280 mm mortar model 1939 (Br-5)

Soviet artillery of high power inherited from the Russian Imperial Army two models of particularly powerful artillery systems - the 280 mm Schneider mortar arr. 1914/15 (25 guns) and a 305-mm howitzer mod. 1915 (31 guns). By the mid -1930s, these tools were outdated both morally and physically, in addition, their number was estimated as insufficient (in particular, taking into account the mobilization reserve in 1941, it was necessary to have at least 66 pieces of a 280-mm mortar) ^{[1 ]} . There was a need to create and launch into serial production of new samples of particularly powerful guns, including a 280-mm mortar. The caliber of the new artillery system was determined by the desire to use the available stocks of ammunition. Since the 203 mm B-4 howitzer was adopted and the design of the 152 mm long-range gun was developed, it was decided to create a triplex - three different artillery systems using the same gun mount , which greatly simplified the production and operation of guns. As in the case of the 152 mm long-range cannon, the competing design bureaus of the Bolshevik and Barricades plants took up the creation of the 280 mm mortars ^[2] .

The mortars project of the Bolshevik plant received the B-33 index; the project was managed by engineer Krupchatnikov. The mortar barrel was made in 1935, and the mortar was sent to factory testing on February 1, 1936 . The design features of the gun were a bonded barrel of pipe, casing and breech , as well as a piston bolt from the Schneider mortar. The barrel was mounted on the carriage of a B-4 howitzer without a balancing mechanism, since it was balanced by the addition of cargo to the breech. The mortar was sent to proving ground tests on April 17, 1936, in general, they were completed successfully and, according to their results, it was recommended that the mortar be sent to military tests after eliminating the identified shortcomings ^[2] .

At the Barricades factory, the project of the 280-mm mortar, which received the Br-5 index, was led by I. I. Ivanov . Factory tests of the mortar took place in December 1936. Testing of the mortars began in April 1937 , according to the conclusion of the Br-5 commission, it could not stand the test. Nevertheless, it was Br-5 under the official name 280-mm mortar arr. 1939 , with the first order for the manufacture of mortars was issued even before the end of the field tests, in May 1937. The reasons for choosing the Br-5 instead of the B-33 are unknown; in the tests, the latter showed better results, in particular, greater accuracy and higher rate of fire, and was also less massive compared to the first. The historian A. B. Shirokorad believes that the choice was voluntaristic in nature. A prototype B-33 was used in the interests of the Br-5 program, and in March 1939 was transferred to the Barricades factory for study ^[2] .

The first order for the 8th mortar Br-5 was issued to the Barricade factory in May 1937. Later, due to the underdevelopment of the system, the number of guns ordered for 1937 was reduced to two, but neither in that nor in the following year they were made. These two experimental mortars were submitted to the training ground in June 1939 and differed from each other in the way of loading. According to the test results, a loading method was chosen, similar to that used in the B-4 howitzer. In addition to these two prototypes, in 1939 another 20 mortars were manufactured, and in 1940 the last 25 guns, on which their serial production was discontinued ^[2] .

From the report of the Barricades factory on marketable products in 1932-42

1936 - 1

1939 - 22

1940 - 25

Only 48 howitzers. The same number of them were listed in the Red Army on 1.06.1941.

The unsuccessful design of the gun carriage of the triplex guns became the basis for initiating work on the development of a new wheeled carriage, devoid of the shortcomings of the original tracked structure. In 1938, the Main Artillery Directorate approved the tactical and technical requirements for a new wheeled carriage for high-power duplex (152-mm Br-2 gun and 203-mm B-4 howitzer), in 1940 it was proposed to develop this carriage for the Br-5. The contractor for the task was Design Bureau of Plant No. 172 ( Perm Plant ) under the direction of F.F. Petrov . The gun carriage received the M-50 index, but work on it went extremely slowly due to the heavy workload of the design bureau on other systems. As a result, by the beginning of the war, everything was limited to the development of the project, after which all work was stopped ^[2] .

