THE EVOLUTION OF JAPANESE NAVAL TACTICS, 1895-1904

Within the context of this heightened professional competence As the new century opened, the tacticians at the Japanese Naval Staff College began to Ima their attention to the major tactical problems of the day. They were influenced undoubtedly by what they knew of similar study and thought in Western navies, yet worked independently toward practical solutions. During these years, staff college tacticians reached the same conclusion as their counterparts in other navies, that the column or line ahead was the most advantageous formation for A decisive fleer engagement. First suggested in fleet exercises in the early nineties, then confirmed by the navys victory at the Yalu, its continuing validity was demonstrated repeatedly in war games by Akiyama and other instructors at the college. Yet, for tacticians the world over, the line ahead formation posed serious problems. For example, it was unsuitable as a cruising formation in the age of the torpedo, since an extended line of warships was obviously more vulnerable to torpedo attack than a line abreast. Other Problems presented themselves: How did a commander move from A cruising formation to a column? Where in the column should lie place himself? Perhaps most difficult was the problem of how to overcome an enemy column of equal strength.

In a battle fought in parallel courses victory would depend en which side had more guns or superior gunnery. But if one side could concentrate all the firepower of most of its ships against the enemy - an activity made possible by the advent in the latter half of the nineteenth century of long-range naval guns mounted in rotating turrets-while preventing him from doing the same, victory would be almost inevitable.

At the Japanese Naval Staff College Lt. Comdr. Yamaya Tanin first worked on these problems and first suggested a solution that would concentrate firepower against an enemy column in the shortest possible time while keeping him within range. Critical to Yamayas thinking was the assumption that Japanese ships would be faster than their opponents. (The tactical effectiveness of superior speed had received dramatic confirmation in the Sino-Japanese War-and thenceforth became an article of faith in the Japanese navy.) Yamaya foresaw A Japanese column of warships heading toward an enemy column. When the two fleets had closed to 5,000 meters, the Japanese flagship would turn either to port or to starboard so that the Japanese column began to describe A circle As it moved forward. Yamaya guessed that the unsuspecting enemy would consider the movement odd, but would initiate no counter movement of his own. The Japanese ships would meanwhile continue on their circular course, so that within a minimum amount of time alt the ships in the Japanese column could bring their guns to bear upon the head of the enemy column while only a few of the enemy's ships could concentrate against the circling Japanese. For this brief time, the Japanese fleet would have maximum opportunity to inflict major damage on the enemy (fig. 3-2). Should the enemy turn instead of holding to course, supposedly the Japanese van would immediately inscribe a circle in the opposite direction, to bring the enemy van under fire from all the ships in column for at least a period of time. Yamayas en senjutsu (circle tactics) appeared sufficiently promising that they were extensively tested in war games at the staff college in 1901.62 Those pondering the problem realized that the ideal position for achieving such A concentration would be to place one's column at right angles to the enemy's column, so that, in effect, it formed the top bar of the letter T. In the British navy Admiral "Jackie" Fisher had employed this tactic during the maneuvers of the Mediterranean and Channel Fleets in 1901. In his report to the admiralty in September of that year, Fisher wrote that "the lesson that has been emphasized is that the one all important, immediate imperative step is to form the Fleet in one single line at right angles to the direction in which the enemy is sighted. How far we can keep this a secret remains to be seen. lf both sides practice this golden rule and employ the single line of Bearing then the Fleet with the superior speed must win, that is Battleships of superior speed.-" The Japanese could not have been tat behind the British in their appreciation of the T disposition, because Capt. Shimamura Hayao gave a lecture that explained the tactic in detail at the Naval Staff College in 1902. He maintained that the tactic was already being practiced in fleet maneuvers. 64 At the Japanese Naval Staff College the T tactic was tested in war games played under Akiyama's direction. In them, Akiyama demonstrated that when two columns in line ahead were approaching a common point on converging courses, the column closest to that point would have the advantage because it could bring more guns to bear upon the other. The greater the angle of convergence (up to 90 degrees) between their courses, the greater the advantage to the closer fleet. The ideal situation would therefore be to place one's own column at right angles across the enemy's line, thus forming the letter T (fig. 3-3)

Fig. 3-3. Crossing the "T." Fleet A concentrates all its guns on the leading ships of Fleet B, which has difficulty replying because only its forward gun can be brought into action and the fire of its rearmost ships by its leading ships. Not to scale

In this classic position of "capping the T" a maximum number of one's own guns could bear upon the enemy, while he, by virtue of his position, was limited in the numher of guns with which he could respond. (Experiments at the college showed that rarely would the T be capped perfectly; more often the victor would achieve a position more like the top bar of the Japanese katakana phonetic symbol I, in which the cross bar is at an angle). The tactic of capping the T, or as the Japanese called it, tei sempo, "the tei tactic" (after the Chinese character tei), soon became the tactical holy grail sought by naval commanders worldwide. But questions remained: how could one maneuver most rapidly to achieve this position, and in achieving it, what maneuver would best minimize the effects of changes in the enemy's range and course? During the war-gaming sessions at the college, Akiyama noted that the T tactic often failed because of the enemy's ability to turn away: "The problem with the 'T' formation is that it is very difficult to maintain for any period. One way to maintain it is to carry out simultaneous turns of eight or sixteen points [45 and 90 degrees in timely fashion."" Another solution of Akiyama's, called the otsu tactic because of its resemblance in shape to the Chinese character otsu (somewhat like an L in the Roman alphabet), was a deceptive maneuver designed to produce a converging attack. Using it, the Japanese fleet would approach the enemy in two separate formations. While the first engaged the enemy directly (attempting to cap the T), the second, approaching from an unexpected quarter, would position itself to catch the enemy in a crossfire. The two forces would each form one leg of an L, encircling the enemy and preventing him from escaping. Akiyama wrote, "The tactic for opposing a single enemy flag line is the otsu tactic, in which we subject the enemy to a scissoring attack .... Once we have succeeded in maneuvering in his [L] formation against him, we can deal him a mortal blow”. This concentrated attack upon the enemy (fig. 3-4), tested on the war-gaming boards of the staff college and then practiced at sea, was incorporated into the navy's accepted battle tactics.

