T-40 in the Kubinka Tank Museum, Russia
|Armor and armament|
|Armor||5 to max. 15 mm|
|Main armament||12.7 mm MG Degtjarjow-Shpagin DSchK or
20 mm MK L / 82 SchWAK -T
|Secondary armament||1 × 7.62 mm MG Degtjarjow DT|
|drive||a 6-cylinder gasoline engine GAS-11
85 PS (63 kW)
|suspension||Torsion bar suspension|
|Top speed||44 km / h (road), 20-25 km / h (terrain), 6 km / h (water)|
|Power / weight||15.5 hp / t (11.4 kW / t)|
|Range||300 km (road)|
The design office of Plant No. 37 in Moscow developed the T-40 in the first half of 1939. Nikolai Alexandrovich Astrov , one of the leading specialists in the development of light tanks at the time, was the chief designer . The Red Army accepted the tank in December 1939 and Plant No. 37 produced it in series until December 1941.
During series production, the developers modified the T-40 several times, both to simplify production and to strengthen armor and firepower . The later versions, in the literature as T-40S and T 30 denotes, had a better armor protection and carried as the main armament of a small-caliber automatic cannon instead of a super-heavy machine gun . At the same time, the tanks lost their buoyancy. These variants represented transitional models to the successor model, the light tank T-60 .
The Red Army used the T-40 mainly in the fighting in the early stages of the German invasion of the USSR . Most of the T-40 tanks were used in the Battle of Moscow in the late autumn of 1941 . Almost all tanks were lost here and in a row, so that the type disappeared from the armored forces as early as 1942. The army used a few remaining vehicles for training purposes until the end of the war.
In addition to heavy, medium and light tanks, the Red Army's tank equipment system provided for a special class of tanks, the so-called small tanks (Russian малые танки ). They formed a subspecies of the light tank. Reconnaissance, protection of the infantry during the march , fighting against enemy saboteurs , paratroopers and partisans as well as communication links were typical tasks for the small tank of the Red Army in the late 1930s. They should also be able to overcome water hazards without preparation.
In the late 1930s, the Red Army had two types of small tanks, the T-37 A and the T-38 . Both vehicles were further developments of a British swimming tank prototype whose license to build and further develop the design was held by Carden-Loyd Tractors Ltd. had been bought. The adaptation of the British design to the Soviet production conditions took over the design office of the Moscow plant No. 37 under the direction of NN Kozyrevs and NA Astrows . The result of this work, the small T-38 floating tank, was only able to meet the great expectations placed on it to a small extent. Two subsequent modernizations only remedied some of the defects. The T-38 still had the following main weaknesses:
- weak armament with only one 7.62 mm DT machine gun ;
- weak armor that could not protect against hits from anti-tank rifles , shrapnel and hand grenades ;
- Spatially separate places for the driver and the commander, so that the tank would fail completely if the driver was injured or killed;
- insufficient swimming ability; the tank could not carry two soldiers or any other payload even in good weather, T-38s sank several times during exercises and tests due to insufficient sealing of the tank hull or due to slight waves;
- poor mobility on soft soils.
Therefore, in the second half of 1937, the design office of Plant No. 37, headed by N. A. Astrow, began work on a project for a new small floating tank that would no longer have these defects. A main development direction was in the area of the armored hull, which should have better swimming properties due to a more favorable shape in order to reduce the existing restrictions in the dimensions of the hull. In addition, cheap and reliable parts from the automotive industry should be used for the drive as well as new technical developments for the drive. Some elements of the new design were adopted from the T-38 , but the project with the designation 010 was not a further development of the British ancestor of the T-37A and T-38 tanks, but an independent new development by Astrow's design office.
The fate of Project 010 was acutely threatened at an early stage of development. The commissioner of the armored vehicles, main battle tank Office of the Red Army ( GBtu (ГБТУ РККА - Russian Главное БронеТанковое Управление Рабоче-Крестьянской Красной Армии Glawnoje BronjeTankowoje Uprawlenije Rabotschije-Kreßtjanskoj Krasnoj Armii ) wanted instead of a tank such as the T-38 as a floating reconnaissance a vehicle similar to the vehicles of the BT series , was able to move both on wheels and with the chains on (when driving off-road) (колёсно-гусеничный танк, Koljossno-Gussennitschnij Tank)). The required weight was five to six tons and a diesel engine with around 150 to 180 hp was required. This project carried the army designation T-39 . At that time, Astrow represented the arrested N. N. Kozyrev as director of Plant No. 37. He reported to the GBTU that it was impossible to build such a tank within the framework of the weight and cost specifications. There was also no suitable diesel engine available, there wasn't even a project to develop it. These objections only led to instructions to develop such an engine by autumn 1937. The inspection by the GBTU followed in July 1937, and the report was unsatisfactory for Astrow and his staff. In the spring of 1938, however, the new leadership of the GBTU (the previous cadres had fallen victim to the Stalinist Chistka ) changed the tactical and technical requirements for the new floating tank significantly. Now it should only be able to drive on chains and a gasoline engine with 90 hp should be used. Astrow's Project 010 met these requirements well. At the same time, the project received the army designation T-40 .
During this time, the 010 project was developed by the small design office at Plant No. 37. In addition to the chief designer, who actively participated in the design, engineers R. A. Anselevich and A. W. Bogachev were busy developing the new tank. Each wheel was individually sprung with a torsion bar . The designers paid special attention to the ergonomics of the vehicle. Unlike the T-38 , the T-40 crew sat in one room; the driver had his workplace in the middle of the armored hull with a good field of vision. Its viewing port was placed high in the front armor to prevent water from entering when sailing on the water; space was also provided for the bulky 71-TK-3 radio system. In contrast to the open attachment of the screw propeller on the T-38 , it was placed in a special hydrodynamic niche at the rear of the new vehicle to protect it from possible damage.
