Since at least the late 1950s, carrier aircraft have been able to match up evenly against land-based aircraft. While several major innovations made it possible to swap thousands of feet of concrete ashore for a steel deck afloat, the one without which the others would not have mattered was the steam catapult. Despite the leading role that U.S. naval aviation has played, the steam catapult was a British, not an American, invention. Moreover, its advent opened the U.S. Navy to two other British innovations that would prove invaluable.
At the beginning of the naval jet age in the late 1940s, the U.S. Navy was using hydraulic catapults to launch many of its propeller airplanes, but most of them could get by with rolling (unassisted) takeoffs. Their big propellers pushed so much air over their wings, even when they were moving slowly, that they generated enough lift for takeoff after rolling a few hundred feet. In contrast, a jet engine pushed no air at all over the wings. All it did was accelerate the aircraft. At some point, the airplane’s speed moved enough air to lift the aircraft off the deck. The only way to do that in a limited distance was to catapult the plane off the deck. But that was barely possible using existing hydraulic catapults and the considerable wind generated by the ship’s motion.
The Bureau of Aeronautics (BuAer) understood the problem. Hydraulic catapult performance only could go so far. In a hydraulic catapult, a system of pulleys multiplies the motion of a hydraulic ram belowdecks. The wire running over the pulleys is only so strong. Beyond a point, the wire breaks and the catapult fails. BuAer designed the most powerful hydraulic catapult it could (the H-8, which was mounted in carriers rebuilt to handle jets), while it searched for something better.
The bureau realized that the carrier’s key mission was to launch heavy nuclear bombers. Jet fighters might find hydraulic catapults marginally capable. A big jet bomber needed something much more powerful or it could not be launched at all. That mattered enormously. The nascent U.S. Air Force had tried and failed to monopolize what everybody thought was the crucial weapon of the future: the atomic bomb. Success in foiling the Air Force’s bid left the Navy with the problem of getting a 10,000-pound bomb plus bomber airborne from a carrier deck. The bomb alone weighed more than a 1941 carrier fighter. Moreover, the carrier should be able to launch the bomber from beyond the reach of enemy attack.
The H-8 could barely launch a short-range nuclear bomber, the North American AJ Savage (later redesignated A-2). The Navy’s goal, however, was to acquire a high-performance nuclear bomber with a range of at least 1,200 miles. A competition produced a variety of exotic designs, several of them for huge composite aircraft. The winner was a Douglas design for a twin-jet bomber, which became the A3D (later redesignated the A-3) Skywarrior. It weighed about three times as much as a contemporary jet fighter but had to be accelerated to about the same speed.
BuAer’s solution was a catapult that was similar to a gun. Instead of the elaborate pulleys of a hydraulic catapult, it would consist of a cylinder (the gun barrel) in which a piston (the bullet) would move. A shuttle attached to an airplane was fixed atop the piston. Firing a charge at one end of the cylinder would accelerate the piston down the tube and the airplane across the flight deck.
This catapult was included in the design of the huge supercarrier United States, which was intended to launch nuclear bombers. When the supercarrier was canceled in 1949, its role was shifted to the three big Midway-class carriers, which were to be rebuilt for their nuclear mission using the new type of catapult. The A3D was somewhat scaled down, but it retained its key capability (it helped that somewhat lighter nuclear bombs were developed). All of this made it essential that the first rebuilt Midway be ready when the A3D completed development. The deadline was about 1953.
Unfortunately, despite considerable work, the explosive-driven catapult did not function properly. That was aside from the practical question of how a carrier could accommodate the considerable weight of special explosive cartridges needed for multiple launches.
At this point, the steam catapult entered the picture. Like their American counterparts, the British realized the necessity of developing a better alternative to the hydraulic catapult. For them it was an even more urgent matter. Their carriers tended to be smaller than U.S. flattops, and their catapult tracks shorter. Like the Americans, the British knew they needed a direct-acting catapult, using a piston to drive its shuttle. They were luckier in that one of their engineers, C. C. Mitchell, realized that another way to drive the piston was by using the ship’s own steam (BuAer had considered and rejected this idea). Mitchell’s approach turned out to be much simpler than the bureau’s explosive one. The British provided his designs to the U.S. Navy, but BuAer was not interested in an idea it already had vetoed.
It took a crisis to resolve the situation. As the first flight of the A3D approached, the Office of the Chief of Naval Operations (OpNav) kept asking BuAer if its catapult would be ready in time to install on board the Midway (CVB-41). The repeated reply was that a few more details had to be ironed out, but everything would work as intended. OpNav, which realized how vital the A3D’s success was, began to grasp that the explosive catapult could not possibly be ready in time.
Fortunately, the U.S. naval attaché in London, Rear Admiral Apollo Soucek, was an aviator and fully realized what was at stake. He made sure OpNav understood there was a viable alternative to BuAer’s explosive catapult, and he personally arranged for the British test platform, the modified aircraft repair ship Perseus, to visit the United States to demonstrate the steam catapult. The tests, which took place between December 1951 and February 1952, persuaded the Navy to adopt the steam catapult, which was built under license in the United States as the C-11.
Even before the demonstration, the combination of explosive catapult setbacks and Soucek’s account of British catapult success had pushed the U.S. Navy toward an appreciation of the value of British carrier ideas. Until that point, U.S. aviators generally remembered the Royal Navy as flying American Lend-Lease airplanes, which replaced clunkier British ones such as the Swordfish biplane. Now they saw British thinking in a new light, resulting in the adoption of two other key British carrier innovations: the angled deck and the mirror landing sight. But even without those, the steam catapult made it possible to launch heavy bombers from carriers.
To paraphrase the subtitle of retired Navy Vice Admiral Jerry Miller’s book Nuclear Weapons and Aircraft Carriers (Smithsonian Institution Scholarly Press, 2001), the nuclear bomb saved naval aviation. And it took a large heavy bomber, at least initially, to give the Navy a credible nuclear punch. In the 1950s, after the Korean War, U.S. national strategy was to keep the peace by nuclear deterrence. A navy that could not have contributed to the deterrent would have been decimated—with unfortunate consequences for the United States when its carriers and aircraft would be badly needed in the non-nuclear Vietnam War.
Afterward, as smaller nuclear bombs became available, smaller airplanes could deliver them, and strategic submarines largely, but not completely, eclipsed carrier bombers in the strategic role. The ability to launch really heavy airplanes remained and made possible heavy high-performance fighters such as the McDonnell F-4 Phantom II.
Later during the Cold War, the nuclear-attack role and the fighter role in effect reversed. In case of war, the carrier’s ability to deliver nuclear strikes forced the Soviets to plan to wipe out the carrier force as quickly as possible using their own naval bomber force. Because carriers could launch really large airplanes, they could operate long-range heavy fighters, such as Grumman F-14 Tomcats. In the 1980s the Navy envisaged an “Outer Air Battle” in which the Tomcats would destroy the Soviet naval bomber force in a decisive fight for air superiority. But without the steam catapult, there would have been no heavy fighter and no Outer Air Battle.