The commander-in-chief must, therefore, continually bear in mind that while his carriers are indispensable to the fleet they are also extremely vulnerable and cannot easily be replaced. At first glance the problem of protecting them would seem simple enough. Carriers are designed to have a high rate of speed/ and if they can attain some ten knots in excess of the speed of the battle-line there would appear, at first sight, to be no difficulty in keeping them in a position of safety relative to the enemy fleet. But it must be remembered that the enemy destroyers and cruisers will have a speed at least equal to our carriers, while the latter win not always be free to use their speed for the sole purpose of seeking the cover of the battle fleet.
In order to fly machines off and on, a definite wind speed over the deck is required. To obtain this in a flat calm it is only necessary for the carrier to steam at a sufficiently high rate of speed. Under these conditions her course can be entirely governed by the tactical situation and she will have little difficulty in remaining in a position of safety. Her speed will be adequate for avoiding attack by enemy craft of all types and her maneuver will not seriously interrupt the flying service.
If there is any appreciable wind, however, her movements are likely to be considerable restricted, for, to perform the operations of flying off and on, she must steam either directly into or directly away from the wind. The latter, of course, can only be done with a very low wind force and by a carrier with a high speed, because the speed of the ship through the air must be such as will overcome the velocity of the following wind and, in addition, produce a wind speed over the deck sufficient for the flying service.
In most cases the weather conditions will be such that no planes can be dispatched or received excepting with the carrier steaming head to wind, when the maintenance of her position relative to the battle fleet will be further handicapped by the fact that her speed must be varied according to the wind velocity at the moment of any particular flying operation. Thus it will become a difficult matter to forecast her position at any particular moment.
The operations of flying off and flying on must be considered separately. In flying off, the time during which the carrier is required to steam into the wind is small. The aircraft to be launched can all be ranged on the flying deck, or decks, previous to turning head to wind, and as soon as the ship is ready the machines are flown off in rapid succession.
Let it be assumed that the wind is from right astern of the fleet. It will take the carrier some five minutes to turn 180 degrees. It is then necessary for her to steam at 20 knots for, say, three minutes head to wind while flying off a flight of machines. She then turns again to regain station. In all, thirteen minutes has elapsed, during which time the fleet (at 20 knots) has proceeded 4.3 miles and the carrier has steamed one mile on the opposite course. To regain station the carrier has to make good 5.3 miles. Assuming she is able to develop a relative speed of 10 knots, this will take thirty-two minutes.
In the above case it was assumed that the wind was in the worst direction relative to the course of the fleet. Let us suppose, however, that the carrier was originally stationed well up with the advance forces. After her initial flying off she has dropped back to some position near the battle fleet. If the commander-in-chief now requires more aircraft from this same carrier, he must either wait until she has regained her station, accept another drop in her position, which will probably place her astern of the fleet and open to attack from enemy cruisers or destroyers disposed astern, or he must effect some drastic reduction in the fleet's speed.
Now let us assume that the wind is at right angles to the line of advance of the fleet. Allow two minutes for the turn into the wind, three minutes either out from or in towards the line of advance, and then three minutes for the turn back on to the course to regain station. The distance now to be made good is just under three miles at a 10 knots relative speed. So it is seen that, even in this case eighteen minutes at high speed must elapse before the carrier is once more in station. She has, however, only dropped back roughly two and three-quarter miles from her original position, and she would have time to carry out another similar operation before falling astern of the fleet's protection.
Flying on presents a far greater loss in position under the conditions considered above. The time taken to fly on will vary according to the type of carrier and the facilities available for restowing machines. As a general rule, the landing deck must be cleared before the arrival of each successive machine. These intervals will necessitate the carrier maintaining her course for some eighteen minutes as against the three required for flying off. The drop in position under adverse wind direction is correspondingly very much greater and the maintenance of the carrier in a position of safety becomes doubtful.