Work on the draft was almost finished in the spring of 1939 and tests of the first four experimental tanks began as early as July 1939. Two vehicles drove with the new torsion bar suspension, the other two tanks were equipped with the old suspension with two roller carriages and leaf springs . The extensive test program included testing the running and maneuvering properties on land and water, overcoming artificial and natural obstacles, testing the weapons and assessing the user-friendliness of the weapons and the tank as a whole. Since the GAS plant had problems with the start of series production of the 85 hp GAS-202 gasoline engines , all four experimental tanks were equipped with imported prototypes of the GAS-202 engine ( Dodge Export) . The test program was a lot more extensive than that of the predecessor, as all the weaknesses of the design should now be found and remedied before the end of the development phase, so that the T-40 can function reliably even in the hand of a low-skilled soldier.
The tests showed a large number of necessary changes to the design, but Plant No. 37 was able to remedy these deficiencies quickly. In particular, the tank hull was lengthened by twelve centimeters and widened by five centimeters, while the height was reduced in order to improve the stability on land and water. The designers also reinforced the torsion bars of the suspension, increased the diameter and width of the rollers and replaced the three-bladed propeller with a four-bladed one. As a result of the tests, the torsion bar suspension proved to be superior to the old version with two roller carriages and leaf springs and was therefore recommended for future series vehicles. After the improvements had been made to the tank, it was accepted by military experts and the state management of the tank industry.
On December 19, 1939, by Resolution No. 433ss, the USSR Defense Committee had taken the improved small tank of the 010 project under the same army designation T-40 into service at the same time as several other new military vehicles. This document introduced a series of new tasks for Plant No. 37: by March 1, 1940, the plant was to produce three experimental T-40 tanks; by August 1, 1940, a small pilot series of 15 vehicles was to be completed. Series production of the T-40 was to begin in October 1940 .
In the late spring of 1940, Plant No. 37 built two more experimental tanks, all of which were taken into account based on the results of the tests. At this point in time, the first Soviet GAS-11 engines from series production were delivered, at exactly the right time, as the wear and tear of the imported gasoline engines in the previous test vehicles required increased maintenance costs to continue. In the summer of 1940, the People's Commissar for Defense S. K. Timoshenko and the Chief of Staff G. K. Zhukov visited the plant to inspect the new T-40 pre-production tanks. The latter had a particular interest in the T-40 and the factory's ability to mass-produce the T-40 .
Development during the war
After the attack by the German Wehrmacht on the Soviet Union, Plant No. 37 was ordered to stop production of the small T-40 floating tank and to prepare production capacities for the production of the T-50 light tank . Meanwhile, the Red Army demanded the construction of as many tanks as possible in view of their high losses in the early stages of the war and in view of the further advance of the Wehrmacht . For Plant No. 37, however, the technological process of the T-50 series production was too complicated. In this situation, Astrow began work on a new light tank, mainly using the parts and equipment of the T-40 , and the Defense Committee quickly ordered the serial production of the T-50 in favor of increasing the production of the "land variant" of the T-40 , the T-40S (Russian Т-40С ) revoked. This version was developed in July 1941 on the initiative of Colonel S. A. Afonins, head of one of the departments of the GBTU. Since the buoyancy of the T-40 was not used in the fighting in the first months of the war, there was an opportunity to simplify the construction of the tank while doing without the necessary propulsion means for water travel. The propeller with cardan shaft , the PTO , rudder, heat exchanger , bilge pump , water shield and compass were removed and the weight savings were used to reinforce the armor up to 15 mm at the most important points of the armored hull. The niche for the screw propeller was retained. Later on, a radio system could no longer be installed because there was a lack of these devices.
The last remnant of the original concept of a floating tank, the now useless hydrodynamic niche, was abolished in the following and also at the same time last version of the T-40 . After its project name 030 , it is called T-30 in the literature . The Russian historian M. N. Swirin explains on the basis of his research in the archival documents of the Armored Industry People's Commissariat that Astrov in a letter to Josef Stalin in relation to the proposal to produce a further improved version of the T-40 instead of the overly complicated T-50 s reported on this same variant. After Stalin's approval in August 1941, this vehicle was originally called the T-60 , which was later also used for the successor to the T-40 , the actual T-60 . According to Swirin, this explains the unusually short development time of the actual T-60 , which is thus erroneously stated in the literature, as a confusion with the last T-40 variant, which was previously to be found in the documents as the T-60 .
The version still listed as the T-40 in the army's troop and production reporting at that time was a revision of the T-40S by Astrow in July 1941, with armor reinforced by up to 20 mm. The internal structure of the tank was also changed slightly with the aim of using the space that has been freed up as a result of the abandonment of the propulsion means for water travel and the niche at the stern. From September 1941 the new T-30 was equipped with the automatic 20 mm SchWAK -T cannon .
Using the available space and the arrangement of the devices in the T-30 , the designer AW Bogachev developed a new, lower armored hull for the new tank of Project 060 . The 060 experimental tank with this armored hull became the prototype for the later production version of the T-60 . At this point in time, the development of the T-40 ended and all personnel and material resources were now used to work on the direct successor in production, the T-60 .
The light tank T-40 in all its variants was only produced in Plant No. 37 in 1940-41.
After the restructuring and expansion of the production capacity, series production of the T-40 began in October 1940. The operating plan provided for 100 T-40s to be produced by the end of 1940, but series production suffered from difficulties and so the customer was able to do so that year only 41 tanks from series production and six experimental tanks will be accepted. 1941 was more successful; By June 22, 1941, 179 T-40s could be delivered to the Red Army, along with completed vehicles from the previous year. Series production of the floating version of the T-40 was ended in July 1941 with the delivery of the last 16 vehicles of this version. Instead, the “land variant” T-40S took its place in the company's production lines. In July, August and early September 1941, 136 T-40S were built, from then on this in turn was replaced by the T-30 variant equipped with reinforced armor . This version was in series production up to and including October 1941, at the same time as the new T-60 light tank .
