The Pacific War was the heyday of the aircraft carrier. Before war broke out, carriers were regarded as an important supporting element for the battle line; by the time the war ended, they effectively were the battle line, displacing battleships as the queens of the fleet. Five major carrier engagements were fought during the war: Coral Sea, Midway, Eastern Solomons, Santa Cruz, and Philippine Sea. By contrast, there were only two battleship engagements: Guadalcanal and Surigao Strait.
Aircraft carriers themselves are nothing but floating airfields. A few of the earliest carriers, converted from battle cruiser hulls under the terms of the naval disarmament treaties, carried 8" (20cm) guns and had substantial armor belts. But most carriers were armed only with dual-purpose and antiaircraft guns, and their armor protection was comparable to that of a cruiser. Their power lay in their air groups, which typically were composed of three to five squadrons of fighters and light bombers, a total of 60 to 90 aircraft. Whereas a battleship could fire shells to a distance of perhaps 30 miles (and rarely hit a maneuvering target at that distance), the air group of an aircraft carrier could project accurate firepower out as far as 300 miles. Its aircraft also gave a carrier group a tremendous search area.
An aircraft
carrier had to have a
combination of high speed and a long flight deck to operate a large air
group. Carrier commanders thought in terms of the deckload strike,
which was the largest group of aircraft that could be assembled on deck
and successfully launched in a single operation. Aircraft were spotted
(positioned on deck for launch)
by the flight deck crew, who manhandled the aircraft into place. In
1943, the
Americans began equipping their aircraft carriers with jeeps equipped
to hitch to the aircraft and move them more
rapidly. Fighters were
invariably stationed in front to be launched first, in spite of their
lesser endurance, because they required a shorter deck run to get
airborne. American
carriers were equipped with catapults to decrease the minimum required
run, which allowed them to operate larger groups of heavier
aircraft.
It was also necessary to get the aircraft back down
after they completed their mission. Arrestor wires were used to bring
landing aircraft to a quick halt. These were steel cables suspended
across the rear half of the flight deck, just above deck level, where
they could be caught by a tail hook lowered from the rear fuselage of a
carrier aircraft. The arrestor wires were hydraulically loaded so that
they offered considerable resistance to being pulled forward by the
aircraft, thereby bringing the aircraft to a rapid halt.
There was also a crash barrier forward of the arrestor wires. This was a strong net about 15 feet high. If the tail hook failed to catch any of the arrestor wires, or if an arrestor wire malfunctioned, the crash barrier prevented the aircraft from rolling into the forward area of the flight deck, where aircraft that had just landed or were about to take off were usually parked. The crash barrier was a last ditch: An aircraft that went into the crash barrier was likely to be damaged, and its crew could easily be injured.
Once an aircraft landed, the crash barrier was lowered and the aircraft taxied forward to make room for the next aircraft to land. Aircraft were then usually moved the hangar deck for refueling and rearming, using large deck elevators. Early carriers placed these elevators down the centerline of the flight deck, but beginning with the Wasp, carriers began to be built with elevators on the edges of the flight deck, where they would be less likely to interfere with flight operations if they malfunctioned.
Most Japanese and American carriers could carry more aircraft than they could effectively operate, and the number of aircraft that could be operated also depended on the size of the aircraft. This leads to some ambiguity in the aircraft carrying capacities quoted for aircraft carriers. Unless otherwise noted, the aircraft capacities listed in this encyclopedia are the nominal operating capacities at the time the ship went into war service.
Both Japanese and American carriers proved potent but fragile. Their air groups could wreak tremendous damage on the enemy, but the carriers themselves were a highly vulnerable combination of gasoline tanker and munitions ship, albeit with heavy antiaircraft defenses and some armor protection. The Americans greatly improved their damage control techniques during the war, which allowed some carriers (such as the Franklin) to make it home in spite of incredible damage. The Japanese did not improve their damage control as much and continued to lose carriers unnecessarily.
A peculiarity of Japanese carriers was that, whereas Allied carriers used landing signal officers (LSOs) to guide aircraft in to land, the Japanese carriers used an ingenious system of signal lamps. On each side of the flight deck, a red lamp was mounted thirty to fifty feet aft of a green lamp. A Japanese carrier pilot only needed to aim between the pairs of lights and adjust his glide path so that the red lamps appeared to be just above the green lamps. The system was effective enough that even the poorly trained carrier pilots of 1944 were usually able to get their planes down safely. Its only limitation was that there was no way to signal speed adjustments. The U.S. Navy developed similar systems only after the war ended.
