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Chapter 17

This webpage reproduces a chapter of
History of
United States Naval Aviation

Archibald D. Turnbull
and Clifford L. Lord

published by
Yale University Press
New Haven

The text is in the public domain.

This page has been carefully proofread
and I believe it to be free of errors.
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Chapter 19
This site is not affiliated with the US Naval Academy.

 p193  Chapter XVIII

The Bombing Tests

In the fall of 1919 Lt. Comdr. Bartlett had suggested that much information about bombing by aircraft might be gathered from a series of experiments using either captured German warships or vessels of the United States Navy which had been condemned to the scrap heap. His suggestion was well received but nothing definite was done until November, 1920, when the battleship Indiana, veteran of the Spanish War, was selected as the target for special tests. Bombs placed at calculated distances from her hull were detonated in an effort to learn the effect of "near-misses." After 14 of these, weighing 200 to 600 pounds and placed at distances varying from 25 to 75 feet, had been exploded the ship began to settle. She was then towed into shallow water and run aground, after which heavier bombs were placed upon her deck. The explosion of one bomb of 1,800 pounds burst her superstructure and damaged her turrets to such an extent that only one conclusion was possible: a direct hit by such a bomb would put a ship of her class out of action. As far as they went these experiments were enlightening, but it was clear that many more tests must be made before exact conclusions could be drawn. Naval aviators were therefore eager to get more old ships and blow them to pieces in different ways under varying conditions.

A number of dilapidated German ships had been delivered to the United States. They included the battleship Ostfriesland, the cruiser Frankfurt, some destroyers, and a number of submarines. In February, 1920, a strong recommendation by the Bureau of Ordnance urged that some or all of these ships be used for tests. Originally it was suggested that the ships would make good targets for the Fleet's guns, which would destroy them in accordance with international agreement. Later it was decided that if the ships could "also be bombed from aircraft" there would be an excellent opportunity to gather information. This proposal led to months of discussion until, on January 1, 1921, the Secretary of the Navy  p194 gave orders to proceed with both types of tests and a few weeks later invited the Army to participate in them. The War Department referred this invitation to the Aeronautical Board, but before that board had acted the Chief of the Army Air Service submitted a proposal that obsolete ships be obtained from the Navy for bombing experiments.

Representative R. Anthony, Jr. and Senator New both introduced resolutions which directed the Navy Department to turn over to the Army one old battleship, two old destroyers, and two old supply ships, "to be used for the purpose of serving as targets for the development of aerial armament and methods of aerial attack against sea craft." Before these resolutions were passed, however, the Secretary of the Navy explained that they were unnecessary in view of the tests already proposed by the Navy.

During discussions between the Bureau of Ordnance and the Chief of the Army Technical Staff a debate on the possible effect of torpedoes made it apparent that the Army and the Navy saw eye to eye when examining the possibility of aerial bombing and the claim of the army airmen. A significant feature of the agreement reached was the statement made after the conference by the Army's representative, who said that he "would furnish no information to the Army Air Service" except through the Secretary of War.

Meantime the Navy's plans were announced as designed to determine three things: the ability of aircraft to locate ships in the coastal zone; the probability of scoring bomb hits on ships under way; and the damage which such hits might inflict upon ships of relatively modern design and construction. To begin with, the radio-controlled Iowa was to approach the coast somewhere  p195 within fixed limits on the Virginia coast while both the Army's and the Navy's planes searched for her. If found she was to be bombed only with dummies because the radio control had been very costly and the Navy could not afford to sink her. This was unfortunate because General Mitchell, while he agreed to participate in the search, declined to drop dummies on the ground that no useful information could be gathered without sinking her. He also held that the Iowa should be brought well inshore because to locate her 100 miles off would require a 400‑mile flight by army planes from Langley Field. The mathematical basis for this calculation is not apparent at this late date.

In due course the Army Air Service asked for the old battleship Kentucky as a target, but she was in such bad condition that her repairs would cost more than could be spared from the Navy's scant funds. Because it was clear that the Army Air Service attack, although described as "purely experimental," would make certain that the target was sunk, it was important that the target should be in the best watertight condition when the attacks began. Nevertheless, the Navy was entirely willing that some ship should be attacked, and further conferences led to the substitution of the Alabama, about as old as the Kentucky but much more shipshape.