In November 1941, the war-related evacuation of Plant No. 37 to Sverdlovsk began . At the new location, Plant No. 37 built the last 20 T-30s from still existing armored hulls in December 1941 . With this, the series production of all variants of the T-40 was finally completed, the production was switched to the production of the T-60 . The last series T-30s were equipped with the 20-mm SchWAK -T automatic cannon instead of the DSchK heavy machine gun. In Plant No. 37, some earlier T-40s were armed with this cannon as part of the repair of front damage. The armored hulls and turrets of the T-40 for Plant No. 37 in Moscow were manufactured in the Kuibyshev engineering plant in Kolomna and in the Podolsk plant. The production numbers of the T-40 are shown in the following table:
|Series production of the T-40|
|January – June||July||August||September||October||November||December||total|
|T-40 (Plant No. 37, Moscow)||100||179||16||295|
|T-40S (Plant No. 37, Moscow)||36||90||10||136 *|
|T-30 (Plant No. 37, Moscow)||200||115||315|
|T-30 (Plant No. 37, Sverdlovsk)||20th||20th|
|All in all||100||179||52||90||210||115||20th||766 *|
|* - including 44 chassis for the self-propelled missile launcher BM-8-24 , ie a total of 722 T-40 tanks of all designs|
The T-40 was intended to replace the floating tank types T-37 A and T-38 in the Red Army. However, the structure of the armored and mechanized units was revised several times in the pre-war period. Furthermore, the production number of the T-40 was below the target. For these reasons, there is very little accurate information about the distribution of the T-40 in the Red Army before the war.
As a result of the catastrophic losses in 1941 and the layout plans that had been redesigned several times, the Soviet units had very different light tanks in their ranks, so that even during the war it was not possible to establish a specific layout. Rather, due to the gradual conversion of the production of the T-40 , via the variants T-40S and T-30 to the T-60, there was no precise specification of the vehicle types in the installation plans. Instead, the total number of light tanks in the specific tank units was given. These light tanks could be of different types: BT-5 , BT-7 , T-26 , all variants of the T-40 and, since October 1941, also T-60 tanks, as a result all vehicles that were still available or being delivered could.
Even so, the T-40s were used at all levels of the Red Army's tank units, from the independent tank battalions to the tank armies . The deployment plans were revised several times during the first phase of the war, for example 64 of 93 tanks in an independent tank brigade , which was set up in August and early September 1941, were light tanks ( T-40 and its variants). In the second half of September the total number of tanks in the brigades was reduced to a total of 67 vehicles, followed by a second reduction to 46 vehicles (of which 20 were T-40s or their variants).
Later, due to the lack of vehicles, the Soviet leadership had to change the focus of the unit deployment, as not enough brigades could be deployed even with the reduced number of vehicles. They started to set up independent battalions with 9 medium and 20 light tanks, but a small number of brigades continued to be organized.
Since the beginning of 1942, when the confusion that prevailed in the Red Army after the outbreak of war due to the catastrophic defeats could be partially overcome, clear plans of the tank units appeared for the first time. Instead of the independent tank battalions, which were set up with all available material, new tank corps were to be formed for large-scale offensives. So in March 1942 the new layout plan for tank corps with 100 tanks (20 KW-1 , 40 T-34 and 40 T-60 ) was adopted. The increased production of the Soviet tank industry made it possible in April 1942 to reinforce the tank corps to one and a half times (30 KW-1 , 60 T-34 and 60 T-60 ). Although the main type of light tank was the T-60 , at the beginning of 1942 some units were equipped with the last T-30 in series production or repaired T-40s with SchWAK-T cannons.
Since mid-1942 the T-40 tanks disappeared from the front reports of the Red Army and the individual remaining tanks of this type were used as training vehicles in the rear.
As a result of its overall low production figures, there are no details about the use of the T-40 . On June 1, 1941, the Red Army commanded 131 T-40 tanks, 113 of them combat vehicles, 16 command vehicles and 2 training vehicles. 115 of them were assigned to western military districts, mainly the Special Kiev Military District ( Russian Киевский Особый военный округ , German transcription Kiewskij Osoby Wojenny Okrug ). The crews were not trained on the T-40 , their combat training was inadequate and the T-40 was used by them like an ordinary main battle tank, so that as a result practically all pre-war T-40s were lost in the first days of the war for example the Northwest Front on July 17th only five of the former 88 T-40s ). But the losses of other armor material were also very high. The 216th Panzer Regiment of the 108th Panzer Division on the Brjansk Front serves as an example : During six days of combat from August 30 to September 4, 1941, this unit had 3 out of 5 KW-1 , 25 of 34 T-34 and 23 of 25 T-40 lost.
The T-40 was most widely used in the late autumn of 1941 in the Battle of Moscow . For example, on October 28, 1941, the Western Front had 441 tanks (33 KW-1 , 175 T-34 , 43 BT , 50 T-26 and 32 T-60 ), of which 113 were T-40 . As early as mid-1942, there were only a few tanks of this type left in the front units of the Red Army. On July 1, 1942, the Southwest Front and South Front had only four T-40s in service in the 478th Independent Tank Battalion, and by the end of the same month they were all lost. The T-40 was used the longest in the north-western theater of war near Leningrad . There the 124th Panzer Regiment on the Volkhov Front still owned a T-40 on January 16, 1944.
In active use, the Red Army leadership tried to use the T-40 for relief purposes, for example for battles in moorland and forest areas. Due to the insufficient number of stronger tanks, however, one was forced to use the small tank for infantry support despite its weak armor and armament.
In this use they were even inferior to the light German PzKpfW II , with the numerous PzKpfW 38 (t) , PzKpfW III and PzKpfW IV of the Wehrmacht at that time they could not generally be compared. The destruction of a T-40 with the light German 3.7 cm anti-tank guns Pak 35/36 was no problem from any range and from any angle. As a result, the losses were very high. In addition to these combat losses, there were only a few casualties without enemy influence, so the maneuverability and reliability in the Red Army were considered good in comparison to other types in this phase of the war.
Individual captured T-40s were used by the Wehrmacht under the designation 733 (r) in security units in the occupied hinterland of the Soviet Union and as tractors. A T-40 was found in the Romanian army on November 1st, 1942 .
The structure of the T-40 served as a model for the subsequent Soviet light tanks that went into series production during the war. The vehicle can be divided into five sections (from front to back):
- Gear room,
- Driver's compartment,
- Engine compartment on the right side of the tub with air inlet on the top of the tub,
- Combat area in the left part of the tub and in the tower,
- Rear area with the fuel tanks, the equipment for water travel, cooler and the heat exchanger.
