The classes of ships which constitute a fleet are, or ought to be, the expression in material of the strategical and tactical ideas that prevail at any given time.—Corbett
IN THE early days of the gun as the principal armament of naval forces, the conception of using units of ships of particular sizes and characteristics for particular missions either did not exist or had little influence on the course of events. When fleets consisted of hastily collected and armed merchant vessels there was naturally no choice other than to take the ships available, their size often depending on little else than the conditions under which they were used for private gain, including the important factor of the relative wealth of the owner. In the days of the Spanish Armada, of the naval wars between the Dutch and the English, fleets were collections of vessels of all sizes and rates, all of which took part in the promiscuous fighting of the fleet actions of the day. But as the development of rudimentary tactics led to the establishment of the line of battle as the basic fighting formation of fleets, a differentiation was made between “ships fit to lie in the line” and those not so fit.
The classification of ships of war into “rates” was a more or less unscientific arrangement for many years, the “rate” depending on size and not on any strategical or tactical function. Under Anson’s administration of the British Navy, however, appeared a clear-cut rating of ships according to their intended function and construction commenced to follow the demands of intended function. Colomb in his treatise on naval warfare demonstrated the tendency of naval force of the pre-torpedo era to differentiate itself into three classes: (1) the line-of-battle ship, (2) the frigate or heavy cruiser for fleet service, and (3) the light cruiser for attack and defense of commerce, greatly inferior to the frigate class but much more numerous.
As the increased power of minor attack, due to the perfection of the torpedo, commenced to influence naval construction, types became more numerous. There were introduced the surface and subsurface torpedo vessel and other types designed to combat them; consequently the threefold classification became less distinct. However, there continued to be built heavy gun-carrying vessels to form the line of battle—battleships and battle cruisers. There continued to be built fleet cruisers to perform the lookout and scouting functions of the old frigates. The light cruiser class for use on the trade routes tended to become confused with the heavy cruiser class in a period in which navies were experimenting with armored cruisers, protected cruisers, first and second class cruisers, and scouts, but during the World War the same demand for numbers, even at the expense of the power and effectiveness of individual units, led to the rush to construct light cruisers, sloops, destroyers, and to the use of old cruisers and converted merchantmen, even ancient gunboats, to protect the trade routes and military lines of communciation by sea against raiding vessels of various types.
The ultimate aim of sea warfare is the control of sea communications in order to exert pressure on the enemy nation by cutting off its trade, and preventing its military use of sea communications. Success in this aim also insures the free use of the sea for our commerce and for our operations of war. Before these things can be certain of accomplishment it is necessary to destroy, disable, or blockade the enemy naval force. On the degree of success in this effort will depend the degree of control of sea communications which can be exercised. Command of the sea can be secured only by the defeat of naval forces which dispute it. Yet, at the commencement of hostilities between two maritime powers, naval force cannot be entirely concentrated for use in gaining command of the sea by battle. Each power has its own sea-borne trade to safeguard and is forced to detach forces for that purpose. Due to geographic and commercial considerations, ocean traffic tends to become congested at certain focal points of trade routes and in certain terminal areas. Adequate disposition of naval forces for the protection of shipping in these congested areas automatically ensures adequate disposition for the attack on enemy vessels in the same areas. Therefore, unless one power withdraws its ocean shipping into the shelter of its own and neutral ports and accepts the handicap of this tremendous economic sacrifice, the commencement of a naval war finds certain naval forces distributed over wide areas in comparatively small units engaged in what are termed “cruiser operations” on the trade routes. These operations continue until one contestant gains a definite supremacy at sea.
The period since 1914 has seen the widespread introduction into naval forces of a new weapon—the airplane. This weapon, because of its new and comparatively untried status at sea, has been taken to sea in ships in a manner just as haphazard as was the gun in the days of the Armada. Airplane handling facilities of various sorts have been superimposed on the equipment of existing combatant types. Even aircraft carriers have been chosen for considerations other than their fitness for that use. We have two battle cruiser hulls and one collier hull which were made available to carry the new weapon. Great Britain has one battleship hull, three cruiser hulls, one merchant vessel, and one specially designed carrier, the Hermes. Japan has three converted hulls carrying aircraft and France, one. It is logical to assume that there will eventually develop the same tendency, the working out of the same principles, which caused scientific differentiation of types of gun vessels. It seems obvious that a vessel designed to operate in defense of trade routes will differ materially from a vessel designed to take part in a fleet action whether its armament be airplanes, guns, or both.
