Post by Avatar on Jun 20, 2024 13:30:50 GMT
A look at foreign torpedo tactics?
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The article is a cold war era one with reference to the Russians, who were and are incompetent at naval warfare. Their Rube Goldberg approach to msaking a hot sauce of the naval operational art has so many fail points, it is ridiculous.
Compare their confused dubious approach with Kantai Kassen.
At least the Imperial Japanese Navy understood that it was not about how to shoot a target, according to a rote lesson plan. Naval warfare by its nature was and is chaotic, and rather attritional. Furthermore it is based on a tactical, operational, and strategic objectives. The tactical objective might be to deny an enemy fleet fuel to keep most of it in port. The operational objective desired, to fight the enemy piecemeal in detail, by tactically killing his oil tankers until the enemy fleet is fuel starved; allows that operational objective. Here your numerically inferior fleet can face the enemy on equal terms, since he can only send a third or a half of his battle fleet to face your whole force. The strategic objective, engendered by your tactical objective achieved, and furthered by your desired operational objective to achieve the naval initiative, is Mahanic; to deny your enemy local control of the sea at a time and place of your choosing, to ultimately destroy his navy piecemeal. That was the World War II American naval answer to Kantai Kassen. It was not about decisive battle at all.
You get the impression that the American referant naval enemy of Japan did not understand that naval warfare was a logistics contest? In the American view, the victor was the one who could use the sea after the shooting stops.
The Kantai Kassen doctrine was actually a political sales job to get money from the Diet. (^^^). The whole idea about how the IJN really intended to fight the Americans actually was to bleed the Americans down by attrition. This is not decisive battle doctrine at its core. It is a naval attritional campaign doctrine that was wrongfooted from the start. As an operational art solution to the Japanese problem of how to fight a bigger more powerful enemy, it is a repeat of the Russo-Japanese experience. This is not a good template.
The Russians were beatable in the Russo-Japanese War; because they were logistically and technically incompetent. They never improved. You could not expect the Americans to remain operationally incompetent or technologically inept during what could be expected to be a LONG war. Anyone with half a brain (Yamamoto, Isoruku), would understand that Kantai Kassen was a public relations ploy, while the whole IJN was built to bleed down the enemy.
In that case, you can instantly see why the Japanese went in for big banger torpedoes as the means to attrite the Americans? Long range, big warheads and first strike, from their "light forces", consisting of destroyers, cruisers and aircraft carriers was their technological and tactical doctrine? Interestingly, the Japanese submarines were supposed to attrite warships, too. Here, we can see the major operational error in how the Japanese employed their navy. Any American naval intrusion into Japanese controlled waters had to be logistically supported. Obviously, with the weaponry and launch platforms the Japanese had in their submarine arm, the correct way to attrite the Americans was to go after their merchant fleet and naval logistics ships.
The Japanese did not understand this operational naval requirement. They misused their magnificent torpedo launching platforms in vainglorious and showy battles to sink American ships.
The Americans shrugged off a hundred sunken attrition units (destroyers and cruisers), absorbed Pearl Harbor (Battleline smashed and ruined.), swallowed the loss of a half dozen flattops in set piece battles that decided nothing, except that they would keep pushing forward against a superior enemy. who squandered his own ships in one for one exchanges, while burning up his lead in veteran ship's crews / aviators. Meanwhile, the Americans could sink the Japanese merchant marine, with their sputtering submarine force. Their no-good torpedoes took two years to fix to become mediocre torpedoes. Their torpedo tactics took those same two hard years to learn. At the end, the murder year (1944), showed what naval operational art, married to decent tactics could do.
Note that the American submarines conducted operations as part of an expensive learning experience? As this timelimne will develop, it will become obvious that this learning experience, even with much better pre-war weapons, remains in place.
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Their Torpedo Tactics
By Milan Vego
June 1984 Proceedings Vol. 110/6/976
This htmlligence article is produced from an uncorrected text file through optical character recognition. Prior to 1940 articles all text has been corrected, but from 1940 to the present most still remain uncorrected. Artifacts of the scans are misspellings, out-of-context footnotes and sidebars, and other inconsistencies. Adjacent to each text file is a PDF of the article, which accurately and fully conveys the content as it appeared in the issue. The uncorrected text files have been included to enhance the searchability of our content, on our site and in search engines, for our membership, the research community and media organizations. We are working now to provide clean text files for the entire collection.
Four years’ service in command of “Sher-shen”-class torpedo boats such as these (with their M-57 torpedo tubes) gave this former Yugoslavian lieutenant commander the bedrock on which to build this assessment of Soviet torpedo warfare, which occupies so important a place in the tactical employment of their submarines, surface ships, and ASW aviation.
In the late 1950s and 1960s, the Soviets extolled the value of antiship cruise missiles for destroying enemy ships at sea. Not until the early 1970s did a more balanced view regarding the significance of cruise missiles and underwater weapons emerge among Soviet naval theoreticians. Since then, the Soviets have argued time and again that torpedoes have not lost their importance in conducting naval warfare, especially in carrying out missions aimed at destroying enemy surface combatants.
Torpedo-Armed Platforms: The attack submarines are the Soviet’s primary torpedo-armed platforms. The nuclear-powered attack submarines (SSNs) and some modem classes of conventionally powered attack submarines (SSs) are principally intended to seek, detect, and destroy enemy, especially nuclear-powered, submarines. Other targets include aircraft carriers, major surface combatants, amphibious forces, naval auxiliaries, merchant vessels, and “coastal objectives.”
Soviet cruise missile-armed submarines will use their torpedoes to finish off enemy surface combatants or merchant ships already heavily damaged by missiles, and for defense against enemy escorts. Similarly, Soviet ballistic missile submarines (SSBNs/SSBs) will use torpedoes when pursued by enemy antisubmarine warfare (ASW) ships or submarines. The SSBNs, after carrying out their primary missions, can also use their torpedoes to conduct antisurface warfare (ASUW), anti-sea lines of communication (SLOC), or possibly ASW tasks.
Soviet major surface combatants will use their torpedoes against enemy submarines and, if the opportunity arises, against enemy warships. Large surface-to-surface missile-armed combatants can fire their torpedoes to finish off enemy surface ships previously damaged by antiship missiles. They are also expected to employ, besides their antiship missiles and guns, torpedoes to attack enemy amphibious forces, if the latter get close to Soviet-controlled shores. In this case, Soviet torpedo-armed fast attack craft will be used as well.
Soviet surface warships also are expected to conduct anti-sea lines of communication (SLOC) missions in coastal waters close to enemy shipping terminals, as well as in choke points. The Soviets do not exclude the possibility of using their major surface combatants for performing commerce-raiding missions in distant areas of the world’s oceans.1
Finally, the Soviets envision using torpedo-armed platforms to conduct strikes against enemy “coastal objectives,” such as port jetties, oil terminals, and floating docks.
Soviet patrol aircraft and ASW helicopters will obviously use torpedoes principally against enemy submarines, and only exceptionally against surface ships.
Types of Torpedo Attack: A torpedo strike is defined in Soviet naval theory as “a strike conducted in respect to the time and fire of the torpedo weapons against formations of (1) combat ships, (2) transports in convoy, and (3) other targets, with the aim of destroying or forcing them out of service.”
In regard to the platform and launching position, the torpedo attack can be conducted from a submerged, surface, or air position. The torpedo attack can be conducted either at night or in daylight, and either in good or bad weather conditions. The Soviets emphasize the advantages offered by combat employment of their submarines and surface combatants at night or under bad weather conditions. Of course, the principal weather conditions a torpedo-firing unit considers are sea state and visibility.
In respect to forces employed, the Soviets distinguish between torpedo attacks conducted by a “single,” “combined,” or several tactical groups of surface ships or submarines. Torpedo attacks by single surface ships or submarines or “groups” (pairs) will be most common. Those conducted by several tactical-sized units of surface ships will be rare, except perhaps in the case of torpedo-armed fast attack craft. A surface ship strike force will usually be comprised of destroyers, “guard ships” (frigates and guided missile frigates), and “torpedo cutters” (torpedoarmed fast attack craft).2 In addition, one-type ship or submarine units or “mixed” (composite) forces can conduct torpedo attacks.
Regarding place and objective, torpedo attacks can be “concentrated” or “non-concentrated.” A torpedo strike is conducted from two or more directions. However, tach' cal groups of one-type ships or submarines normally carry out torpedo strikes from one direction. In addition, a torpedo strike can be carried out either simultaneously or 1° succession. The former method requires—when a large number of surface ships or submarines are employed--;3 well-organized and effective forces’ control. Hence, it's very difficult, if not impossible, to organize and carry °ut such torpedo strikes even in peacetime exercises. The Soviets prefer the successive torpedo attack—“wave torpedo attacks.” Each preceding strike must weaken the target’s defenses, creating more favorable conditions for the joint attack can be employed in cooperation with one-type craft. For example, strikes conducted by Soviet nuclear submarines (SSNs) against enemy surface combatants or convoys may be possible after the target has been detected. It must employed between “independent” and “joint” torpedo attacks. The surface ships or submarines, surface ships and aircraft, bmarines and aircraft, or surface ships, submarines, and air needed by a strike conducted by air-to-surface missile-armed bombers or cruise missile submarines. Similarly, e Soviet torpedo-armed fast attack craft may strike after attacks by missile-armed fast attack craft or aircraft.
Forces’ Control: The Soviets emphasize surprise, coordination, separation and mass use of forces and weapons. The principle features of a torpedo strike are sudden and swift movement of the attacking forces toward the target, relative spontaneity of the torpedoes’ employment against the selected objective, and skillful maneuvering against the weak spots in the enemy’s defenses, sub °ordinated’ direction coordinating the movements of two or more submarines during a torpedo strike is nearly impossible, tactical control cannot remain undetected, because no underwater (6) means for communication and coordination of such movement exists.
According to the Soviets, an encounter will be won, not by a side that possesses the greater number of weapons, but by the one that detects the enemy forces first, uses its weapons first, and obtains a hit with the first salvo. This describes Soviet fascination with the “battle of the first strike". Howwever, the concept has never been tested in battle. The Soviets maintain that a surpise strike must occur with superior forces from different directions and from the weapons’ maximum effective ranges. It must use all availed weapons and it must employ different types of weapons. The principal objective then is to overwhelm the opponent’s defenses, prevent the target from dodging the attack, and inflict losses and damages upon the opponent, while minimizing the same for its own forces.
By firing a torpedo from its maximum effective range, a Soviet submarine will reveal her position. Thereby, in a case of missing the target, she will be subjected to the enemy countermeasures, but without accomplishing her mission objective. In contrast, the risk of being detected when firing from a closer range is acceptable in order to achieve an optimal firing position. In other words, it is better to get a hit from close in rather than miss from further out and still reveal your position.
