INTRODUCTORY NOTE.—These two short articles by Lieut. A.C. Dewar, R.N., a prize medalist of the Royal United Service Institution, are e- printed not only because of their intrinsic merit, but particularly because they treat of subjects in which the Navy is greatly concerned, and in which it is desired to interest the readers of the PROCEEDINGS. The interlined comments—objections and criticisms—are added merely in the way of suggestion, to induce the readers to think about and discuss the statements made and views expressed.
SPEED IN NAVAL TACTICS.
(Reprinted from the United Service Magazine for Sept., 1907.)
WITH COMMENTS.
Tactics may be classified as:
(a) Distant touch (over 20 miles).
(b) Visible touch (10 to 20 miles).
(c) Battle approach (4 to 10 miles).
(d) Battle tactics (under 8000 yards).
Distant and visible touch are interrelated with strategy, and in both the principal object will be to meet or avoid the enemy, both of which, and particularly the latter, are dependent on speed. Maneuvering for sun and sea gauges, which may often be important factors in a battle, will take place during battle approach.
[Having the "sun gauge" presumably means being so placed with regard to the enemy that the sun is at your back and in his eyes, and having the "sea gauge" means being so placed as to be less inconvenienced by sea than the enemy is. A better term than "sea gauge" would be "weather gauge" or "weather vantage," thus including the wind and other elements which may be more important than the mere state of the sea.]
Sun gauge calculations are too complicated and too lengthy for this article, but generally a speed superiority of at least 3 knots will be required to make certain of obtaining the sun gauge before nightfall.
[The following calculation seems to show this statement to be an error:
Let R be the radius of the slow ship's circle about common center, and S her speed, both expressed in knots. Let R + 5 and S+ a be corresponding values for the fast ship, the distance 5 knots, or 10,000 yards, being taken as just beyond effective range.
Then R/R+5 = S/S+a
Whence R=5S/a
But the time in hours that it would take to complete the circle is T=2?R/S, or substituting the foregoing value of R, T= 10?/a
Therefore the number of degrees of change of course, or the number of degrees change of compass bearing of one ship from the other, per hour, is 360/T = 36a/? =11.5a (approximately).
If now ?Z is the change of azimuth of the sun per hour, the effective change of bearing of the sun glare will be 11.5a±?Z, according as the fast ships so move as to have the change of the sun's azimuth help or hinder getting the sun gauge. ?Z varies within wide limits, the more rapidly as the sun is high, when sun gauge is of relatively small importance, but if we take it at 10° (per hour), and let a=3, the author's value, we see that the change of bearing of the sun glare is 44.5° at best and 24.5° at worst. That is, the bearing of the sun glare may be changed 90° in from 2 to 4 hours.]
Togo thought it worth while altering course to obtain the sea gauge, and there is little doubt that a sun angle of 30° (i.e., the angle between the enemy and sun) would seriously handicap firing.
[If this refers to Togo's change of course at the beginning of the Battle of the Sea of Japan, when he stood across the head of the advancing Russian columns—and it can hardly refer to anything else—then by this change Togo did not obtain the sea gauge but gave it to the Russians. The wind was fresh from the South or Southwest, and the Japanese, remaining to the North of the Russians until after the battle had been decided, were in the inferior position as far as sea and wind are concerned—also in the matter of sun glare, if any sun shone that day, which it probably did not. Of course the author may in this place use the term sea gauge" in a strategical sense, but, if so, it is a peculiar use and should have been explained.
It seems worth remarking that all the disadvantages of sun
glare can be completely overcome by the use of darkened glasses, and that this should lead to their being supplied for use with all observing glasses and telescope sights.]
Battle tactics proper will open with the fleet on an initial battle course, with the maximum arcs of all ships bearing and with a good mean range, conditions which are fulfilled by the line of bearing of the column being at right angles to the point of attack—a proposition clearly formulated by the late Rear-Admiral May in 1897, and also by Lieut.-Commander Niblack, U. S. N., in a paper on "Gun-fire and Tactics" in 1903.
It was Rear-Admiral May's paper, published in the R. U. S. I. Journal, which gave birth to P. Z. exercises and relegated equal speed quadrilles to a subsidiary position.
