Depth charges of the Second World War. Depth charges: history, description of weapons and principles of their operation
The appearance of the first depth charges is closely related to the commissioning of submarines by the world's leading armies. Submarines could move secretly underwater and in the first years of use caused serious harm to their enemy's forces.
To counter carefully camouflaged submarine forces, depth charges began to appear in fleets. At first they were primitive, freely diving into the depths and exploding there in the event of contact with a submarine. But later, technology was constantly improved, turning into a truly effective weapon that the submarine fleet was forced to reckon with.
History of creation
Submarines were most widely used in the fighting of the First World War. The superiority of the German submarine fleet was serious, so the Allies had obvious problems stopping Germany's unchallenged dominance under the sea.
Various means were used to fight. The first to use “diving” shells were fired from naval guns in the direction of enemy submarines. They were equipped with a flat fairing (which prevented them from ricocheting off the surface of the water) and a fuse that operated with some delay. Such shells went to a depth of 10-15 meters and detonated there.
The military received orders to immediately shoot in the direction of the discovered periscope or visible part of the submarine. But in fact, the diving shells had a low weight warhead, which could not cause significant damage to the submarine. The effect was achieved only with an accurate hit and preferably multiple times. Therefore, a more effective and simpler weapon was found quite quickly. These were the first generations of depth charges, which first entered service with the British Navy in 1914.
At first, this type of weapon resembled the shape of an ordinary barrel with a warhead inside.
They were not very accurate, so it was only possible to really hit an underwater object with a massive attack.
Due to their low efficiency, depth charges were constantly improved. A special qualitative leap was required after the Second World War, when submarines became a strategic fleet, receiving nuclear warheads. This led to the need for a weapon that could accurately hit a submarine even underwater.
The most modern models can be delivered to the location of an enemy submarine by airplanes, helicopters, speedboats or torpedoes. For some of them, high accuracy does not matter, because they can carry a nuclear warhead that can cause significant damage even at a distance of several thousand meters under water, not to mention detonation in close proximity.
Operating principle and types of depth charges
A depth charge operates on the principle of water hammer. An explosion underwater has more serious consequences than an explosion in the open air. The fact is that a shock wave in the atmosphere quickly fades, and the same wave in water propagates over long distances. If the charge is significant, then a direct hit is not even necessary to guarantee destruction of an underwater target.
The design of all depth charges is extremely simple.
They have a warhead and a fuse. Modern analogues often have their own delivery vehicles (torpedo), as well as guidance systems.
But both the first and the last models differ in the way they operate:
- contact fuses;
- proximity fuses;
- with specified response parameters.
A contact fuse reacts to direct damage to the enemy. Non-contact can be triggered by vibration of boat propellers.
Fuses were also used that detonated a warhead at a certain depth under pressure or after a given time. Modern types can have several methods of detonation, which, of course, increases their efficiency and versatility.
The evolution of depth charges in the USSR and Russia
The first depth charges in the USSR began to be produced in the 30s of the 20th century. The pioneer was the BB-1 (Bolshoi Bomb, first model), which had the simplest operating principle: it was dropped from the ship when the acoustics detected the presence of a submarine nearby.
Structurally, the BB-1 consisted of a cylindrical body (all foreign analogues of that time had the same shape), a fuse and a warhead inside.
Inside, BB-1 was filled with TNT (135 kg), and the total weight was 165 kg. A time fuse was installed in the upper part, which was triggered at a depth of up to 100 meters (and was not very reliable).
Of course, BB-1 had a lot of disadvantages:
- After each explosion (not necessarily a successful one), acoustic contact was lost for a long time, and the enemy submarine could leave the affected area.
- Already during the Second World War, submarines could easily dive to 200 meters or even more, and the limit for the BB-1 was only 100 meters, after which detonation occurred.
- Even primitive stabilizers were not used on the hull, and the shape did not allow one to count on the accuracy of the hit, since the BB-1, falling into the currents of the ship’s wake, spun and strayed from a straight trajectory.
- The non-streamlined shape of the hull also did not allow for rapid immersion. BB-1 sank to the bottom at a speed of 2-2.5 m/s. That is, there was a margin of 40 seconds left to hit the target at a depth of 100 meters, which naturally reduced the chances of a hit.
