The arrival of the U.S. Navy’s large aircraft carriers USS Lexington (CV-2) and USS Saratoga (CV-3) at the end of the 1920s heralded an era of breathtaking progress in shipboard aviation. Built upon battlecruiser hulls, the new carriers completely overshadowed the comparatively primitive USS Langley (CV-1). Their massive size permitted the embarkation of air groups of nearly 100 aircraft each, coupled with speeds in excess of 30 knots, well exceeding that of the battleship fleet, raised the prospect of independent missions for carriers.
Although the aircraft carrier was initially intended to support the fleet’s battleships by protecting their all-important gunfire spotter planes—and denying the enemy his own—new horizons beckoned. Carrier-based aircraft could carry bombs and even torpedoes on attack missions, and the swiftness of the new behemoths demonstrated that carrier planes could indeed strike from over the horizon, catching ships and shore bases unaware.
The Navy’s annual exercise in 1929 validated the concept of independent carrier task forces with surprise attacks on the Panama Canal. In 1932, Admiral Harry Yarnell demonstrated the effectiveness of the carrier even further when he launched a dawn raid off Oahu with both Lexington and Saratoga’s air groups. The raiders arrived over Army and Navy installations with complete surprise and inflicted simulated damage on the fleet’s battleships inside Pearl Harbor.
The Washington Naval Treaty, which permitted the conversion of Lexington and Saratoga, allotted a total of 70,000 tons for further carrier construction for the U.S. Navy. After considerable debate, naval planners opted for smaller carriers to fulfill the allotment to provide more flight deck space for aircraft. The result was the USS Ranger (CV-4). Commissioned in 1934, Ranger was America’s first ship designed and built from the keel up as a carrier.
Just under half the displacement of Lexington, Ranger could nevertheless embark nearly as many aircraft. However, Ranger’s smaller hull necessitated a compact engineering plant, generating barely 30 knots maximum speed. Ranger proved to be a compromised ship with disappointing performance.
Meanwhile, the aircraft side of carrier aviation progressed steadily and rapidly. A major advance was the development of dive bombing, which solved the problem of hitting maneuvering ships with falling bombs. By diving steeply towards a target and releasing at a lower altitude, an aircraft could place a bomb much more accurately than dropping from level flight at high altitude. Though the technique was introduced in 1926, the evolution of more powerful engines permitted ever greater payloads and combat radiuses, so that by 1936, shipboard aircraft began to pose a lethal threat to capital ships. Additionally, better engines permitted refinements in airframe design with all-metal structures, retractable landing gear, and monoplane layouts becoming commonplace.
In 1926, Congress mandated that naval aviation squadrons, ships, and bases be commanded by “qualified” aviators only. By then, naval aviation was already a prestigious arm of the Navy, and several ambitious mid-career officers applied for aviation training in order to assume such commands. Unlike the carrier arms in Britain and Japan, this act infused U.S. naval aviation with officers of sufficient seniority to give it credible standing with the service’s other arms, and ultimately provided much of the top leadership during World War II.
With the hard-won lessons of Ranger in mind, designers opted to retain the advantages of maximum aircraft capacity, but with a better engineering plant. The results were the USS Yorktown (CV-5) and USS Enterprise (CV-6), commissioned in 1937 and 1938, respectively. Both carriers displaced 10,000 more tons than Ranger, but with aircraft complements and top speeds rivaling those of Lexington and Saratoga. Though exceedingly capable designs, Yorktown and her sister ships were vulnerable to damage, particularly with the concentrating of boilers and engines in shared spaces to save tonnage.
Even after the completion of the Enterprise, enough tonnage remained for another Ranger-sized carrier, the USS Wasp (CV-7). Completed in 1940, two years after the treaty impositions disappeared, Wasp featured novel weight saving measures such as an asymmetrical upper hull to balance the weight of an island, and the first deck-edge elevator. Unfortunately, squeezing into the 15,000-ton margin meant the new carrier utterly lacked any damage protection.
By decade’s end, the world was drifting steadily towards war, but U.S. carrier aviation was well prepared to hold the line until the inevitable wartime build up took hold and the United States was drawn into the global conflict. That wait for war, however, was shorter than many imagined.