1. Nearly all naval officers are agreed that sub-caliber drill is an important feature of gunnery training; but in spite of this, conversations with various officers show that there exists a wide diversity of opinion as to the best method of conducting this drill, and in some cases even a confusion of thought as to the object to be accomplished. That junior officers should have vague and indefinite ideas about gunnery training is not at all surprising, in view of the bewildering way in which this topic is treated in conversation, in reports, and even in published articles.
2. It is with great hesitancy that I enter upon a discussion of this subject, because I appreciate the difficulty of dogmatizing on questions respecting which officers differ so widely in opinion. But I believe that our gunnery, although good, falls far short of the excellence it should attain, and that a potent reason for this is a lack of system and method in our manner of training. This criticism is particularly true of our manner of conducting subcaliber drill, and I therefore present these ideas with no claim to originality, but with a hope that an attempt to follow them to logical conclusions will assist in the development and adoption of a systematic plan for conducting this drill.
3. A cogent reason for the adoption of a definite plan is that it will result in economy of time. That this economy of time is of great importance, is shown by the complaint prevalent throughout the fleet, that there is not sufficient time available to devote to preparation for target practice. It is a regrettable fact that there is much justice in this complaint; but in view of the great number of things which the fleet has to do, the trouble is difficult, if not impossible, to correct. For this reason comparatively little sub-caliber drill has been held during the past year. However, in spite of the paucity of time, it is logical to believe that the adoption of a well thought out plan, perfected and followed by all ships, will result in more drill, because all ships will then be better prepared to take advantage of every opportunity that presents itself. Moreover, greater interest will be taken in the drill, both because of this economy of time and because a well defined plan will result in a clearer understanding of the drill.
4. In the first place, it might be well to make clear just what is meant by the term sub-caliber drill. Sub-caliber drill may be defined as a device for gunnery training by which a gun of comparatively small caliber is so attached to a big gun that the small or sub-caliber gun is pointed, fired, and the fire controlled, by operating the same mechanical appliances, and performing the same duties required to point, fire, and control the fire of the big gun. The members of the crew of the big gun are thus trained in their regular duties, except that the firing mechanism is so connected that when the firing key is pressed it operates to fire the sub-caliber gun instead of the big gun. In this way sub-caliber drill affords a manner of training by which the firing of the big gun, with all the attending problems of fire control, is simulated to a very profitable degree without the expenditure of big gun powder and shell, and without subjecting the big gun to the wear and tear of actual firing. It is evident that the greater the range and the accuracy of the sub-caliber gun used, the greater will be the benefit of the drill, but for reasons of expediency the department has adopted the 1-pounder for use with the. 12-inch gun, and therefore this specific arrangement will be considered for convenience in this discussion, although whatever may be the size of the sub-caliber the principles of the training remain the same.
5. In order not to get adrift from the main issue of this discussion, it will be necessary to accept the opinion of the Target Practice Office as expert on general questions respecting proper battle training. Confusion of ideas may thus be prevented by admitting the point that, as it is theoretically true, so is it reasonable to believe that training with sub-caliber exactly along the lines prescribed for target practice will produce the very best results. It follows that improvement in the rules and instructions for target practice will result in a corresponding improvement in the plan for conducting sub-caliber drill.
6. The groundwork of gunnery training consists of stationing the men in the gun crews and fire control part, and drilling them in their individual duties. The selection of pointers is perhaps the most difficult part of this groundwork, but it can be satisfactorily accomplished by means of the mechanical contrivances known as the Morris Tube, the dotter and the check sight. After this initial stage of preliminary training has been completed, the preparation of a division of ships for battle may be conveniently divided into three distinct steps: first, developing team work with a gun or a turret acting singly; second, developing team work with a ship acting singly; third, developing team work with a division of ships acting singly. (Gunnery training may be considered as completed with the division, as the grouping of divisions into fleets is more a question of tactics than one of gunnery.)
