Off-road capability is very important, sometimes of decisive importance for army transport and special vehicles. This quality is primarily due to the passability on various types of soil and the ability to overcome all kinds of obstacles - ditches, walls, slopes, fords. The caterpillar is preferable to the wheel in these circumstances. And if the wheel remains in service, it will not be quite ordinary. Rice. above Yuri Yurov
Conventional two- and multi-axle four-wheel drive vehicles, with all the design improvements, are still classified as "off-road". In the niche of "cross-country vehicles" or "all-terrain vehicles" the first places are occupied by caterpillar tracks. A pair of tracks of sufficient width, with a certain length of the supporting surface, the proper arrangement of road wheels, drive and idler wheels, provides low ground pressure and good traction, more traction, confident overcoming of various obstacles and agility.
Multipurpose tracked transporter-tractor MT-LBu, USSR. The mass of the vehicle in running order is 10.4 tons, the carrying capacity is 4 tons, the engine is diesel, 300 liters. sec., road speed - up to 60 km / h, afloat - 5 km / h, cruising range - 500 km.
The desire to unify cross-country vehicles led to the emergence of multi-purpose tracked chassis suitable for transporting troops and property, mounting weapons and special equipment in armored and unarmored versions. A classic example of a tracked multipurpose chassis of a light class was the Soviet armored transporter-tractor MT-LBu with a carrying capacity of 4.0 tons, the basic machine of a unified (and perhaps the most diverse) family of tracked vehicles, which are still widely used today. One can also cite as an example the Russian MT-SM and MT-T transporters, used for towing various systems weighing up to 15-25 tons (while part of the cargo or the calculation is transported on the conveyor itself), the installation of missile, cannon-missile systems, engineering equipment. The speed of such "self-propelled vehicles" is quite decent - up to 70 kilometers per hour.
Martin Vought Systems Corporation). MLRS system
In the USA, the M987 (with a carrying capacity of up to 10 tons) based on the Bradley BMP with a chassis extended by one roller was adopted as a multipurpose chassis. On the basis of the M987, MLRS MLRS, command and staff vehicles, an electronic warfare vehicle, ambulance and cargo transporters were created.
Most transport and special tracked vehicles, like combat vehicles, are "shod" in steel tracks, consisting of separate links. However, on a number of units, hingeless tape tracks are successfully operated. They are lighter than link ones, less sensitive to clogging and have a 10-15% higher efficiency, although they are much less durable - even when reinforced with cord and steel crossbars. An example of a machine with such tracks is the BR-100 Bombi three-seater snowmobile of the Canadian company Bombardier Limited. Its lightweight non-metallic "summer" caterpillar, in combination with the tires of the road wheels, gives a specific ground pressure of about 0.1 kilogram per square centimeter (this is about six times less than the pressure on the ground of an adult's feet), and the "winter" one - only 0.08 This snowmobile also visited the sands of the Middle East, where he felt quite confident.
Of course, each type of mover has its own advantages and disadvantages, which are often the flip side of the advantages. It is not surprising that the search for new, original all-terrain chassis schemes has been going on for many years. Moreover, the "all-terrain vehicle", both military and dual-use, is a specific vehicle and is created for special conditions. And in order to meet the requirements of the customer, designers often have to resort to non-standard solutions. Let's take a closer look at some of them.
Heavy multipurpose tracked transporter-tractor MT-T, USSR. The mass of the vehicle in running order is 25 tons, the carrying capacity is 12-17 tons, the weight of the trailer is up to 25 tons, the engine is diesel, 710 liters. sec., speed - up to 65 km / h, cruising range - 500 km.
Caterpillar transformations
"The car … turned off the road to the virgin lands, crossed a roadside ditch, then passed at a considerable speed on soft grassy ground, freely and smoothly overcoming various obstacles", - this is how the protocol of quality tests of the "car sleighs" created by the French inventor for Russian roads was recorded …
In 1911 in St. Petersburg there were tests of "motor vehicles" intended for movement on snow - "seasonal" transport has always been relevant for Russia. Compared to other auto and snowmobiles, the car of Adolphe Kegress was not distinguished by originality: he simply attached skis to the front wheels of the car, and wrapped the rear with chains. Two years later, in the workshop of the imperial garage, Kegresse, who, being a French citizen, served as the head of the technical part of the garage, tried a different system, installing a caterpillar drive instead of the rear wheels. In 1914, Kegresse was given the privilege of producing "sleigh cars running by means of endless pressure roller belts." The Russian-Baltic Carriage Works signed a contract for the installation of its propellers on its C24 / 30 cars. The Kegress propeller consisted of caterpillar trolleys with rubber-fabric tracks, loosely attached instead of wheels on the rear axle half-axle. The set for the Russo-Balta car weighed 490 kilograms, but provided a specific ground pressure of only 0.8-1.0 kilograms per square centimeter. They put skis on the front wheels. The vehicle handling has not changed. During tests on the frozen Neva, the speed reached 60 kilometers per hour. However, the wheels slipped along the track, mud was packed between them, the tracks jumped off and broke. Refinement of the propulsion unit continued.