Superiority may be that of fire arcs—increasing the fire volume, or of mean range—increasing the fire accuracy. Both, however, are closely related to the angle of approach, or the angle formed by the direction of the column and a line joining the two opposing leaders.
The initial battle course may be entered on by following the leader round in succession (as Togo did at Tsushima), or by coming up on a line of bearing and turning simultaneously into line ahead. The value of speed is least evident here, for the principal consideration is to turn on to a course which will bring all maximum arcs to bear at a good mean range. A slow fleet at 15 knots can turn simultaneously as quickly as a fast at 18 knots, and the gain of the latter when turning in succession is quite inappreciable (about 1 minute).
[This is for a fleet of 8 ships at 400 yards distance.]
When one fleet has turned and brought its maximum arcs to bear at an effective range (say 7000 yards), the other must follow suit and turn parallel to it, or expose itself to superior fire. This is the law of parallel courses—that fleets within gun range, endeavoring to exert their maximum powers of offence, tend to turn on to approximately parallel courses—a well-known feature of battle maneuvers. Speed, then, is useful in obtaining the sun or sea gauge, but is not required in order to turn on to the initial battle course on equal terms. Both admirals are here supposed to be maneuvering in single-line tactics, which is the formation which gives the greatest liberty of movement to each vessel, permits of a rapid change of direction and course, and, above all, is simplest and easiest to maintain under battle conditions of smoke from funnels and bursting shells. Admiral Fournier's tactics—which are simply those of our old friend, the group, reduced to a carefully digested system—are not simple enough for battle.
The value of speed in battle tactics proper must now be considered.
Movements in battle will have two objectives.
Range movements—To alter or maintain the range.
Position movements—To gain a position of advantage. [These are admirable terms, expressing a great deal very concisely and yet with precision.]
Range movements will consist either of turns in succession or together, ships turning till the maximum arcs are just obscuring. Any obscuration of maximum arcs within 6000 yards is uneconomical and therefore faulty. In parallel tactics a speed superiority of 3 knots will be required to close 1000 yards in 20 minutes with maximum arcs bearing. Anything less is not of much use, e.g., 2 knots difference gives a change of moo yards in 30 minutes, which is too slow to be really useful.
[These statements open up a large field. The author evidently is considering the case of two fleets, abreast of one another, each in line ahead, on parallel courses, the faster of which wishes to reduce the range while the slower opposes the change. Under such circumstances the ships of the faster fleet turn toward the enemy, changing course simultaneously through the largest angle which will permit them to continue to use their entire broadsides, say4o0. In response, the slower ships must turn away simultaneously, changing course by the same amount. If now the original distance between the fleets was 6000 yards, and their respective speeds are 18 and 15 knots, in 5 minutes each of the faster ships will have transferred 321 yards and advanced 383 yards relative to her slower opponent, so that the range will have changed to √(6000—321)2+(383) 2=5692 yards, or diminished 308 yards, while the bearing of each opponent is now only about 36° forward a beam instead of 40°. The fast ships can now turn about 4° further towards the slower ones, which latter must turn further away by an equal angle, and after another 5 minutes the range is reduced to 5384 yards, each fleet meanwhile maintaining its original line of bearing.
Thus we see that, by this method, the author's assumed excess of speed (3 knots) will enable the range to be reduced 1232 yards in 20 minutes, instead of 1000 yards as he states, and the question arises, what method of closing had he in mind, if not the one described. It is not apparent how mere change of course by head of column, keeping broadsides bearing, can change the range, provided the slow fleet, wishing to prevent change of range, always turns by head of column to the same extent as the fast one. Perhaps the explanation of the discrepancy is that Lieut. Dewar assumed a simultaneous change of course less than 40°, which would be necessary if the guns trained less than 40° forward a beam. Taking 30° instead of 40°, the change of range works out at 49.3 yards a minute, or 986 yards in 20 minutes, Practically the figure he gives. On the other hand, the always interesting and well informed Black Joke, criticising Lieut. Dewar in an article which appeared in the October number of the United Service Magazine, says in reference to the subject under discussion, "By the book a speed superiority of 3 knots will enable the range to be altered in 20 minutes by 860 yards only." "But it has been discovered by actual experience that the practical alteration of range is less, very much less, than that which is theoretically possible." "It would not be overstating the case to say that not 1000, nor even half of that alteration of range, could be brought about in 30 minutes" (with 2 knots superiority of speed).
