Radar and radar countermeasures were the most important of the sensory tools that came of age in World War II, Fleet Tactics and Naval Operations explains:
This category also includes the proximity fuze—a tiny, shock-resistant radar that significantly improved the effectiveness of weapons of many kinds. Used in shells fired against aircraft by a 5-inch, dual-purpose gun, the proximity fuze not only increased the allowable fire-control dispersion error by two or three times, it also simplified a three-dimensional fire-control problem by effectively turning the target area into a two-dimensional challenge.
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Britain established the first five radar stations, on the east coast of England, in December 1935.
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The radiation laboratory at the Massachusetts Institute of Technology, for example, increased its hiring a hundredfold—from forty to four thousand—to accommodate research in the new field of technology.
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As a tool of war, radar was ubiquitous. By the end of 1939 shipboard prototypes were being tested for long-range aircraft detection, antiaircraft fire control, and surface tracking. British and American collaboration produced a series of remarkable breakthroughs beginning in 1940. Centimeter-wavelength radars were ready for production in 1942, offering sufficient definition to be used for detection of single aircraft, for fighter direction, day or night, and for accurate gun-laying for both surface and AAW targets. By 1943 radar had been fitted in enough reconnaissance aircraft to have a major influence on search-and-attack missions against surface ships, and in enough antisubmarine patrol aircraft to reverse the momentum of the U-boat campaign in the Atlantic. From 1940 on, radar was vital to fighter defenses over land, and it was the key to the effectiveness of the offensive fighter and bomber sweeps before the Normandy invasion. For antiaircraft defenses, radar was just as important over land as at sea.
Radar quickly became an indispensable navigating tool as well. It permitted high-speed surface operations in narrow seas, and it came to be relied upon so much that when a ship lost her radar at night she was literally and psychologically lost.
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From the outset, Japanese tactics usually called for approaching in short, multiple columns, getting all ships into action at once, and maneuvering in defense against torpedoes. Sometimes destroyers would be positioned ahead as pickets to avoid ambush. When the pickets detected an enemy force, they would close, pivot, fire torpedoes, and turn away. Sometimes they would not fire their guns at all.
The U.S. tactic was to use a long, single, tightly spaced column. The Navy expected and achieved first detection and tried to position its columns so that all guns would bear across the enemy’s axis of approach, crossing its T.
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It was at the Battle of Vella Gulf on 6 August–7 August 1943 that U.S. tactics came together.
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Both divisions would move in, their bows to the enemy torpedo threat, wheel around, and launch their fish. As with Japanese tactics, all this would be done stealthily, without gunfire. After the shock of the torpedo barrage was over, gunfire and aggressiveness could be used in proportion to the damage done, but at that stage the destroyers would have to watch out for the death-sting of the now alerted enemy.
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The firing range was just 6,300 yards for a running range of 4,000 yards—as good a setup as could be expected, and all one could ask for. A minute later, a “turn nine” order came from Moosbrugger. His division executed a simultaneous 90-degree turn to starboard to clear out, combing the wakes of the predictable enemy torpedo counterattack. At the same time, Simpson wheeled his three destroyers to port and bored in.
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As in all good naval battles, the outcome was determined by the adoption of a feasible plan whose tactical cohesion came from training, good scouting, and the swift thrust of a killer weapon.
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They could now beat the Japanese with torpedoes—their adversary’s superior weapon. Good sensors, tactics, and scouting could overcome better firepower. And the United States would win with small ships because the destroyers carried the big weapon. It was the destroyers’ torpedoes—not the cruisers’ guns—that ruled at night. Hit-and-move was the answer, not crossing the T; units had to be nimble rather than fixed in a sturdy, steady, cohesive—and suicidal—column.
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In the conditions under which these battles were fought, crossing the T meant very little. The best tactic was to approach on a broad front, bows on (short columns abreast in practice), wheel anywhere within range and fire a barrage of two or three dozen torpedoes, then point all sterns toward the enemy’s reply. One of the American errors was to forget that combat is two-sided competition. Line tactics were based on the strength of the broadside, which nominally had twice the firepower that could be unleashed end-on. Line tactics overlooked the fact that a beams-to column exposed ten times as much hull to torpedoes as a line abreast pointed toward or away from the enemy. In force-on-force computations, by using the line-ahead formation the U.S. Navy imposed a fivefold penalty on itself.
There was a no-man’s-land of at least five miles in which no cruiser belonged. Experience had shown that with a torpedo barrage a handful of small ships could destroy a force that was larger and superior in killing power, at least by conventional reckoning. Somewhere in the Valhalla of warriors, Jellicoe must have looked down on those dark nights punctured with the violence of the torpedo and with a thin smile, shaking his head at the Americans who took so long to learn what he knew in 1916.
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If one counts large, light, and escort carriers together, then during World War II the aircraft of all countries sank twenty carriers, totaling an aggregate 342,000 tons. By comparison, submarines sank fifteen carriers amounting to 306,000 aggregate tons. For their part, surface warships sank only two carriers, for a total of 30,000 tons.
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Nazi Germany missed a golden opportunity to exploit land-based aircraft at sea. After the fall of France, a few sorties by the Luftwaffe demonstrated that its medium-range bombers could attack Allied Atlantic convoys effectively. But Hermann Goering’s penchant for attacks on land targets ruled out the development, production, and commitment of German aircraft to attack shipping in great numbers. The possibility that Germany might wake up to the opportunity haunted the harried Royal Navy through much of the war.
I have heard that Göring, and indeed his boss, did not believe in carriers. The one Germany was developing was scrapped before completion, as Göring wanted to have a say in all air activity, even at sea. I cannot speak for the US but the Royal Navy understood naval air power (via the Fleet Air Arm) was confined to local situations, requiring immediate answers rather than long term planning — and permission.
Had the Germans launched their aircraft carrier it would have had to become the number one target for the Royal Navy, as bombing and aerial born torpedos couple with submarines would have ended the convoys and Britain would have surrendered.