Fig. 3-4. The "L" tactic

(Source: Battle Plan of 9 January 1904; see NRKK, 1:388)

THE JAPANESE NAVY AND THE DAWN OF FIRE  CONTROL

During the decade preceding the Russo-Japanese War, naval powers had generally recognized that the potential of the relatively new rifled steel naval guns, especially at long range (greater than 2,000 meters), was not being exploited. But in order to do so, naval gunners needed to know accurately the range to the target and, with comparable accuracy, the internal ballistics (such as barrel wear and powder temperature) of the gun, the external ballistics (the motion of the projectile alter it left the gun as affected by gravity, air resistance, wind, etc.), and the difference between the present or range finder range and the gun range at which the projectile was expected to hit the target. The difference between these ranges depends on the dead time (from the last range observation to the firing of the gun) plus the time of flight of the projectile and the courses and speeds (or the relative course and speed) of the firing and target ships.

None of this was well understood at the end of the nineteenth century, but around 1900 there appeared the first glimmerings of modern naval fire control the entire process of directing a gun in such a way as to hit the target. Eventually, it came to be understood that the surface fire control problem essentially was divided into five major elements: target tracking and position prediction, interior ballistics, exterior ballistics, computation, and correction. Of these, only exterior ballistics and deck motion were reasonably well understood. Captain Percy Scott's invention of a continuous aim system in 1898 had partially solved the problem of deck motion in the employment of smaller guns. The most significant progress in target tracking in the years before the Russo- Japanese War was the development of optical single-observer range finders-most notably by the British firm of Bart and Stroud-and the adoption of telescopic sights to replace open sights. By the early 1900s, the majority of the major warships of the world's navies were equipped with both these important devices." By the time of the Russo-Japanese War, the Japanese navy had made significant progress in keeping up with the latest developments in fire control. Its principal warships were well supplied with Barr and Stroud range finders, some ships having as many as six of these important instruments. Range tables (firing tables) for guns were supplied by the firm of Armstrong and provided at least rudimentary data for ranges at various elevations. The navies gum sights were calibrated for the ballistics of the gun system and had been fitted with telescopes to improve their performance. The major deficiency in the navy was the incomplete understanding of the importance of the change of range associated with the relative motion of the firing ship and the target. As it turned out, the immature understanding of this aspect of the fire control problem was not crucial to the outcomes of the major naval engagements of the war. Most firing during the two main battles of the war was done while Russian and Japanese ships were on approximately the same courses and making approximately the same speed, so that target range and bearing changed relatively slowly. In any event, while Japanese naval fire control on the eve of the Russo-Japanese War apparently was somewhat behind that in Britain and the United States, it was on a par with, or even slightly ahead of, that of the Russian navy.

TACTICAL  PLANNING

Because of his reputation and his expertise, Akiyama Saneyuki, first as an instructor at the staff college and later as A staff officer with the Combined Fleet, was at the center of operational planning to defeat Russian naval forces in northeast Asian waters. Indeed, Shimamura Hayao, his immediate superior for the first half of the war, station flatly: "There was not a single major operational plan of the war -hat was not drafted by Akiyama. "  Shortly alter his assignment as staff officer with the Combined Fleet Akiyama was given the responsibility of drafting the secret operational plan that would guide the fleet in the decisive battle with the Russians. His Rengo kantai sensaku (Combined Fleet battle plan) was completed in 9 January 1904 and distributed to all units of the fleet. In the plan, under Togo's name, were set forth the responsibilities, the formations, and the movements for each unit of the Combined Fleet. The First and Second Divisions (the battleships and the armored cruisers), constituting the main force, would be responsible for the destruction of Russian battleships, armored cruisers, and protected cruisers; the Third and Fourth Divisions were to account for the smaller enemy cruisers and destroyers and to annihilate isolated or damaged warships. Finally, the destroyers and torpedo boats were to await the opportunity to attack the retreating Russian fleet

The First and Second Divisions were to carry out the T and L Tactics for which detailed instructions and diagrams were provided. Akiyamas plan directed that "the First Division will choose the formation of the enemy that is easiest to attack, forming a line against it, a "T", . . . maneuvering so as to put as much pressure as possible on the enemy's lead ship; it will make efforts to maintain the T formation with respect to the enemy by carrying out simultaneous turns as appropriate. " Regarding the L tactic it specified, "The Second Division will pay attention to the enemy's movements with the aim of carrying out a cross-firing or scissoring attack on the enemy formation that is engaging the First Division. It will maneuver as appropriate, either following the First Division or taking an opposite course, so as to form the letter "l" with the First Division .... Our two divisions will then carry out a fierce attack on the enemy with crossfire." The plan also included tactical instructions for each division by its commander that essentially echoed the movements described above. Significantly, alter the war, Togo himself affixed the following note to the text of the Battle Plan in the navy's secret and exhaustive history of the war: "The Battle Plan described for the Combined Fleet and each of its Divisions was the basis of all engagements in this war. From the Battle of the Yellow Sea to the great Tsushima Battle and other, smaller clashes in between, there was not a single action not based Upon it."