Without further attempt to reconcile these discrepancies, it may be remarked that the rate of change of range which can be brought about by the fast fleet depends to a very large degree upon the skill with which the individual ships are handled, and that, with the arcs of train now usually given to main battery guns, even with 3 knots superiority of speed, the time necessary to alter the range 1000 yards may well be sufficient to decide an action.]
Ability to select the range certainly permits one to exploit superior fire skill, for at shorter ranges the increased dangerous space compensates for inferior fire control.
Thus if fire skill is good, speed would enable one to exploit it; and if poor, to neutralize the inferiority. There is, however, too great an inclination towards the idea of keeping at long ranges (7000-9600 yards) and exploiting fire control. Too long a range is distinctly uneconomical, the projectile's penetrative energy is greatly decreased, and the percentage of hits must be much less than at medium ranges. Probably under battle conditions hits would not exceed an average of 20 percent at over 7000 yards. This means 6 hits out of 30 shots. It would be inadvisable to expend more than 30 shots at such long ranges; and it may be said that long-range firing (over 6500 yards) can never be more than a prelude to medium ranges. Three knots speed superiority will certainly give a fair ability to alter the range; but if fire skill and armament are equal, command of the range will give little or no advantage.
["If fire skill and armament are equal "it is clear that choice of range will affect nothing but the duration of the combat. But superior speed should be taken to imply inferior armament, whence we may deduce as its advantage nothing more, in the aspect now under consideration, than the power it gives to refuse close action.]
With regard to position movements, speed is not required to obtain a position of equality. Speed permits a fleet to draw ahead, but the slower fleet can always place itself in a position of equality by turning parallel. This, however, postulates plenty of sea room, which may not be available, and then speed gives a decided advantage and binds the slow fleet down to particular tactics.
[The real advantages of speed seem to be these—the fast fleet can get in any direction it pleases from the slow fleet and can make the latter take any desired line of bearing, by threatening to cap; it can avoid action altogether or can force an action; and, having engaged, it can to a very limited extent choose whether to fight at long range or to come to close quarters. It is often claimed that the fast fleet has a great advantage from having the initiative; that the slow fleet's movements are parries and only effective if perfectly executed. But if it be assumed, as it should be, that the slow fleet is the more powerful in armor and armament, then it becomes clear that very often the fast fleet will be the one on the defensive—the slow fleet, wishing to force the fighting, turns towards the fast fleet, not away from it, and it is the latter that must evade the blow.
The proximity of land may hamper the movements of one as well as the other fleet, and for a fair comparison we must assume Plenty of sea room.]
One writer has argued that if the fast fleet draws ahead, the slow fleet can always turn 16 points and so reverse the position. The fast fleet, however, would never turn 16 points in reply. It would turn into towards "slow's" rear ship (former leader), then, forming line abreast, concentrate on the rear ship and force Slow to once more turn parallel.
[Slow would be under a great disadvantage as regards gun fire while turning (for 33i, or 4 minutes), and the movement of reversing by a simultaneous turn does not seem to be a good one, but, supposing it to be made, there is stillroom for argument as to whether fast's proper reply is that suggested. The danger from slow's torpedoes must be considered.]
In what may be called the primary movements, such as turns in succession, and together, speed will enable a fleet to assume its new formation or course a little quicker. Thus a fleet of eight ships at 18 knots will turn in succession on to a new course in 4.6 minutes, while a fleet at 15 knots would require 5.6. This is inappreciable, but combined with shortness of column will give a certain advantage, which is an argument for short columns of fast heavily gunned ships. Thus a fleet of eight ships at 18 knots is on a new course in 4.6 minutes, while a fleet of 12 ships at 15 knots will require 8.8 minutes to draw parallel. Columns being of equal length, however, 5 knots superiority would be required to make three minutes difference.