Both Congress and the public displayed considerable interest in what was planned. In the House Mr. Hicks deprecated the tests as not likely to prove much if the target were immobile, undefended by its own guns, and unprotected by friendly aircraft. Mr. Anthony, an aisle or two away from Mr. Hicks, demanded to know "whether or not the Navy Department intends to furnish proper targets to the Air Service of the Army." As to the public, it was clear that what the public might think, after the tests, would have a considerable effect of future expenditures for the Navy.

In a series of conferences on details of the test, General Mitchell represented the Air Service while Capt. Alfred W. Johnson, then commanding the Atlantic Fleet Air Detachment, represented the Navy with Whiting as his special assistant. From the very first Johnson emphasized the point that the Navy was not seeking merely to sink ships but rather to determine, by careful procedure and frequent inspection of the targets, the effect of bombs of different weights, exploded at varying distances. It was with this in mind that the rules governing the tests were written, and General Mitchell, although he registered an objection against serving under Johnson, who was his junior in rank, agreed that he would  p196 abide by the rule. As to the Alabama, he recommended that the Navy use torpedoes against her because, a he put it, "neglect of . . . this weapon will permit foreign nations to obtain a lead which will be difficult to overcome"; a recommendation not clearly understood because the Navy had for years been devoting all available time and money to the development of torpedoes. Finally the general suggested that an attack upon the Iowa so far offshore would necessitate the use of seaplanes, which he considered too "sluggish" to be of any value against an enemy certain to be equipped with carriers and pursuit planes. The Navy's reply to this took the view that the purpose was not to test types of aircraft but to learn as much as possible about bomb dropping and its effect. This position on the point did not get much space in public print.

At this time Moffett wrote a long memorandum on the "Publicity Propaganda of General Mitchell Running Contrary to President's Policy." In this Moffett invited attention to what President Harding in his message to Congress had said of the need for close cooperation between Army and Navy in their flying efforts, and cited numerous instances in which he held that Mitchell had been uncooperative. He cited the crash of an army plane in which five officers had been killed — a disaster caused by the plane's lack of a radio over which he could have received the Weather Bureau's warnings but attributed by Mitchell, who had been "entirely and directly in charge of the operation," to the lack of a united air service. Mitchell's activities, said Moffett, "in advocating a policy opposed to that of the President and the Navy Department, and his false and misleading statements are delaying and hampering the efforts of those who are responsible for Naval Aviation . . . who are endeavoring to loyally cry out the orders and the policies of their superiors."

These exchanges were unpleasant, but meanwhile progress toward final plans continued and at the end of May, 1921, they were issued in detail. They covered attacks upon the German submarines, the Iowa, the German destroyers, the Frankfurt and the Ostfriesland, in that order. The U‑117 was to be the first target, attacked by three waves of F‑5‑L planes with each wave dropping 12 165‑pound bombs; then by five of the Navy's Martin bombers dropping 30 bombs; then by a division of six of the Marine Corps' De Havillands dropping 12 bombs. All these were to be followed by three waves of army Martins dropping 18 250‑pound bombs,  p197 then by a wave of army De Havillands dropping 12 bombs, and finally by five more army De Havillands dropping ten bombs.

After three other U‑boat had been sunk by destroyer gunfire, the games would continue with the Iowa test. Under radio control from the Ohio, five miles away, the Iowa, at the hour set, was to be somewhere between Cape Hatteras and Cape Henlopen, 50 to 100 miles offshore, headed west. When located she was to be attacked by navy planes of the F‑5‑L type, carrying 165‑pound dummies of standard size and form dropped from 4,000 feet, then by NC flying boats with 500‑pound dummies, and finally by army Martins carrying 1,000‑pound dummies.

Continuing into July, the plan provided for an all‑Army exercise in which one German destroyer would be bombed in any way the Army chose. Two others would then be sunk by destroyer gunfire. Ten days later the Frankfurt would be attacked from the air and two days after that there would follow the main effort against the Ostfriesland. If these larger ships survived bombing, they were to be turned over to the guns of the Fleet.

Few, if any, doubted that even a heavily armed battleship would sink if she were hit by enough big bomb. The uncertainty was chiefly over how big the bombs would have to be, how many small ones the ship could take without crippling damage, and similar unanswered questions. To get as many of these answers as possible, a special board of naval observers was appointed with orders to visit the target ship between the attacks by successive waves, inspect her decks, turrets, bridge, smoke pipes, engine room, and fireroom, and note the progressive disintegration. To cover the Ostfriesland completely on these points, it was specifically stated in the rules that not more than two of the 250‑pound or 300‑pound bombs should be dropped at a time, and where the 1,000‑pound bomb was used, only one should be dropped between successive inspections.

