Anti-aircraft guns caliber 37 mm were popular not only in the Wehrmacht and Luftwaffe, but also in the Kriegsmarine. However, the German admirals were not satisfied with the ballistic characteristics of anti-aircraft guns developed for the ground forces. The sailors believed that deck 37-mm anti-aircraft guns should have better accuracy and greater firing range.
In the late 1920s, Rheinmetall Borsig AG and Friedrich Krupp AG began developing small-caliber naval rapid-fire cannons capable of solving air defense missions and fighting high-speed torpedo boats. After the creation of a number of experimental artillery systems, the Rheinmetall concern presented the 37-mm universal rapid-fire gun 3, 7 cm SK C / 30. The letters "SK" in the marking of the gun stood for Schiffskanone (German ship gun), and "C" stood for Construktionsjahr (German for the year of creation), indicating the last two digits of the year separated by a fraction. The actual adoption of the naval 37-mm gun took place in the mid-30s, after the Nazis came to power and refused to comply with the terms of the Treaty of Versailles. Thus, the 3, 7 cm SK C / 30 became the first 37-mm anti-aircraft gun, which entered service with the German fleet after the end of the First World War. For this artillery system, a very powerful unitary shot for this caliber with a 381 mm case length was created. The total length of a unitary shot is 516.5 mm. In an extremely long barrel (2960 mm or 83 caliber length), an armor-piercing high-explosive tracer projectile 3, 7 cm Pzgr Patr L'spur Zerl weighing 745 g accelerated to 1000 m / s. Also, the ammunition load included shots with fragmentation-tracer and fragmentation-incendiary-tracer shells. To reduce barrel wear, projectiles with metal-ceramic leading belts were adopted.
In terms of effective fire range and height reach, the 37-mm naval gun significantly surpassed land anti-aircraft guns of the same caliber, but the 37x380R round was not interchangeable with 37-mm anti-tank, anti-aircraft and aircraft guns. According to German data, at a range of 2,000 m, the 3,7 cm SK C / 30 was twice as accurate as the 3,7 cm Flak 18 towed anti-aircraft gun.
The twin anti-aircraft gun 3, 7 cm SK C / 30 paradoxically combined the most advanced design achievements with frankly archaic technical solutions. So, in the mid-30s, the Germans became pioneers, installing a 37-mm marine twin on a platform stabilized in three planes. The twin stabilized anti-aircraft gun received the designation Dopp. LC/30 (German: Doppellafette C / 30 - Two-gun carriage model of the 30th year). With a total mass of 3670 kg, almost 20% of the weight of the installation (630 kg) was the weight of the stabilization actuators, which could compensate for the inclination from the side and pitching of the ship within +/- 19.5 °. Angles of vertical guidance: from -9 ° to + 85 °, and in the horizontal plane, circular fire was provided. The twin guns had a hydraulic recoil mechanism and a spring recoil mechanism. The paired 37-mm anti-aircraft guns initially did not have any armor protection, not counting the 14-20 mm steel "parapets" on cruisers and battleships. However, since 1942, these installations have been equipped with shields of 8 mm armor steel.
Although the 37-mm German naval twin was superior in firing accuracy to all 37-40-mm naval and land anti-aircraft guns existing at that time, it had a semi-automatic vertical sliding wedge bolt with manual loading of each shot. At the same time, the practical rate of fire of the paired anti-aircraft gun directly depended on the level of training of the crew and in most cases did not exceed 60 rds / min, which was almost two times less than that of the land single-barreled anti-aircraft gun 3, 7 cm Flak 18. Despite this, the paired 37 -mm installation was produced in a large series, became widespread in the German fleet and was used on most of the German warships of the destroyer class and above. Destroyers carried 2 such systems, light cruisers had 4 twin systems, heavy cruisers had 6, battleships housed 8 paired installations. Very often they were placed on large mobilized ships of the merchant fleet, which were involved in military transport. Production of the 3, 7 cm SK C / 30 ended in 1942, with a total of about 1,600 single and twin guns produced.
After the outbreak of hostilities, it turned out that with strong waves and splashing, the stabilization system often fails due to the ingress of sea water into the electrical circuits. In addition, during intensive maneuvering of destroyers attacked by enemy aircraft, weak electric drives did not always have time to compensate for angular accelerations. Numerous failures in the operation of the stabilization system and the low combat rate of fire became the reasons that the Germans in 1943 began replacing semi-automatic guns 3, 7 cm SK C / 30 37-mm single and twin anti-aircraft guns 3, 7 cm Flak M42 and 3, 7 cm Flak M42. These automatic cannons were created by Rheinmetall for the needs of Kringsmarine on the basis of the artillery unit of the 3, 7 cm Flak 36 anti-aircraft machine gun.
