The first torpedoes differed from modern ones no less than a paddle-wheel steam frigate from a nuclear-powered aircraft carrier. In 1866, the "skat" carried 18 kg of explosives at a distance of 200 m at a speed of about 6 knots. Shooting accuracy was below any criticism. By 1868, the use of coaxial propellers rotating in different directions made it possible to reduce the yaw of the torpedo in the horizontal plane, and the installation of a pendulum control mechanism for rudders stabilized the depth of travel.
By 1876, Whitehead's brainchild was sailing at a speed of about 20 knots and covered a distance of two cables (about 370 m). Two years later, torpedoes had their say on the battlefield: Russian sailors with "self-propelled mines" sent the Turkish escort ship "Intibah" to the bottom of the Batumi raid.
The further evolution of torpedo weapons until the middle of the 20th century is reduced to an increase in the charge, range, speed and ability of torpedoes to stay on course. It is fundamentally important that for the time being the general ideology of weapons remained exactly the same as in 1866: the torpedo was supposed to hit the target's side and explode on impact.
Direct-going torpedoes remain in service to this day, periodically finding use in the course of all kinds of conflicts. They were the ones who sunk the Argentine cruiser General Belgrano in 1982, which became the most famous victim of the Falklands War.
The British nuclear submarine Conqueror then fired three Mk-VIII torpedoes at the cruiser, which have been in service with the Royal Navy since the mid-1920s. The combination of a nuclear submarine and antediluvian torpedoes looks funny, but let's not forget that the cruiser built in 1938 by 1982 had more museum than military value.
The revolution in torpedo business was made by the appearance in the middle of the 20th century of homing and telecontrol systems, as well as proximity fuses.
Modern homing systems (CCH) are divided into passive - "catching" physical fields created by the target, and active - looking for a target, usually using sonar. In the first case, we are talking most often about the acoustic field - the noise of screws and mechanisms.
The homing systems, which locate the wake of the ship, stand somewhat apart. Numerous small air bubbles remaining in it change the acoustic properties of the water, and this change is reliably "caught" by the torpedo's sonar far behind the passing ship. Having fixed the trail, the torpedo turns in the direction of the target's movement and searches, moving like a "snake". Wake tracking, the main method of homing torpedoes in the Russian navy, is considered reliable in principle. True, a torpedo, forced to catch up with the target, wastes time and precious cable paths on this. And the submarine, in order to shoot "on the trail", has to get closer to the target than it would in principle be allowed by the torpedo range. This does not increase the chances of survival.
The second most important innovation was the torpedo telecontrol systems that became widespread in the second half of the 20th century. As a rule, the torpedo is controlled by a cable that is unwound as it moves.
The combination of controllability with a proximity fuse made it possible to radically change the very ideology of using torpedoes - now they are focused on diving under the keel of the attacked target and exploding there.
Catch her with your net
The first attempts to shield ships from the new threat were made in a few years after its appearance. The concept looked simple: on board the ship were attached folding shots, from which a steel net hung down, stopping torpedoes.
On trials of the novelty in England in 1874, the network successfully repelled all attacks. Similar tests carried out in Russia a decade later yielded a slightly worse result: the net, designed to withstand a burst of 2.5 tons, withstood five out of eight shots, but three torpedoes that pierced it got entangled with screws and were still stopped.
The most striking episodes of the biography of the anti-torpedo networks relate to the Russian-Japanese war. However, by the beginning of the First World War, the speed of the torpedoes exceeded 40 knots, and the charge reached hundreds of kilograms. To overcome obstacles, special cutters began to be installed on the torpedoes. In May 1915, the English battleship Triumph, which was shelling Turkish positions at the entrance to the Dardanelles, was sunk by a single shot from a German submarine despite the lowered nets - a torpedo penetrated the defense. By 1916, the collapsed "chain mail" was perceived more as a useless load than as protection.
Fence off with a wall
The energy of the blast wave decreases rapidly with distance. It would be logical to put an armored bulkhead at some distance from the outer skin of the ship. If it can withstand the impact of the blast wave, then damage to the ship will be limited to the flooding of one or two compartments, and the power plant, ammunition storage and other vulnerable spots will not be affected.
Apparently, the first idea of a constructive PTZ was put forward by the former chief builder of the English fleet E. Read in 1884, but his idea was not supported by the Admiralty. In the projects of their ships, the British preferred to follow the traditional path at that time: to divide the hull into a large number of watertight compartments and cover the engine-boiler rooms with coal pits located on the sides.
Such a system for protecting the ship from artillery shells was repeatedly tested at the end of the 19th century and, on the whole, looked effective: the coal piled in the pits regularly “caught” the shells and did not catch fire.
The system of anti-torpedo bulkheads was first implemented in the French Navy on the experimental battleship "Henri IV", built according to the design of E. Bertin. The essence of the idea was to smoothly round the bevels of the two armored decks down, parallel to the board and at some distance from it. Bertin's design did not go to war, and it was probably for the best - a caisson built according to this scheme, imitating the "Henri" compartment, was destroyed during testing by an explosion of a torpedo charge attached to the skin.
In a simplified form, this approach was implemented on the Russian battleship "Tsesarevich", built in France and according to the French project, as well as on the EDR of the "Borodino" type, which copied the same project. The ships received as anti-torpedo protection a longitudinal armored bulkhead 102 mm thick, which was 2m away from the outer skin. This did not help the Tsarevich too much - having received a Japanese torpedo during the Japanese attack on Port Arthur, the ship spent several months under repair.