Due to this low efficiency, the BB-1 was rarely used. During the Great Patriotic War, preference was often even given to those depth charges that were supplied under Lend-Lease terms and had better characteristics. To increase the effectiveness of the BB-1, in the 40s they began to use not a conventional ramp for freely dropping bombs, but a mortar or bomb launcher (BMB-1), which was specially designed for the size of the BB-1 and made it possible to increase the drop area. They also began to use a new fuse, which ignited the gunpowder when it reached a depth of 210 meters.
At the same time as the BB-1, the BM-1 (Small Bomb), a similar design, was in service, which was only inferior in size and lethality (the weight of the charge was only 25 kg). It was practically useless to use it in battle, since it could not cause serious damage. But it also found its use: it was used for mine clearance after the war, since when it exploded, it detonated enemy mines.
The next step for the Soviet Union was the development of a new bomb launcher and ammunition for it. They were RBM bombs, which were based on the BM-1, but received a tail fin, a solid-fuel jet engine and a streamlined nose. There was more explosive material (32 kg), and the acceleration of the dive reached 6-8 m/s, which increased the chances of blowing up the enemy.
In 1949, a new bomb launcher was developed, which largely duplicated the achievements of its English counterparts.
This time, the effectiveness of the work depended on the number of bombs dropped. The launcher consisted of 24 rods with a given release vector.
The B-30 shells had only a 13-kilogram warhead, but were configured in such a way that, in addition to reacting to contact with a solid object, they detonated from the explosion of other depth charges. Thus, a huge area under water was covered, which reduced the enemy’s chances of leaving the affected area. Later, the system was improved mainly by improving the characteristics of the bombs used.
In 1957, the Smerch system with RSL-25 bombs began to be installed on ships of the Soviet fleet. They had a jet engine, stabilizers and fairings to reach depth as quickly as possible. The first generation allowed the bomb to sink at a speed of 11 m/s and move away from the empty site to 500-2500 meters, and explode there.
The next generation, RSL-60, already received less warhead, but could reach a distance of up to 5800 meters from the ship and up to 450 meters of depth. Later the RSL-10 was adopted. These bombs (one might already say torpedoes) had an even larger charge, but a much shorter operating range: only 1000 meters.
The evolution of depth charges in the USSR
| BB-1 | BM-1 | RSL-12 | BM-30 | RSL-25 | RSL-60 | RSL-10 | |
|---|---|---|---|---|---|---|---|
| Length | 71 cm | 45 cm | 124 cm | 115 cm | 134 cm | 183 cm | 170 cm |
| Diameter | 43 cm | 25 cm | 25 cm | 18 cm | 21 cm | 21 cm | 30 cm |
| Warhead | 135 kg | 25 kg | 32 kg | 13 kg | 25 kg | 23 kg | 80 kg |
| Dive speed | 2-2.5 m/s | 2.5 m/s | 6-8 m/s | 5-6 m/s | 11 m/s | 11 m/s | 11-12 m/s |
| Firing range | 5-20 m | 5-20 m | 1200-1400 m | 200 m | 2500 m | 5800 m | 1000 m |
| Maximum depth | 100 m | 100 m | 330 m | 200 m | 320 m | 450 m | 450 m |
| Fuse | hourly | hydrostat. | hydrostat. | from impact | from impact | from impact | from impact |
Domestic samples were often equal to the indicators issued by foreign analogues. In general, the military industry of states in this component demonstrated amazing unanimity, releasing generations of projects with comparable characteristics. This also applies to the USSR’s eternal rival, the United States, as well as to the pioneers in creating depth charges, the British.
Depth charges have low range, power and accuracy. Unfortunately, this is a given with ease of use. These weapons have become a relic of the past, which were once in great need, but less so today.
Today, the progress of the submarine fleet has made it possible to achieve its own protective mechanisms on each side, the strength of the plating, and the speed of movement.
To counter submarines, it has become much more profitable to order missile systems that include nuclear warheads and detection equipment. Dropping bombs or launching simple torpedoes has become a pointless exercise.
It is probably reckless to say that the time of depth charges has passed. Still, they will remain an additional protective tool for each ship. But such weapons are not suitable for strategic warfare, and therefore are absolutely rightly considered obsolete.