This design determined the advantages and disadvantages of the T-40 and the other vehicles in its class. In particular, the location of the gearbox and chain drive wheel on the front made the design vulnerable, as the front is most exposed to enemy fire. On the other hand, the location of the tank in the stern space behind a special fire bulkhead was an advantage, unlike medium and heavy Soviet tanks (the T-34 and the tanks of the IS and KW series each had fuel tanks directly in the combat compartment). It reduced the risk of fire in the event of a hit - a problem particularly with vehicles with gasoline engines - and thus increased the crew's chance of survival. Another advantage of the T-40 was its low weight compared to differently constructed tanks (the French Automitrailleuse AMR 35 , which is comparable in armor and armament , for example, weighed 6.6 tons). The crew consisted of two men: a driver and the commander, who simultaneously took over the work of the gunner and the loader.
Tub and tower
The armored hull of the T-40 was welded together from various rolled armor plates with thicknesses of 5 and 13 mm (as well as 15 and 20 mm for the T-40S and T-30 variants ) . The surface has been flame hardened to increase strength . The T-30 was not given hardened armor in order to simplify serial production and save costs. In return, the armor thickness was increased to compensate.
The front and turret armor protected against fire from heavy machine guns , while the side armor resisted rifle fire. Front and rear armor as well as the sides of the superstructure were clearly inclined. The sides were vertical in the area of the drive and welded from two plates, the weld seam was reinforced by a riveted steel beam. Some of the armor plates (for example above the engine and the radiator) could be removed to ensure accessibility for maintenance purposes. The driver's seat was slightly shifted to the left in the front of the tub. The hatch for the driver to get in and out of was embedded in the top of the chassis. In addition, the driver had a special small hatch in the front armor plate for driving under combat conditions. The commandant sat behind the driver in the tower. The two positions were in a contiguous fighting compartment, so that, unlike the T-38 , the positions could be changed in the event of a crew member being wounded or killed. The ammunition for the main weapon was stored around the turret ring, the ammunition for the machine gun in the turret and in the fighting compartment of the armored hull. The floor and the hydrodynamic niche consisted of several welded plates. In the land variant, an emergency exit hatch was cut into the bottom of the tub behind the driver's seat. Various smaller hatches, ventilator and maintenance openings (tank or drain openings for fuel, water, oil) were distributed over the armored hull. Some of them were provided with armored covers or plugged.
The tower was shaped like a truncated cone . The 15 mm (20 mm on the T-30 ) armor was clearly inclined (25 °) in order to improve armor protection ( armor optimization by inclination ). Due to the arrangement of the engine on the right side of the vehicle, it was mounted offset to the left. A rectangular mount for the weapons and the straightening mechanism was welded to the front part of the tower, protected by an armored screen 10 mm ( T-40 and T-40S ) or 20 mm (T-30) thick. The aperture had three openings, one each for the SchWAK-T cannon or the DSchK machine gun, the DT machine gun and the sighting telescope. The tower ceiling had a large hatch for the commander to get in and out of. This hatch, in turn, had a smaller opening to keep signal flags out . Special locks on the turntable of the tower prevented the tower from moving when the vehicle was tilted.
The main weapon of the T-40 was a super heavy machine gun DSchK with a caliber of 12.7 mm. The DSchK had a barrel length of 78.7 caliber lengths (L / 79), the line of fire was at a height of 1590 mm. The maximum core range was about 3.5 km. The secondary armament was a Degtjarjow DT 7.62 mm machine gun mounted axially parallel to the DSchK . The DT -MG could easily be dismantled and the tank soldiers used it dismounted. The heavy machine gun DSchK could also be expanded by the crew for infantry use, but this was quite difficult and time-consuming. Both weapons had an elevation range of −7 ° to + 25 ° and, by rotating the turret, a lateral alignment range of 360 ° - they were not, however, suitable for aircraft combat. To make it easier for the commander to use, both machine guns were shifted from the center of the tower: the DSchK was on the right and the DT was attached to the left of the center of the tower. The machine gun system was mounted with stub axles in the frontal niche of the turret, which was protected with an armored cover at the front and an armored jacket on the side. The toothed gear to the side of the tower and the leveling mechanism with helical gear were attached to the left and right of the commander's workplace. The two straightening units were hand-driven. For faster pivoting of the tower, the commander could disengage the straightening gear and turn the tower directly. Each of the machine guns had a trigger released by means of a pedal mechanism as well as normal, manually operated triggers (for dismounted use). The straightening units and the triggers were adopted without changes in the following models and in the light tank T-60 .
The combat set for the DSchK -MG was 500 cartridge ammunition in ten cartridge belts. The muzzle velocity was 850 to 870 m / s, the theoretical rate of fire was 80 rounds per minute. In practice, the DSchK's bursts of fire were shorter in order to avoid overheating, wear and tear and loss of accuracy. Various types of projectiles with a weight of around 50 g were available for the DSchK :
|Type||Name ( Transl. / Russian)||Penetration capacity in mm||Firing range in m||Impact angle in degrees|
|Incendiary and armor-piercing projectiles||B-32 / Б-32||20
|Armor-piercing projectiles||B-30 / Б-30||20
|Incendiary and armor-piercing projectiles with tracer||BST / БЗТ||20
|Incendiary and armor-piercing bullets with a tungsten carbide core||BS-41 / БС-41||20th||750||20th|
|These data were determined using the Soviet method (Jakob-de-Marres formula, cement armor of high hardness (1.1 to 1.3 strength of the RHA ) as the target). It must be noted that the penetration ability significantly depended on the production batch of ammunition and the technology of manufacture. A direct comparison with similar data from other artillery pieces or machine guns is not possible.|
For the coaxial DT MG 2016 rounds of ammunition were (32 Disc Magazine ) carried. The T-40 variants with the SchWAK-T cannon carried 750 20-mm shells, the combat set for DT was reduced to 1512 rounds (24 target magazines) in this case.
