There is hardly a subject upon which more has been written, in the field of naval policy, than speed in battleship design, yet to the writer's knowledge the logical argument for speed has never been advanced, or if advanced he has not recognized it.
As far as he can learn opinion is divided (about equally) between the advocates of high speed on the one hand and on the other those who would put this additional weight in guns and armor.
The advocates of the latter policy give as their defense that the slower and consequently stronger fleet can by always maintaining the faster leader abeam of its leading ship render negative this speed superiority, and, at the same time by the mere fact of its heavier fire and greater protection against the enemy's fire, keep the faster fleet from entering torpedo water. This has been many times demonstrated on the game board as now played.
it is an axiom of gun fire that a shell will not hit, no matter if the gun pointer is the most skilled individual in the world, if the sight bar on the instant of firing is not reasonably accurate; in fact, at a range of 6000 yards, the sight bar at the instant of firing should read the range about eight seconds after the shell has started on its flight. However, we can not in the navy worry over such trifles; that is left to our more accurate brothers in the coast artillery to struggle with. Another point quite as important as the range is the change of range. Knowing the range at a given instant will be of small value if the change and the sign of the change is unknown.
In order to demonstrate more clearly, two fleets have been maneuvered to scale in the drawing on page 248.
At position I, the two squadrons are taken to be at a distance of exactly 6000 yards, measured from the plotted positions of the two hostile squadrons.
The red squadron has three knots superiority of speed, or 18 against 15 knots. The slower blue squadron, by the terms of the problem must keep the red leader abeam to counteract the advantage of speed. At the first position the squadrons are exactly abeam of each other and the time between positions is one minute.
At position 2 red changes simultaneously toward the enemy, bringing the enemy's leader to bear from its own leader 60 from the bow, which is within its speed angle and fire arc.
The total change of range is made up of two changes: 1st. The change of red from a stationary point (the blue vessel at the instant of observation); 2d. The change of blue from such a point. Combining these two we get more or less accurately the number of yards which the red and blue vessels increase or diminish the distance between them during a small increment of time; say one minute. Curves have been plotted by the writer for speeds of 18, 16, 15 and 12 knots.
By reference to Fig. 2, as blue constantly keeps the red leader abeam of its leader, the change of range will consist in this case of only one of the two changes; that due to blue's bearing and red's speed.
Then from position 2 (Fig. 1), the fire control on red will find from the 18-knot curve for the angle of 60 the change of range 235 yards a minute, decreasing. This is used on the instrument and at position 6 the range sent to the guns will be 4940 yards. The actual distance by measurement is 4875 yards. At position 6, red is shown to change simultaneously away from blue, bringing blue to bear 120 from the bow. Now the change of range from the curve is 320 yards, thus the sight bar range of red at position 10 is 6220 yards. The measured distance is 6150 yards. At this position red again changes towards blue, making the bearing 60 and uses a change of range of 265 yards a minute. The sight bar range at 14 will be 5160 and the measured distance 5100 yards.
No allowance in the above maneuver has been made for the advance and transfer in turning, and the times used are two small for practice, but do well enough for a demonstration.
If red finds the bearing of blue is changing it will know that the red is drawing ahead because it is not using all of its speed angle, and can change its rate of range according to the changing angle.
With the slower fleet the change of range can be but a matter of guess, helped in a measure by good spotting the shorts only can be spotted and the best spotter known has an average error of over two hundred yards at 6000 yards.
The slower fleet's only chance for success is to be able to quickly and accurately observe the movements of its enemy and in estimating the course may use a more or less accurate change of range. Estimating the course of the enemy can be done by observing the apparent spacing of its enemy's smoke pipes or its masts, but the experience of officers so far has given us but little accurate data on the results of this method. A genius may now and then appear who can tell, through an unexplained "gift of the gods," the enemy's heading within even a point, but that error will lose many well aimed shots. Then the enemy's speed is an uncertain factor to those who are simply depending upon snap judgment, or as Commander Niblack aptly puts it, "the vernier eye."
On the other hand the faster fleet is holding the range with ease and is hammering its shells home as if it were engaged in target practice at an anchored target.