The early exercises were carried through without untoward incident, the U‑117 being sunk in 12 minutes by naval planes and the German destroyer G‑102 readily sunk by army planes. While the Iowa was still far offshoot the navy planes located her and carried out their dummy attack exactly as planned. In the Frankfurt test a 600‑pound bomb landing in the water close to her bridge exploded with the effect of a mine, lifting her bow several feet and blowing out a hole big enough for the sea to fill two forward compartments, take her down by the head, and sink her. This  p198 brought the exercise up to July 20, the day set for the Ostfriesland tests.

The army planes were furnished with the Navy's compasses and bomb sights. To help them in their attack, destroyers, at seven-and‑a‑half-mile intervals, formed a line of "buoys" extending from Thimble Shoals in Chesapeake Bay seaward toward the target. Two of the Navy's planes flew with each army group, to give a hand to any landplane that might be forced down. Blimps from the Fleet were sent up to keep the Army informed, by radio telephone, of the wind's direction and velocity. Another blimp hovered over the Ostfriesland at 3,000 feet taking photographs, while three planes from each Service circled the ship at 2,500 feet for the same purpose. To make sure that each attack stopped when the prescribed number of bombs had been dropped, or whenever the board of observers wished to visit the ship, special signals were arranged by Captain Johnson, embarked in the Shawmut and in charge of the exercises. The procedure was laid down in these words:

No bombs will be dropped unless an "All Clear" signal, consisting of a large red cross and a ball, is displayed on white canvas on the Shawmut's forecastle. In case signal is rolled up, planes will cease bombing and await orders. This is particularly important as the target-ship will be inspected by a Board at certain times. In case of emergency, heavy smoke from the stacks of the Shawmut may be used as a signal to cease bombing in addition to withdrawing the "All Clear" signal.

To provide further against mis­understanding, General Mitchell was given written instructions that the "All Clear" must be recognized immediately preceding each successive attack. If the signal were withdrawn after an attack had begun but before an army group had dropped all its bombs, that group must at once cease fire. As still another emergency signal, a naval plane cutting the figure S in sharp curves ahead of the attacking unit was to be understood as an order to stop bombing. Finally, these special instructions emphasized once more the importance of dropping only the prescribed number of bombs, as well as the vital importance of stopping the fire if any 1,000‑pound bomb made a direct hit, to allow time for inspection by the board. With these elaborate details in mind, it is easy to appreciate the significance of what followed during the attacks, which lasted two days.

 p199  On the first day the take‑off of the first planes was delayed by weather too rough for the small boats that must transport the observers and by a low ceiling. Consequently the Army's request, repeatedly broadcast, for authority to make its attack had to be denied until about 2.15 P.M. Unhappily the army planes "jumped the gun" at 1.30, with the result that they reached the Ostfriesland before the Navy had completed its attack. Insisting that his planes had only enough fuel to stay in the area another forty minutes, General Mitchell pressed for permission to begin bombing and finally got it, even though the meant that the board of observers was deprived of any chance to visit the ship. Thus the "between attacks" data for that day were not obtained, from the Navy's standpoint a most unfortunate circumstance. This, however, was much less serious than the events of the second day, when both the Army and the Navy were scheduled to have their heavy bombers over the target at 8 A.M.

A few minutes before seven General Mitchell told Captain Johnson by radio that the Army's planes were already on their way out, adding the request that "they be not interfered with by Naval aircraft." The first army bomb having scored a direct hit, the rules required that attack be suspended until the board had made its inspection, and the Shawmut accordingly rolled up the all‑clear signal. When the army planes paid no attention either to the notice or to the dense smoke immediately belched up from the Shawmut, Captain Johnson steamed toward the Ostfriesland until he was inside the 1,000‑foot danger circle, at the same time telling the general by radio: "Cease firing. Observers going aboard. Acknowledge." The general's only answer was: "Martin bomber Number Twenty-three will let you know when it is safe to board the target," and this was followed by the dropping of five more 1,000‑pound bombs, three of which scored direct hits. The army planes then went on to drop seven 2,000‑pounders, some of which hit the ship and finally sank her.