Torpedo Firings: A torpedo firing can take place for one of four reasons: (1) practice, (2) experiment, (3) preparation, or (4) “combat” testing. The practice torpedo firing trains the ship or submarine commanding officers (COs), group commanders (pair COs), and ship or submarine “torpedo-mine department” crews in practical and proper application of torpedo fire regulations and norms.
The experimental firing tests new torpedo models or new tactical procedures in the torpedoes’ use. The preparatory torpedo firing, usually organized within a ship or submarine “division” (squadron) or larger unit, trains COs and their crews in proper employment of torpedoes. Then, the best unit’s CO and his torpedo-mine department is directed to carry out the exercise, while other COs and respective departments observe the exercise.
Application of the ship’s movements on the open ocean in the merge. One must run on a zigzag course and when within range: employ their guns against the target or against the ships in target’s protective screen.
To carry out the closing-in phase, a ship or submarine must be positioned within the area limited by the size the “critical course’s target angle” (CTA)- This is usually the greatest course’s target angle value at which the manneuvering ship [submarine] with a given speed can close-merge to the [torpedo’s] firing position.” The size of the critical CTA. That is the course’s target angle is directly related to the speed that the “maneuvering ship” (submarine) versus the target.
The combat torpedo firing is conducted periodically in accordance with the annual plans of the ship’s or submarine’s tactical training. The combat firing checks the crew’s readiness in and proficiency for “torpedo activities in combat.”
Types of Torpedo Attack: Regarding time available to make an attack, there are either “prepared” or “urgent” torpedo attacks. The former includes all the prescribed procedures and attack phases and is usually conducted whenever the target is detected early, and there is sufficient room for the torpedo-firing platform to conduct required maneuvering.
When a target has been detected suddenly, the urgent attack is executed. In this form of attack, though, the submarine’s chance of scoring a hit will be low, and the torpedo complement probably will be depleted.
The force/unit can conduct a torpedo strike either on a “parallel” course (toward the target) or on a “countermarch” course (away from the target). In the open ocean, the parallel course is the more common of the two. The countermarch course will be used by Soviet submarines fitted with stem 16-inch ASW torpedo tubes (“Novembers,” “Echo-Is,” “Foxtrots,” and “Romeos”). It will be used against enemy submarines or escorts. Small ASW surface ships fitted with fixed 16-inch stem tubes can also practice the countermarch course, along with other surface ships that suddenly encounter enemy surface ships or submarines.
Considering the target’s movement, torpedo attacks can be conducted from “head-on” (bow), the flanks, or the stem. The time for the torpedo strike delivered from head-on courses generally is much shorter than that conducted from the flanks, because of the high rate of relative movement (provided the speeds of the torpedo-firing platform and the target are the same). Hence, attack from the head-on course enhances the valuable element of surprise.
However, a torpedo attack from head-on creates complications for a submerged submarine in an ambush position since her sonar cannot obtain accurate range and speed information from a target with a constant zero or close-to-zero bearing rate. In contrast, a maneuvering submarine can obtain precise range and speed measurements of the target because the head-on attack offers maximum generated bearing rate and Doppler effect. However, a conventionally powered submarine attacking high-speed surface warships from head-on on the open ocean will have difficulty in disengaging and successfully avoiding pursuit by ASW forces (unless she has much greater speed than the target). A submarine CO’s principal problem in carrying out a head-on attack is maintaining significant distance from the surface ship’s track to avoid being run down, detected, or driven off the firing solution.
Striking from the flanks is the most-favored torpedo attack of the three since, at a given speed ratio for surface ship / submarine versus target. It offers a moderate rate of relative movement and enhances the chances of successful disengagement, even if the torpedo-firing platform is only slightly faster than the target. In addition, the target’s range and speed are more accurately obtained because of the steady change in the target’s bearing rate. In this type of torpedo strike, a submarine using straight-running torpedoes must not pass the closest point of approach (CPA)- The Soviets usually avoid torpedo attacks from the stern. Soviet SSNs attacking enemy surface ships capable of making only 20 knots or less can deliver a torpedo strike within the effective range of their torpedoes from practically any direction. The SSNs are particularly well-suite0 to conduct torpedo attacks from head-on directions in the open ocean, where their high speed and deep-diving capabilities can be fully exploited.
Torpedo Attack Phases: A torpedo attack is normally comprised of four phases: (1) “sneaking-in” (approach)- (2) “closing-in for engagement” (attack), (3) “comhat course” (firing course), and (4) “withdrawal from the object of attack” (disengagement).*
Depending on the circumstances, a surface ship or submarine can omit some or most of the prescribed tactic2 procedures for a torpedo attack. For example, if a torpedo armed fast attack craft or submarine conducts a torpeedo attack in the coastal waters, then the sneaking-in phase may be much longer than the closing-in phase. If a target is suddenly encountered, there may be only a short closing in phase followed by a torpedo firing, and then an energetic withdrawal from the object of attack. Soviet attack submarines, when vectored by the command post ashore or flagged command post afloat toward the “probable attack object" (PAO) begin the closing-in phase as soon as their own sensors detect the target, thus eliminating the sneaking-in phase. During the sneaking-in phase, the torpedo-firing formation or unit obtains data on the target’s whereabouts and movement, then sets a course toward the POA assuming a position of tactical deployment. The target’s range at the point of the deal deployment is chiefly selected with regard to the angle of relative movement. When more than a single ship is to attack, all participating units must assume their position for the tactical deployment at the time assigned. Afterward, torpedo-armed ships set the closing-in course, merge and initiate “combat maneuvering” toward their respective “salvo positions” (firing positions).
The closing-in phase is defined as “a tactical maneuver of a ship / formation to close distance in order to enable the most effective use of weapons and combat means of such a formation.” A Soviet surface ship or fast attack craft is usually detected by enemy surface combatants during this phase. Of necessity this phase must be kept as short as possible prior to weapon employments.
*The corresponding U. S. Navy terms are given in parentheses.
"Flank maneuver” (VJVk in Russian; or "beam attack".). When a torpedo platform enjoys a margin of speed over the target, closing in to salvo position is possible in two courses. If the speed of the maneuVering ship equals that of the target, the approach to the target is possible in only one course. When the target possesses superior speed over the maneuvering ship, closing on to the salvo position is impossible. In general, the higher the speed of the maneuvering ship or sub ovedr the PAO, the §reater the critical course’s target angle. (CTA) Hence, a torpedo platform will have the greater choice of salvo positions.
For example, Soviet SSNs, because of their high speed, can reach the firing area submerged from almost any point around a surface ship or formation within the effective range of their torpedoes. However, a submarine should be somewhat well inside the salvo position, because a zig away will carry the target outside torpedo range.
For a submarine, attacking a surface ship or formation, it also depends on her position in respect to the “attack sector.” (Vector fan) The attack sectors or “maximum target angle” (angle solutions AvK ibn Russian, or "fan spread".) is defined as “the greatest course’s target angle” value at the target’s range, the speed ratio of the submarine versus the target, and the torpedo’s range and speed allowing closing to shoot at the maximum torpedo fire range. The "maximum course’s target angle” (MCTA) represents the sum of the critical course’s target angle and AQ (see Figure 1). The value of X *s directly dependent on the speed ratio of the submarine versus the target. The higher the submarine’s speed is over that of the target, the greater the AQ value. In practical terms, the “small course’s target angles” (0 to 0.5 QKR) allows a submarine to close in to a firing position from ead-on and on either of the target’s flanks. From a “medium course’s target angle” (0.5 to 1.0 QKR), a submarine can only select a firing position on the target’s flank closest to the submarine. Then, the submarine’s closing-in courses from the target’s other flank will be limited. When a submarine. Positioned at great target angles (QKR - QPR), she can attack the target only from the flank from which the target was detected. Then, the possibility for the submarine to select the optimal torpedo fire range is decreased.
Shortly before reaching the computed salvo position, a surface ship or submarine turns onto a combat course (attack or launch vector). for five to ten seconds. When the last-minute torpedo fire solution selections are made, the torpedo is fired. The combat track or course (attack or launch vector) for small missile armed fast attack craft is identical with the torpedo’s track- Larger surface ships, however, use a “gyro angle” solution a “deflection angle” (lead angle) for torpedo attacks. (The USN term is Predict Lead Merge or Lag Lead Merge. (PLM or LLM).). The gyro angle is the computed angle between the angle of thc torpedo tube and the final track of the target's predicted course, port or starboard (taking into account corrections atitude (USN term is "aspect".), torpedo deflection, maneuvering ship’s tum-rate, and gyro incaging time). The “angled fire” is then achieved in combination with the tube’s train and estimated solution in the gyro angle.” Torpedoes can accept a gyro offset to run a true curved track. The only. reason large surface ships rely on the predict lead steer merge method is because of the the torpedo bank rotation capability of the platforms, rather than the combat course launch method. is because the larger ships are fitted with with rotating torpedo tubes. They lack the maneuverability of torpedo-armed fast attack craft and cannot point the whole ship. They seldom use the straight torpedo fire method, since the entire boat would have to be trained to bring the tubes into the proper firing position, which is often an impracticable process. Submarines for a different reason cannot point the whole ship at the predicted torpedo intercept course with the target. Hence, the torpedo must be made to move onto the correct course after it leaves the large surface ship's, or submarine’s tube. This is achieved by using the gyro angle in fire control. However, a submarine could use straight torpedo fire if necessary by steering to the deflection course but leading it slightly, then holding steady and firing the torpedoes at the instant the computed deflection angle equals the angle between the tube axis and line of sight to the target.
The withdrawal from the object of the attack will begin immediately after the platform fires her torpedoes against the maneuvering target on the open ocean. A Soviet surface ship or craft will turn away sharply from the target, increase her speed to the maximum possible in the given circumstances, and set a course providing the most rapid increase in distance from the target. A Soviet SSN will turn away from the target by using both her high speed underwater and her deep-diving capabilities in order to avoid pursuit by the enemy ASW forces.
Firing Position: A surface ship or submarine may assume salvo position from the bow, bow quarters, flanks, stem quarters, or stem. Theoretically, the course’s target angle of 90° on either of the target’s flanks is the most favorable for firing torpedoes, because the entire target’s length is exposed, the maximum margin for error in computing the torpedo fire elements is allowed, and the target, in taking evasive maneuvers, must run the greater distance. However, in practice, the torpedoes must be fired from a course’s target angle (angle on the bow) less than 90° (normally 60°-70°); otherwise, the torpedo would have much greater distance (hence much longer time) to run until its impact with the target.
In contrast, when firing from the bow quarters target angle, the target is relatively narrow (and narrower still with deflection angle), the torpedo run is shorter than when fired from the flank target angles, the track angle is smaller, and the target, in taking evasive maneuvers, needs only a small course alteration.