The safety of carriers with the fleet depends on two things - their powers of self-protection, i.e., speed and armament, and their position relative to the battle fleet, in action. With regard to the first, speed and armament are, of course, a question of design. The ship herself is very vulnerable in that the hull presents a big target and the large stores of petrol, including that standing the aircraft make her more than ordinarily inflammable, Added to this very little damage is necessary to the flying deck to make it useless to aircraft. As regards armament it is not possible to carry anything more powerful than that of a cruiser. Designs have been suggested for a combined battleship and aircraft carrier, but such a type is not likely to materialize, for the result would be useful neither as the one nor the other. As a battleship, this hybrid would be unable to take her place in the battle-line owing to the necessity of flying off and on. As a carrier she would be hampered by the space occupied by turrets and, if attempts were made to fight her guns when she was working aircraft, the latter would be considerably disturbed by blast. Moreover, as speed is essential to the ship in her capacity as carrier, it seems extremely doubtful whether all these requirements could be combined in a ship conforming to the Washington Treaty.
It is far more probable that development will be along the lines of high speed · and improved facilities for handling aircraft, while the armament will be no more than one which will enable ship to defend herself to some extent against small cruisers and destroyers.
Turning to the question of the position of carriers in the fleet while in cruising and battle order, we see that there can be no set position and every operation has to be considered separately; first in the light of the probable force and direction of the wind; second, from the point of view of the probable course of the fleet in cruising disposition, its direction of deployment and subsequent probable movements; last, with regard to the position and course of the enemy.
In studying the problem it must be borne in mind that the functions of a carrier are, broadly speaking, two-fold. She has to provide aircraft for reconnaissance during the approach and, subsequently, for observation of fire and for reporting movements of the enemy ; she has also to be ready to launch torpedo and fighter airplanes. Of these two, the former duties are the most important because the fighting power of the whole fleet may be dependent on airplane observation whereas the second are, as yet, only auxiliary forms of attack and defense. So great has become the value and importance of aircraft reporting that in the near future, under favorable weather condit1ons, we may find it superseding the cruiser screen. Should this become possible, it will enable the cruisers to be concentrated before actual contact with the enemy, instead of keeping them spread until the last moment.
To maintain a continual supply of reconnaissance machines will necessitate very close cooperation between the carriers themselves. In fact a squadron of carriers is really a most important command. Each ship will probably have to fly off and on at least every two hours. It is essential, therefore, that the carriers should be so stationed relative to the main fleet that they will not drop astern of the battle fleet during the approach. They must also be clear of the line of advance so that their movements are not likely to hamper the course of the main fleet. This is the more important as the time of deployment draws near. If sufficient information is available they can be stationed so as to ensure that the enemy light forces will not at the outset make contact with them. The strategical plot, therefore, becomes of great importance and the carrier squadron must amend its position as the plot progresses so as to ensure that they do not come under fire of the enemy's main forces. It must be borne in mind that ·the carriers may get out of direct touch with the commander-in-chief, in which case they must take such action as appears necessary to remain in or regain safety without awaiting instructions. Finally, they must anticipate the direction of deployment of the battle fleet from their own strategical plot. It may be possible for the commander-in-chief to inform his advance forces of his intentions, but that this information will penetrate to all carriers cannot be relied upon.
It is essential that the carriers should not be left "in the air" after deployment and they must leave no doubt in the mind of the commander-in-chief that they are proceeding to their battle position in plenty of time before deployment.
It may be the enemy's intention to allocate a portion of his light forces for the express purpose of attacking our carriers. In this case the latter must rely on units of their own fleet for protection and, abandoning flying for the time being, retreat under the protection of these protective forces.
In the case of the wind being in an adverse direction, an initial position on the disengaged beam of the battle cruisers appears best. Here the carriers will be covered from attack by enemy craft crossing ahead of the battle-line and they can best afford to lose distance during their flying operations. The distance away from the line of advance of the battle-line is governed by the amount the carriers will increase or decrease this distance while operating, the limitation being, of course, that such operation must not bring her within gun range of the enemy fleet. At the same time they must keep sufficiently in touch with their own fleet to observe its movements and to be able to conform to them as soon as they are free to do so.