Carrier operations as at present visualized may be grouped under three major categories: (1) The air offensive against the enemy main body, (2) scouting and screening, (3) air support and assistance to the surface offensive.
The air offensive using heavy bombs and torpedoes will always require the largest carriers because of the larger airplanes involved. Since such operations are carried on by a force acting with a high degree of freedom from rigid formation with the main body it must as a unit have a high degree of surface strength and a fairly high speed. If the carriers themselves lack gun power it must be supplied by attaching cruisers in support. The Saratoga and Lexington with their high sustained speed, heavy batteries, and enormous airplane capacity are well suited to this employment. They are too valuable to use to furnish air scouts for a detached cruiser line. Their high strategic mobility has been well demonstrated by the Lexington’s day’s run of 770 nautical miles and by the Saratoga’s spectacular simulated attack on Panama after a passage from San Diego via a point south of the equator. Vessels of their type and approaching their type, for they are of extreme size, will form the nucleus of a highly mobile naval air striking force, which, with the addition of the necessary attendant light forces, will form a major unit of the fleet of the future.
The modern line of battle includes ships with batteries of the longest ranges practicable incident to the increase of elevations in new and reconditioned ships. Air support is essential to the proper functioning of these batteries; they must be furnished spotting planes which must in turn be protected by the action of fighting planes. Enemy spotters must be attacked, local tactical information must be furnished to the surface ships, and enemy attack flights must be intercepted. All these local tasks call for a considerable number of air units under the direct control of the battle-line command. Those air units not actually carried in capital ship units must be carried by a vessel or vessels in the immediate vicinity of the battle line. These requirements can best be met by the provision of battleline carriers whose characteristics are determined by their intended employment.
For such carriers fairly high airplane capacity is a desideratum. Speed may be moderate subject to the requirement of sufficient speed to maneuver without losing distance on the force to which attached. As at present visualized this means a carrier of about ten thousand tons, about 28 knots top speed, and cruising radius sufficiently in excess of that of the battle line to permit of the extra steaming incident to the demands of carrier service. The characteristics of a battle-line carrier and of its airplane complement will render it entirely suitable for use in escorting large convoys and major oversea expeditions. Battle-line carriers, with their equipment of observation and fighting squadrons will be well adapted to the support of landing force operations. Merchant vessels can readily be converted into this type of carrier.
The service of information and security with a fleet at sea involves the use of cruisers and aircraft in close cooperation; and the aircraft, if their recovery is to be positive and assured in heavy weather, must come from the decks of a carrier. Certainly the heavy carrier of the striking force laden with the main air attack strength of the fleet should not be exposed with an advanced scouting line. Its loss in an early surprise contact would be too serious a blow.
The battle-line carrier in which high sustained speed has been sacrificed to capacity is too slow for work in cooperation with cruisers unless the high sustained speed of the cruisers is to be wasted. There is a definite need for a light fast carrier able to make speed to the front equal to the speed of advance of a scouting line, which incidentally means speed around the 35-knot figure, and of small enough size and value so that the cruisers may be free to perform their mission with relation to information rather than to be forced to consider the safety of their attached carrier. These requirements point to a carrier of small proportionate airplane capacity as well as of small size.
Lieutenant Commander B. G. Leighton, U. S. Navy, since resigned, in addressing the Naval War College in 1928 on the subject of carriers of the 10,000-ton class said:
It is admittedly no match for a gun cruiser once the two are placed within gun range. But due to its great superiority in range of vision; due to its great superiority in effective striking range; due to its decided superiority in offensive value in direct attack against capital ships, which grows out of its superior striking range; due to its superiority in repelling enemy air attacks, either by direct attack against enemy carriers or by the use of its fighting planes in direct offensive against airplanes in flight; due to its superior ability to shift its striking power rapidly from point to point over a wide area in battle, without the necessity for changing the position of the ship in relation to other units; due to its superior qualities in striking shore objectives from beyond gun range of shore batteries; due to its superior ability in covering landings of troops and maintaining communications between ship and shore; it appears that the advantages distinctly outweigh the disadvantages.