When straight-running torpedoes are used, a firing position from the bow target’s angles is the most disadvantageous since the target’s length exposed is very small, the angle solution on a surface target is smaller in hit probability to sink it. Thus: the track solution angle is small, and the target can avoid torpedoes with very small alteration in its course. However, if acoustic homing torpedoes are employed, this position increases the chances of obtaining a hit because the Doppler effect is the greatest at this sxet of solutions.
Firing positions from the stem quarters and stern target angles have disadvantages similar to those of the bow quarters and bow target angles, respectively.
With wire-guided torpedoes, the gyro angle does not play a role in computing torpedo fire elements, since these torpedoes can be fired from practically any position. Hence, submarines and surface ships have far greater latitude in selecting a combat course. Also, the advantages and disadvantages of the firing position mentioned previously pertain to conventional nonhoming torpedoes fitted with a contact exploder. Wire-guided and acoustic-homing torpedoes with the influence type of exploder approach the target in the terminal phase of trajectory from the stem and explode under the target’s keel.
Torpedo Fire Forms: The Soviets maintain that “experience of the war (World War II) showed the necessity of using several varied methods of fire, combining them in range and number of torpedoes.”3 With straight-running torpedoes, the Soviets distinguish between “single torpedo fire” and “area fire with several torpedoes” (ripple torpedo fire, or a salvo or spread in the US naval terminology.). The latter includes “torpedo spread fire” and “method of successive torpedo launching” (longitudinal spread). Two methods are used in torpedo spread fire: “sector fire” (divergent spread) and parallel spread. In sector fire, two or more torpedoes are fired almost simultaneously, but so that their trajectories diverge for a certain angle (usually from 1° to 4°) called “spread angle.” The spread angle is the angle between the final tracks of any two adjacent torpedoes fired in salvo from the same tube mount (surface ships) or setting (submarines' torpedo banks). By using the spread, fewer hits will be scored, but more error can be accommodated. However, acoustic homing torpedoes cover a much wider swath, and if they are wire-guided, they can follow nearly any detected maneuver of the target.
In a parallel spread, the torpedoes’ trajectories are parallel but so spaced that one torpedo will hit a point at the target’s bow and the other at the stem.
In the method of successive torpedo launchings, torpedoes are fired in predetermined time intervals, depending on the target’s speed and length. The torpedoes can be set for straight bow or stem fire at zero angle, or each torpedo can be angled the same amount. Then, each torpedo is fired in succession at different portions of the target.
The purpose of a spread is to accommodate errors and target maneuvers. Spread and salvo firings refer to straight-running torpedoes. Acoustic homing torpedoes are difficult to fire in salvo because of acoustic interference problems in the water, and because the fire control system may be capable of preparing only one torpedo at a time. There would be considerable delay in bringing up the next one for firing.
When Soviet surface combatants attack enemy submarines, they will use all their antisubmarine weapons available to overwhelm the target’s defenses, maximize the odds of getting a hit, and limit the target’s evasive maneuvering. A ship will usually fire its ASW torpedoes fjrst- After the torpedoes reach the target’s computed positi°n’ the attacking ship will close at high speed and, when within range, fire a full salvo of antisubmarine rockets- Soviet surface ships armed with both the 6,000-meter-plu* range antisubmarine rocket launchers (RBU-6000s) an short-range ASW torpedoes apparently attack in the re verse order thus described.4
Torpedo Fire Volume: The number of torpedoes a ph form has to fire at a target depends on many factors, 1(1 eluding type of target, the target’s size and value, the taf get’s status prior to the torpedo’s firing, the attack objective, type of warhead used, and type of the torped° exploder.
Table 1 Torpedo Fire Volume
__________________ Objective___________
................................Sinking...........................................Heavy Damage
................................Contact................Influence..............Contact................Influence
Ship Type...................exploder...............exploder...............exploder...............exploder
Aircraft carrier.............5-6......................4-5.....................3-4......................2-3
Cruiser.......................4-5......................3-4.....................3-4......................2-3
Destroyer...................2-3......................1-2......................1........................1
Transport—
18,000 tons................3-4......................2-3......................1-2.....................1-2
Transport—
10,000 tons................1-2......................1-2......................1........................1
Transport—
5,000 tons..................1.........................1.........................1........................1
Many torpedoes are necessary to sink (or inflict heavy damages on) a surface target; while, in most cases, only one torpedo can destroy an “underwater” target. Considering the objective of the attack, Soviets believe that only or two less torpedoes are required to inflict heavy damage.
One torpedo can sink or inflict heavy damages on even the largest enemy surface combatants.
The fire volume of torpedoes fitted with high-explosive warheads depends on whether contact or influence type of exploders are used. When an influence type of exploder is fitted, usually one torpedo less than prescribed is fired against a target to accomplish a particular objective. (See table 1).
Torpedo Launching: A heavy 21-inch torpedo fired by a surface ship or craft usually requires at least a depth of water of 100 feet at its launching point. An acoustic-homing torpedo needs a minimum depth of about 60-85 feet during its search phase, and at least 33 feet during the terminal phase of its trajectory.
^ ^A Soviet submarine can fire her torpedoes from either deep nwater (The depth is greater than 76 feet or 23.25 meters) or periscope depth t-76 feet, less than 23 meters). In peacetime training, the Soviets emphasize torpedo firing from deep water.
The conclusions: the Soviets have great faith in the effectiveness of torpedoes in a war at sea. Torpedo warfare occupies an important place in the tactical employment of Soviet submarines, surface ships and craft, and ASW aviation. The Soviets devote much attention to developing of such weaponry and the tactical training of commanding officers and torpedo-mine departments in the employment of such weapons.
Currently, the Soviet Navy possesses almost three times as many torpedo-armed platforms as the U. S. Navy. Soviet submarines and surface ships are generally armed with larger caliber (21-inch) torpedoes and fitted with larger (Presumably much more destructive.), high-explosive warheads. Soviet torpedo warfare doctrine and tactics are an integral part of their naval theory, as well. However, Soviet torpedo warfare capabilities are not as great as they first appear. The Soviet “operational-tactical” doctrines of Command and Control are too rigid to effectively task naval forces, especially in antisurface warfare. It is difficult, if not impossible, to control in a real war the employment of torpedo-armed platforms and coordinate their movements in regard to time, place, and objective assigned. This is especially true when such forces’ control is exercised by the command post ashore, and an engagement occurs far from the Soviet-controlled coast.
The Soviet emphasis on firing weapons from their maximum range to enhance the element of surprise and obtain a hit with the first salvo is another weakness in their torpedo warfare tactical doctrine.
The American Navy can counter the Soviet torpedo threat by exercising more innovative tactical methods and procedures in employing its own torpedoes and other weapons, by maintaining (and, if possible, widening) the current American technological lead in quality of detection sensors, and by having longer-ranged, faster torpedoes fitted with more advanced guidance systems than their Soviet counterparts. But, the key to success in neutralizing the Soviet torpedo threat is better tactics. The U. S. Navy must always be more creative, faster, and more flexible than its Soviet opponent.
*B. Balev, “Sea and Oceanic Communications and Warfare on Them,” Voyennaya mysl, October 1971, p. 47; G. Kostev, “Commerce Raiding as a Form of Combat Actions on the Oceanic Communications of an Adversary,” Morskoy Sbornik, February 1972, pp. 36-37.
2The Soviet Military Encyclopedia (Moscow: Voyenizdat, 1980), vol. 8, p. 77. 3I. Kosikov, “Torpedo Weaponry in the Great Patriotic War,” Morskoy Sbornik, May 1976, p. 76.
4Krasnaya Zvezda (Moscow), 22 December 1976, p. 1; 26 July 1977, p. 2; 10 October 1977, p. 1; 21 June 1979, p. 1.
A graduate of the Yugoslav Naval Academy, Dr. Vego served 12 years in the Yugoslav Navy and attained the rank of lieutenant commander before coming to the United States. He served for four years as a CO/pair commander of Soviet-designed “Shershen”-class torpedo boats. Dr. Vego has been published widely in the Western press on naval matters.
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Digital Proceedings content made possible by a gift from CAPT Roger Ekman, USN (Ret.)
By Milan Vego
June 1984 Proceedings Vol. 110/6/976
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Four years’ service in command of “Sher-shen”-class torpedo boats such as these (with their M-57 torpedo tubes) gave this former Yugoslavian lieutenant commander the bedrock on which to build this assessment of Soviet torpedo warfare, which occupies so important a place in the tactical employment of their submarines, surface ships, and ASW aviation.
In the late 1950s and 1960s, the Soviets extolled the value of antiship cruise missiles for destroying enemy ships at sea. Not until the early 1970s did a more balanced view regarding the significance of cruise missiles and underwater weapons emerge among Soviet naval theoreticians. Since then, the Soviets have argued time and again that torpedoes have not lost their importance in conducting naval warfare, especially in carrying out missions aimed at destroying enemy surface combatants.
Torpedo-Armed Platforms: The attack submarines are the Soviet’s primary torpedo-armed platforms. The nuclear-powered attack submarines (SSNs) and some modem classes of conventionally powered attack submarines (SSs) are principally intended to seek, detect, and destroy enemy, especially nuclear-powered, submarines. Other targets include aircraft carriers, major surface combatants, amphibious forces, naval auxiliaries, merchant vessels, and “coastal objectives.”
Soviet cruise missile-armed submarines will use their torpedoes to finish off enemy surface combatants or merchant ships already heavily damaged by missiles, and for defense against enemy escorts. Similarly, Soviet ballistic missile submarines (SSBNs/SSBs) will use torpedoes when pursued by enemy antisubmarine warfare (ASW) ships or submarines. The SSBNs, after carrying out their primary missions, can also use their torpedoes to conduct antisurface warfare (ASUW), anti-sea lines of communication (SLOC), or possibly ASW tasks.
Soviet major surface combatants will use their torpedoes against enemy submarines and, if the opportunity arises, against enemy warships. Large surface-to-surface missile-armed combatants can fire their torpedoes to finish off enemy surface ships previously damaged by antiship missiles. They are also expected to employ, besides their antiship missiles and guns, torpedoes to attack enemy amphibious forces, if the latter get close to Soviet-controlled shores. In this case, Soviet torpedo-armed fast attack craft will be used as well.
Soviet surface warships also are expected to conduct anti-sea lines of communication (SLOC) missions in coastal waters close to enemy shipping terminals, as well as in choke points. The Soviets do not exclude the possibility of using their major surface combatants for performing commerce-raiding missions in distant areas of the world’s oceans.1
Finally, the Soviets envision using torpedo-armed platforms to conduct strikes against enemy “coastal objectives,” such as port jetties, oil terminals, and floating docks.
Soviet patrol aircraft and ASW helicopters will obviously use torpedoes principally against enemy submarines, and only exceptionally against surface ships.
Types of Torpedo Attack: A torpedo strike is defined in Soviet naval theory as “a strike conducted in respect to the time and fire of the torpedo weapons against formations of (1) combat ships, (2) transports in convoy, and (3) other targets, with the aim of destroying or forcing them out of service.”