With the beginning of the war, Kegress did not fail to present his invention to the Main Military-Technical Directorate of the Ministry of War. They were interested in them - not even because the offer came from the garage of His Majesty, but because it seemed sensible and promising. The tracked and half-tracked course was not new: the Russian army, like the British and French, already purchased tracked tractors as tractors for artillery. By that time, the inventor A. A. Porokhovshchikov with his single-tracked "All-terrain vehicle", which was not at all a prototype of a tank, to which it is often referred, but an attempt to create an all-terrain vehicle - an original, but not very successful design. Kegress's proposal made it possible to turn almost any car into an all-terrain vehicle with a relatively small alteration. In August – September 1916, the kegress was tested by a run between Mogilev and Tsarskoe Selo - the above quote is from the test report.
As a result, a program was developed to create a whole "fleet" of all-terrain "self-propelled" vehicles, from light staff to trucks and armored vehicles. The improved track was made at the Triangle plant. The Putilovsky plant was ordered half-tracked armored vehicles and alteration of cars "Russo-Balt", "Renault", "Packard", "Morse".
But other events were looming - a financial crisis, factory strikes, revolution. Guessing that nothing good awaits him in the new Russia, Kegresse returns to his homeland and again finds himself at the court, although not to the imperial one. The fruit of his joint work with the engineer M. Hinstein and the car maker A. Citroen was the Citroen Auto Caterpillar 10CV B2, which appeared in 1921. France did not have snowy winters, but she owned colonies with extremely bad roads. And although the 1924-1925 Black Raid from Algeria to Madagascar was presented as a test run and a scientific expedition, it was clear that a "colonial" transport was being tested. The fate of people is strange: the participants in the raid were Kegress's nephew and artist A. E. Yakovlev, the son of one of the creators of the first Russian car, E. A. Yakovleva. Then there was the "Yellow", the trans-Asian raid of "Citroens", after which it was possible to interest the French military. In particular, Citroen-Kegres and Panar-Schneider-Kegresses were used in battalions of “transported dragoons” (motorized infantry) and in reconnaissance units.
Nyberg in Sweden, Kornberg in Denmark, the Italian firm Alfa Romeo, the British Burford and Crossley tried to develop Kegress's ideas. They also experimented with Kegress's mover in Germany, but they preferred half-tracked vehicles of a slightly different scheme.
Specialized amphibious all-terrain vehicle "Argo" in a four-axle version (carrying capacity 0.5 t). Engine - petrol, 25 HP with., land speed - up to 35 km / h, afloat - 4 km / h, there is a removable caterpillar. Rice. Mikhail Dmitriev
Yes, and in Russia "kegresses" did not forget. In 1919, the Putilovsky plant finally began to build half-track armored cars - in total, 6 of them were built under the guidance of technician A. Ermolaev. It is interesting that on October 25, 1919, three such "half-tanks" successfully attacked Yudenich's troops north of Detskoye (Tsarskoye) Selo, where the history of "kegresses" began ten years earlier. Passenger car sledges, "kegres", converted from Rolls-Royce, drove Vladimir Lenin between Moscow, Gorki and Kostino. In the mid-1920s, the French Citroen-Kegresse was tested, but they were not entirely satisfied with it. In the 1920s-1930s, Professor N. S. Vetchinkin, head of the garage of the Economic Council A. S. Gusev, engineers of NATI A. S. Kuzin, B. V. Shishkin, G. A. Sonkin. The half-track NATI-3 based on GAZ-AA was tested in the Karakum Desert, Chukotka and Taimyr, and served as the basis for the serial GAZ-60 truck. The "Kegress" course with improved engagement was used in the ZIS-22M and ZIS-42, removable kits were produced for the GAZ-MM and ZIS-5 - these models were called GAZ-65 and ZIS-33. The half-track truck (artillery tractor ZIS-42M) served well during the Great Patriotic War.
Kegresse himself died in 1943. A year later, the Allies were traveling from west to east across France on American half-track armored personnel carriers created by Diamond Motors back in 1940 without Kegress's participation, but according to his scheme - on the basis of a serial truck with a rubber-metal track on the rear axle and a protective drum in front of in front of him. These armored personnel carriers of the M2 to M17 models have become the most massive "kegresses".