7. Inasmuch as the general scheme for target practice recognizes these steps by prescribing different kinds of practices and supplying a separate allowance of ammunition for each, so in like manner should the plan for conducting sub-caliber drill recognize these same distinct steps. Therefore, the following proposed plan begins with the kind of sub-caliber drill to be held in accomplishing the first step in the preparation of a division of ships for battle, namely, to develop team work with a gun or a turret acting singly. The other two steps will also be discussed separately and in turn.
METHOD OF CONDUCTING SUB-CALIBER DRILL TO DEVELOP TEAM WORK WITH A GUN OR TURRET ACTING SINGLY.
1. In this method economy in time and development of team work require that, in so far as it is practicable, the entire system, consisting of the gun crews, range finder party, spotters, fire control party, and ship control party, be exercised at the same time. Perhaps the most important feature in this method is the training afforded the gun pointer group, but in laying particular stress upon this point, care should be taken not to overlook the necessity of affording, at the same time, training for the men who occupy less conspicuous stations, but who have, nevertheless, difficult and important duties to perform in the complicated system by which hitting efficiency is attained.
2. To assure fairness, for reasons of competition, and in order that weight may be given to the scores in qualifying gun pointers for extra pay, all gun pointers should fire under approximately the same conditions, and official report should be made of the drill, whenever this method is carried out. To accomplish this end, conditions similar to the following should be prescribed:
(a) Firing to commence when the target is 27° forward of the beam and to cease when the target bears 27° abaft the beam.
(b) The distance of the target when abeam to be not less than 1000 yards.
(c) A difference of three knots to be maintained between the speed of the firing ship and the speed of the target.
(d) The scores to be computed in accordance with the rules for elementary target practice for the current year, and a load to be simulated for each shot fired consuming an interval of time equal to the average loading interval for that particular gun as computed by the ordnance officer of the ship.
(e) The screens to be of a prescribed size (20'x 15' if practicable).
(f) Only one or two turrets to fire at a time, and the number of screens and color of shells to be so arranged that the score of each pointer may be determined.
Note.—It is important that both sub-caliber guns of a turret be so boresighted and calibrated that the shells will fall as nearly together as practicable at the range at which the drill is held.
3. The arguments against attempting to fulfill these conditions, because of the time consumed and trouble involved, are admitted, but, nevertheless, it is believed that with skilful management this exercise can be carried out in smooth water expeditiously and to a very good advantage. The details of fulfilling the prescribed conditions should be left to the discretion of commanding officers. In this connection attention is called to the smart work done by the repair parties during the recent elementary target practice. In some instances the four screens were shifted in less than 15 minutes after the firing vessel had finished her run. It would appear that at shorter range with lighter material and slower speeds, screens could be shifted with even less delay and difficulty than was the case during the elementary practice.
4. It is suggested that a ship acting singly could probably carry out this drill advantageously by having the target anchored, or towed by a steam launch. After each run the repair party in the steam launch could count the hits and either paint out the holes or shift the screens. Time might be saved by having the firing vessel steam between two targets, firing at both simultaneously. When firing at towed targets the danger of ricochets to the right must always be guarded against.
5. Another plan suggested for carrying out this method is to have two ships working together, each towing one or two rafts similar to the experimental raft designed by Lieutenant-Commander A. M. Proctor. Both ships to fire at the same time, regulating their speeds to give the desired rate of change in range and deflection, and alternating in taking the superior speed. Repair boats could probably be handled to advantage by having them towed from the lower booms. At the completion of the run both ships to stop, paint out holes or shift screens and then proceed on another run. The towing ship to count the hits after each run and signal the number of each color on each screen to the firing vessel.
6. The benefits resulting from this drill are:
(a) That it creates interest and incites competition among pointers, turrets and ships. (It might be a good plan for each ship to offer a small money prize from the ship's Welfare fund for the turret or gun which makes the best score on each day that this exercise is held.)
(b) That it affords a means of obtaining an efficiency report of pointers, which may be given weight in qualifying pointers for extra pay.
(c) That it is a training for the range finder party.
(d) That it is a valuable training for sight-setters, and impresses upon the minds of sight-setters and pointers the importance of having the sights set promptly and correctly. For obvious reasons, training for sight-setters is a very important factor in preparing for battle, and it is therefore desirable, during this drill, to regulate the speed of the firing vessels so as to require as much sight-setting as practicable, without introducing uncertainties in range and deflection to handicap the pointers.