In regard to the platform and launching position, the torpedo attack can be conducted from a submerged, surface, or air position. The torpedo attack can be conducted either at night or in daylight, and either in good or bad weather conditions. The Soviets emphasize the advantages offered by combat employment of their submarines and surface combatants at night or under bad weather conditions. Of course, the principal weather conditions a torpedo-firing unit considers are sea state and visibility.
In respect to forces employed, the Soviets distinguish between torpedo attacks conducted by a “single,” “combined,” or several tactical groups of surface ships or submarines. Torpedo attacks by single surface ships or submarines or “groups” (pairs) will be most common. Those conducted by several tactical-sized units of surface ships will be rare, except perhaps in the case of torpedo-armed fast attack craft. A surface ship strike force will usually be comprised of destroyers, “guard ships” (frigates and guided missile frigates), and “torpedo cutters” (torpedoarmed fast attack craft).2 In addition, one-type ship or submarine units or “mixed” (composite) forces can conduct torpedo attacks.
Regarding place and objective, torpedo attacks can be “concentrated” or “non-concentrated.” A torpedo strike is conducted from two or more directions. However, tach' cal groups of one-type ships or submarines normally carry out torpedo strikes from one direction. In addition, a torpedo strike can be carried out either simultaneously or 1° succession. The former method requires—when a large number of surface ships or submarines are employed--;3 well-organized and effective forces’ control. Hence, it's very difficult, if not impossible, to organize and carry °ut such torpedo strikes even in peacetime exercises. The Soviets prefer the successive torpedo attack—“wave torpedo attacks.” Each preceding strike must weaken the target’s defenses, creating more favorable conditions for the joint attack can be employed in cooperation with one-type craft. For example, strikes conducted by Soviet nuclear submarines (SSNs) against enemy surface combatants or convoys may be possible after the target has been detected. It must employed between “independent” and “joint” torpedo attacks. The surface ships or submarines, surface ships and aircraft, bmarines and aircraft, or surface ships, submarines, and air needed by a strike conducted by air-to-surface missile-armed bombers or cruise missile submarines. Similarly, e Soviet torpedo-armed fast attack craft may strike after attacks by missile-armed fast attack craft or aircraft.
Forces’ Control: The Soviets emphasize surprise, coordination, separation and mass use of forces and weapons. The principle features of a torpedo strike are sudden and swift movement of the attacking forces toward the target, relative spontaneity of the torpedoes’ employment against the selected objective, and skillful maneuvering against the weak spots in the enemy’s defenses, sub °ordinated’ direction coordinating the movements of two or more submarines during a torpedo strike is nearly impossible, tactical control cannot remain undetected, because no underwater (6) means for communication and coordination of such movement exists.
According to the Soviets, an encounter will be won, not by a side that possesses the greater number of weapons, but by the one that detects the enemy forces first, uses its weapons first, and obtains a hit with the first salvo. This describes Soviet fascination with the “battle of the first strike". Howwever, the concept has never been tested in battle. The Soviets maintain that a surpise strike must occur with superior forces from different directions and from the weapons’ maximum effective ranges. It must use all availed weapons and it must employ different types of weapons. The principal objective then is to overwhelm the opponent’s defenses, prevent the target from dodging the attack, and inflict losses and damages upon the opponent, while minimizing the same for its own forces.
By firing a torpedo from its maximum effective range, a Soviet submarine will reveal her position. Thereby, in a case of missing the target, she will be subjected to the enemy countermeasures, but without accomplishing her mission objective. In contrast, the risk of being detected when firing from a closer range is acceptable in order to achieve an optimal firing position. In other words, it is better to get a hit from close in rather than miss from further out and still reveal your position.
Torpedo Firings: A torpedo firing can take place for one of four reasons: (1) practice, (2) experiment, (3) preparation, or (4) “combat” testing. The practice torpedo firing trains the ship or submarine commanding officers (COs), group commanders (pair COs), and ship or submarine “torpedo-mine department” crews in practical and proper application of torpedo fire regulations and norms.
The experimental firing tests new torpedo models or new tactical procedures in the torpedoes’ use. The preparatory torpedo firing, usually organized within a ship or submarine “division” (squadron) or larger unit, trains COs and their crews in proper employment of torpedoes. Then, the best unit’s CO and his torpedo-mine department is directed to carry out the exercise, while other COs and respective departments observe the exercise.
Application of the ship’s movements on the open ocean in the merge. One must run on a zigzag course and when within range: employ their guns against the target or against the ships in target’s protective screen.
To carry out the closing-in phase, a ship or submarine must be positioned within the area limited by the size the “critical course’s target angle” (CTA)- This is usually the greatest course’s target angle value at which the manneuvering ship [submarine] with a given speed can close-merge to the [torpedo’s] firing position.” The size of the critical CTA. That is the course’s target angle is directly related to the speed that the “maneuvering ship” (submarine) versus the target.
The combat torpedo firing is conducted periodically in accordance with the annual plans of the ship’s or submarine’s tactical training. The combat firing checks the crew’s readiness in and proficiency for “torpedo activities in combat.”
Types of Torpedo Attack: Regarding time available to make an attack, there are either “prepared” or “urgent” torpedo attacks. The former includes all the prescribed procedures and attack phases and is usually conducted whenever the target is detected early, and there is sufficient room for the torpedo-firing platform to conduct required maneuvering.
When a target has been detected suddenly, the urgent attack is executed. In this form of attack, though, the submarine’s chance of scoring a hit will be low, and the torpedo complement probably will be depleted.
The force/unit can conduct a torpedo strike either on a “parallel” course (toward the target) or on a “countermarch” course (away from the target). In the open ocean, the parallel course is the more common of the two. The countermarch course will be used by Soviet submarines fitted with stem 16-inch ASW torpedo tubes (“Novembers,” “Echo-Is,” “Foxtrots,” and “Romeos”). It will be used against enemy submarines or escorts. Small ASW surface ships fitted with fixed 16-inch stem tubes can also practice the countermarch course, along with other surface ships that suddenly encounter enemy surface ships or submarines.
Considering the target’s movement, torpedo attacks can be conducted from “head-on” (bow), the flanks, or the stem. The time for the torpedo strike delivered from head-on courses generally is much shorter than that conducted from the flanks, because of the high rate of relative movement (provided the speeds of the torpedo-firing platform and the target are the same). Hence, attack from the head-on course enhances the valuable element of surprise.
However, a torpedo attack from head-on creates complications for a submerged submarine in an ambush position since her sonar cannot obtain accurate range and speed information from a target with a constant zero or close-to-zero bearing rate. In contrast, a maneuvering submarine can obtain precise range and speed measurements of the target because the head-on attack offers maximum generated bearing rate and Doppler effect. However, a conventionally powered submarine attacking high-speed surface warships from head-on on the open ocean will have difficulty in disengaging and successfully avoiding pursuit by ASW forces (unless she has much greater speed than the target). A submarine CO’s principal problem in carrying out a head-on attack is maintaining significant distance from the surface ship’s track to avoid being run down, detected, or driven off the firing solution.
Striking from the flanks is the most-favored torpedo attack of the three since, at a given speed ratio for surface ship / submarine versus target. It offers a moderate rate of relative movement and enhances the chances of successful disengagement, even if the torpedo-firing platform is only slightly faster than the target. In addition, the target’s range and speed are more accurately obtained because of the steady change in the target’s bearing rate. In this type of torpedo strike, a submarine using straight-running torpedoes must not pass the closest point of approach (CPA)- The Soviets usually avoid torpedo attacks from the stern. Soviet SSNs attacking enemy surface ships capable of making only 20 knots or less can deliver a torpedo strike within the effective range of their torpedoes from practically any direction. The SSNs are particularly well-suite0 to conduct torpedo attacks from head-on directions in the open ocean, where their high speed and deep-diving capabilities can be fully exploited.
Torpedo Attack Phases: A torpedo attack is normally comprised of four phases: (1) “sneaking-in” (approach)- (2) “closing-in for engagement” (attack), (3) “comhat course” (firing course), and (4) “withdrawal from the object of attack” (disengagement).*
Depending on the circumstances, a surface ship or submarine can omit some or most of the prescribed tactic2 procedures for a torpedo attack. For example, if a torpedo armed fast attack craft or submarine conducts a torpeedo attack in the coastal waters, then the sneaking-in phase may be much longer than the closing-in phase. If a target is suddenly encountered, there may be only a short closing in phase followed by a torpedo firing, and then an energetic withdrawal from the object of attack. Soviet attack submarines, when vectored by the command post ashore or flagged command post afloat toward the “probable attack object" (PAO) begin the closing-in phase as soon as their own sensors detect the target, thus eliminating the sneaking-in phase. During the sneaking-in phase, the torpedo-firing formation or unit obtains data on the target’s whereabouts and movement, then sets a course toward the POA assuming a position of tactical deployment. The target’s range at the point of the deal deployment is chiefly selected with regard to the angle of relative movement. When more than a single ship is to attack, all participating units must assume their position for the tactical deployment at the time assigned. Afterward, torpedo-armed ships set the closing-in course, merge and initiate “combat maneuvering” toward their respective “salvo positions” (firing positions).
The closing-in phase is defined as “a tactical maneuver of a ship / formation to close distance in order to enable the most effective use of weapons and combat means of such a formation.” A Soviet surface ship or fast attack craft is usually detected by enemy surface combatants during this phase. Of necessity this phase must be kept as short as possible prior to weapon employments.
*The corresponding U. S. Navy terms are given in parentheses.
"Flank maneuver” (VJVk in Russian; or "beam attack".). When a torpedo platform enjoys a margin of speed over the target, closing in to salvo position is possible in two courses. If the speed of the maneuVering ship equals that of the target, the approach to the target is possible in only one course. When the target possesses superior speed over the maneuvering ship, closing on to the salvo position is impossible. In general, the higher the speed of the maneuvering ship or sub ovedr the PAO, the §reater the critical course’s target angle. (CTA) Hence, a torpedo platform will have the greater choice of salvo positions.
For example, Soviet SSNs, because of their high speed, can reach the firing area submerged from almost any point around a surface ship or formation within the effective range of their torpedoes. However, a submarine should be somewhat well inside the salvo position, because a zig away will carry the target outside torpedo range.