[The times given are merely those required to cover the distance from center of leader to center of rear ship, or 2800 yards for an 8 ship fleet and 4400 yards for a 12 ship fleet. As a matter of fact, taking 8 ships at 15 knots, 5.6 minutes from the time the leader begins to turn, the rear ship should begin to turn, but the completion of the movement will take about 1 minute, 40 seconds longer if the turn is 9.9°, or about 1 minute for 45°. This consideration reduces the relative gain, due to speed, supposing slow and fast ships to turn in equal times. But actually, the fast ships will probably be longer than the slow ones, and their length of column for an equal number of ships will be greater. The longer the ship, the greater distance between ships is necessary for safety.
The difference between the time of turning for 12 ships at 20 knots and another 12 at 15 knots is 2.2 minutes, not 3 minutes, as the author claims, and this supposes that all ships keep station and 400 yards distance. The 20 knot ships would probably be at 500 yards, or even 600 yards, in which latter case it would take them 1.1 minutes longer than the 15 knot ships to make the turn.
In fact it seems clear that superior speed gives no advantage worth speaking of in maneuvering by head of column.]
Wheels and direct movements to alter the line of bearing depend on the difference of speed between the pivot and the wings, and not on the actual speed. In range movements 10° of fire arch as the same effect as 4 knots of speed; thus 4 knots will enable a fleet to alter the range 1000 yards in 15 minutes, keeping its maximum arcs bearing; while a superiority of 10° in fire arcs, with equal speeds, would enable a fleet to do the same in 13 minutes. Thus a fleet at 15 knots with 10° greater fire arcs would have an advantage in range movements over a fleet of 18 knots.
[Here as before, verification of the author's figures is impossible without further explanation of what he assumes. If the maximum turn which will keep the broad side guns of the vessels of both fleets in action is 4o0, and each fast ship turns so as to keep her slow opponent 40° forward abeam, the latter constantly turning away so as to keep her opponent 400 abaft abeam, the range will decrease 1640 yards in 20 minutes, or 1000 yards in 12.2 minutes (for 4 knots difference of speed). If the fleets are of equal speed, say 15 knots, and the guns of the one attempting to close train 10° further than those of the one keeping away, so that the bearings are 50° forward abeam and 400 abaft abeam respectively, then the range will be decreasing at the rate of 61 yards a minute, or 1000 yards in 16.4 minutes. So, with this data, it is not true that 10° of fire arch as the same effect as 4 knots of speed. The important point, however, is that there is a certain superiority in fire arc which, in the matter of range movements, is the exact equivalent of a given superiority in speed. And, whether the fore going figures are correct, or the author's, in any event it is clear that a few degrees increase of train of a ship's main battery guns will balance the advantage of a considerable excess of speed, in range movements.]
It has been shown that in "T" tactics speed gives no advantage so long as the slow fleet has sea room; in attempts to cross the rear also, no advantage is obtained from speed, as the slow fleet can immediately reply by the same movement, which ends in counter circling. In pursuit tactics, in which fire would usually commence with fleets in line abreast, astern of one another, the fast gradually closing on the slow, speed gives a considerable advantage. Fast can reduce the distance 2000 yards in 20 minutes, and then, forming single line, bring all its maximum arcs on a flank ship of slow for 672 minutes. This maximum arc fire would be possible for 18 minutes every hour.
[If fast is 18 knots, slow 15 knots, and the initial distance 6000 yards, in 20 minutes it will be 4000 yards. If then the fast ships turn simultaneously 450, which will take about a minute, they can open with their entire broadsides, and after steaming on the same line of bearing for 6.5 minutes, range from the leading fast to the flank slow ship will still be with in 6000 yards. Then it would take another minute to turn into line abreast again. This may work out at 18 minutes of fire per hour, though the result is not self evident. But during this movement, fast would afford an excellent target for slow's torpedoes, and what if slow turned to starboard when fast turned to port?]
Each disabled ship in the slow fleet would drop behind or be lost, while damaged ships in the fast fleet would drop to the rear in safety. In pursuit, a superiority of 3 knots is required to bring a fleet in sight to action within 6 hours, and a weak fleet, With a speed inferiority of 2 knots, could not, therefore, afford to go much beyond 170 miles from its base.
Thirty percent fire superiority may be considered as equalizing 3 knots speed, which would correspond in 2 opposing fleets of 8 Formidables to an additional fleet broad side in one of 109.2 and 16 6-inch. The same advantage would be obtained by 30 percent greater hitting skill.
