280 mm mortar Br-5

This article or the following section is not adequately provided with supporting documents ( e.g. individual evidence ). Information without sufficient evidence could be removed soon. Please help Wikipedia by researching the information and including good evidence.

280 mm mortar Br-5

The 280-mm mortar Br-5 ( Russian 280-мм мортира образца 1939 года (Бр-5) , transcribed 280-mm mortira obrasza 1939 goda (Br-5) ; GAU index 52-G-675) was a Soviet mortar with a caliber of 280 mm. This artillery system was the heaviest of the mass-produced Soviet guns. It used a gun carriage on caterpillar tracks , which was still used in two other heavy artillery systems. Despite the small number of Br-5s built, these were used in World War II , modernized after the war and kept in active service until the 1970s.

history

The Soviet heavy artillery has taken over two heavy artillery systems from the Imperial Russian Army - the Schneider 280 mm mortar (25 pieces) and the 305 mm M-1915 howitzer (34 pieces). In the mid-1930s, the Red Army was of the opinion that the number of these guns was insufficient, as the army would need at least 66 280 mm mortars according to the plan. A development contract for a modern 280 mm mortar was then awarded. The caliber should correspond to that of the Schneider mortar in order to be able to use the available projectiles. It was decided to use the chain mount of the B-4 howitzer for the new mortar . The 152 mm M1935 (Br-2) cannon had the same mount to simplify construction and use.

The development of the 280 mm mortar was carried out simultaneously by the design offices of two factories : the Bolshevik factory (formerly the Obukhov factory ) in Leningrad and the Barrikade factory in Stalingrad . The Bolshevik project was named B-33 and was developed under the direction of the engineer Kruptschatnikow. It had the mount for the B-4 howitzer and the screw lock for the Schneider mortar. The B-33 was successfully tested in 1936.

The Barricade factory mortar with the index Br-5 was completed and tested with a delay of nearly a year compared to the B-33, with the tests leading to poor results. The Br-33 showed improved accuracy and cadence , but was simpler and lighter. However, the Br-5 was selected for series production for reasons that are not yet clear.

The first order for eight Br-5 mortars was placed in May 1937. Since the Br-5, as had been found during testing, still had various defects, further development time was needed, which is why the order was reduced from eight to two howitzers . Its completion took place in 1939, with different methods of ammunition feeding were tested. In the first example, the grenade was transported along the track in a cart and, as with the Schneider mortar, inserted mechanically; in the second example, the grenade was delivered with a wagon without a track and, as with the B-4 howitzer, should be lifted to the required height by a lifting crane. After the tests, the second charging method was selected. In addition to the two mortars mentioned, 20 more were built in 1939, and another 25 followed in 1940.

modernization

280 mm Br-5 mortar in the St. Petersburg Military History Museum

In 1940, the Headquarters for Missiles and Artillery decided to develop a wheel mount for the Br-5. This work was supported by the designer's office no. 172 in Perm under the direction of Fedor Petrow performed. After the Soviet Union entered the war, this work was stopped. In 1955, a single wheel carriage for the types B-4, Br-2 and Br-5 was completed. With this new carriage, the Br-5 (now under the index Br-5M) could be transported without dismantling. In the original version, the tube and carriage should be separated before transport.

In 1944, under the direction of Grabins, the development of a mixture of 180 mm cannon and 210 mm howitzer on a common mount began; in 1945 a 280 mm mortar was added here. However, this project was not implemented.

commitment

During the final phase of the Winter War , four Br-5 mortars were successfully used against the Finnish Mannerheim Line . 414 HE shells were fired.

With the mortar Br-5 and the Schneider mortar, so-called "independent artillery departments of special firepower" were equipped. Each department had three batteries with two mortars each. A total of eight of these departments worked on the Eastern Front. Nine mortars were lost during the Red Army's withdrawal in 1941.

Use of the 280 mm mortar began in 1943 (1,000 rounds were fired) and rose sharply in 1944 (4,700 rounds fired). The peak of intensity was reached in 1945 when 8,450 rounds were issued, mainly during the fighting in East Prussia and East Pomerania. During the storm of the Graudenz fortress, the mortar broke through the walls with direct shots from a distance of 300 to 400 meters.

Preserved copies

Br-5 in the Lenino-Snegiri Military History Museum, in the background the B-4 howitzer

Two copies of the mortar have survived : the first is in the Military History Museum in St. Petersburg, the second in the Lenino-Snegiri Military History Museum .

description

The mortar had a rifled barrel with 17 caliber lengths and 88 trains with a depth of 3 mm each. The chamber was 0.5214 meters long. A screw lock was used that was technically identical to that of the B-4 howitzer, but larger. The pipe brake worked hydraulically and required 41 liters of oil, the pipe retractor was hydropneumatic and contained 63 liters of oil at an air pressure of 40 bar. The return length was between 85 and 141 cm, depending on the firing angle. The Br-5 mortar had a crawler carriage, but only reached a maximum speed of 8 km / h. On longer routes, the carriage and pipe should be transported separately by Voroshilovets and Comintern tugs. The weight of the limber was 1300 kg.

ammunition

Several different propellant charges were used. All Russian HE shells that were used with the Br-5 were developed during World War I and could also be used with the Schneider mortar. French HE shells from the Schneider mortar were also used. These grenades were originally filled with trinitrophenol ( picric acid ), which was replaced by TNT in the 1930s . The G-675 armor-piercing projectile was not tested until 1939.

Type	index	Ammunition weight, kg	Length, caliber	Explosives weight, kg	Muzzle velocity, m / s	Maximum range, m
Armor-piercing projectile	G-675	246	4.61	44.8	356	10,410
HE grenade	F-674	286.7	4.5	58.7	290	7350
HE grenade	F-674K	200.7	3.25	33.6	423	10,950
French cast iron explosive grenade	F-674F ( Grenade type FA modèle 1915 )	205	3.25	36/45 (trinitrophenil / TNT)	360	9350

Technical specifications

parameter	value
caliber	279.4 mm
Total pipe length	4.75 m
Weight in firing position	18,400 kg
Weight in march position (with a limber)	19,700 kg
Total weight of the carriage	13,800 kg
Weight of the pipe (with a screw cap)	5,900 kg
Elevation range	0 ° to + 60 °
Side straightening area	± 4 °
Cadence (shot / minute)	0.25
team	15th

Individual evidence

1. ↑ Обеспеченность Красной армии вооружением и боеприпасами накануне Великой Отечественной войны. - по книге: Артиллерийское снабжение в Великой Отечественной войне 1941—45 гг.
2. ↑ АРТИЛЛЕРИЙСКОЕ СНАБЖЕНИЕ в Великой Отечественной войне 1941–1945 гг. Издательство Главного артиллерийского управления Министерства Обороны СССР, Тула 1977.
3. ↑ Расход артиллерийских боеприпасов в Великой Отечественной войне.
4. ↑ Казаков Константин Петрович. Огневой вал наступления. М .: Воениздат, 1986.

Web links

Commons : 280mm Br-5 Mortar  - Collection of pictures, videos and audio files

literature

• 203-мм гаубица обр. 1931 г. (Б-4), 152-мм пушка обр. 1935 г. (Бр-2), 280-мм мортира обр. 1939 г. (Бр-5). Руководство службы. Ministry of Defense Publishing House, Moscow 1954.