Video
Ship depth charges and bomb launchers
Depth charges continued to be the main means of destroying submarines in a submerged position during the Second World War. Under Lend-Lease, at least five types of conventional (as opposed to those used for multi-barrel bomb launchers) depth charges were serially supplied to the USSR.
From the analysis of the table it is clear that imported samples of depth charges were significantly superior in their characteristics to domestic bombs BB-1 and BM-1, which were put into service back in 1933. The characteristics of the Allied bomb weapons improved during the war, while our bombs did not modernized. In particular, the increase in the maximum diving depth of enemy submarines to 200-220 m by the end of the war made them completely ineffective. At the same time, it should be noted that a number of even more advanced models of Allied bombs were not supplied to the USSR. For example, in England, since the end of 1940, a “heavy” Mk VII bomb was used with a immersion speed of 5.1 m/s and an effective explosion radius of 7.9 m1. In the USA in 1943-1944. depth charges Mk 8 with magnetic and Mk 14 with acoustic fuses were developed. In the spring of 1943, the Mk 9 depth charge was put into service, in which, by reducing the weight to 154 kg (the weight of the explosive is 91 kg of torpex), giving it a teardrop shape, a special stabilizer and cargo, it was possible to increase the immersion speed initially to 4.4 m/ s, and then up to 6.9 m/s2. The domestic analogue - a bomb with an increased dive speed "BPS" (weight - 138 kg, explosive weight - 96 kg, dive speed - 4.2 m/s) - entered service with the Soviet fleet only in 1950.
The most effective way to use depth charges in the British fleet was initially considered to be an attack by a single ship, according to the GAS. Having established the course, speed and approximate diving depth of the submarine (it was determined based on the distance at which contact was lost due to the fact that the target was under the sonar beam), the ship passed over it on a catching course, after which it took a lead corresponding to the diving time of the deep bombs and the speed of the submarine, and dropped a series of bombs. Depending on the type and armament of the ship, at the beginning of World War II it consisted of no more than 3-7 depth charges. Already in 1940, it became clear that in order to reliably destroy a submarine, it was necessary to simultaneously drop at least 10 Mk VII depth charges, according to which by the middle of the war, most anti-submarine ships were able to drop 10-14 bomb series.
Subsequently, a method was developed that was called the “sneaking attack.” It consisted of the interaction of two anti-submarine ships, one of which maintained hydroacoustic contact with the submarine and directed the second ship, which carried out an attack using stern bomb releasers and on-board bomb throwers.
In the Soviet Navy (Northern Fleet), the first cases of using imported depth charges dated back to the end of 1941, but they began to be used regularly only in 1944-1945. The total deliveries of imported depth charges were: 7093 conventional and 1426 for multi-barrel bomb launchers from the UK, as well as 9198 and 20630, respectively, from the USA. The “Final Report on the Combat Activities of the Northern Fleet during the Great Patriotic War” noted that imported bombs were first used without descriptions and without equipment for checking fuses, which arrived very late. This, as well as the insufficient mastery of foreign equipment by personnel, led to the fact that in the first months of use, Lend-Lease bombs gave up to 50-60% failures. Subsequently, with the elimination of the above shortcomings, failure rates were reduced to 1-3%.
To increase the area of destruction, on-board bomb launchers were used, firing at the beam of the anti-submarine ship. Together with the Allied ships, two types of onboard single-barrel bomb launchers were supplied to the armament of our fleet: the English rod-mounted Mk II (on the “Daring” type EM) and the American rodless Mk 6 (also called the “K” gun”; installed on frigates, minesweepers “AM” and big hunters "BO-1"). Imported bomb launchers could throw British Mk VII bombs at distances of 37 and 62 m, respectively. According to technical specifications, they roughly corresponded to the Soviet BMB-1 rod bomb launcher. throwing BB-1 bombs at 40-110 m. At the same time, the reporting documents noted that the presence of rods, with which there was no centralized supply to the warring fleets, significantly complicated the use of bomb throwers. In this situation, the Northern Fleet command had to organize the production of wooden rods using local industry8. The reports noted that rodless bomb throwers are somewhat more complex in their design, but much simpler to use, however, due to the limited supply of imported depth charges, all Lend-Lease ships must be re-equipped with domestic bomb throwers." The first domestic rodless bomb launcher, VMB-2, was put into service in 1951, when this type of weapon was already obsolete.