[This would seem to be a mere statement of opinion; at all events no data are given upon which to base it.]
The Japanese victory in the Battle of Tsushima was partially due to speed, the causes of success being:
(a) Taking up a position with sea gauge ahead of the Russian line, due to superior tactical skill assisted by speed.
[Not if "sea gauge" means what it ought to mean.]
(b) Speed enabling the Japanese to keep ahead and carry out " T" tactics.*
[Speed alone would never have enabled the Japanese to T the Russians; it required also the Russian ineptitude.]
(c) Superior fire skill (according to Brassey's Annual, 4 hits to 1), which was probably them a in factor of success.
According to" Nauticus," 1906, however, the Japanese never seem to have been more than 10° before the Russian beam, which would mean that success was almost entirely due to fire skill. It must be remembered also that five of the Russian battleships were designed for, and on paper possessed, equal if not superior speed.
The general conclusions may be summed up by the classification of speed superiority in three grades.
A. Under 2 knots, i.e., for a standard of 16 knots, 1 1/8.
B. From 2 to 4, i.e., 1 1/5 to 1 1/4.
C. Over 4, i.e., 1 1/3 to 1 ½.
Grade A is a " slight" superiority and will not materially affect the action if the slower fleet is moderately well handled; but if the action lasts any time, the faster fleet will be able to dictate the course. This opportunity may be considered neutralized by a 10 percent hitting superiority, due either to heavier armament or fire skill.
Grade B is an "appreciable" superiority; it will give the fast fleet great initiative, and will ties low down to certain movements. Fast can dictate the course and will also possess considerable power to alter the range. It would require 20 percent hitting superiority to counteract it.
Grade C is a "definite" superiority. Slow will have to observe fast's movements very accurately, and it will be difficult to prevent fast obtaining temporary advantages, when one considers that it draws ahead at the rate of 400 yards in 2 1/2 minutes. Such a superiority would require 30 per cent greater skill to counteract it. Speed superiority is, however, only really useful if a fleet possesses an approximately equal armament. Superior fire skill will not only neutralize a considerable difference of speed, but will be constantly operative, while speed can only give a temporary advantage. As no possible speed superiority can place a
*The term "P" tactics is given to an attempt to draw ahead and concentrate on the head of an enemy's fleet, and in perfection consists of passing at right angles across it and so crossing its "T."
fleet at once, or maintain it permanently, in a position of advantage, an equality of armament and fire skill is required for those phases of the action when the fleets are relatively in positions of equality. Speed, then, tactically is a useful complement of, but can never be a substitute for armament.
[The foregoing statements as to the percentage of greater skill Which would counteract various degrees of superiority in speed are of course mere dicta, but the percentages named are more than excessive in view of the author's failure to establish a definite and material advantage from even 3 knots excess speed. Finally, when the author states that speed superiority is only really useful When armaments are approximately equal, and indeed in all his concluding remarks, he seems to range himself on the side of those who have persistently, but unfortunately with little effect, contended that speed is a secondary quality in fighting ships, and
is not properly to be exalted to the sacrifice of armor and armament.]
SPEED IN BATTLESHIP STRATEGY.
(Reprinted from the United Service Magazine for October, r907.)
WITH COMMENTS.
Position and numbers are factors so dominating in strategy that speed apparently sinks to a secondary place, but when wanted it is vitally necessary. There are two functions of speed which must be distinguished—one enables you to get to a particular area with a greater margin of time, the other to force or evade action. The first gives a slightly greater area of control, the other in a given are a gives a greater certitude of it. In the first case, if the destination is at any distance, full speed will be impracticable on account of strain and possible breakdown. This ability to reach a distant place in a shorter time may be termed the distantial function of speed, the power to force action on a fleet when sighted the combative function. The latter is partially strategical and partly tactical: not purely strategical, for the enemy's fleet is in sight; nor purely tactical, for battle is not joined, and may with- out pedantry be termed strategico-tactical.
In the distantial or purely strategical use, two knots will give a margin of about five hours in a 600-mile run, which will ordinarily be of little importance.
[If the two speeds are 18 and 16 knots, the fast fleet will take 33% hours, and the slow fleet 372 hours to go 600 miles, giving a margin of only 4-hours. A margin of 5 hours corresponds to speeds of 16% and 142 knots.]