(e) That it is a training for spotters, especially in their duties for elementary practice, and should make clear the advantages of placing reliance on the range finder; at the same time emphasizing the fact that while a little spotting may be most necessary, still too much spotting may be most harmful. The spotter should take station near to, or within easy communication, of the range finder, and spot much the same as he would in elementary practice.
NOTE.—In order that spotters may be benefited by sub-caliber drill, it is important that its limitations should be appreciated. It is true that a 1-pounder shell fired at a range of moo yards and falling 300 yards short, does not look the same to the spotter as would a 12-inch shell fired at a range of 10,000 yards and falling 300 yards short; therefore it is reasonable to suppose that sub-caliber drill is of no particular benefit to the spotter in training him to estimate the amount of the corrections to be applied when firing at battle ranges'. However, it must be remembered that the estimating of the amount of the corrections to be applied is only a part of a spotter's duties, and though it is an important part, still it is my belief that it has been emphasized to such an extent that the other equally important, and perhaps more difficult duties of the spotter have been neglected. It appears to me that sub-caliber exercise may be made useful in training those faculties which are used by the spotter in performing these other duties. Moreover, some benefit in training the spotters to estimate amounts over or short may result by stationing them in such a low position that the t-pounder splash will appear to them, relative to the sub-caliber target, just as the splash of a 12-inch shell would appear, relative to the actual target, when fired at battle range and viewed from the spotting top.
METHOD OF CONDUCTING SUB-CALIBER DRILL TO DEVELOP TEAM WORK WITH A SHIP ACTING SINGLY.
1. It is believed that a valuable training would result if this method were frequently combined with general quarters drill and carried out with battle stations manned and all hands performing their respective duties exactly as would obtain during actual battle.
2. It is suggested that when held as a dress rehearsal for individual ship battle practice, it would be well to carry out the rules and instructions for target practice in making the approach and in firing, with the following exceptions:
(a) The range to be reduced to approximately the range at which the angle of fall of the I-pounder is the same as the angle of fall of the 12-inch when fired at the battle range.
(b) The speed of the firing vessel to be reduced by the amount which will make the run over the reduced range consume an interval of time equal to that consumed in making the run at the prescribed battle speed over the prescribed battle range.
(c) The target screen to be similar to the battle practice screen, but reduced in size corresponding to the reduction in range.
3. The desirability of having this drill frequently as a means of assuring preparedness for battle, necessitates a modification by which the approach is omitted and one requiring as little time and trouble as possible to carry out. It is believed that this modification could be conveniently used by vessels cruising in company by forming two columns at an interval equal to the prescribed range; each ship to put over a sub-caliber target and all ships to fire at the same time, the desired rate of change in range and deflection being produced by first one column steaming a little faster than the other and then vice versa.
4. A further modification is suggested by which sub-caliber rifles are fired instead of sub-caliber 1-pounders. This modification may be carried out when holding rehearsals at the prescribed battle range at battle speed, and at such other times as it may be necessary to economize in 1-pounder ammunition.
METHOD OF CONDUCTING SUB-CALIBER DRILL TO DEVELOP TEAM WORK WITH A DIVISION OF SHIPS ACTING SINGLY.
1. When using this method as a dress rehearsal for division battle practice, it would seem advisable to steam at battle speed and fire at battle range, following, without exception, the rules and instructions for Division Target Practice.
2. The point of gunnery training in this step not covered by the two preceding steps is the training afforded the fire control parties in working together under the direction of the Division Commander. The new problems introduced are those of concentration of gun fire and of interference of gun fire between ships.
3. It is evident that, because of the long range, the 1-pounder shells will fall nearer the firing vessels than the target; but the spotters and fire control parties may be trained by having them move the bunched splashes of their respective I-pounders from one place to another in obedience to orders to shift the point of aim from one target to another.
4. It is believed that a modification of this method, using either sub-caliber 1-pounders or sub-caliber rifles, could be advantageously carried out during the simulated battle contacts which take place in fleet maneuvers and exercises.