In 1955, the Br-5 (along with other tools of the B-4 and Br-2 triplex) underwent major modernization; a new wheeled carriage was developed for these mortars (the chief designer of the project was G.I. Sergeev). The cart of the gun became inseparable, and its speed increased significantly - up to 35 km / h on the highway . The upgraded mortar received the Br-5M index ^[2] .

In 1944, the TsAKB led by V. G. Grabin began work on creating a duplex of a 180-mm gun and a 210-mm howitzer on a single gun carriage, in 1945 the duplex turned into a triplex - a 280-mm mortar was added. In 1947, a 203 mm howitzer gun appeared in the system. The project was completed in 1953 , in 1955 the Barricades plant delivered seven 180-mm S-23 guns, one 203-mm S-33 howitzer and one 280-mm S-43 mortar. On this, work on the system was stopped, and the manufactured guns were sent to the Moscow Military District . In the 1970s, the production of C-23 was restored ^[2] .

In 1954-1955, the Central Research Institute-58 developed a triplex project on a self-propelled carriage, which included a 210-mm S-110A gun, a 280-mm S-111A howitzer gun and a 305-mm howitzer. Detailed information on the fate of this project is missing ^[2] .

Trunk

The mortar barrel is bonded, two-layer, consists of a pipe, a casing and a breech. The pipe consists of a threaded part and a chamber ; in the barrel part, the pipe has a thickening to balance the barrel. The threaded part has 88 grooves of constant steepness, the groove width is 6.97 mm, the field width is 3 mm, the groove depth is 3.4 mm. Camora consists of two conical and one cylindrical parts. The length of the chamber is 521.4 mm, the volume of the chamber is 18.159 dm³ (with a concrete-piercing shell ). The casing is put on the pipe in a hot state with an interference fit of up to 0.4 mm into the lock, which eliminates the displacement of the pipe relative to the casing. The breech is a steel forging screwed onto the end of the casing; the breech device is generally similar to that of the B-4 howitzer. The piston bolt, such as Schneider, is locked in two clock strokes, similar in design to the B-4 howitzer bolt, but larger in size ^[3] .

Wheel chocks

Anti-recoil devices are air-hydraulic. The brake and recoil brake cylinders are installed in couplings secured by gujouns to the cradle . The cradle with trunnions lies in the trunnion sockets of the upper machine and its sector is connected movably with the gear of the main shaft . Hydraulic recoil brake, contains 41 l of spindle oil . Hydropneumatic paddle, contains 63 l of spindle oil, air pressure - 40 atm. Rollback at elevation angles from 0 to 30 ° is long (1300-1410 mm), variable at elevation angles from 30 to 42 ° (850-1410 mm), short at elevation angles from 42 to 60 ° (850-880 mm). Anti-recoil devices during rollback are motionless. Unlike the B-4 howitzer gun carriage and the Br-2 gun, the recoil brake of the Br-5 howitzer carriage has dowels of variable cross-section, which made it possible to rearrange the barrels of different guns to the same gun carriage only in the factory (replacement of the recoil brake is necessary) ^{[ 3]} .

Carriage

Tracked carriage, consists of an upper machine, lower machine and chassis. The upper machine is a riveted structure, supported by three rollers on the supporting surface of the lower machine and moving using a rotary mechanism on the combat pin in the horizontal plane. The lower machine in the frontal part is fastened to the combat axis of circular cross-section, the ends of which are movably connected to the caterpillar track. The trunk part of the lower machine has two openers - permanent for hard ground and folding for soft ground. The lower Br-5 machine, compared with the early B-4 howitzer machine, is additionally reinforced with riveted sidewalls and a thickening of the upper sheet. The chassis includes a caterpillar, a braking device , a suspension , a winch for howitzers to turn ^[3] .

Guiding mechanisms and sights

Sector-type lifting and swivel mechanisms. There is a special mechanism for bringing to loading, providing a quick reduction of the barrel in a horizontal position. The sighting device consists of a sight , a panorama and a sight drive with an arm ^[3] .