In the second case two knots may enable one to bring the enemy's fleet to action, or evade action, which may be of vital importance.
[If the slow fleet becomes aware of the position of the fast fleet at a distance of 24 miles, it will take 10 hours for the latter to get within 8000 yards range, supposing the former to wish to avoid action; and more time than would be left in an average day would be required to bring about a decisive engagement, assuming that slow’s offensive qualities are not immensely inferior to fast's. It would seem that any superiority in speed would give power to avoid action, supposing there is sea room and neglecting the bare possibility of daylight finding the two fleets close aboard, and in the case of narrow waters, or even the mere proximity of land, the particular circumstances alone could determine whether any excess of speed, or how great an excess, would permit an. evasion.]
This power to force or evade action is the primary function of speed, the ability to cover long distances in rather less time is one of subsidiary importance. The circumstances under which speed will usually be required are:
1. Reaching a sea outlet or powerful deflectionary position before enemy's fleet.
2. Reaching an attempted landing spot in a given time.
3. Reinforcing another fleet in a given time. These are dispersive or distant hl functions of speed.
4. Forcing or evading action.
This is the combative or strategico-tactical function of speed. The distantial function of speed can, to a great extent, be supplemented or entirely replaced by position, but this is not the case with the combative. It would involve an excess of refinement to review in detail all the probable cases in which speed would be required under these particular categories, as it depends on the position of the various fleets, and on communication efficiency, but a short summary will be attempted.
1. Reaching a sea outlet before an enemy's fleet so as to ensure deflecting it or bringing it to action: e.g., to reach Gibraltar before a fleet from Toulon, or Dover before a fleet from the Jade. It will be seen that the possibility of interception depends largely on previous positions and rapid and accurate communication. A speed difference of three knots in the first case will give a margin of 140 miles, Toulon to Gibraltar being 710 miles, or 47 hours at 15 knots.
47 hours at 15 knots = 710 miles.
47 “ 16 = 760 ‘
47 “ 17 = 805 ‘
47 “ 18 = 850 ‘
If D is distance enemy must go, S speed of enemy, d distance of English fleet, s its speed, c communication interval, then
c must be less than D/S - d/s.
In fact, communication and previous position enter so largely into all distantial problems that it is impossible to dogmatize as to speed.
England is 300 miles ahead of Germany, and if positions are well selected, high speed for distantial purposes ought not to be necessary in the North Sea, if one could be sure of rapid and efficient communication—which is, however, just what one cannot be.
2. Reaching an attempted landing spot. If first news is from "point of landing," and t be time required by enemy to disembark, then maximum distance of coastal torpedo flotilla should be 20t/2 and of cruisers 18t/2.
[Does this mean that to be effective the relieving force of torpedo boats or cruisers must arrive at the landing spot before more than half the enemy's force has disembarked, or does the author assume that it takes as long for the news of the landing to reach the torpedo boats or cruisers as it does for them to get there after the news is received! Neither hypothesis seems altogether unobjectionable. As regards both these points—the greatest distance for effective action at which a suitable naval force of given speed can be stationed, and the period free from attack which the enemy would need to effect his purpose—everything depends upon the character of the hostile expedition.]
Speed-of two knots would here give a margin of one hour or 20 miles in a ten-hour run.
3. Reinforcing another fleet (in action) in a given time. It would probably be necessary to reinforce within,six hours, and a speed superiority of two knots would only mean 12 miles,a comparatively small distance.
This is more a matter of position than speed.
[The author's conclusions regarding the distantial function of speed seems to have been well expressed by Lieut. B. E. Domville in his Gold Medal Prize Essay for 1906, when he said: "Strategical advantage is more likely to be gained by a skilful disposition of forces acting on interior lines, and by rapid and accurate information of the enemy's movements than by a high speed of the main fighting line."]
4. Forcing or evading action. This is pre-eminently the function of speed. The superiority required to bring a fleet in sight to action in a reasonable time is from two to three knots.
[As already remarked, if the distance of slow from fast is 24 miles when the former begins to run, it will take 10 hours for fast to get near enough to open fire (with 2 knots superiority, nearly 7 hours if the superiority is 3 knots), and from opening fire to close, action will be a long time, if the fleets are anywhere near equaling in fire, always, of course, supposing slow to do his best to keep away from fast.]
