The other lucky break was that the U.S. Navy of that era tested its ideas on the game floor of the Naval War College, i.e., not only at sea. Thus the ships and aircraft involved could adopt whatever characteristics seemed relevant to future warfare. Officers could see what the aircraft of the future (rather than existing relatively primitive ones) might contribute to a naval battle. The games showed how important it was to mass aircraft. Capt. (later Adm.) Joseph Reeves took this lesson with him when he assumed command of the aircraft of the Battle Force, which at the time meant mainly the few assigned to Langley. At the time, U.S. naval aviators followed the British practice of stowing each airplane in the hangar before the next landed onto the carrier, much as aircraft on land would be taxied to their hangars to clear a runway. That made for slow operation and limited numbers (hence the British insistence on large numbers of carriers at Washington in 1921). Reeves understood that he had to find some way to pack more airpower into even the small Langley. He found that airplanes did not need the whole deck on which to land. Instead of being stowed below, they could simply be wheeled forward, protected from landing aircraft by a wire barrier. In this way aircraft could be taken on board much more quickly, and they could be massed more easily for attack. Langley ultimately operated about four times as many airplanes as she had before Reeves arrived.
The contrast between Reeve’s view and that of the Royal Navy deserves comment. The difference may have been that the Royal Navy surrendered its aircraft to the new Royal Air Force in 1918. When it decided to run tests to see how many aircraft a carrier could operate, it deferred to the expertise of the pilots, who naturally had little interest in risking a crash into parked aircraft as they landed. They were much less interested in providing the mass of aircraft that a fleet commander might want. Reeves had a much broader outlook. He needed numbers, and the pilots were naval officers responsible to him. Their instincts as pilots were secondary. The new method of operation demanded tight discipline and careful control; it was no accident that U.S. officers visiting British carriers in the 1930s were struck by the looseness of their practices. Nor, probably, was it coincidental that U.S. naval aviators understood, and accepted, that theirs was a very dangerous business (the British view was quite different).
Given Reeves’ innovation, the two much bigger carriers operated about one hundred aircraft each. With such numbers, they could demonstrate the full potential of carrier aviation, to an extent far beyond what the British, who had invented the carrier, could imagine.
On board U.S. carriers, the number of aircraft depended on the size of the flight deck, on which all of them would be parked before taking off, or after having landed. The U.S. Navy therefore favored long flight decks. It thought of carrier hangars mainly as places where aircraft could be repaired. The British tended instead to emphasize hangar capacity. When they could not get enough on a relatively short hull, they developed double-level hangars. Before World War II they became interested in armoring the hangar, which included part of the length of the flight deck. U.S. carriers could not have accommodated a similar degree of protection, the theory being that their light wooden flight decks could simply be repaired at sea. When carriers of both navies suffered Kamikaze hits in 1945, many U.S. officers were impressed by the British designs, commenting that they simply hosed off what was left of the Kamikaze and resumed operations. They did not notice a price the British paid. During World War II they were compelled to adopt U.S. style flight deck practices in order to operate enough aircraft, but their designs made for short flight decks. Shorter flight decks made for many more aircraft missing arresting gear wires and bouncing into (or even over) barriers – and many more dead pilots. U.S. carriers were not nearly so dangerous.
Given Reeves’ innovation, the two much bigger carriers operated about one hundred aircraft each. With such numbers, they could demonstrate the full potential of carrier aviation, to an extent far beyond what the British, who had invented the carrier, could imagine. For example, during her first big fleet exercise in 1929, Saratoga made a surprise attack on the Panama Canal, showing that carriers could extend the reach of the fleet beyond attacking other fleets. The evolving U.S. strategy for a war against Japan, which was considered the most likely enemy, involved seizing island bases as the fleet moved west. Carrier aircraft could provide the Marines with the edge they needed when going ashore. One consequence was that all U.S. naval fighters were designed to carry bombs. By 1929, U.S. strategists understood how important carriers would be in such a war, and they began to discuss converting merchant ships – particularly fast liners – to swell carrier numbers.
Large carrier capacities justified a large naval air arm with considerable effect on the U.S. aircraft industry. Naval officers realized that carriers and naval aviation had a future as bright as that of the battleships, which were then the core of the fleet. It helped that Congress passed a law requiring that commanders of carriers and other naval aviation activities be aviators. By the late 1930s, the Navy’s General Board, responsible for advising the Secretary of the Navy and formulating U.S. warship building policies, was asking when aviation technology would mature to the point that carriers would replace battleships. By that time the main brake on U.S. carrier building was the treaty structure of the interwar years, the irony being that the 1921 treaty had provided an unusually large allowance for the time. That was because, even though the Washington Treaty lapsed in 1936, the pre-World War II U.S. naval build-up was based on a requirement to maintain a modern fleet of the size imposed by the treaty.
The foundation built between the wars made it possible for the U.S. Navy to shift towards a carrier-centered World War II fleet. Thus the very successful wartime Essex class, 24 of which were eventually built, was in effect an enlarged and expanded version of the prewar Yorktown, which was unusually large for its time because Lexington and Saratoga had demonstrated the value of massive numbers of aircraft on board each carrier.
As the United States came closer to war in 1941, work began on converting merchant ships into escort carriers, inspired to some extent by British experience. Once the war began, it seemed urgent to convert warships under construction into carriers. Projects to convert battleships were considered but rejected. However, nine new light cruisers became the Independence-class light carriers, fast enough to serve alongside the larger Essexes. Neither Britain nor Japan could build carriers at anything like this pace.