Training exercises seemed to bear out the conventional analysis; generally, the airplane was not a decisive weapon in the mock naval battles. The planes were used too conservatively, partly to prevent accidents. Built for stability and durability in order to survive the operational hardships of carrier duty, naval aircraft were relatively slow and undergunned, with various performance limitations: Grumman biplane and Brewster monoplane fighters were slow and inadequately armed; the Vought dive bomber was acknowledgedly “obsolescent”; and the standard torpedo bomber, the Douglas Devastator, was slow and so vulnerable to modern land-based fighters that the fliers considered it “unfit for combat service.” The pilots were well trained and versatile, for the vicissitudes of carrier operations bred skill and lack of appropriations and the inherent limitations of the biplane configuration, which militated against aircraft specialization, forced the use of planes in every role, so that fliers became skilled in bomber and fighter tactics. However, since they had similar equipment and employed similar tactics, and practice odds were relatively even numerically, the normal result of the training problems was the mutual attrition of the participating air arms.16
The Fleet’s major defense against air attack was the antiaircraft gun. The new 5-inch dual-purpose gun offered excellent protection against high-altitude, horizontal bombing, a form of attack that was correctly thought to be wildly inaccurate against maneuvering warships anyway. But the ships were defenseless against dive bombers and torpedo planes. The old, reliable .50-caliber machine gun was adapted for shipboard use as an antiaircraft weapon; unfortunately, it could not hit anything at ranges beyond 600 yards. For example, in the summer of 1938, eleven heavy cruisers fired 5,824 rounds at target sleeves, but scored only three hits (0.055 percent). Few gunners could qualify for the cash awards offered for good shooting, and faith in the weapon declined as frustration mounted. About all that could be hoped for was that a heavy volume of fire might force attacking planes to release their bombs prematurely. The vaunted 1.1-inch pom-pom, introduced with such high hopes, increased the rate of fire, but was not much more accurate than the “50” and lacked the reliability of the older gun, jamming frequently. In one practice in March of 1939, five destroyers fired 623 rounds and scored no hits. Eventually, two foreign-made weapons, the Bofors 40 mm. and Oerlikon 20 mm., solved the problem prior to World War II.17
But some in the Navy understood that in defending against the airplane the ancient prescription for catching a thief was relevant: it took an airplane to intercept an airplane.
In the summer of 1938, Vice Admiral Ernest J. King, Commander Aircraft, Battle Force, decided to test the ability of fighters to defend ships against land-based bombers; many felt that the defensive firepower of modern bombers made them virtually immune to successful interception. Three squadrons of patrol bombers were ordered to attack the target ship Utah, defended by two fighter squadrons. Relying on visual contact, the stubby fighters were able to locate and attack the lumbering PBYs before they reached their release point; according to the evidence of gun cameras, the fighters scored about seven hits for every one they sustained.b Despite artificiality in the test, King felt that “fighting planes may engage large bombers . . . with a reasonable expectancy of a favorable outcome.”18
The results of offensive bombing strikes by naval aircraft were misleading, because of the absence of defending fighters or hostile antiaircraft fire. For instance, attacks by torpedo planes on maneuvering ships indicated that a 30 percent hit factor could be attained, even at release ranges of 3,000 yards and beyond. This was recognized as being much too optimistic, and torpedo planes were urged to close to shorter ranges.19
In May 1938, planes from the carriers Lexington, Saratoga, and Ranger conducted bombing exercises. The scout bombers made horizontal attacks from an average height of 13,700 feet and scored 16 hits with 90 bombs, 17.8 percent. The dive bombers released at an average of 3,000 feet, hitting on 51 of 101 bombs, 50.5 percent. One squadron scored heavily with a formation dive, but it was recognized that this type of attack would be too vulnerable to AA fire to be used in combat. The Ranger’s deck hands did very well, recovering seventy-two planes in 37½ minutes, rearming seventy in 82 minutes and relaunching them in less than 24 minutes. By 1940, a squadron of planes could be launched from a carrier in 4 minutes and 57 seconds; recovery took 9 minutes and 53 seconds; speed in launching and recovering aircraft was vital, as carriers were most vulnerable during these operations. Carrier operations were the most dangerous activity of the peacetime Navy; aircraft were damaged at a rate of 5.79 per 1,000 flights.20
It was thought that the patrol bombers would play an important offensive role in wartime,c utilizing tenders to mount surprise attacks from advanced bases.21 However, later experience showed that the PBYs, while possessing excellent endurance characteristics which made them ideal all-weather, high-altitude reconnaissance aircraft, lacked the speed to survive for long at altitudes at which effective bombing was feasible.
Thus, the Navy’s use of the airplane in the thirties was both limited and promising. In the operating forces, practical considerations outweighed conservative theory. The airplane was, and therefore it had to be thought about, lest an officer jeopardize his career by failing in a training problem that involved aircraft. And so, tough and astute men like Admiral King were able to shape the tactics and refine the techniques needed to bring about victories under enemy skies in the distant days of more and better planes.
A major failing of the peacetime Navy was antisubmarine warfare.
Most Navies in the thirties assumed that sonar and the convoy system had ended the menace of the submarine. But technology and tactics do not long remain stagnant; the range, speed, and durability of the submarine increased, and the night surface attack replaced the daylight submerged attack, restoring to underwater craft their former superiority.22
American naval strategy was based on the concept of command of the seas: to destroy the main fleet of the enemy in battle, so as to secure the Western Hemisphere from attack and permit offensive operations elsewhere. A trade war seemed superfluous and timid. Hence, in peacetime exercises, submarines were employed as part of the main fleet, and considered, like the airplane, a tool for whittling down the enemy battleline before it could confront the American heavy ships. American submarine tactics developed for attacking fast and well-defended warships were too cautious, relying on submerged and even futile, “blind” sonar attacks. Escort tactics suffered, too; shepherding destroyers, trained to defend fast warships, whose high speeds were nearly proof against successful attack under normal conditions and whose turbulent wakes fouled sonar equipment, became complacent and inefficient in escort technique. Without slow, unruly merchant convoys to escort in peacetime, there could be little useful antisubmarine warfare and escort doctrine, for doctrine must be built on experience. Hence, there was no agreement on such basic matters as the most effective escort formation, the optimum distance between the screening ships and the convoy, whether the escorts should patrol station, when to leave the convoy unprotected in order to dog a contact, the efficacy of illumination, precise search and attack procedures, and many other significant points of escort technique.23
Small escorts such as subchasers had been improvised during World War I, and many, including President Roosevelt, felt that the experience could be easily repeated, if necessary. Once Admiral King warned the President,” Nothing remains static in war or in military weapons, and it is consequently often dangerous to rely on courses suggested by apparent similarities in the past.” Admiral King was right. The World War I U-boat had been forced by its limitations to operate in the immediate approaches to the United Kingdom, where interception was easiest. Hence, escorts operated out of Queenstown on relatively short trips, not having to cross the ocean, and the strain on men and ships was small. In World War II, however, escorts had to have the size and endurance to fight in mid-ocean.
The General Board of the Navy rejected various escort prototypes in the prewar years because they were almost as expensive to build as destroyers, yet nowhere as efficient or versatile. Corvettes were too slow; “Treasury”-class cutters and destroyer-escort types lacked the speed, ruggedness, versatility, and firepower of modern destroyers, and specialized escorts were not always economical—one modern destroyer could be built for less money, for