In the event of the commander-in-chief reversing the course of the fleet during the engagement, in view of a similar movement on the part of the enemy or massed torpedo attacks, it will probably be necessary to cease operating aircraft until a position of comparative security is again attained by the earners. This possible fleet movement would be an argument in favor of stationing the carriers initially further back from the battle cruisers and nearer the battle fleet and, consequently, accepting the resultant shorter distance available for loss in operating aircraft under adverse wind conditions.
Generally speaking it must be the object of the commander-in-chief to save his carriers from contact with enemy forces by countering enemy movements against them; on the carriers' part it is their duty to ensure that the commander-in-chief’s anxiety shall be a minimum.
It is difficult to lay down whether flying or the safety of the carriers themselves should be the first consideration. It has been seen that it will take considerably longer to fly the same number of machines on than to fly them off. Of these two operations flying off is the more important and, in regard to types of machines the provision of reconnaissance and spotting airplanes should come first. Nevertheless, there is the psychological moment at which the torpedo planes should be launched to the assault. They should be timed to attack in conjunction with the destroyer forces and when the enemy battle-line is fully engaged. This will have the maximum effect in dislocating the enemy's line, and throwing out his gunfire. Once a carrier is committed to launching her torpedo planes the flying off of accompanying fighter machines will not add greatly to the loss in distance.
The return of these machines is another matter. The attack completed, the craft will probably return at a time when the carrier is still endeavoring to regain her position in preparation for flying off a relief supply of reconnaissance machines and landing on other similar machines for refueling. Again the reconnaissance service is of the first importance and it seems that the returning attack machines must take their chance. It may be possible to land on at the same time as the more important reconnaissance machines but it seems likely that, under certain conditions, they must be sacrificed in order that the carrier may maintain her position.
Throughout the foregoing no consideration has been taken of the probable attacks on the carriers by enemy aircraft. This further complicates matters. While flying off or on, a carrier presents a steady target. During these operations indiscriminate anti-aircraft firing is impossible and the carriers' primary defense must be aircraft. Allowance has, therefore, to be made in her movements to ensure a supply of machines for defense purposes. Probably the best method of defense would be the harrying of the enemy's carriers with aircraft. The enemy, however, may concentrate on the destruction of reconnaissance and spotting machines, in which case fighters must be maintained in the air for their protection.
The whole matter becomes more involved the deeper it is probed. Over and above all is the question of the safety of the carriers themselves. That is of primary importance, at least until such time as the defeat of the enemy is assured. As long as there is a likelihood of further operations at sea the safety of the carriers must remain a most important matter to the fleet.
The answer to these problems can only be obtained by constant trials and exercises in peace time. Unfortunately there are matters which greatly hamper the attainment of satisfactory results. Economy reigns supreme and the limited supply of fuel prevents the carrying out of fleet exercises at high speed; besides which, the life of a warship is short and wear ·and tear of machinery must be considered. Finally, it is not possible to assess the effectiveness of anti-aircraft measures. Up to date there are no data on which to base an estimate of casualties and it is very difficult to say what proportion of aircraft are likely to return on completion of their duties, thus making it difficult for the carrier to make allowances of time for flying under war conditions.
Fleet exercises take place at a proportionally reduced speed. This works satisfactorily until the matter of carriers is considered. They must steam at high speeds to work their aircraft, and as soon as these speeds are employed sense of proportion is lost. A carrier may steam 30 knots down the battle-line while landing on, but if the fleet is moving at 10 knots instead of twenty, she is afforded protection for a proportionately longer period than would be the case in war. In another case, light craft, limited to 17 knots, are in pursuit. The wind is favorable and the carrier employs her full speed away from the enemy while flying off and on. Thus in these peace practices the range is being opened, whereas under war conditions the enemy could keep it more or less constant. It is essential that this lack of reality be remembered or false impressions will be created.
The whole subject is one requiring much investigation and, up to date, it can safely be said that only a beginning has been made in this phase of fleet tactics.
1 This is not so at present with all, but future construction will undoubtedly be given the maximum speed possible.