The British navy relied on coal pits until roughly until the construction of the Dreadnought. However, an attempt to test this protection in 1904 ended in failure. The ancient armored battering ram "Belile" acted as a "guinea pig". Outside, a cofferdam with a width of 0.6 m, filled with cellulose, was attached to its body, and six longitudinal bulkheads were erected between the outer skin and the boiler room, the space between which was filled with coal. The explosion of a 457-mm torpedo made a hole of 2.5x3.5 m in this structure, demolished the cofferdam, destroyed all bulkheads except the last one, and puffed up the deck. As a result, the "Dreadnought" received armor screens that covered the cellars of the towers, and subsequent battleships were built with full-size longitudinal bulkheads along the length of the hull - the design idea came to a single decision.
Gradually, the design of the PTZ became more complicated, and its dimensions increased. Combat experience has shown that the main thing in constructive protection is depth, that is, the distance from the explosion site to the ship's entrails covered by the protection. A single bulkhead was replaced by intricate designs that consisted of several compartments. To push the "epicenter" of the explosion as far as possible, boules were widely used - longitudinal attachments mounted on the hull below the waterline.
One of the most powerful is the PTZ of the French battleships of the "Richelieu" class, which consisted of an anti-torpedo and several dividing bulkheads that formed four rows of protective compartments. The outer one, which had an almost 2-meter width, was filled with foam rubber filler. This was followed by a row of empty compartments, followed by fuel tanks, then another row of empty compartments designed to collect the fuel spilled during the explosion. Only after that, the blast wave had to stumble upon the anti-torpedo bulkhead, after which another row of empty compartments followed - in order to certainly catch everything that had leaked. On the Jean Bar battleship of the same type, the PTZ was reinforced with boules, as a result of which its total depth reached 9.45 m.
On the American battleships of the North Caroline class, the PTZ system was formed by a boule and five bulkheads - though not of armor, but of ordinary shipbuilding steel. The boule cavity and the compartment following it were empty, the next two compartments were filled with fuel or seawater. The last, inner, compartment was empty again.
In addition to protecting against underwater explosions, numerous compartments could be used to level the bank, flooding them as needed.
Needless to say, such a waste of space and displacement was a luxury allowed only on the largest ships. The next series of American battleships (South Dacota) received a boiler-turbine installation of different dimensions - shorter and wider. And it was no longer possible to increase the width of the hull - otherwise the ships would not have passed through the Panama Canal. The result was a decrease in the PTZ depth.
Despite all the tricks, the defense lagged behind the weapons all the time. The PTZ of the same American battleships was designed for a torpedo with a 317-kilogram charge, but after their construction, the Japanese had torpedoes with charges of 400 kg TNT and more. As a result, the commander of the North Caroline, which was hit by a Japanese 533-mm torpedo in the fall of 1942, honestly wrote in his report that he never considered the ship's underwater protection adequate to a modern torpedo. However, the damaged battleship then remained afloat.
Do not let you reach the goal
The advent of nuclear weapons and guided missiles has radically changed the views on weapons and defense of the warship. The fleet parted with multi-turreted battleships. On the new ships, the place of gun turrets and armored belts was taken by missile systems and radars. The main thing was not to withstand the hit of the enemy shell, but simply to prevent it.
Similarly, the approach to anti-torpedo protection changed - the bullets with bulkheads, although they did not disappear completely, clearly receded into the background. The task of today's PTZ is to shoot down the right course torpedo, confusing its homing system, or simply destroy it on the way to the target.
The "gentleman's set" of modern PTZ includes several generally accepted devices. The most important of them are hydroacoustic countermeasures, both towed and fired. A device floating in water creates an acoustic field, in other words, it makes noise. The noise from the GPA means can confuse the homing system, either imitating the noises of the ship (much louder than itself), or "hammering" enemy hydroacoustics with interference. Thus, the American system AN / SLQ-25 "Nixie" includes torpedo diverters towed at a speed of up to 25 knots and six-barreled launchers for firing by means of GPE. This is accompanied by automation that determines the parameters of attacking torpedoes, signal generators, own sonar systems and much more.
In recent years, there have been reports of the development of the AN / WSQ-11 system, which should provide not only the suppression of homing devices, but also the defeat of anti-torpedoes at a distance of 100 to 2000 m). A small counter-torpedo (caliber 152 mm, length 2, 7 m, weight 90 kg, cruising range 2-3 km) is equipped with a steam turbine power plant.
Tests of prototypes have been carried out since 2004, and they are expected to be put into service in 2012. There is also information about the development of a supercavitating anti-torpedo capable of reaching speeds of up to 200 knots, similar to the Russian "Shkval", but there is practically nothing to tell about it - everything is carefully covered by a veil of secrecy.
Developments in other countries look similar. French and Italian aircraft carriers are equipped with the joint development of the SLAT PTZ system. The main element of the system is a towed antenna, which includes 42 radiating elements and 12-pipe devices mounted on board for firing self-propelled or drifting vehicles of the GPD "Spartakus". It is also known about the development of an active system that fires anti-torpedoes.
It is noteworthy that in the series of reports on various developments, no information has yet appeared about something that could knock off the course of a torpedo following the wake of the ship.
The Russian fleet is currently armed with the Udav-1M and Packet-E / NK anti-torpedo systems. The first of them is designed to defeat or deflect torpedoes attacking the ship. The complex can fire projectiles of two types. The 111CO2 diverter projectile is designed to divert the torpedo from the target.
The 111SZG defensive depth shells allow you to form a kind of minefield in the path of the attacking torpedo. In this case, the probability of hitting a straight-forward torpedo with one salvo is 90%, and a homing one - about 76. The "Package" complex is designed to destroy torpedoes attacking a surface ship with counter-torpedoes. Open sources say that its use reduces the likelihood of hitting a ship by a torpedo by about 3–3, 5 times, but it seems likely that this figure has not been tested in combat conditions, like everyone else.