Table 1. Basic tactical and technical data of depth charges used by the USSR Navy in 1941-1945.
Bomb type Bomb weight, Explosive weight, Explosive type Effective speed depth
(country) kg kg explosion radius, m** immersion, m/s immersion, m
MkVII (B Br) 185 136 minol 6.1 2.1-3 to 305
MkVIII,XI (B Br) 113 77 torpex approx. 4 approx. 3* 7.6*
Mk 6(SSA) 191 136 TNT 6.4 2.4-3.7 183
Mk 7 (USA) 348 272 TNT 8.8-10.7 2.7-4 183
BB-1 (USSR) 165 135 TNT approx. 5 2.3-2.5 up to 100
BM-1 (USSR) 41 25 TNT approx. 1.2 2.1-2.3 up to 100
* English depth charges Mk VIII, XI were created for use from aircraft, but in the USSR Navy they were used from surface ships (features of combat use were not found in archival materials). The bombs were equipped with a hydrostatic fuse with an explosion depth set at 7.6 m - against submarines on the surface or making an urgent dive.
** The radius of a bomb explosion, at which a 22 mm german casing is penetrated. VIIC series submarines.
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The W-7 nuclear charge was used not only in the Mk.7 aerial bomb, but also in the first atomic depth charge, the Mk.90 “Betty”. By the end of World War II, anti-submarine aircraft literally drove submarines under water, but with the advent of nuclear submarines (1954 in the USA, 1958 in the USSR), the fight against them again became a serious problem. The high underwater speed allowed the nuclear submarine to escape the attack during the time between its detection and the start of depth-bombing. In the early 1950s, during a period of general military fascination with the capabilities of nuclear weapons, the atomic depth charge seemed to be the best solution to the problem. Tests in 1946 on the Bikini Atoll showed that the shock wave of an underwater nuclear explosion with a power of about 20 kt destroys the durable hull of a submarine even at a distance of several hundred meters. A nuclear submarine in itself is such a formidable weapon that the use of an atomic bomb against it is completely justified.
However, the use of atomic depth charges is associated with serious problems. First: due to the large radius of destruction of an underwater nuclear explosion, the use of free-falling depth charges is possible only from aircraft, but not from ships. Second: radioactive contamination that persists for a long time after the explosion, dangerous for surface ships. Third: a disruption in the hydrology of the sea due to an explosion blinds the hydroacoustic instruments of anti-aircraft ships for a long time, reaching several hours. But the most important problem lies in the very use of nuclear weapons to solve such a narrow tactical problem as the destruction of a submarine. Unlike other types of nuclear weapons, even tactical ones, an atomic depth charge is precisely a weapon, but not a means of deterring a potential enemy.
In the armed forces of all nuclear powers, the decision to use atomic weapons is made at the highest military-political level. Under these conditions, the fleet, which has based its anti-submarine defense on nuclear weapons until their use is authorized, risks remaining unarmed. If the right to use nuclear weapons is delegated to a lower level, for example, to the commanders of fleets or naval formations, this could lead to a dangerous lowering of the threshold for the outbreak of a nuclear war. Therefore, at present, in the fleets of all nuclear powers, atomic depth charges have been replaced by precision-guided weapons. However, awareness of these problems came later, after the Cuban missile crisis; in the 1950s, we repeat, the nuclear depth charge was considered the best means of combating nuclear submarines.
Preliminary studies of the use of nuclear weapons in anti-submarine defense have been carried out since 1950 by the Massachusetts Institute of Technology (MIT). It was found that the best way to achieve this goal was an atomic depth charge of low power, detonated by a hydrostatic fuse at a fixed depth of about 300 m. On April 14, 1952, the development of such a bomb was entrusted to the Los Alamos Laboratory (nuclear charge W-7) and the Military Laboratory -Naval Weapons in Silver Springs, Maryland (robust bomb casing and detonation system). Serial production of the world's first atomic depth charge, designated Mk.90 "Betty", began in June 1955. A total of about 225 such bombs were produced.