The time for weighing the 8-inch gun cruiser against the 10,000-ton carrier as to its merits for future construction is ended. Our 8-inch cruiser tonnage and carrier tonnage have been definitely settled by two treaties and we require all that we are allowed in both categories.
As has been previously stated the role of cruisers in naval warfare is one not only of participation in major fleet operations and in the fleet battle itself but also one of the direct protection of trade, and of the direct control of sea communications. It is timely and valuable to briefly examine the cruiser operations of past wars and to attempt to evaluate the effectiveness of carrier type cruisers in similar operations, since upon their effectiveness in such operations must depend, to a large extent, their value as a cruiser type and the advisability of taking advantage of the provisions of the London treaty which permit their construction. Experience certainly should have taught us that operations to control sea communications form a major part of our naval activities. The operations of the American Navy in the Revolutionary War and War of 1812 were almost exclusively direct attacks on commerce. The outstanding naval achievement of the Civil War was the establishment and maintenance of the blockade, while in the World War we directed our principal effort to the protection of shipping against submarines and raiders. Certainly with an ocean-borne commerce worth over fifteen billions of dollars a year, while to quote Mr. Hoover, “Our total volume of exports translates itself into employment for 2,400,000 families,” it will in case of hostilities become necessary for us to make a major effort to insure a minimum disturbance of our economic life. Conversely economic pressure on an enemy should commence as soon as practicable on the outset of hostilities. This means cruiser warfare from the start.
There is a well-developed trend of thought in the world today along lines typified by Mr. J. H. Rose’s essay on The Indecisiveness of Modern Naval War to the effect that:
Great battle fleets, like those which did not close at Jutland, are not likely to achieve a decisive result, and that naval warfare will probably resolve itself into a prolonged blockade, exerted in reality against the enemy’s civil population.
Certainly our conceptions of two opposing fleets watching each other at short range and finally coming to close action have, by the combination of the existing treaty strength ratios and the distances involved in both Atlantic and Pacific, become unlikely of fulfillment until increased construction, conversion of merchant vessels, attrition by minor attack, or some unforeseen factor, enable one fleet to gather sufficient preponderance of strength to permit it to project itself into enemy waters. Meanwhile cruiser operations would probably be of great importance.
In the wars of the eighteenth and early nineteenth centuries the British system of trade defense was to hold in strength the terminal areas and important focal areas where trade routes converge and to leave the intervening trade routes undefended except for the escorts assigned individual convoys. The regions in the approaches to defended areas were more liable to attack, so the movement of important convoys was covered by additional danger zone escorts. Where possible the ocean escort of an important convoy included a line-of-battle ship, particularly if attack by a heavy enemy vessel threatened.
In a discussion of our operations in the year 1812 Mahan says:
Historically, as a military operation, for the injury of an enemy’s commerce and the protection of one’s own, it may be considered fairly demonstrated that vessels grouped do more effective work than the same number scattered.
He repeatedly points out the effectiveness as a measure of protection to our shipping of the offensive cruise of Commodore John Rodgers’ squadron. Within an hour after receiving the Declaration of War in 1812 Rodgers sailed with a squadron of five ships including the two heavy frigates President and United States. As it turned out one objective, the Jamaica—England convoy, was missed and few prizes were taken, but extensive defensive measures were forced on the enemy and in Rodgers’ own words which Mahan considers justified:
Our being at sea obliged the enemy to concentrate a considerable portion of his most active force, and thereby prevented his capturing an incalculable amount of American property that would otherwise have fallen a sacrifice.
For example Rodgers’ threat forced Captain Broke of H.M.S. Shannon to escort a convoy a thousand miles to sea with his entire squadron of one ship of the line and four frigates.