The effect of these violations of carefully drawn rules was to destroy the value of these tests to the Navy. Much had been expected from the bombing of the Ostfriesland because, although the Germans had left her in poor condition, she was the largest, most modern vessel bombed up to that time. As matters stood, the Navy's board of experts, in its report upon the various bombings, recognized several important factors. All ships except the Iowa had been at anchor, waiting for planes which would be guided to their targets  p200 by other ships and make their attack under ideal conditions of visibility and low altitude. Not a man was aboard any ship bombed to make repairs or, which might be much more vital, handle antiaircraft defense. Nevertheless, said the board, "the fact remains that in every case of attack by airplanes by bombs, the ships so attacked, whether submarine, destroyer, light cruiser, or battleship, were eventually sunk, and by airplanes with bombs alone." In short, those hulls going down off the Virginia capes made a realistic picture more convincing than any amount of abstract speculation. Moreover, as noted by the board, aviation was as yet by no means fully developed. To provide against that development the board, before plunging into technical detail, recommended that the Navy immediately look to its defenses: passive in the redesigning of hulls and the alteration of certain features, active in the form of antiaircraft guns and especially in planes based aboard the ships. Urging the adaptation of planes to battleships and other combat craft, the board went much further to emphasize the necessity of carriers, both to defend their own ships and to attack those of the enemy. Peering into the future, what the board saw was not the extinction of the battle line, but instead a force of battleships and cruisers proceeding under the cover of their own air protection.

Not all officers were so deeply impressed. Adm. Hilary P. Jones, then Commander in Chief of the Atlantic Fleet, in his endorsement of the board's report, held that "the artificiality under which these tests were carried out" had not been sufficiently emphasized. Comdr. (later Rear Adm.) Alexander H. Van Keuren, a special observer for the Bureau of Construction and Repair, made a report freely admitting the power of aerial bombs but stressing what a crew well trained in damage control might be able to do for a ship attacked as the Ostfriesland had been. To these general conclusions should be added a great many technical recommendations made by the board itself, covering everything from the need of better instruments for aerial navigation to the importance of more efficient types of ordnance.

In his own report to the Navy Department Captain Johnson pointed out that the army planes, by their disregard of the prescribed rules, had made it impossible to gather the data sought and thus had defeated the Navy's hope of discovering how existing ships might be given better protection against bombing and how future designs should be modified to the same end. He guessed  p201 correctly that the publicity given to the sinkings would leave the public unaware that the tests had not been carried out according to plan. In a letter subsequently written in the Navy Department serious charges were made against Mitchell, but Theodore Roosevelt, Jr., then Acting Secretary of the Navy, decided that such a letter would stir up further political pother over the pros and cons of a single air force and also intensify ill‑feeling between the Army Air Service and the Navy. As he did not send the letter the argument was left to the press, where it was carried on briskly. "Day of the Battleship Ended" was a ready-made headline. General Mitchell, for his part, made the public statement that he had himself originated the whole series of tests, and later, in his book Winged Defense, he asserted that the bombings had been carried out far at sea because it had been the Navy's intent to hazard the lives of army fliers.

In September the Army's planes bombed the Alabama. The night attack, with blazing flares, gas bombs, and machine‑gun fire, was very spectacular but not markedly successful. No hit was scored with any 100‑pound bomb, and of the seven 300‑pounders dropped, two scored hits. In the first day attack, however, as many as 11 out of 36 small fragmentation bombs hit, as did two out of 14 300‑pound demolition bombs. Of six 1,000‑pound armor piercers dropped, none hit. Next day two hits were made with this weight bomb and one with a 2,000‑pounder, while of several near-misses with both sizes, one or two were very close. Although no examination of progressive damage was made, the naval board agreed that this test confirmed the conclusion drawn from the earlier one that the cumulative effect of near-misses, rather than direct hits, had eventually sunk the ship.

General Mitchell during an address to Congress laid new stress upon his belief in a single air force and upon what he considered the Navy's relatively unimportant war effort. Once more he went astray in facts and figures, notably those bearing upon British naval air personnel, with the result that these figures were used in a speech on the floor of Congress attacking a statement by the Secretary of the Navy. At a moment when Congress was considering further reduction in the already inadequate personnel of the Navy, such an attack had its most unfortunate effect.

