Part two. Historical
Tank trawl - a type of mine trawl, attachments of a tank, armored tractor or specialized vehicle, which is designed to overcome or clear anti-tank minefields
THE FIRST SOVIET MINE DRILLS
After the First World War, where mines (albeit primitive in design) began to be widely used for the first time, the question arose of developing a special tool that would minimize the impact of minefields on the pace of advancement of troops and reduce their losses. And such a means was a tank mine trawl - a new type of weapon that was mounted on armored vehicles.
Work on the creation of an anti-mine trawl in the USSR began in 1932 - 1934. in accordance with the "System of Engineering Weapons", which was approved in 1930. This document established a list of models of military engineering equipment necessary to support the combat operations of troops, determined their basic tactical and technical requirements, the procedure for development and adoption. Among the types of engineering equipment was a group of so-called sapper (engineering) tanks. It also included tanks - minesweepers, designed to identify and overcome minefields.
During this period, the teachers of the Military Engineering Academy E. Grubin, N. Bystrikov and others developed and experimentally tested different designs of mine trawls: knife, shock (striker, chain) and roller. All trawls were ruled and trawled a strip of terrain directly in front of the tank track by initiating mines (shock and roller) or digging mines and pulling them to the side (knife).
The first samples of a knife trawl were created for the T-26 tank in October 1932 in Leningrad. The tank received the index ST-26 (sapper tank T-26). The trawl consisted of two separate sections. Each section was attached to a special bearing that could throw the trawl off the tank in emergency situations. The trawl, fixed on the tank, was transferred to the firing position by lowering, and into the transport position by raising the sections. The machine gunner supervised this process without leaving the combat vehicle. But on tests, the trawl showed unsatisfactory results: the trawls had low resistance to detonation, the knives broke or deformed when hitting solid objects, the trawl did not work well in frozen areas and in areas that were overgrown with bushes, and the like. The trawl was not adopted for service.
The first version of the knife trawl on the T-26 tank
During 1932-1933. at the VIU RKKA test site, three samples of a knife-type mine trawl were tested.
The transfer of all trawls from the traveling position to the combat position was carried out without the crew leaving the tank. Emergency uncoupling and turning of the tank while moving in a combat position were impossible.
The working bodies of the knife trawls were not explosion-proof, and when hitting hard objects, the knives broke or deformed so much that they lost their efficiency.
All three variants of the knife trawl showed unsatisfactory results during tests and were not accepted into service due to a number of shortcomings:
- the impossibility of trawling mines in hard and frozen soils and on areas overgrown with bushes;
- impossibility of maneuvering the machine when sweeping mines;
- insufficient strength of the frame structure and rapid wear of the knives;
- low speed of movement of a tank with a trawl;
- cutting knives into the ground or spontaneous exit from the ground.
The presence of defects of a fundamental nature, revealed during the tests, led to the termination of further work on knife-type trawls.
The second version of the ST-26 trawl
In November 1934, much earlier than the British, in Leningrad, under the leadership of B. Ushakov and N. Tseits, a project of a shock trawl for the BT-5 tank was developed. Its design already provided continuous minesweeping in front of the front projection of the tank. In 1937, a continuous mine sweep was developed for the BT-7 tank. The design of the trawl provided continuous trawling in a strip of 3.5 m at a vehicle speed of up to 8 km / h.
Design Engineer Nikolay Valentinovich Tseits
Shock trawl project for the BT-5 tank
In 1936, several samples of shock-type trawls were developed and tested, which were installed on T-26 tanks. The trawl was attached to the front of the tank and consisted of a metal frame on which drums were mounted - two opposite each track. The drums were driven by driving (front) wheels. On the drums, 55 percussion (working) elements were attached with cables in a certain order. During the rotation of the drums, the working elements hit the soil and thereby caused the explosion of mines.
Tank T-26, equipped with a shock track trawl
The moment of testing the shock trawl. In the foreground is an anti-tank mine.
In July - August 1936, a continuous sweeping strike mine sweep for the T-28 (TR-28) medium tank was tested. It was developed by the engineers of the design bureau of plant No. 185 I. Belogurtsev and A. Kaloev and provided minesweeping in front of the tank in an area 3.5 m wide.
The striker trawl had a drum, on which strikers were located in a certain order, suspended on cables with a diameter of 10-12 mm. When the tank was moving, the drum was driven into rotation using a chain drive from the tank guide wheel. For this purpose, two sprockets were installed on the side of the guide wheel: one (small) for a chain drive, the second (large) for engaging with the track pins of the track tracks and eliminating slippage of the guide wheel. The trawling speed was 10-15 km / h. The trawl was not accepted for service.