The "in sight" condition brings it into the sphere of tactics, but it has been included because (1) if the enemy are not in sight information of their position and course, even if accurate, takes time to pass, and unless these factors are accurately known, high speed can not be fully utilized; (2) if the enemy are over 24 miles distant, which is just over "in sight" distance, the possibility of forcing them to action within daylight hours is not great, and if night falls, the value of high speed is much less, on account of the uncertainty which attaches itself to the enemy's movements.
The value of speed in this sphere is very great. The power it gives of evading action permits isolated ships to traverse the sea in safety and frees all reinforcements and junctionary strategy of the incubus of being brought to action by a superior force.
[Which is to say fast canal ways runaway and "he who fights (not at all) and runs away may live to fight another day," which nobody denies.]
It is asserted that speed is only valuable in running away, but advocates of this view forget that it will be equally efficacious in running after.
[Running after what,' If commerce, yes. But we are considering the speed of battleships.]
The ability to run away means freedom of the sea, and so imperfect control by the stronger, slower fleet. A small fleet of faster and powerful ships could dislocate and very effectively dispute the control of an area by a much stronger but slower fleet, and as it could attack isolated vessels, would compel the latter to keep its forces concentrated. Briefly, then, speed gives freedom of the sea, and control interference, for an area cannot be said to be effectively controlled so long as a fast squadron of battleships can move about in it.
[But the fast squadron can't keep on moving very long; it will have to go somewhere to coal; sooner or later it will be rounded up and have to surrender or fight. Captain Darrieus well says in La Guerre sur Mer: "Whether it be a little sooner or a little later, at the beginning or at the end of the war, battle is unavoidable, and the moment always comes when the two antagonistic forces find themselves face to face."]
Admiral May's strategy of 19(36 is an example of this: his fleet,
Which had only knot superiority, first threatened an important trade route and, when driven off it, appeared on the East Coast with ample fuel to take it back to port.* It is argued that Admiral Wilson was at his heels; but even if a fleet coaling at Portland can be described as being at another fleet's heels, the principal point is that Admiral Wilson could not bring him to action, and there is no reason why May should not have fuelled and carried out a similar movement again as repeatedly as a recurring decimal; for a fast fleet can always get to sea untouched, unless closely blockaded, and close blockade strategy with an enemy that is not absolutely somnolent is extremely risky, if not impracticable, in modern warfare.
[It seems rather abroad assertion to say that "a fleet can
*Admiral May's fleet suffered severely, but this was due to its formation and to lack of speed in some of his ships. The fleet was spread over some 200 miles and the two wing ships—the Victorious and Royal Oak—were cutoff. Three other ships—the Majestic, Magnificent, and New Zealand— lacked staying power and had to drop out, but were not captured.
always get to sea untouched unless closely blockaded." Certainly there are conditions under which a blockade may be close enough to prevent the escape of an enemy's fleet and yet not too close for a reasonable degree of safety. Under modern conditions a blockade may be more effective at zoo miles than it would have been formerly with the blockaded port closely guarded.]
Unless you can bring the enemy to action, scouring the ocean at his heels will scour the trade off it almost as effectively as if he had it to himself, and to bring the enemy to action, at least an equality of speed is required, which, in conjunction with suitable positions, will probably attain the desired end.
The faster fleet, however, will require at least two bases within a convenient distance from one another to carry out such strategy successfully; one base would hardly be sufficient.
Speed, then, is essential in order to bring the enemy's fleet to action when sighted; this function may be termed strategicotactical, and the speed required is2 to 3 knots.
[This should be qualified so as to read at least 2 or 3 knots; and it might well be added that the sacrifice of offensive and defensive qualities necessary to obtain such a superiority of speed is so great that the faster fleet, if of approximately the same total dis- placement as the slower, would have no occasion to wish to bring the latter to action.]
In its purely strategical or distantial aspect, speed is attended by severe boiler rooms and fuel limitations. The mobility given by speed is only marginal; a slower fleet will cover 48, or at the most 72 miles less per diem, and the idea that speed will enable one to appear to-day here, to-morrow there, and the day after elsewhere is a false conception of its true sphere of utility.