After the dismantling of the unnecessary stabilization system, the freed anti-aircraft installations strengthened the air defense of naval bases and ports. Due to the lack of wheeled carriages, the rather heavy Dopp. LC/30 twin pairs were placed in stationary positions, and they were also used to arm railway anti-aircraft batteries.
On various auxiliary vessels of small displacement, single 37-mm semi-automatic guns Einh. LC/34 (Einheitslafette C / 34 - Single-gun carriage, model 34) were installed with vertical guidance angles: -10 … + 80 °. The horizontal guidance of the gun was carried out due to its free rotation in the horizontal plane using the shoulder rest.
For vertical guidance, there was a gear lifting mechanism. The mass of a single installation did not exceed 2000 kg. Since 1942, an armored shield has been used to protect the crew from bullets and shrapnel.
In 1939, the Ubts. LC/39 single-barreled 37-mm universal artillery system with a 3, 7 cm SK C / 30U cannon, intended for arming submarines, was adopted. The weight of this installation was reduced to 1400 kg, and the maximum vertical guidance angle was increased to 90 °. In addition, corrosion resistant alloys were used in the construction of Ubts. LC/39. Although the combat rate of fire of the semi-automatic gun did not exceed 30 rds / min, it was more reliable and compact than the anti-aircraft guns used on land and could be brought into a firing position more quickly. Conceptually, the German 37-mm universal artillery mount was close to the Soviet 45-mm semi-automatic 21-K universal gun, but had better ballistics and rate of fire.
Beginning in 1943, a significant number of Einh. LC/34 and Ubts. LC/39 installations were transferred to air defense units and placed in the fortifications of the Atlantic Wall. Although by 1945 single and twin semi-automatic 37-mm universal guns were considered obsolete, their operation continued until the end of hostilities.
In addition to 37-mm anti-aircraft guns produced at their own enterprises, the armed forces of Nazi Germany had many captured guns of the same caliber. First of all, mention should be made of the 1939 Soviet 37mm automatic anti-aircraft gun, also known as the 61-K.
After the plant named after. Kalinin No. 8 in Podlipki near Moscow, in the first half of the 30s, failed the development of serial production of a 37-mm anti-aircraft machine gun, the documentation and semi-finished products for which were received from the Rheinmetall company, in the USSR in 1939 they adopted a 37-mm copy of a 40-mm automatic anti-aircraft gun Bofors L60. In terms of its characteristics, the Soviet 37-mm anti-aircraft machine gun was close to the Swiss prototype. The mass of 61-K in a combat position without a shield was 2100 kg, the combat rate of fire was up to 120 rds / min. Vertical guidance angles: from -5 to + 85 °. Loading was carried out with clips of 5 shots, the weight of the clip with cartridges was more than 8 kg. A fragmentation tracer grenade weighing 732 g had an initial speed of 880 m / s, and a tabular range of up to 4000 m. A solid armor-piercing tracer projectile weighing 770 g with an initial speed of 870 m / s, at a distance of 500 m along the normal could penetrate 45 mm armor … Compared to the German 37-mm anti-aircraft gun 3, 7 cm Flak 36, the Soviet 37-mm automatic anti-aircraft gun of the 1939 model had a slight advantage in ballistic characteristics. The combat rate of fire of 3, 7 cm Flak 36 and 61-K was approximately the same. The German anti-aircraft gun had a more compact and convenient two-axle carriage, which could be towed at a higher speed.
From 1939 to 1945, more than 12,000 37-mm 61-K guns were delivered to the anti-aircraft units of the Red Army. As of June 22, 1941, the troops had about 1200 anti-aircraft guns. During the fighting, the Germans managed to capture up to 600 Soviet 37-mm anti-aircraft guns, which were adopted by the Wehrmacht under the designation 3, 7 cm Flak 39 (r).
However, in the second half of the war, the Germans experienced a serious shortage of ammunition for captured Soviet 37-mm anti-aircraft guns, which limited their use for their intended purpose. In this regard, in 1944, most of the captured 61-K anti-aircraft guns were used as anti-tank guns in fortified areas.
After Italy's withdrawal from the war in September 1944, more than 100 37 mm 37 mm / 54 Breda Mod anti-aircraft guns became trophies of the German troops. 1932/1938/1939, which received the designation from the Germans 3, 7 cm Flak Breda (i).