British carrier operations were restricted to the Indian Ocean until late 1944, and there was never a carrier battle between the British and the Japanese. This was just as well for the British. Their aircraft carriers had armored flight decks and other features that made them considerably less vulnerable to damage than American or Japanese carriers. This became clear during the Okinawa campaign, when kamikazes hit several British carrier flight decks without putting the ships out of action. But the armored decks came at the cost of smaller air groups, and the British carrier punch was further weakened by the miserable quality of British naval aircraft. It was only after the British began using American naval aircraft provided under Lend-Lease that their carriers could operate effectively against the Japanese.
The Japanese and American aircraft carrier fleets were fairly balanced at the start of the war. The Japanese had ten aircraft carriers, but only six were first-line carriers capable of operating large air groups. The Americans had seven aircraft carriers, one of which (the Ranger) never served in the Pacific because of its design flaws. The other six were comparable to their Japanese counterparts, but they were committed piecemeal to the Pacific theater because of the priority given to the European war.
Both sides launched additional carriers during the war, but the United States had a tremendous advantage in new naval construction. The Japanese completed four fleet carriers, four light carriers, and a small number of escort carriers during the war. The United States completed seventeen fleet carriers of the Essex class, eleven light carriers of the Independence class, and 77 escort carriers. The Japanese would have been overwhelmed even if they had been able to maintain a unit-for-unit quality advantage.
Though Coral Sea and Santa Cruz were clearly Japanese tactical victories, it can be argued that every one of the carrier battles of the Pacific War was a strategic American victory, since the Japanese failed to attain their objectives while the Americans succeeded, at least marginally. At Coral Sea, the Japanese were forced to call off their Port Moresby invasion, while the Japanese victory at Santa Cruz failed to relieve the Japanese land forces on Guadalcanal. The American victories at Midway and Philippines Sea were decisive both tactically and strategically. Only at Philippines Sea did the Americans have a decisive numerical advantage.
The American ascendancy in carrier combat can be traced to three factors.
Recruitment and training. American naval pilots were elite airmen, though not as good as their Japanese opponents at the start of the war. American naval fighter pilot training emphasized deflection shooting and team tactics, which received less emphasis in the Japanese naval fighter arm. This did much to compensate for greater Japanese combat experience and better Japanese aircraft performance (best exemplified by the Zero) early in the war.
With a population 60% greater than Japan's, and with an automobile culture that encouraged the development of mechanical skills, the Americans had a large pool of potential airmen to draw on. They also adopted rotation policies that supported a training organization capable of turning out large numbers of qualified pilots. The Japanese training system would have been inadequate to keep up with the heavy attrition in the South Pacific campaign even if there had been adequate numbers of young Japanese men with the mechanical aptitude required for air combat. The decrease in Japanese pilot skill became apparent as early as 1943.
Fighter direction. Though fighter direction was inept in the Battle of the Eastern Solmons, it improved considerably thereafter. The Americans were superior in radar technology, which greatly assisted American fighter direction. In addition, American aircraft radios were much superior to Japanese radios, which were so poor that they were often removed by fighter pilots to save weight. The Americans carefully selected and trained fighter direction officers to work from the flag carrier of a task force and coordinate fighter interceptions. Curiously, many were former stockbrokers, who seemed to have an aptitude for correlating data and making snap decisions.
Technology. The American carrier air groups started the war equipped with fighters that were noticeably inferior to their Japanese counterparts. However, by 1944, the Japanese had lost their aircraft performance advantage with the introduction of second-generation Allied aircraft like the Hellcat. Together with the decreasing quality of Japanese pilots, this spelled disaster for the Japanese.
In addition to superior aircraft, the Americans developed superior antiaircraft defenses. American antiaircraft gun directors started out good and steadily got better. The 5"/38 dual-purpose gun was a solid design that was further enhanced with the introduction of the VT radar proximity fuse and radar direction. Air attack on an American carrier task group became an increasingly suicidal activity even for those aircraft that managed to break through the fighter defenses.
It is notable that history has seen only five carrier battles, all during the Pacific War between the Japanese and the Americans. Carrier combat was a unique feature of that war, unlikely to ever be repeated. Each battle lasted only two or three days, during which both sides experienced heavy losses in their carrier air groups, necessitating the withdrawal of at least part of their surviving carrier forces. Yet the possibility that the enemy might commit his carriers always had to be taken into account when planning operations, which accounts for the dominance of these ships in the Pacific War.
References
The Pacific War Online Encyclopedia (c) 2007-2008 by Kent G. Budge. Index