For the installation of the SchWAK-T cannon, the mounts for the stub axles of the weapon did not have to be changed, as the stub axles from DSchK and SchWAK-T were compatible. Only the weapon mount and armored cover were removed and replaced by the SchWAK-T cannon with the old, but modified, armored cover. In addition, an armored jacket protected the parts of the weapon mechanism that were outside the fascia. In addition, the ammunition holders in the hull were rearranged to accommodate more shells for the SchWAK-T and fewer cartridges for the DT -MG.
The T-40 was powered by a 6- cylinder , four-stroke , in- line gasoline engine of the GAS-11 type (other designation GAS-202 ). The water-cooled engine developed around 62.5 kW (85 hp) at 3400 revolutions per minute. The engine was equipped with a carburetor -type K-23 equipped, but some vehicles received two carburettors GAS-M-9510 instead of the planned K-23 .
The engine air inlet on the right top side of the pan was protected by an armored hood (5 mm thick).
The engine was by an SL-40 - starter with a switch-on relay (total output about 0.6 kW and 0.8 PS) is started. It was also possible to start it using a hand crank, an internal pedal mechanism or towing it with another tank.
The T-40 had three fuel tanks in the stern. They contained 206 liters and the driving range was 300 kilometers on the road. The aviation fuel B-70 or KB-70 ( octane number 70) was used.
The T-40 was equipped with a fully mechanical power transmission . The individual assemblies were:
- the main single-plate dry clutch with friction linings made of Ferodo composite material (material named after the British manufacturer Ferodo );
- the four-speed transmission (four forward gears, a reverse gear), in many parts identical with the transmission of the GAS-51 - trucks (at that time a test vehicle);
- two side single-disc clutches with dry friction steel on steel and steel brake band with Ferodo pads;
- two simple side gears ;
- two mechanical control levers and pedals
The track drive of the T-40 was a novelty in Soviet tank construction - for the first time a Soviet series vehicle (at the same time as the heavy tank KW-1 ) was equipped with torsion bar suspension. The roller drive consisted of four rollers with three support rollers and a front drive wheel with rack teeth . The guide wheel at the rear was identical to the rollers. It was also part of the chain tensioning mechanism. The one-piece castors with a diameter of 550 mm and rubber bandages were individually torsion bar sprung without additional shock absorbers . The earlier versions T-40 and T-40S had stamped rollers, some later T-30 tanks were equipped with coarser, but cheaper, cast spoke rollers . The deflection of the first and fourth swing arm (counting from the front) was limited by limiters with rubber buffers welded close to the armored hull. The support rollers of the pre-war T-40 also had rubber pads to make the run quieter, but after the beginning of the war, due to the lack of rubber, the supports of the support rollers were abolished and these were only made of steel. In addition, special limiters were attached to the armored hull, which were supposed to prevent the crawler from slipping if the chain lay at an angle. The crawler belt consisted of 87 short chain links, cast from abrasion-resistant Hartfield steel, with two rows of teeth, 98 mm long and 260 mm wide. The track drive was adopted without changes in the following model, the T-60 , and the designers also used many parts of the T-40 / T-60 for the track drive for the T-70 , which was a further development of the Soviet light tank .
Devices for water travel
The components of the water drive were the screw propeller in the hydrodynamic niche at the stern, the cardan shaft between the screw and the PTO on the engine and the two rudders lying next to each other directly behind the propeller. The T-40 had a special heat exchanger in addition to the usual cooler to ensure effective cooling of the engine when traveling in water . A water shield was mounted on the bow to reflect waves. The crew was equipped with swimming belts for rescue at sea if there was a risk of sinking . Penetrating water could be pumped out of the tub. For orientation, the T-40 was equipped with a magnetic compass , which was manufactured at the Aviapribor plant in Moscow . The roadworthiness of the T-40 was good enough that the tank could still perform its tasks in strong seas , and in good weather it could safely carry a considerable payload (three fully equipped shooters).
Fire protection equipment
The T-40 was equipped with two carbon tetrachloride fire extinguishers. One of them was permanently installed, the other extinguisher was portable. Four tubes led from the permanently installed fire extinguisher to the engine, the carburetor and the fuel tanks. At the ends there were spray devices for a better supply of the extinguishing agent. The crews were instructed to put out the fire under gas masks because the carbon tetrachloride on the glowing metal surface reacted with atmospheric oxygen to form phosgene (carbon oxide dichloride) .
The on-board network consisted of a wire to all consumers, the armored hull as the ground potential took over the return line.
The current source was a G-41 - generator with a RRA 264 - control switch (200 W power) and 3-STE-112 - storage batteries with a capacity of 112 ampere hours . The vehicles were equipped with two batteries, but the battle tanks without a radio system only use one of them, the second served as a reserve and remained disconnected from the on-board network. In the T-40 command tanks, the second accumulator was switched on in the on-board network to ensure the radio system worked. The working voltage was 6 volts. The pantographs were:
- the exterior and interior lighting, the illuminating device for the sight scale;
- the horn ;
- the communication means: radio equipment and light signaling device;
- the engine electrics: SL-40 - starter , KS-11 - ignition coil , R-10 - ignition distributor , SE-01 - spark plugs etc.
Sighting devices and vision devices
The 12.7 mm DSchK machine gun (or 20 mm SchWAK-T cannon ) and the coaxially mounted 7.62 mm MG DT of the T-40 were equipped with a TMFP sighting telescope . If the sighting telescope was damaged, the commander could remove it and use the reserve sight. The front sight of this open sight was set up by means of a mechanism. Some visual devices were part of the equipment of each operator station (driver and commander). The driver had three corner mirrors available, one in the observation hatch in the front panel and one in each of the two sloping front armor panels. In addition to the sighting telescope, the commander had two corner mirrors in the sides of the tower.
Compared to the T-38 , the T-40's field of vision was significantly improved: the T-40 was equipped with five vision devices, compared to three in the T-38 , and the shape of the armored hull of the T-40 was designed for better observation from the driver's seat .
The T-40 -LGefechtspanzer had no radio system or an internal anti-tank intercom . The commander could only give orders to the driver with a light signal device. The different combinations of the three colored lights in the display board indicated simple commands such as “stop”, “left”, “right”, “forward” etc. The only possible means of communication between the combat vehicles was a signal flag.