The 37-mm anti-aircraft machine gun was created by Breda by scaling the 13.2-mm Hotchkiss M1930 machine gun, commissioned by the Italian Navy to replace the outdated British 40-mm sea anti-aircraft gun QF 2 pounder Mark II. For the new naval rapid-fire cannon, 37x232mm SR ammunition was adopted. Loading was carried out from box magazines for six rounds. The rate of fire of the artillery machine gun could be adjusted from 60 to 120 rds / min. A high-explosive fragmentation projectile weighing 820 g left the barrel with an initial speed of about 800 m / s. The firing range at air targets is up to 4000 m. The marine twin installation Breda 37/54 mod 1932 on a stationary pedestal weighed about 4 tons.
Although the paired 37-mm anti-aircraft guns "Breda" arr. 1932 and 1938 could fire more than 160 shells per minute, they had an increased vibration when fired in bursts, which significantly reduced their accuracy. In this regard, in 1939, the 37 mm / 54 Breda mod. 1939 with the supply of shells from the left. The gun was originally produced in a stationary version on a tubular carriage, designed to be placed on the deck of a ship or in stationary positions.
In 1942, 37-mm anti-aircraft guns went into series on the original single-axle wheeled carriage and carts borrowed from captured 40-mm Bofors. The mass of the anti-aircraft gun in a combat position on a two-axle gun carriage was 1480 kg, on a Bofors wagon - 1970 kg. Vertical guidance angles - from -10 / +80 degrees.
Talking about the small-caliber anti-aircraft guns used by the Germans during the war, it is impossible not to mention the truly "international" model - the 40-mm Bofors L60 assault rifle. A number of sources claim that its design began during the First World War. In 1918, specialists from the Friedrich Krupp AG concern worked on a prototype of a rapid-firing anti-aircraft gun with automatic equipment based on the use of a barrel recoil with a short recoil. Due to the restrictions imposed by the Versailles Treaty on Germany, the existing developments on the anti-aircraft machine gun were allegedly transferred to the Swedish company AB Bofors, which in turn brought the gun to the required level of reliability and offered it to potential buyers in 1932. Initially, the Swedish Navy became interested in 40-mm assault rifles, but the 40-mm Bofors were competing with 20-mm and 25-mm anti-aircraft guns. As is often the case, recognition at home took place much later than abroad. The first customer of the L60 anti-aircraft guns in 1932 was the Dutch fleet, which installed 5 paired 40mm installations on the light cruiser De Ruyter. The anti-aircraft guns were mounted on a stabilized installation developed by the Dutch company Hazemeyer.
In 1935, a land version of this gun appeared. It was mounted on a two-axle towed wagon, which, when transferred to a firing position, was hung out on jacks. In case of urgent need, the shooting could be carried out directly "from the wheels", without additional procedures, but with less accuracy. The mass of the anti-aircraft gun in a combat position is about 2400 kg. Vertical guidance angles: from -5 ° to + 90 °. Rate of fire: from 120 to 140 rds / min. Combat rate of fire - about 60 rds / min. Calculation: 5-6 people. The anti-aircraft gun was loaded from a vertically inserted clip for 4 rounds.
For the anti-aircraft gun created in Sweden, a 40x311R shot with various types of shells was adopted. The main one was considered a fragmentation-tracer 900 g projectile, equipped with 60 g of TNT, leaving the barrel at a speed of 850 m / s. A solid 40-mm armor-piercing tracer projectile weighing 890 g, with an initial speed of 870 m / s, at a distance of 500 m could penetrate 50 mm armor. In terms of effective shot range and projectile weight, the Bofors L60 anti-aircraft gun was slightly superior to the German and Soviet 37-mm machine guns 3, 7 cm Flak 36 and 61-K, had approximately the same combat rate of fire, but was heavier.
In the second half of the 30s towed and naval 40-mm anti-aircraft guns of the "Bofors" company were popular with foreign customers. In Europe, before the start of World War II, they were purchased or licensed for serial production: Austria, Belgium, Great Britain, Hungary, Greece, Denmark, Italy, the Netherlands, Norway and Poland, Finland, France and Yugoslavia.
