chiefly independent actors. By their very nature, submarines are silent and subversive, hiding in the depths and surfacing for air under vast, lonely skies. In this respect, Germany’s massed wolf packs in the mid-Atlantic struggle were very much the exception. In the later stages of the war, it is true, the increasing capacity of American cryptographers to read Japanese naval codes meant that the commander of Pacific submarines at Pearl Harbor could instruct three or four boats to converge on an enemy battle group. Generally, though, submarines were lone rangers, didn’t indulge in frequent reports to headquarters, and liked it that way.52 Thus it is no surprise that the U.S. submarine service wasn’t intimately connected with that four-part operational and technical story outlined above, the quartet of Marine Corps amphibious doctrine, fast aircraft carriers, B-29s, and Seabees, which combined to force their way across the Central Pacific.

  But American subs did play an important role in the collapse of Japan, and very often mixed their independent ghost-rider roles with coordinating actions that helped the broad advance across these wide waters.53 To begin with, since aircraft reconnaissance was limited by range, they were often deployed as the “eyes” or forward scouts of the U.S. Navy, spotting Japanese warships coming out of the San Bernardino Strait, or others heading to reinforce Rabaul. This shadowing role was not very attractive to aggressive submarine captains unless they were also allowed to attack, but it was invaluable to Nimitz in Hawaii and Halsey with the Southwest Pacific Fleet. In late May 1944, the USS Harder was sent to patrol and report from the harbor of Tawi Tawi, which she did with great care; but she also managed to sink no fewer than five Japanese destroyers in four days, provoking the Japanese fleet to sail early and head toward what became the Battle of the Philippine Sea.54 Other U.S. submarines, during the multiple battles at Leyte Gulf later in the year, spot
ted the enemy’s main battleship and cruiser squadron steaming through the Palawan Passage and alerted Halsey to prepare his response (they also sank two heavy cruisers and damaged another before retiring). And at the close of the war it was another pair of submarines that first detected the giant battleship Yamato on its one-way suicide run toward Okinawa.

  As the American war effort in the Pacific reached its crescendo, the submarines were to play additional ancillary, but again extremely valuable, roles. For example, they could act as navigational guides or “course correctors” for the streams of USAF bombers heading toward Japanese cities in obscure weather conditions. They ferried supplies and agents to assist the resistance movements in the Philippines and returned with new intelligence about the enemy’s forces. They also, when needed, acted as a sort of lighthouse for amphibious forces approaching enemy-held beaches in the hours before dawn, a technique that had been perfected earlier by a specially trained squadron of Royal Navy submarines during the North Africa and Sicily landings.

  Finally, this jack-of-all-trades craft was used to rescue American airmen who were forced to ditch their damaged planes as they returned from raids upon enemy targets. This useful service was already in operation by the time of the Gilbert Islands operation in November 1943, and by the end of the following year U.S. submarines had picked up no fewer than 224 downed aviators. By the time Curtis LeMay’s B-29s were flying off the Mariana air bases, three subs were on rescue duty for every aerial mission; another 380 aviators were picked up during the war months of 1945, saving lives, returning skilled airmen to the force, and immensely boosting fliers’ morale.55

  But the greatest feat of American submarines in the Pacific War was the decimation of the warships of the Imperial Japanese Navy and, even more, of the Japanese merchant marine.f 56 Because the U.S. submarine service knew that it, like all the other branches engaged in the Pacific War, would have to grapple with the tyranny of distance, it had constructed large fleet submarines, usually displacing 1,500 tons and a few going up to 2,700 tons, with ample food and fuel supplies, even some refrigeration, giving a boat a range of 10,000 or more miles. They were nothing like the small European submarines that prowled around the shallow waters of the North Sea and the Mediterranean, and even Doenitz’s later U-boats were considerably smaller than the American subs in size.

  On the other hand, at war’s outbreak the U.S. submarine service probably had the worst torpedoes of any major navy: the Mark 14 torpedo, which seemed an impressive instrument of destruction, had not been rigorously tested, since the cost ($10,000 each) was a greater concern to the Torpedo Bureau at Newport, Rhode Island, than its reliability. Even when war broke out, commanders were cautioned to use them sparingly. There were forward U.S. submarine bases in the Philippines (soon shifted to northern Australia) and at Pearl Harbor, and American naval strategy counted upon them doing significant damage, but for a long while no one appreciated that they were using faulty weapons.

  These early American torpedoes had not one but three faults. The first was that the metal contact pin at the head of the torpedo, which was supposed to detonate the mass of TNT upon impact, was simply too weak to do the job. The frustration of submarine captains, who had perhaps spent many an anxious hour maneuvering to get in a good position and fired a spread of torpedoes, only to hear a dull bang against a Japanese hull, was understandable—but the cause was not known for quite a while. The second weakness was even harder to understand. The U.S. submarine service had come into the war with torpedoes possessing highly sophisticated magnetic mechanisms; that is, a torpedo fired at an enemy ship would detonate nearby, and the destructive power of a nearby explosion in water would be greater than a direct hit. Yet the Bureau of Naval Ordnance and the jealously monopolistic weapons development branch at Newport had never tested this ingenious system with a live warhead, nor had they considered that the magnetic field of a target cruising off the Marshalls might be different from that of one off the shores of Rhode Island, where the tests were done. Third, many of the torpedoes that were fired in the early period of the war passed well under their targets because the Mark 14 torpedoes had a tendency to run far deeper than their setting dictated. Often, then, either the torpedo missed entirely or the firing pin malfunctioned upon impact. In either case there was no kill.g