Charger

The loading device consists of a crane with a winch, a kokor , a locking mechanism for the shaft leading to the loading angle, a shelving with a tarp and a shell cart. The loading of the gun was as follows: the shells were taken from the cellar and laid on a wooden platform. A shell prepared for transportation to a mortar is mounted vertically. Next, the fighter from the calculation rolls a shell cart to the shell and covers the shell with grabs. Then the projectile is placed on the trolley and fixed on it, after which it is transported on the trolley to the rack and put on a tarp . The rack is installed at the carriage under the crane, the kokor is lowered into the nest of the rack and the next shell lying in the rack is placed in the kokor. Mortira is brought to the loading angle, after which the shaft of the mechanism for bringing to loading is stopped. Kokor is hung on two hooks located on the breech of the gun barrel. After hanging the cocoon, the cable is slightly weakened, while the paws of the levers of the cocoron release the projectile, which is sent to the barrel using the efforts of four fighters ^[3] .

Front and gun cart

The carts are transported over long distances separately (the barrel is separate from the gun carriage). For short distances (up to 5 km) inseparable carriage of a gun with an extended barrel is allowed at a speed of no more than 5-8 km / h. For transportation by mechanical traction, the gun had a front end weighing 1300 kg with a coupling device. With separate carts, the barrel was transported on a sprung gun wheeled cart Br-10 (the weight of the cart with the trunk is 11,300 kg, without a barrel 5,400 kg) at a speed of up to 25 km / h. The transition of the gun from the combat position to the traveling one with separate carts took from 45 minutes to 2 hours, depending on the time of year and the type of soil. The gun was towed by Voroshilovets caterpillar tractors , the barrel carts by the less powerful Komintern caterpillar tractors ^[3] .

Mortars Br-5 were part of separate howitzer artillery divisions of special power, six mortars in each. Each division had three batteries , two mortars in each. In total, in 1941-1945 there were 8 such divisions with mortars Br-5 and Schneider ^[4] .

Mortars Br-5 were designed for ^[3] :

• destruction of particularly strong concrete , reinforced concrete and armored structures;
• the fight against large-caliber or covered with solid structures enemy artillery.

Mortar Br-5 took part in the Soviet-Finnish war , four such mortars from November 1939 were part of the 40th separate artillery division of high power. Mortars took part in breaking through the Mannerheim line , destroying the Finnish pillboxes . In total, 414 shells were fired by the mortars of Br-5 during this war ^[2] .

By the beginning of World War II, all 48 mortars were part of eight separate artillery divisions of special power:

32nd in ZOVO, 34th, 245th, 315th, 316th in KOVO, 317th in OdVO, 40th, 226th in MBO. Each of the divisions was armed with 6 guns. .

Little information is available on the use of the Br-5 during the Great Patriotic War. It is known about the use of guns of this type in the 32nd separate artillery battalion of special power in March 1945 during the assault of Neustadt (part of Küstrin ) ^[5] , as well as during the assault on Koenigsberg . In the memoirs of the chief of staff of artillery of the 1st Belorussian Front G.S. there is mention of the use of 280-mm howitzers in the assault on Poznan, probably referring to the Br-5. According to the military historian A.V. Isaev , the consumption of shells of a 280-mm mortar was not recorded in 1942 and 1943 ^{[6] [7]} , 3322 shells were used up in 1944, and 7363 shells were consumed in 1945 ^[8] . Before the war, there were about 7000 shells for a 280 mm mortar (or 97 per gun), which was estimated as an insufficient quantity ^[1] . In 1941, nine 280-mm mortars were lost ^[9] .

In the 1950s, the Br-5 mortars were modernized and were in service until at least the 1970s .

Mortira Br-5 had a cap loading. The charge scale is individual for each of the shells used. The Z-675B full variable charge (5 charges) and the Z-675BU variable variable (6 charges) were used for the G-675 shell, the Z-675 full variable charge (2 charges) and the Z-675U reduced variable charge were used (3 charges), to the F-674 projectile - a full alternating charge of the Z-675A (3 charges), to the F-674F projectile - the full variable charge of the Z-675F (4 charges) ^[3] . The range of shells included three types of high-explosive shells and one type of concrete-piercing shells. High-explosive shells were not produced in Soviet times; shell stocks from the 280-mm Schneider mortar, created before the revolution, were used. Concrete projectile has been used since 1942 ^[2] .