The Wehrmacht became the owner of the 40-mm "Bofors" in 1938, when, as a result of the Anschluss, 60 anti-aircraft guns of the Austrian army got. In Germany, these anti-aircraft guns were designated as 4, 0 cm Flak 28. After the occupation of Belgium, Holland, Greece, Denmark, Norway, Poland, France and Yugoslavia, about 400 Bofors L60 anti-aircraft guns were at the disposal of the German army. Moreover, after the German occupation, serial production of 40-mm anti-aircraft guns continued at the following factories: Österreichinschen Staatsfabrik - in Austria, Hazemeyer B. V - in the Netherlands, Waffenfabrik Kongsberg - in Norway. The Hungarian metallurgical and machine-building consortium MÁVAG delivered about 1,300 40-mm Bofors by December 1944. With a rather high rate of production of anti-aircraft guns in comparison with other European countries, Hungarian engineers made many useful innovations, in particular, they developed and introduced into production a new drive for the rotary device of the rotating part of the installation, which made it possible to reduce the guidance time in the horizontal plane. The peak of production of "Bofors" at the enterprises controlled by the Germans fell on March-April 1944, when up to 50 anti-aircraft guns per month were handed over to the customer.
In total, the Wehrmacht and Kringsmarine had more than 2,000 captured and new 40-mm anti-aircraft guns, about 300 Bofors were in the anti-aircraft units of the Luftwaffe. The production of ammunition for them was established at the Renmetall factories. I must say that the Bofors L60 anti-aircraft guns, produced in different countries, were unified in terms of ammunition, but often, due to local design features and differences in manufacturing technology, they had non-interchangeable units and parts. At the first stage, the German command solved this problem by deploying 40-mm anti-aircraft guns in the occupied countries where they were produced, which made it possible to repair and service the guns at local enterprises.
However, as the situation on the fronts worsened, in connection with the need to compensate for the losses incurred, the Bofors anti-aircraft batteries were transferred from positions in the rear closer to the front line, which of course made it difficult to operate and reduced combat readiness. At the final stage of the war, "Bofors", like other anti-aircraft guns, very often fired at ground targets.
A relatively little-known example is the 50-mm automatic anti-aircraft gun 5, 0 cm Flak 41 (Flugabwehrkanone 41). The development of this weapon began in the mid-30s, when the military noticed that between 20-37-mm machine guns and 75-88-mm semi-automatic guns at altitudes from 2000 to 3500 m there is a gap at which rapid-fire small-caliber machine guns are no longer so effective, and for heavy anti-aircraft guns with remote fuses, this height is still small. To solve the problem, it seemed justified to create anti-aircraft guns of some intermediate caliber, and the designers of the Rheinmetall Borsig AG concern opted for a 50-mm 50x345B round.
Tests of the prototype 50-mm anti-aircraft gun began in 1936, and five years later the gun was adopted. 5, 0 cm Flak 41 guns entered the anti-aircraft battalions of the Luftwaffe, which protected important strategic targets.
The operation of the 5, 0 cm Flak 41 automation was based on a mixed principle. Unlocking the bore, extracting the liner, throwing the bolt back and compressing the spring of the bolt knob were due to the powder gases discharged through the side channel in the barrel. And the supply of cartridges was carried out due to the energy of the recoiling barrel. The barrel was locked with a wedge longitudinally sliding bolt. Power supply of the machine with cartridges lateral, along the horizontal feed table using a clip for 5 or 10 cartridges. Rate of fire - 180 rds / min. The real combat rate of fire did not exceed 90 rds / min. Vertical guidance angles: from - 10 ° to + 90 °. A fragmentation-tracer projectile, weighing 2, 3 kg, left the barrel at a speed of 840 m / s and could hit targets flying at an altitude of 3500 m. The self-destruction of the projectile took place at a distance of 6800 m. at a distance of 500 m along the normal 70 mm.
The installation was transported on a two-axle cart. In the combat position, both wheel travels rolled back, and the cruciform base of the carriage was leveled with jacks. The gun turned out to be quite heavy, its mass in a combat position was 4300 kg. Calculation - 7 people. The transfer time from transport to combat position is 5 minutes.
Due to their purpose, 50-mm anti-aircraft guns were mainly located in stationary positions. However, a number of 5, 0 cm Flak 41 were installed on Mercedes-Benz L-4500A all-wheel drive trucks.
Due to the strong recoil, before firing, in order to avoid overturning on an impromptu ZSU, it was necessary to fold back additional side supports. The metal sides of the cargo platform, laid out in a horizontal plane, formed an additional platform when the installation was brought into a combat position. In addition to the anti-aircraft machine gun, there was also an optical rangefinder in the back.
Details of the combat use of the ZSU with 50-mm anti-aircraft guns are not known, but judging by the surviving photographs, 5, 0 cm FlaK 41 were installed on vehicles with light armor protection for the cab and engine compartment. There were also unarmored variants with a fully open cockpit.