Trawl TR-28 on the medium tank T-28
The main disadvantages indicated in the commission's report were: the separation of 7-8 working elements when a mine was blown up, which disrupted the subsequent effective work; entanglement during operation of the cables, which led to the skipping of mines and the formation of clouds of dust, mud or snow during operation in front of the tank, which led to a loss of orientation by the driver-mechanic.
Subsequent work on the aforementioned trawls was discontinued.
As the main type in the Red Army, the roller trawl was adopted as the most effective. The first sample of such a track trawl was designed in 1935. After testing and improvement, in 1937 prototypes of roller trawls were manufactured for the T-26 (ST-26) tanks, and in 1938 - for the T-28.
The trawl was attached to the ST-26 tank with a special frame, consisted of two sections and had a special winch for raising the trawl to the transport position. Each section of the trawl consisted of three rollers. Each roller rotated freely on a common axis and did not depend on the other two. This made it possible to better copy the unevenness of the terrain and, thus, to improve the trawling procedure.
Roller track trawl ST-26
Working body of the trawl ST-26
Despite the low weight (1, 8 tons) and good spring cushioning, the trawl had certain disadvantages: low overall resistance to blasting, and the rollers themselves had to be changed after three blasting operations.
Trawled ST-26 after being blown up by a mine. The rollers of the right (in the direction of the tank) section are completely destroyed
A roller trawl for the T-28 tank was developed at the NATI plant in Moscow in 1938, the test took place in May-June 1939. The trawl could be attached both to the T-28 linear tanks and to the IT-28 engineering tank without reworking the hull cars. After the tests, the military recommended to increase the trawl survivability to 10-15 explosions under the section (instead of 2-3) and improve the maneuverability of the tank with the trawl installed. It was decided to test the upgraded samples in the summer and winter of 1940.
T-28 with a roller trawl overcomes an obstacle
Undermining a mine under a trawl roller
With the beginning of the Soviet-Finnish war, an urgent need arose for various engineering means, and first of all for mine trawls. Leningrad factories №185 im. Kirov and No. 174 named after Voroshilov already in December 1939 made the first samples of trawls. Later, a series of disc mine trawls was manufactured in the amount of 142 pieces. (93 trawls were manufactured by the Kirov plant and 49 by the plant No. 174 named after Voroshilov). The trawls entered the active army in February-March 1940. Despite the low resistance to detonation (after the first mine explosion, the disks were bent), the trawls were successfully used in the 20th and 35th tank brigades and tank battalions of the 8th army.
Disk mine trawl plant No. 174 on the T-26 tank
An interesting project of a tank-electric sweeper was developed in October 1940 at SKB-2 of the Leningrad Kirov plant. Its authors were O. Serdyukov and G. Karpinsky. In April 1941, a mock-up of this machine was made. Subsequent work has been discontinued.
The project provided for the installation of special electrical equipment on the base of the KV-2 serial tank. The dynamo, by means of an antenna located outside in front of the hull, created an electromagnetic field, which at a distance of 4 - 6 m from the tank caused mines with electric ignitors or electric detonators to detonate. The installation was tested on April 14, 1941 and confirmed the possibility of detonating mines in this way. Also, the minesweeper provided equipment for transporting, dropping and remote detonation of explosive charges weighing up to 1 ton (the British would approach such a scheme for destroying fortifications only in 1944 during the preparation of an amphibious operation in Normandy).
The project of the tank-electric sweeper based on the heavy tank KV - 2
Subsequent tests and the experience of the Soviet-Finnish war showed the advantages of a roller trawl, set other requirements for an anti-mine trawl and made it possible to finally form its general appearance.
Unfortunately, by the beginning of World War II, all types of mine trawls remained at the level of prototypes. They did not enter the troops.
IN THE YEARS OF WAR
With the beginning of the Great Patriotic War, the manual method was the main method of overcoming minefields or arranging passages in them. But it required great efforts, considerable time (especially at night) and was accompanied by large losses of sappers. In addition, in some cases, work on equipping passages in minefields could be noticed by the enemy, as a result of which the element of surprise was lost by the attackers (as happened on the Kursk Bulge with German sappers). Therefore, with the beginning of the war, work on the development of mine trawls continued, but at an accelerated pace. In the first year of the war, several types of roller disc trawls were developed.
The first of them was a hitch to a tractor or tank and consisted of 17 welded discs on which special spurs were attached to improve the trawling process. Copying of the terrain relief was ensured by a gap between the axis and the disc hole. A prototype of such a trawl was manufactured in Leningrad.
Leningrad mine trawl project. Summer 1941
The second similar trawl was designed at the Dormashina plant in Rybinsk. It consisted of a frame and eight discs that were planted on a common axle. But none of these trawls were adopted due to their high weight and low resistance to detonation.