For a submarine, attacking a surface ship or formation, it also depends on her position in respect to the “attack sector.” (Vector fan) The attack sectors or “maximum target angle” (angle solutions AvK ibn Russian, or "fan spread".) is defined as “the greatest course’s target angle” value at the target’s range, the speed ratio of the submarine versus the target, and the torpedo’s range and speed allowing closing to shoot at the maximum torpedo fire range. The "maximum course’s target angle” (MCTA) represents the sum of the critical course’s target angle and AQ (see Figure 1). The value of X *s directly dependent on the speed ratio of the submarine versus the target. The higher the submarine’s speed is over that of the target, the greater the AQ value. In practical terms, the “small course’s target angles” (0 to 0.5 QKR) allows a submarine to close in to a firing position from ead-on and on either of the target’s flanks. From a “medium course’s target angle” (0.5 to 1.0 QKR), a submarine can only select a firing position on the target’s flank closest to the submarine. Then, the submarine’s closing-in courses from the target’s other flank will be limited. When a submarine. Positioned at great target angles (QKR - QPR), she can attack the target only from the flank from which the target was detected. Then, the possibility for the submarine to select the optimal torpedo fire range is decreased.
Shortly before reaching the computed salvo position, a surface ship or submarine turns onto a combat course (attack or launch vector). for five to ten seconds. When the last-minute torpedo fire solution selections are made, the torpedo is fired. The combat track or course (attack or launch vector) for small missile armed fast attack craft is identical with the torpedo’s track- Larger surface ships, however, use a “gyro angle” solution a “deflection angle” (lead angle) for torpedo attacks. (The USN term is Predict Lead Merge or Lag Lead Merge. (PLM or LLM).). The gyro angle is the computed angle between the angle of thc torpedo tube and the final track of the target's predicted course, port or starboard (taking into account corrections atitude (USN term is "aspect".), torpedo deflection, maneuvering ship’s tum-rate, and gyro incaging time). The “angled fire” is then achieved in combination with the tube’s train and estimated solution in the gyro angle.” Torpedoes can accept a gyro offset to run a true curved track. The only. reason large surface ships rely on the predict lead steer merge method is because of the the torpedo bank rotation capability of the platforms, rather than the combat course launch method. is because the larger ships are fitted with with rotating torpedo tubes. They lack the maneuverability of torpedo-armed fast attack craft and cannot point the whole ship. They seldom use the straight torpedo fire method, since the entire boat would have to be trained to bring the tubes into the proper firing position, which is often an impracticable process. Submarines for a different reason cannot point the whole ship at the predicted torpedo intercept course with the target. Hence, the torpedo must be made to move onto the correct course after it leaves the large surface ship's, or submarine’s tube. This is achieved by using the gyro angle in fire control. However, a submarine could use straight torpedo fire if necessary by steering to the deflection course but leading it slightly, then holding steady and firing the torpedoes at the instant the computed deflection angle equals the angle between the tube axis and line of sight to the target.
The withdrawal from the object of the attack will begin immediately after the platform fires her torpedoes against the maneuvering target on the open ocean. A Soviet surface ship or craft will turn away sharply from the target, increase her speed to the maximum possible in the given circumstances, and set a course providing the most rapid increase in distance from the target. A Soviet SSN will turn away from the target by using both her high speed underwater and her deep-diving capabilities in order to avoid pursuit by the enemy ASW forces.
Firing Position: A surface ship or submarine may assume salvo position from the bow, bow quarters, flanks, stem quarters, or stem. Theoretically, the course’s target angle of 90° on either of the target’s flanks is the most favorable for firing torpedoes, because the entire target’s length is exposed, the maximum margin for error in computing the torpedo fire elements is allowed, and the target, in taking evasive maneuvers, must run the greater distance. However, in practice, the torpedoes must be fired from a course’s target angle (angle on the bow) less than 90° (normally 60°-70°); otherwise, the torpedo would have much greater distance (hence much longer time) to run until its impact with the target.
In contrast, when firing from the bow quarters target angle, the target is relatively narrow (and narrower still with deflection angle), the torpedo run is shorter than when fired from the flank target angles, the track angle is smaller, and the target, in taking evasive maneuvers, needs only a small course alteration.
When straight-running torpedoes are used, a firing position from the bow target’s angles is the most disadvantageous since the target’s length exposed is very small, the angle solution on a surface target is smaller in hit probability to sink it. Thus: the track solution angle is small, and the target can avoid torpedoes with very small alteration in its course. However, if acoustic homing torpedoes are employed, this position increases the chances of obtaining a hit because the Doppler effect is the greatest at this sxet of solutions.
Firing positions from the stem quarters and stern target angles have disadvantages similar to those of the bow quarters and bow target angles, respectively.
With wire-guided torpedoes, the gyro angle does not play a role in computing torpedo fire elements, since these torpedoes can be fired from practically any position. Hence, submarines and surface ships have far greater latitude in selecting a combat course. Also, the advantages and disadvantages of the firing position mentioned previously pertain to conventional nonhoming torpedoes fitted with a contact exploder. Wire-guided and acoustic-homing torpedoes with the influence type of exploder approach the target in the terminal phase of trajectory from the stem and explode under the target’s keel.
Torpedo Fire Forms: The Soviets maintain that “experience of the war (World War II) showed the necessity of using several varied methods of fire, combining them in range and number of torpedoes.”3 With straight-running torpedoes, the Soviets distinguish between “single torpedo fire” and “area fire with several torpedoes” (ripple torpedo fire, or a salvo or spread in the US naval terminology.). The latter includes “torpedo spread fire” and “method of successive torpedo launching” (longitudinal spread). Two methods are used in torpedo spread fire: “sector fire” (divergent spread) and parallel spread. In sector fire, two or more torpedoes are fired almost simultaneously, but so that their trajectories diverge for a certain angle (usually from 1° to 4°) called “spread angle.” The spread angle is the angle between the final tracks of any two adjacent torpedoes fired in salvo from the same tube mount (surface ships) or setting (submarines' torpedo banks). By using the spread, fewer hits will be scored, but more error can be accommodated. However, acoustic homing torpedoes cover a much wider swath, and if they are wire-guided, they can follow nearly any detected maneuver of the target.
In a parallel spread, the torpedoes’ trajectories are parallel but so spaced that one torpedo will hit a point at the target’s bow and the other at the stem.
In the method of successive torpedo launchings, torpedoes are fired in predetermined time intervals, depending on the target’s speed and length. The torpedoes can be set for straight bow or stem fire at zero angle, or each torpedo can be angled the same amount. Then, each torpedo is fired in succession at different portions of the target.
The purpose of a spread is to accommodate errors and target maneuvers. Spread and salvo firings refer to straight-running torpedoes. Acoustic homing torpedoes are difficult to fire in salvo because of acoustic interference problems in the water, and because the fire control system may be capable of preparing only one torpedo at a time. There would be considerable delay in bringing up the next one for firing.
When Soviet surface combatants attack enemy submarines, they will use all their antisubmarine weapons available to overwhelm the target’s defenses, maximize the odds of getting a hit, and limit the target’s evasive maneuvering. A ship will usually fire its ASW torpedoes fjrst- After the torpedoes reach the target’s computed positi°n’ the attacking ship will close at high speed and, when within range, fire a full salvo of antisubmarine rockets- Soviet surface ships armed with both the 6,000-meter-plu* range antisubmarine rocket launchers (RBU-6000s) an short-range ASW torpedoes apparently attack in the re verse order thus described.4
Torpedo Fire Volume: The number of torpedoes a ph form has to fire at a target depends on many factors, 1(1 eluding type of target, the target’s size and value, the taf get’s status prior to the torpedo’s firing, the attack objective, type of warhead used, and type of the torped° exploder.
Table 1 Torpedo Fire Volume
__________________ Objective___________
................................Sinking...........................................Heavy Damage
................................Contact................Influence..............Contact................Influence
Ship Type...................exploder...............exploder...............exploder...............exploder
Aircraft carrier.............5-6......................4-5.....................3-4......................2-3
Cruiser.......................4-5......................3-4.....................3-4......................2-3
Destroyer...................2-3......................1-2......................1........................1
Transport—
18,000 tons................3-4......................2-3......................1-2.....................1-2
Transport—
10,000 tons................1-2......................1-2......................1........................1
Transport—
5,000 tons..................1.........................1.........................1........................1
Many torpedoes are necessary to sink (or inflict heavy damages on) a surface target; while, in most cases, only one torpedo can destroy an “underwater” target. Considering the objective of the attack, Soviets believe that only or two less torpedoes are required to inflict heavy damage.
One torpedo can sink or inflict heavy damages on even the largest enemy surface combatants.
The fire volume of torpedoes fitted with high-explosive warheads depends on whether contact or influence type of exploders are used. When an influence type of exploder is fitted, usually one torpedo less than prescribed is fired against a target to accomplish a particular objective. (See table 1).
Torpedo Launching: A heavy 21-inch torpedo fired by a surface ship or craft usually requires at least a depth of water of 100 feet at its launching point. An acoustic-homing torpedo needs a minimum depth of about 60-85 feet during its search phase, and at least 33 feet during the terminal phase of its trajectory.
^ ^A Soviet submarine can fire her torpedoes from either deep nwater (The depth is greater than 76 feet or 23.25 meters) or periscope depth t-76 feet, less than 23 meters). In peacetime training, the Soviets emphasize torpedo firing from deep water.
The conclusions: the Soviets have great faith in the effectiveness of torpedoes in a war at sea. Torpedo warfare occupies an important place in the tactical employment of Soviet submarines, surface ships and craft, and ASW aviation. The Soviets devote much attention to developing of such weaponry and the tactical training of commanding officers and torpedo-mine departments in the employment of such weapons.
Currently, the Soviet Navy possesses almost three times as many torpedo-armed platforms as the U. S. Navy. Soviet submarines and surface ships are generally armed with larger caliber (21-inch) torpedoes and fitted with larger (Presumably much more destructive.), high-explosive warheads. Soviet torpedo warfare doctrine and tactics are an integral part of their naval theory, as well. However, Soviet torpedo warfare capabilities are not as great as they first appear. The Soviet “operational-tactical” doctrines of Command and Control are too rigid to effectively task naval forces, especially in antisurface warfare. It is difficult, if not impossible, to control in a real war the employment of torpedo-armed platforms and coordinate their movements in regard to time, place, and objective assigned. This is especially true when such forces’ control is exercised by the command post ashore, and an engagement occurs far from the Soviet-controlled coast.
The Soviet emphasis on firing weapons from their maximum range to enhance the element of surprise and obtain a hit with the first salvo is another weakness in their torpedo warfare tactical doctrine.
The American Navy can counter the Soviet torpedo threat by exercising more innovative tactical methods and procedures in employing its own torpedoes and other weapons, by maintaining (and, if possible, widening) the current American technological lead in quality of detection sensors, and by having longer-ranged, faster torpedoes fitted with more advanced guidance systems than their Soviet counterparts. But, the key to success in neutralizing the Soviet torpedo threat is better tactics. The U. S. Navy must always be more creative, faster, and more flexible than its Soviet opponent.
*B. Balev, “Sea and Oceanic Communications and Warfare on Them,” Voyennaya mysl, October 1971, p. 47; G. Kostev, “Commerce Raiding as a Form of Combat Actions on the Oceanic Communications of an Adversary,” Morskoy Sbornik, February 1972, pp. 36-37.