In various sources, the number of 50-mm anti-aircraft machine guns produced ranges from 50 to 200 units. Such an insignificant series by the standards of wartime is explained by the fact that the 5, 0 cm FlaK 41 gun was frankly unsuccessful. The main complaints were related to ammunition. Even in the daytime, the bursts of shots blinded the crew, and the shells for this caliber turned out to be low-power. The four-wheeled vehicle, when traveling on dirt roads, was too heavy and cumbersome. In addition, the shelling of rapidly moving targets was difficult due to the too low horizontal guidance speed. Nevertheless, 50-mm anti-aircraft guns were used until the surrender of Germany. In the Ruhr area, 24 guns placed in stationary positions became American trophies.
Assessing the actions of the German small-caliber anti-aircraft artillery, it is worth noting its very high efficiency. The anti-aircraft cover of the German troops was much better than the Soviet, and this situation persisted throughout the war. In the comments to the part devoted to 20 mm anti-aircraft guns, one of the readers expressed the following:
And yet, what was the real effectiveness of anti-aircraft artillery at that time? Was it worth the expended resources or is it more profitable to build an aviation? The loss of air dominance / parity foreshadowed collapse then and now. So the impression is created (at least for me) that anti-aircraft artillery is like a dead poultice …
However, the statistics of combat losses indicate the opposite. It was the fire of small-caliber anti-aircraft guns that destroyed most of the Il-2 lost for combat reasons. Authors V. I. Perov and O. V. Rastrenin in his book "Sturmovik Il-2" cites the following data:
… in 1943, from the fire of German anti-aircraft artillery of all calibers of the Air Force, the spacecraft lost 1468 Il-2, then in 1944 (Yasso-Kishinev, Sevastopol, Vyborg, Belorusskaya and other offensive operations) "Ilov" 1859 machines were lost, and in the first six months of the 45th (Vistula-Oder, Königsberg and Berlin operations), the number of downed Ilovs was 1,048. At the same time, the increase in the losses of the Il-2 from the fire of the German anti-aircraft artillery was accompanied by a steady decrease in losses from the actions of the Luftwaffe fighters. If in 43rd in air battles 1,090 Il-2s were shot down, then in 44th - 882 aircraft, and in 45th (as of May 1) - 369 Ilovs. That is, in air battles in the sky of the 44th "Ilyushins" was lost 2, 1 times less than from fire for all calibers, and in the 45th - already 2, 8 times less. The total combat losses of the Il-2 attack aircraft practically remained at the same level: in 1943 the Air Force of the spacecraft lost 3515 Il-2 on the fronts, in 1944 - 3344 combat vehicles, and in the 45th (as of May 1) - 1691.
From all of the above, we can conclude that the enemy partly compensated for the final loss of air supremacy in 1944 by increasing the number of rapid-fire anti-aircraft installations in the front-line zone. Anti-aircraft guns of 88-105-mm caliber in most cases inflicted damage on our attack aircraft only with the first salvo and at a distance of no more than 8 km. High losses of attack aircraft from 20-40-mm anti-aircraft guns are explained by the specifics of their combat use. Unlike bombers and fighters, they operated mainly from low altitudes - which means that they were in the realm of actual fire of the German MZA more often and longer than other aircraft. The extreme danger that German small-caliber anti-aircraft guns posed to our aviation was largely due to the perfection of the material part of these weapons. The design of anti-aircraft installations made it possible to very quickly maneuver trajectories in the vertical and horizontal planes. As a rule, as part of an anti-aircraft battery, the fire was corrected using PUAZO, which gave corrections for the range, speed and course of the aircraft. In the case of individual use, each gun in most cases was equipped with an optical rangefinder, which made it possible to make corrections for range. The German anti-aircraft crews had a very high level of training, due to which the shooting accuracy was high and the reaction time was short. The German small-caliber anti-aircraft battery was ready to give the first aimed shot within 20 seconds after the discovery of Soviet aircraft. The Germans introduced corrections for changing the course, dive angle, speed, range to the target within 2-3 seconds. Correction of anti-aircraft fire was facilitated by the widespread use of tracer shells. The average probability of hitting an aircraft flying at a speed of 400 km / h from a 20-mm single-barreled Flak 38 assault rifle at a distance of 1000 m was 0.01. With an increase in the number of anti-aircraft guns or the use of multi-barreled installations, the probability of destruction increased accordingly. The saturation of the enemy's air defense with rapid-fire anti-aircraft installations was very high. The number of barrels covering the targets of the Il-2 strikes increased steadily, and at the beginning of 1945, 150-200 20-37-mm shells could be fired at an attack aircraft operating in a strip of a German fortified area per second. The concentration of fire from several guns on one target also increased the likelihood of defeat. In addition, in most cases, the Il-2 and Il-10 made several approaches to the target, and the German anti-aircraft gunners had time to shoot.