One knot in is gives 6.6 miles, or 0.44 hour per 100 miles, and 66.5 miles or 4.4 hours per 1000, and so to gain 6 hours on a 600-mile run, a speed margin of 2 knots will be required.
[A 15-knot ship would gain 6 hours on a 13-knot ship in a 600 mile run, but an 18-knot ship would only gain 4.2 hours on a 16-knot ship, and a 20-knot ship would only gain 3.3 hours on one of 18 knots.]
It is clear, then, that a 15-knot fleet with 8 hours' start of a 17-knot on a 1000-mile run would reach its destination safely.
There is one point about speed which does not affect armament or protection to anything like the same degree, and that is its uncertainty. It may be affected by:
(a) State of hull.
(b) State of sea.
(c) Station keeping necessities.
(d) Engineering skill and accidents.
(b) and (c) will probably be the same for both combatants,
but it is quite possible for clean hulls and superior engineering skill to make a difference of 3/4 knot. Full speed has definite limitations. Any attempt to go at full speed for more than 18 hours, or within 2 knots of it for more than 72 hours (i.e., about 1000 miles), is beyond the capacity of the average fleet. The Drake is only intended to obtain 30,000 h. p. for a period of 8 hours, and her maximum sea-going speed is not more than 21 knots (Attwood's " Warships"). In the futile pursuit after Prince Louis in 1902, 3 out of 12 pursuing battleships dropped out (Blue Book "Naval Manceuvres" and Naval and Military Record); in the maneuvers of 1903, 5 of the largest cruisers broke down; and in pursuit of Admiral May in 1906,3 battle- ships out of 12 broke down (Naval and Military Record, July, 1906). There is also the disadvantage of using half of your prospective gunners in the stokeholds on these occasions (Naval and Military Record).
When passages or junctionary work, then, are in question outside 700 to 1000 miles, good steaming qualities, fuel state, and intermediate bases take precedence of the speed, and speed qua speed only asserts itself in entirety when the enemy's fleet are in sight—that is, in the sphere of strategico-tactics rather than of strategy proper. There are two dispositions interrelated with speed which must be generally condemned. One is the separation of a slow battle fleet in order to cover a wider search area. An enemy's fleet will either suddenly slip through or cut off and defeat a portion of the fleet. In the Frnch maneuvers of 1901, for example, the Blockading Fleet of Ajaccio, 3 miles apart, were caught at dawn by a fleet in battle formation 4000 yards off ("United States Reports from Abroad," 1902), and instances of a similar sort could be drawn from other maneuvers. Another disposition is the "chase" in which battleships carry out independent full speed trials after the enemy, who may be in battle formation. The great freedom from defects which characterised the Japanese was probably due to the fact that they never attempted to strain their ships except in action. Separation of battleships characterised Admiral May's 1906 strategy, but most of his battleships could steam faster than the enemy. The value of a combination of speed and fuel superiority in the King Edward class could not have been more definitely demonstrated, and his safe passage of the Channel and Dover Straits without even an attempt at interference on the part of our destroyer flotillas was a bad feature of the maneuvers.
In conclusion, it may be asserted that high speed would not be wanted stragetically by an enemy almost equal in strength who was ready to accept action but not desirous of forcing it. High speed is required by an enemy inferior in strength who aims at disputing or dislocating the control of an area without being forced into action, and conversely by a power with vital sea interests requiring it to force an enemy's fleet to action if it issues from it sports.
[That is to say the weaker needs speed in order to be able to run away from, and the stronger needs it in order to be able to catch, an enemy. For a ship to be both stronger and faster than another, she must be bigger. After she has been made stronger, then the policy of making her faster may be worth serious consideration, but to deliberately make her weaker in order that she may be faster is quite another thing, and it must not be forgotten that, if ships are of equal displacement, on the average and in the long run, the faster must be the weaker.]
High speed is less necessary stragetically in the case of a fleet controlling an area with easily guarded outlets, but strategically the true function of speed is to force or evade action; to force action a superiority of 2 to 3 knots is required, to evade it a superiority of 1 to 2. Such a superiority is desirable, but how far it is practicable is for constructors to decide.