2The Soviet Military Encyclopedia (Moscow: Voyenizdat, 1980), vol. 8, p. 77. 3I. Kosikov, “Torpedo Weaponry in the Great Patriotic War,” Morskoy Sbornik, May 1976, p. 76.
4Krasnaya Zvezda (Moscow), 22 December 1976, p. 1; 26 July 1977, p. 2; 10 October 1977, p. 1; 21 June 1979, p. 1.
A graduate of the Yugoslav Naval Academy, Dr. Vego served 12 years in the Yugoslav Navy and attained the rank of lieutenant commander before coming to the United States. He served for four years as a CO/pair commander of Soviet-designed “Shershen”-class torpedo boats. Dr. Vego has been published widely in the Western press on naval matters.
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Digital Proceedings content made possible by a gift from CAPT Roger Ekman, USN (Ret.)
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The article is a cold war era one with reference to the Russians, who were and are incompetent at naval warfare. Their Rube Goldberg approach to msaking a hot sauce of the naval operational art has so many fail points, it is ridiculous.
Compare their confused dubious approach with Kantai Kassen.
At least the Imperial Japanese Navy understood that it was not about how to shoot a target, according to a rote lesson plan. Naval warfare by its nature was and is chaotic, and rather attritional. Furthermore it is based on a tactical, operational, and strategic objectives. The tactical objective might be to deny an enemy fleet fuel to keep most of it in port. The operational objective desired, to fight the enemy piecemeal in detail, by tactically killing his oil tankers until the enemy fleet is fuel starved; allows that operational objective. Here your numerically inferior fleet can face the enemy on equal terms, since he can only send a third or a half of his battle fleet to face your whole force. The strategic objective, engendered by your tactical objective achieved, and furthered by your desired operational objective to achieve the naval initiative, is Mahanic; to deny your enemy local control of the sea at a time and place of your choosing, to ultimately destroy his navy piecemeal. That was the World War II American naval answer to Kantai Kassen. It was not about decisive battle at all.
You get the impression that the American referant naval enemy of Japan did not understand that naval warfare was a logistics contest? In the American view, the victor was the one who could use the sea after the shooting stops.
The Kantai Kassen doctrine was actually a political sales job to get money from the Diet. (^^^). The whole idea about how the IJN really intended to fight the Americans actually was to bleed the Americans down by attrition. This is not decisive battle doctrine at its core. It is a naval attritional campaign doctrine that was wrongfooted from the start. As an operational art solution to the Japanese problem of how to fight a bigger more powerful enemy, it is a repeat of the Russo-Japanese experience. This is not a good template.
The Russians were beatable in the Russo-Japanese War; because they were logistically and technically incompetent. They never improved. You could not expect the Americans to remain operationally incompetent or technologically inept during what could be expected to be a LONG war. Anyone with half a brain (Yamamoto, Isoruku), would understand that Kantai Kassen was a public relations ploy, while the whole IJN was built to bleed down the enemy.
In that case, you can instantly see why the Japanese went in for big banger torpedoes as the means to attrite the Americans? Long range, big warheads and first strike, from their "light forces", consisting of destroyers, cruisers and aircraft carriers was their technological and tactical doctrine? Interestingly, the Japanese submarines were supposed to attrite warships, too. Here, we can see the major operational error in how the Japanese employed their navy. Any American naval intrusion into Japanese controlled waters had to be logistically supported. Obviously, with the weaponry and launch platforms the Japanese had in their submarine arm, the correct way to attrite the Americans was to go after their merchant fleet and naval logistics ships.
The Japanese did not understand this operational naval requirement. They misused their magnificent torpedo launching platforms in vainglorious and showy battles to sink American ships.
The Americans shrugged off a hundred sunken attrition units (destroyers and cruisers), absorbed Pearl Harbor (Battleline smashed and ruined.), swallowed the loss of a half dozen flattops in set piece battles that decided nothing, except that they would keep pushing forward against a superior enemy. who squandered his own ships in one for one exchanges, while burning up his lead in veteran ship's crews / aviators. Meanwhile, the Americans could sink the Japanese merchant marine, with their sputtering submarine force. Their no-good torpedoes took two years to fix to become mediocre torpedoes. Their torpedo tactics took those same two hard years to learn. At the end, the murder year (1944), showed what naval operational art, married to decent tactics could do.
WORLD WAR II: JAPAN’S DISINTEREST IN MERCHANT SHIP CONVOYING
John Merrill
Preface
Why did Japan wait until late 1943 to implement a central broad Antisubmarine Warfare (ASW) strategy for convoying merchant shipping with escort ships and where feasible, air cover? The Japanese Navy knew from 1939 the U-boat success with guerre de course especially against merchant ships sailing independently, yet did not act.
The Setting
Japan’s aggressive and successful early actions of December 1941 created within a few weeks greatly lengthened merchant ship trade routes covering distances up to 3000 miles from the homeland.
Within eight days of Pearl Harbor, the West Coast of Malaysia thousands of miles from Japan, was a destination for cargo ships supporting the Japanese invasion army. The next month Singapore fell, followed later by the Philippines. Other remote invasion points all required at-sea transport over long distances. In addition to significant activity south of the home islands, the long ongoing intrusion and exploitation in northern China and Manchuria also required continuous sea transport although the distances were shorter.
On December 7, 1941, the Japanese merchant fleet stood at more than six million tons. At war, the burden of this fleet would include both the Japanese Army and Navy. Further, the fleet addressed Japan’s extensive import requirements for her population as well as the huge demand for raw materials to meet extensive armament production and other industrial needs. A 20th century island, Japan survived on imports.
Accounting for the huge loss in Japanese shipping. foremost was the increasing effectiveness and skill of the United States submarine fleet growing and improving during each year of the war. The number of United States submarines in the Pacific Theater went from 47 in 1941 to 104 in February 1943 and 169 at the end of the war in 1945. United States ships. planes and submarines had the advantage of newly-developed sonar and radar systems. Japan’s military technology development and fleet implementation lagged that of the United States by four years.
Further consideration of the demise of the Japanese merchant fleet brings out other factors. The Japanese cult of the naval offensive made merchant ship convoying appear as a defensive role not in keeping with a Samurai’s view of fighting on the sea. Among some naval officers, ASW study and research fell into the category of only common sense.
It is not clear. why the 20th century Japanese Navy with its strong ties to British naval tradition, practices and strategy was not observant of Britain’s success with merchant ship convoying during the last years of WWI. There is no strong evidence that convoying was an important consideration in Japan’s inter-war years of naval planning.
Examination of the ASW state of readiness of Japan in late 1941 indicates ignorance of or disinterest in the heavy loss of merchant ships by Britain and others due to the improved U-boats during the first several years of WWII. Moreover. appreciation that air and sea convoy escorting of merchant ships at least moderated the losses seems to have gone unnoticed. Japan did not mount a significant focused merchant ship convoy effort until October 1943.
Before December 1941
The origins of modem Japanese naval heritage are from the successful Sino-Japanese War of 1894-5 and the Russo-Japanese War 1904-05. In both wars, success at sea came from the two Mahanian like clashes of fleet-versus-fleet with the Battle of the Yalu in the former and the Battle of Tsushima in the latter. At that time, the industrial needs of Japan were primarily agricultural and did not demand extensive seaborne support. Japan was not unique in its naval tradition of at sea-encounters with enemy battle fleets and the consequent large budgets for battleships and supporting craft.
After the Russo-Japanese War, the Army and the Navy began to diverge gradually in their perception of national objectives. The Army opted for a continental direction to the west of Japan on mainland Asia for expansion while the Navy inclined southward in the direction of oil and rubber resources. In the years ahead, this division took a toll in national preparedness, reduced inter-service cooperation, effective expenditure of resources, and, ultimately, in a rivalry for fiscal support.
Japan sided with England in WWI in accordance with an existing treaty and declared war against Germany 23 August 1914. Japan’s role involved occupation of the Marshall and Caroline archipelagos and capture of Germany’s Chinese port of Tsingtao in November 1914. By 1918, Japan’s destroyers were part of the extensive allied armada of support vessels in European waters in the successful convoy opposition to the U-boats.
As the fires of World War I abated in the late fall of 1918 with the armistice, attention turned to peace making and keeping. The new and hard won skills of ASW and the successful protection of merchant shipping by convoying with sea and air escorts were put aside and to some extent forgotten by the primary maritime nations. Awareness of the infrequent use of highly touted battleships by both sides during the almost five years of WWI dominated by the U-boat was forgotten. The concept of control of the sea with final decision based on the clash of great battle fleets again assumed its pre-World War I prominence among the primary powers of England, United States, France, Italy, and Japan. The battleship with its attendant high cost, long-term building requirements, manpower demands and support requirements was the weapon of choice.
In the 1920s and during the international depression period of the 1930s, economics began to play a more significant role in the restrained defense budgets of the primary maritime powers. In Japan, the actual ruling government power divided among the Army, Navy, and the premier’s cabinet with the Anny in the dominant position. Further, the potential enemies were Russia, China, and United States. The Army with a strong position and military needs directed toward China and Russia in Asia met its funding needs at the expense of Navy support. With limited fiscal means and the United States as its anticipated enemy, naval strategy focused on battle groups and the decisive at sea battles. This strategy obscured development of adequate wartime sea and air escort capabilities for shipping protection during armed conflict.
Smaller allocations insured continuing competition between navy and army priorities, and additional increasing attention to air power provided another factor in dividing the limited defense budgets.
Early in the 1930s, Japanese naval planning included ample recommendations for ships, boats, subchasers, air cover and wartime backup. Considerations were directed towards the need for better ASW and conversion of merchant escorts in time of war. There were other Navy voices that held opposing opinions which, when considering the U.S. as an enemy, held to the belief that enemy submarines like their own would not adopt the tactic of guerre de course. Budgetary restraints and lack of support prevented implementation of ASW-related developments.
In September 1940, Japan impressed by the Axis victories in Western Europe including the fall of France joined the Axis powers. Germany’s early 1941 success in the invasion of Soviet Russia triggered Japan’s excursions in southern Asia. On July 26, Japan occupied all of French Indochina with ensuing events leading to December 7′ s strike at Pearl Harbor.
Major Y. Horie, former member of the Imperial Japanese Army, provides some perspective regarding a Japanese view of convoying merchant ships. Horie spent most of the war years (World War II) with the Japanese Navy primarily concerned with the transportation of troops and materiel in his assignment with the Convoy Escort Fleet from its beginnings to its final days. Horie noted, “I found that Japanese high authority had done virtually nothing on convoy escort operation since the end of World War I.”
The importance of escorts is seen in the numbers of escorts required per convoy. Before 1940, transatlantic convoys had 2 escorts; and in 1943, the number was 7. In peacetime, no Japanese ASW escort craft were built. “The war began without a single ship designed for commerce protection on the high seas.”