In January, 1923, General Mitchell, ostensibly as the representative of the President at a meeting of the National Aeronautic Association in Dayton once more, in strong language, eliminated  p202 the surface vessel and talked of a "true system" of national defense which would be to all practical purposes wholly in the air. Meantime he had his army planes darting around New York City laying smoke screens and pouring radio broadcasts over Washington, proceedings not halted by the War Department until they had continued for a month. In February a board headed by Maj. Gen. Indicates a West Point graduate and gives his Class.William Lassiter of the Army General Staff began hearings which led to recommendations for a feasible ten‑year army air program, one, moreover, which would provide "great mobility and independence of action" without impairing unity of command. By April the essentials of these conclusions had become War Department policy. Although it appears to have been an objective of this policy to bring about a general appropriation by Congress for both Services, 60 per cent for the Army, 40 per cent for the Navy, that objective was not attained. Presumably this was because Secretary Denby of the Navy continued the fight to keep the naval air arm the Navy's own.

The sinking of the 20‑year-old Virginia and New Jersey by army bombers in September, 1923, followed the general course of earlier bombings. Some direct hits and many near-misses were scored. On the army side, the chief result was a recommendation for airfields along the coast. It became clearer than ever to the Navy that ships unprotected by aircraft would henceforth be in grave danger of bombing attacks, the more so because as many as two direct hits or near-misses by 2,000‑pound bombs would probably put any ship of the day out of action. For this reason the Navy, in the effort to build up immediately to the strength permitted by treaties, held that its air arm should be sustained with funds, planes, and personnel to give the Fleet true air superiority.

In November, 1924, came the bombing of the unfinished Washington, doomed by the disarmament treaty of 1922. Alone among the ships bombed, she was modern in every respect, particularly in her compartment structure, and against her the Navy had its opportunity to try out armor-piercing air projectiles, mines, and torpedoes in attacks modeled upon those made against the Indiana. At varying distances from the hull 1,000‑pound charges of TNT were detonated and 400‑pound torpedo charges were fired against the side. Fourteen armor-piercing projectiles were dropped from 4,000 feet. After all that, it nevertheless required two-and‑a‑half hours of shelling from turret guns to sink the ship, a fact which led the battleship men to conclude that such ships still had a very  p203 important future. The board of inspection supported this view to the extent of deciding that a ship of the type could withstand eight torpedo hits provided these were not bunched. Moreover the Eberle Board, convened in 1924 to study recent developments in aviation, including the record of all the bombings, came to much the same conclusion. This board, after hearing the statements of officers and civilian experts, held that a Washington-type battleship with personnel to man antiaircraft guns and repair damage and with power on her pumps would be substantially secure against sinking, even by better aircraft than those of the day. Although General Mitchell suggested that the Navy "had not tried" and was unwilling to admit that the battleship was done for, the facts indicated that such ships, provided with protection and aerial cover, would for many years continue to be the Fleet's backbone. To Johnson, Moffett, and others of the Navy, Mitchell's latest attacks were "grave and baseless" as well as "without precedent in the history of our military services." The general's articles, published some months later in the Saturday Evening Post, were even more irritating to them. They knew that the statement by the general, that seaplanes forced to land upon the water would not stay up as long as would landplanes, was simply not true. They knew that the general's accusation that "the Board of Inspection was so slow that they kept us flying around way out at sea about an hour" was equally unfounded. In consequence, excerpts from these articles and from other statements by the general were sent to the War Department with another letter from the Navy Department describing them as "intentionally deceptive." As the Navy saw the controversy, the general appeared to be trying to obscure the real issue.

Notwithstanding such matters, the Navy did learn much from the bombing tests. For example, even though many of the extravagant claims of the Mitchell group were quite unsupported by the facts of that hour and are not fully supported by the facts of this hour, it was no longer possible for even the most hidebound to contend that the battleship was unsinkable. The worst skeptic could not longer dispute the importance of aircraft and the effect they must have upon sea power of the future. The Joint Board, for one body, immediately declared that the experiments "have proved that it has become imperative . . . to provide the maximum possible development of Aviation in both the Army and the Navy." Again, the tests indicated that seaplanes could not meet all of a  p204 Fleet's air requirements because they lacked speed and could not maneuver freely. Forward-looking naval men were right in declaring that "operations on the high seas by aircraft are impossible without carriers. Until we get them, there will be no real Fleet Aviation." They were thinking well ahead of the still infant carrier, into the day when much larger aircraft bearing heavier bombs could be launched from and landed upon the broad decks of carriers.

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