  But how was a submarine commander in distant and dangerous waters to know any of this, when the so-called experts back home were convinced all was well? In fact, only in the summer and fall of 1943 did the Navy scientists at Newport work things out. For almost two years, commanders who complained that their torpedoes were “duds” or were going wide of the target were told to get closer before launching. Only after tough and experienced submarine captains such as Dudley W. Morton and Roy S. Benson had told Rear Admiral Charles A. Lockwood, the Central Pacific commander of submarines—often in purple language—that things were badly wrong did the situation begin to change. The simplest way to test the defects was to fire torpedoes at an isolated stretch of cliffs near Hawaii and watch the dismal results. In June Nimitz ordered the return to contact torpedoes, not magnetic-field ones; the depth control mechanism was improved in September 1943, and the contact pin was replaced by a much more reliable one. It had taken the U.S. Navy a good twenty-one months to produce a reliable torpedo, and most of the initiative came from regional commanders and captains, not the home authorities. This improvement did not happen in the Southwest Pacific because the officer in charge there, Captain Christie, had earlier played a role in developing the magnetic-field torpedo and was loath to see it go—until ordered to do so, right at the end of 1943.57 Allied forces had their own large share of unimaginative, obstructionist bureaucrats, as well as of visionaries.

  A detailed account of the American submarine campaign in the Pacific after June 1944 is not needed here, but its impact is not in doubt. Roskill reports, “Although every year of the war had seen an increase in the rate of loss inflicted upon the Japanese merchant navy, it was not until November 1943 that it rose steeply.”58 Despite the intense battles of 1942, the merchant marine’s net loss was a mere 239,000 tons; by 1943, it was a dangerous 942,000 tons; and by 1944 it was a colossal 2,150,000 tons. Entering 1945, the Japanese merchant marine was about one-quarter the size it had been when Pearl Harbor was attacked. Mass starvation loomed, as did industrial collapse.

  The obvious thing to note about the above statistics is that the surge in sinkings took place from the second half of 1943 onward, through 1944, and then petered out in 1945, as by then there were hardly any targets to sink. In consequence, virtually all of the top ten American submarine aces in the Pacific War made their kills after June 1943, almost the exact opposite to the story of their German U-boat counterparts in the Atlantic campaign.59 There were many other factors to explain the enormous damage that the U.S. submarine service wreaked upon Japan in the last two years of the war (for example, improved radar, more powerful warheads, better intelligence, better air-sea cooperation), but the single most important one was the creation of torpedoes that were reliable, efficient, and deadly. Something that worked came about because certain problem solvers in the middle had pushed things forward.

  After the fall of the central Filipino island of Luzon in January 1945, and though Manila itself was not fully secured by MacArthur’s forces until March 4, Admiral Halsey reported that “the outer defenses of the Japanese Empire no longer include Burma and the Netherlands East Indies; those countries are now isolated outposts, and their products are no longer available to the Japanese war machine.”60 This was true, but in fact those Japanese sea-lanes were being systematically cut (and eventually would be totally interdicted) by the U.S. submarine service, at far less cost than fighting on land. When the war ended, some enthusiasts claimed that the subs alone could have brought an import-dependent Japan to its knees without the A-bombs or the massive landings planned for November 1945.h That of course is a hypothetical, but it shows the long way that the U.S. submarine service had come since the
unsuccessful days of 1942 and much of 1943.

  Any account of submarine warfare in the Pacific also has to note the amazing and catastrophic failure of the Japanese navy to use its own craft and to protect its own merchant marine. This is all the more puzzling, since Japan’s navy had from 1868 almost uniformly followed the Royal Navy’s best practices and ought surely to have drawn tactical lessons about underwater warfare from both the First World War and the current Battle of the Atlantic. The problem was not in the boats themselves—a considerable number of the Japanese submarines were, like their American equivalents, very large, with great cruising range, and possessing the famous “long lance” torpedoes—but in their deployment. There was blatant neglect by the naval high command of the submarine’s natural role as an independent and aggressive commerce destroyer; later, there came the further distortion of that role by Imperial General Headquarters. The battleship-dominated naval leaders were obsessed about using submarines to detect and destroy Allied warships, not their merchant marines. In this, they had some successes early in the war, especially in enclosed waters such as those in the Solomon Islands; the Wasp was sunk under precisely such circumstances, and a Japanese sub finished off the Yorktown after it was badly damaged at Midway.

  But when U.S. antisubmarine warfare tactics improved, when miniaturized radar reached the aircraft and warships of the Pacific Fleet, when the ocean was flooded with dozens and dozens of new destroyers, and when the new fast battleships and fast carriers became the core of the American navy, the prospects of causing large U.S. warship casualties fell away. Japan’s huge subs (some of them designed to carry and deploy spotter aircraft, and several even to be submerged mini aircraft carriers) were easy to detect on the surface by radar and underwater by sonar; they were noisy and difficult to maneuver, and because their hulls were weak, they were easy to hit mortally. No “schnorkel” fast boats were developed along German lines, and a primitive form of radar was placed on the first boats only in mid- to late 1944. Air-sea cooperation was feeble. Before and during the war, Japanese yards constructed 174 oceangoing submarines, of which 128 were lost. Morale in the service was low, since its officers knew that they had no support in high places, and the service steadily shrank until it was a second-class instrument of war, in distinct contrast to the sub forces of the German, British, and American navies.61