As the war opened, the Naval General Staff placed the responsibility for shipping protection in its Operations Division with a one officer billet. Regulations for masters of merchant ships in time of war varied, depending on the geographical locations of the ships. The navy commanders in the various locations issued separate regulations, which created confusion. In the fall of 1942, standardized regulations appeared.
In the early part of the war, Japanese convoys of 10 to 20 merchant ships included merely one warship as escort. Further, the merchant ships went to sea unarmed. It was not until April 10, 1942 that the Japanese Navy assigned units to duty escorting merchant vessels. A shortage of adequate officer personnel to assist in this effort created difficulties. Total Japanese convoy escort (USN term "escon") support for the 2500-mile link from Japan to Singapore consisted of 10 overage destroyers, 2 torpedo boats, and 5 merchant ships converted to gunboats. The escort for the 2000-mile passage from Yokusuka to Truk was composed of four old destroyers, one torpedo boat, and two converted gunboats.
This disarray and escort shortage created additional problems. Inadequate escort capability and independent tanker and freighter sailings did not assure the arrival in Japan of the now available and much needed resources, particularly, oil from the recently conquered areas in Southeast Asia.
In 1940, the Japanese Navy approved construction of four frigates for coastal defense. Later this class of ship provided the basic design for the much-needed and belated merchant ship convoy escorts. Initially these frigates were equipped with 12 depth charges. The reluctance to embark on an extensive escort building program did not start until mid-November 1943 when the disastrous loss of merchant ships signaled the need to provide escorts was finally realized by Japan.
Negligent in building frigates until June 1942, the navy approved 40 frigates with a request for 360. Perspective regarding the risks of Japanese merchant shipping in July-August 1942 comes from an anecdote concerning the third war patrol of the USS Narwhal (SS167}. This older submarine commissioned in 1930 survived the bombing at Pearl Harbor and was then the first submarine to patrol the area between Honshu and Hokkaido. On patrol, the commanding officer Lieutenant Commander W. C. Wilkins observed the Japanese merchant ships and commented that the coastal traffic looked like “a street car line: fat targets chugging up and down the coast with no escorts. We could take our pick.” However, Japanese ASW was not to be overlooked. Three United States submarines were lost in 1941 and 15 the following year.
By late August 1943, the Japanese Navy became alarmed because of greatly increased merchant ship losses. The numbers of submarine attacks increased. Greater numbers of U.S. submarines equipped with communications, sonar, air and surface radar, and improved torpedoes resulted in further sinkings. Growing danger to merchant ships from American bombing planes caused additional dismay to the Japanese Navy.
Postwar accounts by Army Major Y. Horie and Navy Captain Atsushi Oi in the US Naval Institute Proceedings addressed the basis of the inability of the Japanese Navy to cope. Oi suggests failure in ASW largely because the Navy disregarded the importance of the problem. Horie found the Navy indifferent to the problem of escort protection for merchant ships.
It became essential to confront these extreme shipping losses. On November 15, 1943, the Japanese navy established the Grand Escort Command Headquarters with centralized responsibility over all matters of shipping protection. Frequently throughout the war years, the Navy took various steps to improve the protection of merchant ships but always without a cohesive centralized plan, adequate manpower, and material support.
En route from Fremantle, Australia (one of seven trips), to deliver cargo and commandos to the Philippines in November, 1943, the above-mentioned USS NARWHAL encountered what appeared to be a lone Japanese oil tanker. However, three destroyers escorted the tanker. Packed with tons of supplies and armed only with the torpedoes in its tubes, the submarine attacked the tanker but missed. Evading the destroyer escorts, NARWHAL went on to fulfill its mission, delivering the supplies and personnel and rescuing thirty-two.
Frigates previously mentioned and called “Kaibo-kan” (coast defense), initially not intended for escort duty began to be used as merchant ship escorts. The characteristics of these 220-foot frigates of 800-1000 tons included Diesel or steam engines with deck guns and 60 depth charges. Later versions carried 120 depth charges. Ranges of the order of 6000 miles were typical. Speed of 16-20 knots and adequate sonar made them almost exclusively an oceangoing convoy escort. Construction of these frigates was initiated in October 1943. By May 1944, 145 were completed. Now two years into the war, Kaibo-kans began to operate effectively in the southwest Pacific. In contrast, Britain built and had 100 convoy escorts available before the start of WWII.
Regular convoying started in mid-November 1943 but only on the Singapore run. By this time, damage to the merchant fleet was beyond repair and new construction limited. Wooden 100~ton cargo carrying sampans became numerous along the coasts as the number of merchant ships sharply decreased. Somewhat improved convoy methods were still forthcoming the following year, 1944. Late in that year after the battle of Leyte Gulf, the Japanese Navy became a minor factor. However, it was during that fall when the U.S. lost eight submarines in six weeks, the highest rate of the war, possibly due in part to the almost after-the-fact convoy escorting of merchant ships.
According to Pacific submarine war naval historian Theodore Roscoe, “Throughout the Pacific War the behavior of the Japanese escort was completely unpredictable. The escort’s lack of adequate communications equipment, only at this late date being equipped with primitive radar detection devices, could be one of the reasons for Roscoe’s comment. In addition to the deficiency of adequate strategy and tactics for convoying, escort ships, planes, and trained personnel were in short supply.
The Tecbnology Gap
At the start of the war, no Japanese ship was equipped with radar. It was many months before a limited number were supplied. Another year would be required to install radar on the combatant ships. The United States Navy entered the war with radar available and improvements forthcoming.
The delay in the introduction of advanced technology reveals some of Japan’s lag. In other systems as well, the United States continued to excel and increase Japan’s technological lag even further.
Summary
Data from Parillo’ display the final tonnage of the sinkings of Japanese merchant ships during the nearly four years of engagement primarily with U.S. Naval forces over a wide area of the Pacific. During the years 1942-44, U.S. submarines accounted for more than 2/3 of the sinkings of Japanese merchant shipping for each of the years. At the end of 1944, remaining Japanese merchant tonnage was close to or below the 2,000,000 tons required to meet the food supply needs of the country.
Failure to consider and plan for protection of merchant shipping, particularly in view of the industrial power of the United States and the neglect of historical evidence in support of convoying, contributed greatly to the collapse of Japan. This negligence and the presence of more than 150 U.S. submarines in the Pacific by 1945 hastened Japan’s defeat.
ENDNOTES
1. Major Y. Horie, “The Failure of the Japanese Convoy Escort”, Naval Institute Proceedings, October 1956, p. 1073.
2. Mrk P. Parillo, “The Japanese Merchant Marine in WWII”, U.
S. Naval Institute, 1993, p. 95, 97.
3. Atsushi Oi, “Why Japan’s Anti-submarine Warfare Failed”, Naval Institute Proceedings, June 1952, p. 592.
4. Clay Blair, Jr., “Silent Victory: The U.S. Submarine War Against Japan”, J.B. Lippincott Co., 19075, p. 497.
5. Theodore Roscoe, “United States Submarine Operations in World War”, US Naval Institute, 1949, p. 216.
6. Parillo, op, cit. p. 242.
John Merrill
Preface
Why did Japan wait until late 1943 to implement a central broad Antisubmarine Warfare (ASW) strategy for convoying merchant shipping with escort ships and where feasible, air cover? The Japanese Navy knew from 1939 the U-boat success with guerre de course especially against merchant ships sailing independently, yet did not act.
The Setting
Japan’s aggressive and successful early actions of December 1941 created within a few weeks greatly lengthened merchant ship trade routes covering distances up to 3000 miles from the homeland.
Within eight days of Pearl Harbor, the West Coast of Malaysia thousands of miles from Japan, was a destination for cargo ships supporting the Japanese invasion army. The next month Singapore fell, followed later by the Philippines. Other remote invasion points all required at-sea transport over long distances. In addition to significant activity south of the home islands, the long ongoing intrusion and exploitation in northern China and Manchuria also required continuous sea transport although the distances were shorter.
On December 7, 1941, the Japanese merchant fleet stood at more than six million tons. At war, the burden of this fleet would include both the Japanese Army and Navy. Further, the fleet addressed Japan’s extensive import requirements for her population as well as the huge demand for raw materials to meet extensive armament production and other industrial needs. A 20th century island, Japan survived on imports.
Size of the Japanese Merchant Fleet
1217/41 6,384,000 tons
8/14/45 1,465,900 tons
1217/41 6,384,000 tons
8/14/45 1,465,900 tons
Accounting for the huge loss in Japanese shipping. foremost was the increasing effectiveness and skill of the United States submarine fleet growing and improving during each year of the war. The number of United States submarines in the Pacific Theater went from 47 in 1941 to 104 in February 1943 and 169 at the end of the war in 1945. United States ships. planes and submarines had the advantage of newly-developed sonar and radar systems. Japan’s military technology development and fleet implementation lagged that of the United States by four years.
Further consideration of the demise of the Japanese merchant fleet brings out other factors. The Japanese cult of the naval offensive made merchant ship convoying appear as a defensive role not in keeping with a Samurai’s view of fighting on the sea. Among some naval officers, ASW study and research fell into the category of only common sense.
It is not clear. why the 20th century Japanese Navy with its strong ties to British naval tradition, practices and strategy was not observant of Britain’s success with merchant ship convoying during the last years of WWI. There is no strong evidence that convoying was an important consideration in Japan’s inter-war years of naval planning.
Examination of the ASW state of readiness of Japan in late 1941 indicates ignorance of or disinterest in the heavy loss of merchant ships by Britain and others due to the improved U-boats during the first several years of WWII. Moreover. appreciation that air and sea convoy escorting of merchant ships at least moderated the losses seems to have gone unnoticed. Japan did not mount a significant focused merchant ship convoy effort until October 1943.
Before December 1941
The origins of modem Japanese naval heritage are from the successful Sino-Japanese War of 1894-5 and the Russo-Japanese War 1904-05. In both wars, success at sea came from the two Mahanian like clashes of fleet-versus-fleet with the Battle of the Yalu in the former and the Battle of Tsushima in the latter. At that time, the industrial needs of Japan were primarily agricultural and did not demand extensive seaborne support. Japan was not unique in its naval tradition of at sea-encounters with enemy battle fleets and the consequent large budgets for battleships and supporting craft.
After the Russo-Japanese War, the Army and the Navy began to diverge gradually in their perception of national objectives. The Army opted for a continental direction to the west of Japan on mainland Asia for expansion while the Navy inclined southward in the direction of oil and rubber resources. In the years ahead, this division took a toll in national preparedness, reduced inter-service cooperation, effective expenditure of resources, and, ultimately, in a rivalry for fiscal support.
Japan sided with England in WWI in accordance with an existing treaty and declared war against Germany 23 August 1914. Japan’s role involved occupation of the Marshall and Caroline archipelagos and capture of Germany’s Chinese port of Tsingtao in November 1914. By 1918, Japan’s destroyers were part of the extensive allied armada of support vessels in European waters in the successful convoy opposition to the U-boats.