The Mk.90 bomb included: a Mk.1 Mod.0 body, a Mk.7 Mod.1 nuclear charge, a Mk.19 Mod.0 suspension device and a Mk.22 Mod.0 parachute system. The total mass of the bomb was 1120-1140 kg, including 565 kg - the mass of a durable steel body and hydrodynamic tail. The body had a length of 3175 mm and a diameter of 795 mm. A parachute with a diameter of 5 m ensured a smooth splashdown of the bomb directly below the release point. The last requirement follows from the method of behavior of the carrier aircraft but the detected submarine. The carriers of the Mk.90 atomic depth charge were the Grumman S2F Tracker carrier-based anti-submarine aircraft and the Martin P5M Merlin flying boat. In addition, during the testing period, it was suspended under the Grumman F7F-3 Tigercat twin-engine multi-role aircraft. The Betty nuclear charge had excess power for a depth charge, and in 1960 it was replaced by the lighter Mk.101 Lulu bomb with a new generation small-sized nuclear charge.
American WWII depth charge Mark IX
Depth charge- one of the types of weapons of the Navy, designed to combat submerged submarines.
A depth charge is a projectile with a strong explosive or atomic charge enclosed in a metal casing of cylindrical, spherocylindrical, drop-shaped or other shape. The explosion of a depth charge destroys the hull of a submarine and leads to its destruction or damage. The explosion is caused by a fuse, which can be triggered: when a bomb hits the hull of a submarine; at a given depth; when a bomb passes at a distance from a submarine not exceeding the radius of action of a proximity fuse. A stable position of a spherocylindrical and drop-shaped depth charge when moving along a trajectory is given by the tail unit - the stabilizer. They are divided into aviation and ship; the latter are used by launching jet depth charges from launchers, firing from single-barrel or multi-barrel bomb launchers, and dropping them from stern bomb releasers.
The first sample of a depth charge was created in 1914 and, after testing, entered service with the British Navy. Depth charges found widespread use in World War I and remained the most important type of anti-submarine weapon in World War II from 1939-1945. Nuclear depth charges were withdrawn from service in the 90s. Nowadays, depth charges are being intensively replaced by more accurate weapons (for example, the Torpedo Missile).
The PLAB-250-120 anti-submarine bomb is currently in service with the Russian Navy aviation. The weight of the bomb is 123 kg, of which the explosive weight is about 60 kg. Bomb length - 1500 mm, diameter - 240 mm.
Operating principle
Based on the practical incompressibility of water. A bomb explosion destroys or damages the hull of a submarine at depth. In this case, the energy of the explosion, instantly increasing to a maximum in the center, is transferred to the target by the surrounding water masses, through them destructively affecting the attacked military object. Due to the high density of the medium, the blast wave along its path does not significantly lose its initial power, but with increasing distance to the target, the energy is distributed over a larger area, and accordingly, the damage radius is limited.
The fuse is triggered when it hits the hull of the boat, at a certain depth, or when passing next to the hull.
Typically, depth charges are rolled from the stern of the ship or fired from a bomb launcher. Depth charges can also be dropped from aircraft, airplanes, helicopters, or delivered to the location where a submarine is detected using missiles.
Depth charges are characterized by their low accuracy - sometimes about a hundred bombs are required to destroy a submarine.
Notes
Literature
- Kvitnitsky A. A. Fighting submarines (according to foreign data), M., 1963;
- Shmakov N. A. Fundamentals of naval affairs, M., 1947. p. 155-57.
Enclosed in a metal case of cylindrical, spherocylindrical, drop-shaped or other shape. The explosion of a depth charge destroys the hull of a submarine and leads to its destruction or damage. The explosion is caused by a fuse, which can be triggered: when a bomb hits the hull of a submarine; at a given depth; when a bomb passes at a distance from a submarine not exceeding the radius of action of a proximity fuse. A stable position of a spherocylindrical and drop-shaped depth charge when moving along a trajectory is given by the tail unit - the stabilizer. They are divided into aviation and ship; the latter are used by launching jet depth charges from launchers, firing from single-barrel or multi-barrel bomb launchers, and dropping them from stern bomb releasers.