The T-40 -Befehlspanzer was in contrast with a 71-TK-3 - radio equipment provided in the armored pan.
The 71-TK-3 system consisted of the radio transmitter , receiver and converter for connection to the 6 V on-board power supply. From a technical point of view, the 71-TK-3 was a duplex , amplitude modulation , tube and shortwave radio system with a heterodyne receiver . The output was 20 watts. The transmitter and receiver had a frequency range from 4 to 5.625 MHz. At a standstill, the range in voice mode without radio interference and in favorable terrain was 16 km, while the range was reduced while driving. The greatest range was achieved through the pure use of tactile radio.
|Technical data: T-40 light tank|
|classification||Floating, reconnaissance and light battle tanks|
|Chief designer||Nikolai Alexandrovich Astrov|
|Prototype designation||010 or 0-10|
|Manufacturer||Zavod No.37 ( Plant No. 37 ) in Moscow (692 + 6 prototypes)
Zavod No.37 in Sverdlovsk (20)
|Length over all||4110 mm|
|Width over everything||2330 mm|
|Ground clearance||300 mm|
|crew||2 men (driver, commander / gunner)|
|Years of construction||1940-1941|
|number of pieces||722 + 6 prototypes and 44 chassis for the BM-8-24|
|Main armament||1 × 12.7-mm MG Degtjarjow-Shpagin DSchK or
1 × 20-mm automatic cannon SchWAK-T
|Secondary armament||1 × 7.62 mm MG Degtjarjow DT|
|ammunition||500 rounds of DSchK -MG ammunition, 2016 rounds of DT -MG ammunition or
750 SchWAK-T -20 mm grenades, 1512 rounds of DT -MG ammunition
|Bow above||13 mm / inclination 60 °|
|Bow below||5 mm / 15 °|
|Driver front||15 mm / 80 °|
|Tub side up||13 mm / 65 °|
|Tub side below||13 mm / 90 °|
|Rear up||13 mm / 55 °|
|Stern down||13 mm / 60 °|
|ceiling||5 mm / 0 °|
|ground||5 mm / 0 °|
|Tower cover||15 mm / arched|
|Tower front||15 mm / 55 °|
|Tower side||15 mm / 55 °|
|Rear||15 mm / 55 °|
|ceiling||5 mm / 0 °|
|engine||6-cylinder gasoline engine GAS-202 with 85 hp|
|Power to weight ratio||12.0 hp / ton|
|Maximum speed: (road / terrain / water)||44 km / h / 20-25 km / h / 6 km / h|
|Fuel supply||206 liters|
|Fuel consumption per 100 km (road)||145 liters|
|Driving area (road)||300 km|
|Chain width||260 mm|
|Ground pressure||0.46 kg / cm²|
The T-40 was built in different versions. They differed in armor, armament and buoyancy. However, no distinction was made between the types in the front and production reports, they were generally referred to as T-40 . Nevertheless, all production vehicles had their own designation:
- T-40 , pre-war produced and buoyant;
- T-40S , produced between July and September 1941, with slightly reinforced front armor, without the necessary equipment for navigation and buoyancy, but with a niche for the propeller at the stern;
- T-30 (project designation 030 , provisional army designation T-60 ), also not floatable, without a niche and with reinforced armor. Parts of the later production were the 20 mm automatic cannon shvak cannon -T provided (so-called T-30Sch ). The development of a flatter hull without a boat shape and the improvement of the SchWAK-T cannon led to the new light tank T-60 .
The designations T-40S , 030 and T-30 are mainly used in the documents of the post-war period and in modern publications to make it easier to distinguish the T-40 variants.
The weak armament against enemy tanks induced the designers to make efforts in the armament area with the aim of improving penetration capability. As a solution to the problem, the design of a 23-mm automatic anti-aircraft gun was proposed by Ja. G. Taubin and M. N. Baburin adapted for use in tanks.
The tank version of the gun had the designation PT-23TB (Russian ПТ-23ТБ ) and was reworked in the design office of Alexander Emmanuilowitsch Nudelman with his participation. The armored hull of the experimental tank T-40 with PT-23TB cannon was modified slightly to strengthen the armor and to reduce the dimensions of the hull; The structure and position of the hatches, however, remained almost unchanged compared to the series T-40 .
Despite stronger armor and armament, the weight of the vehicle was reduced to 5.32 tons, and it was also able to swim. No changes were made to the drive, motor, transmission or electrical equipment. The experimental tank with the PT-23TB cannon was manufactured in July 1941 and tested in early October. However, during this test the cannon had many failures, so that the tank was not accepted by the Red Army and did not go into production.
Vehicles on the chassis of the T-40
The undercarriage of the T-40 was used as a chassis for the self-propelled missile launcher BM-8-24 . Instead of the turret , a rocket launcher made up of twelve girders with side and elevation gear was placed on the hull. Each carrier held two 82 mm unguided M-8 missiles on the top and bottom; a total of 24 missiles. The designation BM-8-24 (Russian БМ-8-24) is made up of BM , the abbreviation for Boewaja Maschina (Russian Боевая машина, combat vehicle ), the number 8 denotes the caliber of the missile in centimeters and the number 24 the total number of the missiles. The fire control unit of the BM-8-24 could fire all missiles in one salvo or one after the other with a predetermined rate. The vehicles were manufactured in Plant No. 733 “Compressor”; a total of 44 chassis were delivered from Plant No. 37 for the assembly of the launching ramps. After the end of series production of the T-40 , Plant No. 733 continued production of the BM-8-24 with the chassis of its successor, the T-60 .
The small floating tank T-40 was the pinnacle of the development of its vehicle class in the Soviet Union. After him, the Red or Soviet Army did not take any more small tanks into service and soon after the end of World War II, the small (as well as the light) tanks were removed from the tank classification system.