In the World War the Grand Fleet blockaded and neutralized the High Seas Fleet just as the old Western Squadron had blockaded the French fleet in Brest in the old days. Defensive flotillas were again stationed in the focal areas such as the Channel and its approaches, the Straits of Gibraltar, and in the Malta area. These defense flotillas consisted of destroyers, torpedo boats, sloops, and aircraft as against the frigates and sloops of the Napoleonic era, but their strategic function remained unchanged. The ocean escorts were still old line-of-battle ships or cruisers while short radius coastal forces protected coastwise and local traffic. The demand for vessels for cruiser work led to the employment of all available allied units. Even old gunboats, yachts, coast guard cutters, and armed trawlers were called on for escorting convoys, so pressing was the need.
In August 1914, of Great Britain’s 486,700 tons of large cruisers (above 10,000 tons) only 52,800 tons were with the fleet; of her 309,940 tons of smaller cruisers 153,400 tons were with the fleet. The patrol of the trade routes and focal areas employed eleven cruiser squadrons totaling some forty-two ships. To the control of the trade route to Germany north of England were assigned the six Edgar class cruisers of the Tenth Cruiser Squadron. In the Channel approaches were four light cruisers and nine French cruisers of the Western Patrol. To the west of Ireland operated the Eleventh Cruiser Squadron. To the Finisterre station went six cruisers of the Ninth Squadron while the Cape Verdes-Canaries area was to be covered by the Fifth Cruiser Squadron—four ships. In the west Atlantic were Admiral Cradock’s Fourth Squadron of five cruisers. The Mediterranean was strongly held by a force of four battle cruisers, four heavy cruisers, and four light cruisers. On the Cape station were three rather old cruisers; in the East Indies an old battleship and two cruisers; and in China a battleship, two cruisers, two light cruisers, and a flotilla of light craft, to which could be added the Australian squadron of a battle cruiser and three effective light cruisers. Thus the focal areas were held as strongly as practicable.
The assignment of units to stations was soon altered by the developments of the cruiser operations incident to clearing the outer seas of enemy cruisers and raiders and by the demands of the fleet. As rapidly as possible cruiser forces were augmented, and in some cases relieved, by armed merchant cruisers. In addition, in order to stiffen the outlying commerce protection squadrons and furnish them with a strong support against enemy attack, older battleships were attached—the Glory to the Halifax area, Canopus to the Cape Verdes station, Albion to the Finisterre command, and Ocean to the Western Patrol. Corbett says:
For the Grand Fleet to guarantee that battle cruisers could not break out was impossible, and as in the old days it was the practice to strengthen such squadrons with a lesser ship of the line, so now it was thought well to detach some of the oldest battleships to furnish them with a rallying point.
An outstanding feature of the distribution of forces outlined, so far as types are concerned, is the invariable demand for cruisers sufficient in number to form efficient search units and to furnish reliefs on patrol stations. Another is the provision of stiffening or supporting vessels capable of meeting a strong enemy. Corbett, in discussing the old practice of assigning fifty-gun ships as the flagships of cruiser commodores, states:
It is not unreasonable to expect that the strategic value of the supporting intermediate ship will be found greater than it ever was in sailing days, and that for dealing with sporadic disturbance the tendency will be for a cruiser line to approximate more and more in power of resistance to that of its strongest unit.
Since the foregoing statement was made the airplane has made its appearance in sea warfare and changed conditions so as to make it truer than before.
Under current naval policy as given concrete form by the provisions of the Washington and London treaties, the United States Fleet has and can have available for supporting cruiser operations no old battleships and no intermediate ships. Capital ships are few in number and will continue to be so unless a marked change in existing views causes replacement by smaller and less expensive vessels. Many of our heavy cruisers of the Washington-treaty type must be held with the fleet to offset the absence of battle cruisers. In fact as our battleships grow older there is a strong possibility that the method of disarmament by attrition and failure to replace expensive units which took place after 1814 and 1865 may serve to continue the reduction of battleship numbers and total tonnage. Public opinion in most countries seems at present, rightly or wrongly, averse to battleship replacement. This tendency may cause 8-inch gun vessels to become an increasingly vital portion of our battle fleet strength and thus limit their dispersion to outlying units.
It behooves us, therefore, to seriously consider the possibility of utilizing vessels of the “London treaty class,” 6-inch gunned cruisers with flying decks, for the cruiser operations necessary to us, supplementing them with attendant lighter vessels as required.