Shooting from the mortar at elevation angles of less than 15 ° due to the weak stability of the system at small elevation angles was allowed only in exceptional cases.

Among the Soviet artillery systems, the Br-5 occupies a special place, being the largest caliber of the developed and mass-produced guns in the USSR. Most of the advantages and disadvantages of the gun are associated with its gun mount, common to all guns of the “triplex of high power”. On the one hand, the use of a tracked carriage made it possible in theory for a fairly quick change of firing position and significantly reduced the time it takes to switch from a stowed position to a combat position in comparison with semi-stationary guns like the 280 mm Schneider mortar. On the other hand, the design of the carriage was unsuccessful - the gun assembly was hardly moved by the most powerful tractors, but in conditions of poor terrain ( mud road, ice ), this system actually lost mobility. Fire maneuvering capabilities were severely limited by the horizontal angle (GN) of only 8 °. For turning the cannon by forces of calculation beyond the limits of the GN angle, it took at least 25 minutes. Carried out in the postwar years, the replacement of the gun carriage made it possible to get rid of these problems ^[10] .

Comparison with foreign tools is complicated by the lack of complete analogues. In addition to the Red Army, guns of 280 mm caliber were armed only with the German armed forces , but even there guns of this caliber were represented either by railway cannons , or old, from World War I , semi-stationary howitzers 28 cm HL / 12 . The latter, with the same maximum firing range, were significantly inferior to the Br-5 in mobility ^[10] . Also, the captured Czechoslovak mortars 30.5 cm Mrs. (t) used in the German army and howitzers 24 cm H.39 / 40 , both guns were semi-stationary systems that required digging a pit for installation and transported in three carts. The French heavy mortars were represented by the same 280 mm Schneider mortars ^[10] . The largest British siege weapons were the Ordnance BL 9.2-inch howitzer 234 mm howitzer , also a semi-stationary design, the projectile weight of which (131.5 kg) was not comparable with the weight of the Br-5 shell, and the Ordnance BL 12 inch howitzer 305 mm howitzer , which is an enlarged version of the previous one; the British themselves considered these guns, launched into production in 1914 , hopelessly outdated. In the USA in 1942, a howitzer 240 mm howitzer M1 “Black Dragon” (“black dragon”) was adopted; this gun, more than double the Br-5 in its maximum firing range (23 km), was equally significantly inferior in terms of projectile weight (163 kg) ^[11] . Like the Soviet mortar, the “Black Dragon” moved disassembled on two carts, but its carriage with sliding beds made it possible to fire at targets in a significantly larger sector (45 ° ^[12] versus 8 ° for the Br-5). Наконец, аналогичная по баллистике (200 кг, 400 м/с, 10 км) японская 240-мм гаубица Тип 45 была вдвое тяжелее и имела стационарный лафет.

Орудие Бр-5 на гусеничном лафете находится в экспозиции Музея артиллерии и инженерных войск в Санкт-Петербурге .

• Главное артиллерийское управление РККА. 203-мм гаубица обр. 1931 г. (Б-4), 280-мм мортира обр. 1939 г. (Бр-5), 152-мм пушка обр. 1935 г. (Бр-2). Руководство службы. — М. : Воениздат НКО, 1942.
• Широкорад А. Б. Энциклопедия отечественной артиллерии. - Mn. : Харвест, 2000. — 1156 с. — ISBN 985-433-703-0 .
• Shirokorad A. B. God of War of the Third Reich. — М. : АСТ, 2002. — 576 с. - ISBN 5-17-015302-3 .
• Иванов А. Артиллерия СССР во Второй мировой войне. - SPb. : Нева, 2003. — 64 с. — ISBN 5-7654-2731-6 .

• Бр-5 на сайте игр серии «Противостояние» (Sudden Strike) (неопр.) . Архивировано 13 августа 2011 года.