Of all the newer pre-war tanks ( KW , T-34 , T-50 and T-40 ), the T-40 was the most developed for series production and in terms of operational conditions. For the intended use - reconnaissance, communications, protection of the infantry on the march - the T-40 fully met the requirements. In addition to its crew, the T-40 could easily transport two or three riflemen with equipment on the water, which was impossible in practice with its predecessor T-38 . The armament of super-heavy and normal-caliber machine guns enabled the T-40 to be successful in infantry support against an enemy who did not use anti-tank guns and in combat against enemy vehicles with light armor. The T-40 even had a few chances against light tanks with vertical side and rear armor of 10 to 15 mm thickness , as the armor-piercing bullets of the DSchK could penetrate them. The low ground pressure and the relatively low power-to-weight ratio resulted in good mobility on soft ground (for example sand or river banks).
The main disadvantage of the T-40 was the functional overload of the commander. At the same time he had to take over the work of the commander, the loader and gunner and - if radio equipment was available - that of the radio operator.
After the start of the war against the Soviet Union, the T-40 was used for infantry support instead of reconnaissance and amphibious operations, for which it was suitable as a floating tank. Since strong armor and armament were the main requirements for such a tank, the T-40, with its machine guns and armor protection that could only withstand fire from light infantry weapons and partly from heavy machine guns and anti - tank rifles, could not, or even , the more modern light tanks T-50 replace the obsolete T-26 . It was clearly unsuitable as an infantry tank. However, the course of events was determined by the technological and economic circumstances. The attempt to organize series production of the T-50 in Plant No. 37 failed, but after the abandonment of the equipment required for water travel and the reinforcement of the armor of the T-40 , it caught up with the T-26 in terms of armor protection.
The original order to end production of the T-40 was revoked and the "land variants" T-40S and T-30 were manufactured instead . The design of the T-40 still had great potential for improvement and enabled the rapid development of the new light tank T-60 with stronger armor and armament.
Even after the defensive phase of the war, the Soviet armed forces had a need for specialized vehicles like the T-40 . When the Red Army went on the attack, the Soviet commanders remembered the need to have floating tanks available. The outdated, leftover T-37 A and T-38 armored vehicles were used together with T-40 for some amphibious operations (for example, to overcome the Swir River). The amphibious wheeled vehicles DUKW-353 and Ford GPA , which were delivered to the Soviet troops under the lend lease agreement , were also used for these operations. However, both could not fully compensate for the lack of swimming tanks, as they were unarmored and unarmed and could not replace a swimming tank. They were also not available in sufficient numbers. The river flotillas with armored motor boats were mostly unable to intervene. That is why the Soviet soldiers often had to overcome water hazards with improvised swimming equipment. As a result, the losses from German machine gun and mortar fire were very high. The fast and mobile T-40 swimming tank made it much easier to take the other side of the water hazard.
Lightly armored floating vehicles with super-heavy machine guns or small-caliber automatic cannons are now widely used in modern armies. In many cases, the caterpillars have been replaced by large wheels with adjustable air pressure. A good example is the Soviet BRDM-2 .
|Technical specifications||T-40||T-30||Pz.I Ausf. B||AMR 35 ZT||Type 95 "Ha-Go"|
|Country||Soviet Union||German Empire||France||Japan|
|Weight in tons:||5.5||5.8||6.6||7.4|
|Overall length in m||4.1||4.4||3.9||4.4|
|Width over everything in m||2.3||2.1||1.6||2.0|
|Height in m||1.9||1.7||1.9||2.3|
|Year of construction (s)||1940-41||1941||1935-39||1935-40||1936-43|
|Main armament:||12.7 mm, L79||20 mm, L82||2 x 7.92 mm MG||13.2 mm||37 mm, L37|
|Secondary armament:||1 × 7.62mm machine gun||-||-||2 × 6.5 mm MG|
|Grenades in pieces:||550||750||-||?||75|
|Gun ammunition shot:||2016||1512||2250||-||3300|
|Front armor in mm / slope||15/80 ° (below),
13/60 ° (above)
|20/80 ° (below),
15/60 ° (above)
|14/65 ° (below),
18/80 ° (above)
12/90 ° (top)
|Side armor in mm / slope||13/90 ° and 13/65 °||15/90 ° and 15/65 °||14/90 ° and 14/68 °||10||12/90 ° and 12/56 °|
|Tower armor in mm||15th||20th||14-15||13||12|
|Engine type||Gasoline engine||Diesel engine|
|Power in hp||85||100||80||110|
|Power-to-weight ratio in hp / ton:||12.0||17.2||12.1||16.2|
|Maximum speed in km / h:||44||40||55||45|
|Driving range (road) in km:||300||180||180||250|
Outside the Soviet Union, no floating tanks comparable to the T-40 were produced in series at the time. Armor on land tanks from other countries in the weight class of 5 to 7 tons was comparable to that of the T-40 in the German light tank I , the French AMR 35 automitrailleuse and the Japanese light tank type 95 “Ha-Go” . The T-40 was better armed than the Panzer I (12.7 mm and 7.62 mm machine guns against two 7.92 mm machine guns), the AMR 35 was roughly equally armed (13.2 mm). mm machine gun) and the Type 95 was superior to the T-40 with its 37 mm gun. The variants of the T-40 with cannon armament (serial tanks with 20-mm- SchWAK -T or experimental tanks with 23-mm- PT-23 ) could partly compensate for this disadvantage. Considering the high reliability, low production costs and further development potential of the T-40 , this tank can be considered a success for Astrow and his colleagues. However, the level of training in the Red Army in 1941 was too poor for the correct use of this specialized vehicle and so the T-40 shared the fate of the Soviet troops in 1941–42.
The only two T-40s that have survived to this day are exhibited in the Kubinka Tank Museum near Moscow . One is a T-30Sch tank (with a 20 mm SchWAK -T cannon ), the other is a T-40S test vehicle, but also with a SchWAK-T cannon instead of the DSchK machine gun. The T-30Sch was made roadworthy again in 2007, whereas the T-40S is a static exhibit.
- Солянкин А. Г. и др .: Советские малые и лёгкие танки 1941–1945. Москва, Цейхгауз, 2006, ISBN 5-94038-113-8 .
(Russian; German roughly: AG Soljankin et al .: The Soviet small and light tanks 1941–1945. Moscow, Zeughaus, 2006.)