Trawl plant "Dormashina"
At the beginning of 1942, work continued on the PT-34 mine trawl, which began in 1941, and in August of the same year they were to begin their serial production. In 1941, due to the retreat of the Red Army and the relocation of industry, work on trawls was suspended. They remembered them at the end of the Moscow battle, where German anti-tank mines inflicted very significant losses in a number of tank units.
The trawl was developed in two versions. Trawl designed by D. Trofimov was a cheap two-section structure, where the rollers were made of reinforced concrete.
Trawl D. Trofimova
At the trawl of the teacher of the Military Engineering Academy, Colonel P. Mugalev, the working body of the trawl was made of rollers recruited from stamped discs with special steel or cast iron shoes installed on them. In the spring of 1942, work on the trawls was continued.
Military engineer Pavel Mikhailovich Mugalev
In May 1942, three tank mine trawls were manufactured, two of them were designed by D. Trofimov and P. Mugalev. The third trawl was designed from the road wheels of the T-34-76 tank, but due to the high price and heavy weight, it was not allowed to be tested. According to the test results, the following conclusions were made: D. Trofimov's trawl showed the ineffectiveness of trawling, especially in winter. Rollers of a wide shape did not sink well into the snow and did not sufficiently act on the pressure covers of the mines. P. Mugalev's trawl turned out to be more reliable and simpler. The state commission recommended that the Mugalev trawl be converted from a three-section to a two-section one and put into service.
The first (experimental) version of the Mugalev trawl
The second (simplified) version of the Mugalev trawl, which was put into service under the PT-34 brand
Mugalev trawl proposal
In the summer of 1942, under the brand name PT-34 (mine trawl for the T-34 tank), it was put into service, but the start of serial production was delayed until the fall of 1942. the next tests in March 1943 began its production under the symbol PT-3 at the Tula machine-building plant "Komsomolets".
Trawl PT-3 on the T-34-76 tank
The total weight of the PT-3 trawl was 5300 kg; trawl length - 2870 mm, width - 3820 mm; trawling speed - 10-12 km / h. The width of the trawling strip is two tracks of 1200 mm each. The time of mounting the trawl by the crew is 60 minutes. Unfortunately, no emergency discharge from the tank was foreseen. Trawl PT-3 withstood from 3 to 5 explosions, after which repair or its complete replacement was needed. He was easily versed in the field for repair and transportation. Transportation was carried out on two ZIS-5 vehicles or one Studebaker US6 vehicle.
The trawl easily overcame slopes up to 25 ° and slopes up to 30 °, shrubs and single trees up to 20 cm thick in the lower cut, wire fences, trenches, communication trenches, ditches up to 2.5 m wide and vertical walls up to 0.6 m. could work even in the presence of a snow cover up to 0, 4-0, 5 m thick.
Insurmountable obstacles for the trawl were: wetlands, large fragments of stone walls, trees thicker than 20 cm, ditches and craters more than 2.5 m wide, escarps with a wall height of more than 0.6 m and areas with a sharp transition from descent to ascent and back …
Tests of the PT-3 trawl for detonation. Summer 1942
The trawl is arranged as follows: in the lugs of the cast structure, welded to the lower front inclined armor plate of the tank hull, the metal welded frame of the trawl is hinged. Fastening is carried out using inserted cylindrical pins with cotter pins. The frame of the trawl is held suspended in front of the tank by a cable suspension. At the end of the frame, a traverse is pivotally attached, through the spacer pipe of which the axis of the trawl passes. On an axle with a large gap, ten trawling discs sit, forming two sections. Free fit of the discs on the axle makes it possible to copy small uneven terrain. The stable position of the discs during trawl movement over the terrain is ensured by the shoulders of the spacer couplings. Spacer couplings are also put on the trawl axle. Each disc along the perimeter is equipped with trawling spurs, which are designed not only to transfer pressure to the mine drive, but also to increase the stability of the disc body against a mine explosion. When an ordinary anti-tank mine explodes, 3-4 spurs fly off, which somewhat reduces the reliability of trawling. As individual parts of the trawl are destroyed (spurs, spacer couplings, discs, etc.), they are replaced with new ones. Reverse chains are designed to ensure the movement of the minesweeper tank in reverse, to limit the lowering of the axle with rollers in the trenches and to ensure the rotation of the minesweeper tank.
The design of the PT-3 trawl is collapsible. Its installation on any linear medium tank and dismantling can be carried out in the field by the tank's crew, and without the use of special lifting equipment.
Trawl PT-34 (PT-3). Drawing
Along with the PT-3, other trawl designs were developed and tested during the Great Patriotic War. Noteworthy is an experimental model of an explosive trawl, which was a special device for the tank. It consisted of a cassette and ten charges weighing 5 kg each. When the tank moved, the charges were thrown from the cassette onto the minefield alternately at a certain interval and exploded, forming a passage. However, due to serious design flaws, this trawl was not adopted for service.
The end follows …