The extensive operation of airplanes from a carrier requires the presence of attendant light vessels to a greater degree than would at first thought appear necessary. Carrier scouting planes and light squadrons from carriers can and have operated at long distances from their carriers, but their ability to arrive at the right place at the right time, to furnish useful information with the highest accuracy, and finally their ability to return directly to their carrier after a long flight are dependent to a great extent on the presence of linking and reference vessels. It is true that, as aerial navigational equipment including directional radio apparatus is improved, reference vessels will become less essential, but under the stress of war conditions it is believed that their presence will continue to be necessary. Even a small carrier can readily send powerful attack flights capable of destroying cruisers and of giving pause to a battleship. The attached units may, therefore, be of the smallest size.
It should be sound to contemplate the employment for control operations, and for scouting and screening, of units composed of a carrier or carrier cruiser and attendant light vessels such as small cruisers with an armament of not over 6-inch guns and with speed enough to enable them to delay action in high visibility while awaiting aircraft support. In low visibility when surprise contact is possible the 6-inch gun cruisers can be depended on to give a good account of themselves unaided. The carrier cruiser is capable of performing all the functions of the supporting or stiffening ship with cruiser squadrons by means of its light bombing squadrons. A carrier cruiser in the place of the old battleship Canopus would have changed the story of Coronel. A carrier cruiser in the forces trailing the Goeben and Breslau in 1914 might have had a far- reaching effect on the course of the World War. One with von Spec at the Falklands would have prevented him from walking into the trap awaiting him. Furthermore, the cruiser with airplane armament is the only answer to the merchant cruiser armed with airplanes—always a possibility.
The gun armament of a carrier cruiser is adequate for the general duties of control of trade routes insofar as they require superiority of force over merchantmen. Its airplane equipment will enable it to greatly increase the radius of its effectiveness in search or patrol, and if need be, enable it to overcome an ordinary cruiser without coming under fire. As a convoy escort vessel it will be effective not only against surface types, but also, by means of its airplanes, against subsurface attack. Its airplanes will be highly effective as antisubmarine patrols, either in place of or in addition to surface antisubmarine craft. In brief, a 10,000-ton cruiser armed with a respectable battery of 6-inch guns and two or more squadrons of airplanes of the light bombing type can under most conditions better perform the duties of “cruiser operations” than can an 8-inch gun cruiser or than can an equivalent tonnage of small 6-inch gun cruisers. Moreover, the use of carrier type cruisers and small carriers enables the advantageous use of a greater number of small cruisers.
The great weakness of carriers lies in the restrictions imposed upon air operations under unfavorable conditions of weather and the danger of surprise contact in low visibility. The weakness of the small cruiser lies in the danger of a long-range action in high visibility against a cruiser of superior gun power. It is evident that these two conditions do not arise at once and that a mixed armament of airplanes and 6-inch guns may prove to be very successful.
Our cruiser needs for detached operations and for fleet purposes are such that large numbers are essential; the use of carrier cruisers as supports will enable the use of smaller units for duties otherwise demanding powerful vessels; and, within the limits imposed by the treaties, our naval efficiency will be improved by the devotion of a maximum of cruiser tonnage to vessels carrying flight decks and effective offensive airplanes.
From the foregoing it will be seen that from our 135,000 carrier tons and 73,000 carrier-cruiser tons we need airplane-carrying vessels of four types for four distinct classes of operations:
- Air force carriers, large and powerful and of high speed.
- Battle-line carriers, of intermediate size and moderate speed.
- Scouting carriers, small but of very high speed.
- Carrier cruisers, carrying light bombing planes and a fair 6-inch battery.
The aircraft carrier has become an accepted type in the navies of the leading naval powers and in preparing for the eventualities of a war at sea we must bear in mind the unvarying rule that, in the development of weapons and tactics, each war begins where the last one left off. No one can say just what the composition of the fleet of the future will be but it seems certain that its carriers will tend to follow the same principles of differentiation of force and type according to the strategical and tactical uses to which put as have vessels armed with guns. There is no doubt whatsoever that the United States Fleet should include every flight deck permitted by the treaties, even if they are not used to capacity until mobilization produces the full complement of pilots and planes.