As the fires of World War I abated in the late fall of 1918 with the armistice, attention turned to peace making and keeping. The new and hard won skills of ASW and the successful protection of merchant shipping by convoying with sea and air escorts were put aside and to some extent forgotten by the primary maritime nations. Awareness of the infrequent use of highly touted battleships by both sides during the almost five years of WWI dominated by the U-boat was forgotten. The concept of control of the sea with final decision based on the clash of great battle fleets again assumed its pre-World War I prominence among the primary powers of England, United States, France, Italy, and Japan. The battleship with its attendant high cost, long-term building requirements, manpower demands and support requirements was the weapon of choice.
In the 1920s and during the international depression period of the 1930s, economics began to play a more significant role in the restrained defense budgets of the primary maritime powers. In Japan, the actual ruling government power divided among the Army, Navy, and the premier’s cabinet with the Anny in the dominant position. Further, the potential enemies were Russia, China, and United States. The Army with a strong position and military needs directed toward China and Russia in Asia met its funding needs at the expense of Navy support. With limited fiscal means and the United States as its anticipated enemy, naval strategy focused on battle groups and the decisive at sea battles. This strategy obscured development of adequate wartime sea and air escort capabilities for shipping protection during armed conflict.
Smaller allocations insured continuing competition between navy and army priorities, and additional increasing attention to air power provided another factor in dividing the limited defense budgets.
Early in the 1930s, Japanese naval planning included ample recommendations for ships, boats, subchasers, air cover and wartime backup. Considerations were directed towards the need for better ASW and conversion of merchant escorts in time of war. There were other Navy voices that held opposing opinions which, when considering the U.S. as an enemy, held to the belief that enemy submarines like their own would not adopt the tactic of guerre de course. Budgetary restraints and lack of support prevented implementation of ASW-related developments.
In September 1940, Japan impressed by the Axis victories in Western Europe including the fall of France joined the Axis powers. Germany’s early 1941 success in the invasion of Soviet Russia triggered Japan’s excursions in southern Asia. On July 26, Japan occupied all of French Indochina with ensuing events leading to December 7′ s strike at Pearl Harbor.
Major Y. Horie, former member of the Imperial Japanese Army, provides some perspective regarding a Japanese view of convoying merchant ships. Horie spent most of the war years (World War II) with the Japanese Navy primarily concerned with the transportation of troops and materiel in his assignment with the Convoy Escort Fleet from its beginnings to its final days. Horie noted, “I found that Japanese high authority had done virtually nothing on convoy escort operation since the end of World War I.”
December 1941 – November 1943
The rule developed by the Allies in the battle with the U-boats based on analysis of the statistics of convoyed merchant ship losses revealed the following:
Number of escorts = (Number of merchant ships/10) + 3,
if with air escort
Number of escorts x 2, if no air escort.
The rule developed by the Allies in the battle with the U-boats based on analysis of the statistics of convoyed merchant ship losses revealed the following:
Number of escorts = (Number of merchant ships/10) + 3,
if with air escort
Number of escorts x 2, if no air escort.
The importance of escorts is seen in the numbers of escorts required per convoy. Before 1940, transatlantic convoys had 2 escorts; and in 1943, the number was 7. In peacetime, no Japanese ASW escort craft were built. “The war began without a single ship designed for commerce protection on the high seas.”
As the war opened, the Naval General Staff placed the responsibility for shipping protection in its Operations Division with a one officer billet. Regulations for masters of merchant ships in time of war varied, depending on the geographical locations of the ships. The navy commanders in the various locations issued separate regulations, which created confusion. In the fall of 1942, standardized regulations appeared.
In the early part of the war, Japanese convoys of 10 to 20 merchant ships included merely one warship as escort. Further, the merchant ships went to sea unarmed. It was not until April 10, 1942 that the Japanese Navy assigned units to duty escorting merchant vessels. A shortage of adequate officer personnel to assist in this effort created difficulties. Total Japanese convoy escort (USN term "escon") support for the 2500-mile link from Japan to Singapore consisted of 10 overage destroyers, 2 torpedo boats, and 5 merchant ships converted to gunboats. The escort for the 2000-mile passage from Yokusuka to Truk was composed of four old destroyers, one torpedo boat, and two converted gunboats.
This disarray and escort shortage created additional problems. Inadequate escort capability and independent tanker and freighter sailings did not assure the arrival in Japan of the now available and much needed resources, particularly, oil from the recently conquered areas in Southeast Asia.
In 1940, the Japanese Navy approved construction of four frigates for coastal defense. Later this class of ship provided the basic design for the much-needed and belated merchant ship convoy escorts. Initially these frigates were equipped with 12 depth charges. The reluctance to embark on an extensive escort building program did not start until mid-November 1943 when the disastrous loss of merchant ships signaled the need to provide escorts was finally realized by Japan.
Negligent in building frigates until June 1942, the navy approved 40 frigates with a request for 360. Perspective regarding the risks of Japanese merchant shipping in July-August 1942 comes from an anecdote concerning the third war patrol of the USS Narwhal (SS167}. This older submarine commissioned in 1930 survived the bombing at Pearl Harbor and was then the first submarine to patrol the area between Honshu and Hokkaido. On patrol, the commanding officer Lieutenant Commander W. C. Wilkins observed the Japanese merchant ships and commented that the coastal traffic looked like “a street car line: fat targets chugging up and down the coast with no escorts. We could take our pick.” However, Japanese ASW was not to be overlooked. Three United States submarines were lost in 1941 and 15 the following year.
By late August 1943, the Japanese Navy became alarmed because of greatly increased merchant ship losses. The numbers of submarine attacks increased. Greater numbers of U.S. submarines equipped with communications, sonar, air and surface radar, and improved torpedoes resulted in further sinkings. Growing danger to merchant ships from American bombing planes caused additional dismay to the Japanese Navy.
Postwar accounts by Army Major Y. Horie and Navy Captain Atsushi Oi in the US Naval Institute Proceedings addressed the basis of the inability of the Japanese Navy to cope. Oi suggests failure in ASW largely because the Navy disregarded the importance of the problem. Horie found the Navy indifferent to the problem of escort protection for merchant ships.
It became essential to confront these extreme shipping losses. On November 15, 1943, the Japanese navy established the Grand Escort Command Headquarters with centralized responsibility over all matters of shipping protection. Frequently throughout the war years, the Navy took various steps to improve the protection of merchant ships but always without a cohesive centralized plan, adequate manpower, and material support.
En route from Fremantle, Australia (one of seven trips), to deliver cargo and commandos to the Philippines in November, 1943, the above-mentioned USS NARWHAL encountered what appeared to be a lone Japanese oil tanker. However, three destroyers escorted the tanker. Packed with tons of supplies and armed only with the torpedoes in its tubes, the submarine attacked the tanker but missed. Evading the destroyer escorts, NARWHAL went on to fulfill its mission, delivering the supplies and personnel and rescuing thirty-two.
Frigates previously mentioned and called “Kaibo-kan” (coast defense), initially not intended for escort duty began to be used as merchant ship escorts. The characteristics of these 220-foot frigates of 800-1000 tons included Diesel or steam engines with deck guns and 60 depth charges. Later versions carried 120 depth charges. Ranges of the order of 6000 miles were typical. Speed of 16-20 knots and adequate sonar made them almost exclusively an oceangoing convoy escort. Construction of these frigates was initiated in October 1943. By May 1944, 145 were completed. Now two years into the war, Kaibo-kans began to operate effectively in the southwest Pacific. In contrast, Britain built and had 100 convoy escorts available before the start of WWII.
Regular convoying started in mid-November 1943 but only on the Singapore run. By this time, damage to the merchant fleet was beyond repair and new construction limited. Wooden 100~ton cargo carrying sampans became numerous along the coasts as the number of merchant ships sharply decreased. Somewhat improved convoy methods were still forthcoming the following year, 1944. Late in that year after the battle of Leyte Gulf, the Japanese Navy became a minor factor. However, it was during that fall when the U.S. lost eight submarines in six weeks, the highest rate of the war, possibly due in part to the almost after-the-fact convoy escorting of merchant ships.
According to Pacific submarine war naval historian Theodore Roscoe, “Throughout the Pacific War the behavior of the Japanese escort was completely unpredictable. The escort’s lack of adequate communications equipment, only at this late date being equipped with primitive radar detection devices, could be one of the reasons for Roscoe’s comment. In addition to the deficiency of adequate strategy and tactics for convoying, escort ships, planes, and trained personnel were in short supply.
The Tecbnology Gap
At the start of the war, no Japanese ship was equipped with radar. It was many months before a limited number were supplied. Another year would be required to install radar on the combatant ships. The United States Navy entered the war with radar available and improvements forthcoming.
The delay in the introduction of advanced technology reveals some of Japan’s lag. In other systems as well, the United States continued to excel and increase Japan’s technological lag even further.
Japanese Technology Introduction
1942 Shipboard radar detector
Aircraft warning radar
1943 Battleship, medium bomber
lOcm radar
1944 Air convoy escort radar
Escort ship radar detector (in Dec.)
1942 Shipboard radar detector
Aircraft warning radar
1943 Battleship, medium bomber
lOcm radar
1944 Air convoy escort radar
Escort ship radar detector (in Dec.)
Summary
Data from Parillo’ display the final tonnage of the sinkings of Japanese merchant ships during the nearly four years of engagement primarily with U.S. Naval forces over a wide area of the Pacific. During the years 1942-44, U.S. submarines accounted for more than 2/3 of the sinkings of Japanese merchant shipping for each of the years. At the end of 1944, remaining Japanese merchant tonnage was close to or below the 2,000,000 tons required to meet the food supply needs of the country.
Failure to consider and plan for protection of merchant shipping, particularly in view of the industrial power of the United States and the neglect of historical evidence in support of convoying, contributed greatly to the collapse of Japan. This negligence and the presence of more than 150 U.S. submarines in the Pacific by 1945 hastened Japan’s defeat.
ENDNOTES
1. Major Y. Horie, “The Failure of the Japanese Convoy Escort”, Naval Institute Proceedings, October 1956, p. 1073.
2. Mrk P. Parillo, “The Japanese Merchant Marine in WWII”, U.
S. Naval Institute, 1993, p. 95, 97.
3. Atsushi Oi, “Why Japan’s Anti-submarine Warfare Failed”, Naval Institute Proceedings, June 1952, p. 592.
4. Clay Blair, Jr., “Silent Victory: The U.S. Submarine War Against Japan”, J.B. Lippincott Co., 19075, p. 497.
5. Theodore Roscoe, “United States Submarine Operations in World War”, US Naval Institute, 1949, p. 216.
6. Parillo, op, cit. p. 242.
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