- Прочко Е. И .: Лёгкие танки Т-40 и Т-60. (Бронеколлекция). 1997, No. 4
(Russian; German roughly: EI Protschko: The light tanks T-40 and T-60. (Tank collection). 1997, No. 4)
- Мощанский И. Б .: Лёгкие танки семейства Т-40. «Красные» разведчики. Вече, Москва 2009, ISBN 978-5-9533-4330-5 .
(Russian; German roughly: Ilja B. Moschtschanski: The light tanks of the T-40 vehicle family. The “red” reconnaissance aircraft. Wetsche, Moscow 2009)
- Свирин М. Н .: Броневой щит Сталина. История советского танка 1937–1943. Москва, Эксмо, 2007, ISBN 978-5-699-16243-7 .
(Russian; German roughly: Michail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. Moscow, Eksmo, 2007)
- Коломиец М. В. Танки-амфибии Т-37, Т-38, Т-40. (Фронтовая иллюстрация). альманах 2003, No. 3.
(Russian; German roughly: MW Kolomietz: Die Amphibienpanzer T-37, T-38, T-40. (Front illustration). Almanach 2003, No. 3.)
- Коломиец М. В. Битва за Москву 30 сентября - 5 декабря 1941 года. (Фронтовая иллюстрация). альманах 2002, No. 1.
(Russian; German roughly: MW Kolomietz: The Battle of Moscow September 30 - December 5, 1941. (Front illustration). Almanach 2002, No. 1.)
- Свирин М. Н .: Стальной кулак Сталина. История советского танка 1943–1955. Москва, Эксмо, 2007, ISBN 978-5-699-14628-4 .
(Russian; German roughly: Michail N. Swirin: The steel fist of Stalin. The history of the Soviet tanks 1943–1955. Moscow, Eksmo, 2007.)
- Желтов И. Г. и др .: Неизвестный Т-34. Москва, Экспринт, 2001, ISBN 5-94038-013-1 .
(Russian; German roughly: IG Scheltow et al .: The unknown T-34. Moscow, Exprint, 2001.)
- Alexander Lüdeke : captured tanks of the Wehrmacht - Great Britain, Italy, Soviet Union and USA 1939–45. Motorbuch Verlag, Stuttgart 2011, ISBN 978-3-613-03359-7 .
- ArmorSite: T-40, technical data, photos (Russian)
- ArmorSite: Chief Designer NA Astrow's Memories of the T-40 Tanks (Russian)
- ArmorSite: T-40, technical description, photos, sketches (corresponds to description in: AG Soljankin et al .: The Soviet small and light tanks 1941–1945. Moscow 2006, ISBN 5-94038-113-8 .) (Russian)
- Lüdeke: captured armor of the Wehrmacht. 2011, p. 51.
- (M) Ilja B. Moschtschanski: The light tanks of the T-40 vehicle family. The “red” scouts.
- Ilja B. Moschtschanski: The light tanks of the T-40 vehicle family. The “red” scouts. P. 65, V, 73.
- (S) Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 8, 26.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 35.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 32.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 40.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 36.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 38.
- Michail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 285.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 287.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. Pp. 287, 288, 289.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 291.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 41.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 39.
- Mikhail N. Swirin: The armored shield of Stalin. The history of the Soviet tanks 1937–1943. P. 282.
- (F) Michail N. Swirin: The steel fist of Stalin. The history of the Soviet tanks 1943–1955.
- Mikhail N. Swirin: The steel fist of Stalin. The history of the Soviet tanks 1943–1955. P. 229.
- (P) AG Soljankin u. a .: The Soviet small and light tanks 1941–1945.
- AG Soljankin include: The Soviet small and light tank 1941-1945. P. 3.
- AG Soljankin include: The Soviet small and light tank 1941-1945. P. 10.
- A. G. Soljankin et al: The Soviet small and light tanks 1941–1945. P. 4.
- A. G. Soljankin and others: The Soviet small and light tanks 1941–1945. Pp. 6-11.
- AG Soljankin include: The Soviet small and light tank 1941-1945. P. 13.
- (T) IG Scheltow u. a .: The unknown T-34.
- I. G. Scheltow and others: The unknown T-34. P. 116.
- IG Scheltow et al: The unknown T-34. P. 120.
- (K) MW Kolomietz: Front illustration
- M. W. Kolomietz: The amphibious tanks T-37, T-38, T-40. (Front illustration), Almanach 2003, No. 3.
- MW Kolomietz: The Battle of Moscow September 30 - December 5, 1941. (Front illustration), Almanach 2002, No. 1.
- (B) " Russian BattleField " website
- "Russian BattleField", based on EI Protschko's article The light tanks T-40 and T-60 (English), accessed on September 17, 2008.
- Website "Russian BattleField", based on EI Protschko's article The T-40 and T-60 Light Tanks. (Russian), Retrieved September 17, 2008.
- The memories of the chief designer NA Astrow about the T-40 tanks : Плавающий танк Т-40 был разработан перед самой войной. Оригинальная, не имевшая прототипа машина… - German for example: The T-40 tank was developed before the war. The vehicle was original, it didn't have a prototype ...
- M. Kolomietz gives similar numbers in his article in “Frontillustration” - 44 tanks in 1940 and 252 in 1941, making the result 296 T-40 against 295 in the representation Protschko or Scheltov.
- The Pak 35/36 cannon was able to penetrate about 35 mm at 500 m with an impact angle of 30 °, the Soviet specialists rated 45 mm as the minimum armor thickness for reliable protection against 37 mm tank shells - MN Swirin: The armored shield Stalin's. The history of the Soviet tanks 1937–1943. P. 123.
- Instructions for the 12.7 mm machine gun «Utjos» (NSW-12.7). Wojenisdat MO USSR, Moscow, 1978 (Russian Руководство по 12,7-мм пулемёту «Утёс» (НСВ-12,7). - М .: Военное издательство МО С .СР, 1978.) This machine gun uses the same ammunition and has the same external ballistics as the DSchK.
- For the technical data of the 71-TK-3 and other Soviet wartime radio systems, see here (Russian), accessed on August 1, 2008.
- Tanks were now only divided into medium and heavy tanks and floating tanks; the pre-war system knew tankettes, small, light, medium and heavy tanks.