The first sample of a depth charge was created in 1914 and, after testing, entered service with the British Navy. Depth charges found widespread use in World War I and remained the most important type of anti-submarine weapon in World War II from 1939-1945. Nuclear depth charges were withdrawn from service in the 90s. Nowadays, depth charges are being intensively replaced by more accurate weapons (for example, the Torpedo Missile).
The PLAB-250-120 anti-submarine bomb is currently in service with the Russian Navy aviation. The weight of the bomb is 123 kg, of which the explosive weight is about 60 kg. Bomb length - 1500 mm, diameter - 240 mm.
Operating principle
Based on the practical incompressibility of water. A bomb explosion destroys or damages the hull of a submarine at depth. In this case, the energy of the explosion, instantly increasing to a maximum in the center, is transferred to the target by the surrounding water masses, through them destructively affecting the attacked military object. Due to the high density of the medium, the blast wave along its path does not significantly lose its initial power, but with increasing distance to the target, the energy is distributed over a larger area, and accordingly, the damage radius is limited.
The fuse is triggered when it hits the hull of the boat, at a certain depth, or when passing next to the hull.
Typically, depth charges are rolled from the stern of the ship or fired from a bomb launcher. Depth charges can also be dropped from aircraft (airplanes, helicopters) and delivered to the location where the submarine is detected using missiles.
Depth charges are characterized by their low accuracy - sometimes about a hundred bombs are required to destroy a submarine.
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Notes
Literature
- Kvitnitsky A. A. Fighting submarines (according to foreign data), M., 1963;
- Shmakov N. A. Fundamentals of naval affairs, M., 1947. p. 155-57.
Excerpt characterizing Depth Charge
“To resist the evil that reigns in the world...” Pierre repeated, and he imagined his future activities in this field. He imagined the same people as he himself was two weeks ago, and he mentally addressed them with an instructive and mentoring speech. He imagined vicious and unhappy people whom he helped in word and deed; imagined the oppressors from whom he saved their victims. Of the three goals named by the rhetorician, this last one - the correction of the human race - was especially close to Pierre. Some important sacrament mentioned by the rhetorician, although it incited his curiosity, did not seem significant to him; and the second goal, cleansing and correcting himself, occupied him little, because at that moment he felt with pleasure that he was already completely corrected from his previous vices and ready for only one good thing.Half an hour later, the rhetorician returned to convey to the seeker those seven virtues corresponding to the seven steps of the Temple of Solomon, which every Mason had to cultivate in himself. These virtues were: 1) modesty, respect for the secrets of the order, 2) obedience to the highest ranks of the order, 3) good morals, 4) love of humanity, 5) courage, 6) generosity and 7) love of death.
“Seventhly, try,” said the rhetorician, “by frequently thinking about death to bring yourself to the point that it no longer seems to you a terrible enemy, but a friend... who frees the languishing soul from this miserable life in the works of virtue, to introduce it to a place of reward and reassurance.
“Yes, this must be so,” thought Pierre, when after these words the rhetorician left him again, leaving him to solitary reflection. “This should be so, but I am still so weak that I love my life, the meaning of which is only now gradually revealed to me.” But the other five virtues, which Pierre remembered as he ran through his fingers, he felt in his soul: courage, generosity, kindness, love for humanity, and especially obedience, which did not even seem to him to be a virtue, but happiness. (He was so happy now to get rid of his arbitrariness and subordinate his will to those and those who knew the undoubted truth.) Pierre forgot the seventh virtue and could not remember it.
The third time, the rhetorician returned quickly and asked Pierre if he was still firm in his intentions, and whether he dared to subject himself to everything that was required of him.
“I’m ready for anything,” said Pierre.
“I must also tell you,” said the rhetorician, “that our order teaches its teaching not only in words, but by other means, which, perhaps, have a stronger effect on the true seeker of wisdom and virtue than verbal explanations alone.” This temple, with its decoration, which you see, should have already explained to your heart, if it is sincere, more than words; You will see, perhaps, with your further acceptance, a similar image of explanation. Our Order imitates ancient societies that revealed their teachings in hieroglyphs. A hieroglyph, said the rhetorician, is the name of some thing not subject to feelings, which contains qualities similar to the one depicted.