After the Second World War, "kegresses", it would seem, left the scene, like all half-track all-terrain vehicles. Nevertheless, the idea of a replaceable light caterpillar track, which was inspired by the Russian snow, and was first implemented in Russia, continued to attract designers. An example of this is the British car "Centaur", which was tested in the 1980s. And the American "Matrex" has released a set of propellers with a rubber-metal caterpillar, which can replace all 4 wheels on jeeps - fortunately, all the wheels are driven. It was reported that such a kit was tested on an HMMVW car, although such kits are not yet visible on army vehicles.
Very, very large wheel
The idea of increasing flotation by increasing the diameter of the wheel is not just old. It can with good reason be called even ancient. Let us recall the high-wheeled carts of Transcaucasia and Central Asia, medieval projects of huge high-wheeled chariots. In the 19th century, new opportunities appeared for its implementation, because the caterpillar drive was still too "young". In 1823 in England, D. Gordon proposed a steam tractor with driving rear wheels with a diameter of 2, 7 meters, driven through inner rims. At the beginning of the 20th century, tractors with not so impressive, but still large drive wheels and wide rims, no longer surprised anyone, including in the army. Interest was aroused, for example, by the Austrian tractors M.16 and M.17 with surprisingly high wheels. The German firm "Hansa-Lloyd" in 1917 built an army tractor with two drive wheels with a diameter of 3 meters with a wide steel rim and a front swivel roller.
"Fragile" chassis of a heavy tractor P4-110 by Italian engineer Pavezi, early 1930s. Rice. Mikhail Dmitriev
The successes of tracked chassis have reduced interest in high-wheeled vehicles. However, in 1928, a detailed project of a wheeled "desert ship" appeared in Germany: a multi-storey hull 48 meters long and 15 meters high rested on 4 wheels with a diameter of 12 meters and a rim width of 2.5 meters, the fuel cruising range was supposed to be 8000 kilometers. The transport-passenger version of the car would provide transportation of 100 passengers and 200 tons of cargo; also provided for a version of the machine "for police service and defense purposes." The author of the project, engineer Bischoff, conceived a similar machine back in 1905, serving the transport of the German colonial troops in Africa. In 1916-1917, the idea allegedly attracted the attention of the Turkish government, which dreamed of transferring its troops across the Arabian Desert to the Suez Canal.
The giants dreamed of the designers for a long time. In the USSR in 1936, for example, a professor at the Air Force Engineering Academy. Zhukovsky G. I. Pokrovsky offered a transpolar cargo-passenger all-terrain vehicle weighing 1000 tons, however, tracked. In 1938, the engineer of the ZIS plant Yu. A. Dolmatovsky proposed an equally fantastic project of a large transport unicycle "Autosphere ZIS-1001" with a spherical body. The tail support wheels were attached to the beam along with the empennage: on the move, the empennage would raise the beam and provide stabilization of the Autosphere.
The idea of high-wheeled transport vehicles did not leave the designers even later - and also in connection with the military development of distant territories. So, in the United States in 1956-1957, the Snow Buggy car of the Le-Turno Westinghouse company was tested, which had four unsprung gable wheels with a diameter of about 3 meters with wide tires of the Giant type and a diesel-electric drive of the motor- wheel . In the same period, a heavy-duty road train was developed for the supply and maintenance of anti-aircraft and anti-missile defense radars in the Arctic regions. The train consisted of 12 vehicles with wheels with a diameter of 3 meters: 10 two-axle 13-ton cargo platforms and two extreme three-axle vehicles with power plants and crew cabins. The power unit, located on the extreme machines, included three gas turbine engines of 350 liters each. with. (more profitable in the Arctic than piston engines).
In general, for the northern regions, designers often offer schemes for wheeled all-terrain vehicles, including military ones, with tires of large diameter, wide profile and low pressure. An example of this is the experienced Russian "Vector" with a wheel arrangement of 8x8, which, as far as is known, interested the Ministry of Internal Affairs.
"Flexible" all-terrain vehicles
One of the old ideas for increasing the cross-country ability of ground vehicles is a flexible all-wheel drive chassis made of articulated links, a kind of "fully active" road train. In the 1920s, the Italian engineer Pavezi drew much attention to his work. In an effort to increase the cross-country ability of wheeled vehicles, he combined the all-wheel drive scheme and the articulated body of the vehicle. Mutual rotation of the front and rear links of the body relative to each other in three planes ensured constant contact of the wheels with the ground on any terrain (the car seemed to "flow around" the terrain) and reduced the turning radius of the car. The specific ground pressure and slippage decreased, and the grip improved. Since the wheels did not need to turn relative to the body, it was possible to put wheels of large diameter (1, 2-1, 7 meters) with a wide rim, without reducing the useful volume of the body, place a more powerful engine. The supporting permeability of the machine, that is, the ability to move on weak deformable soils, was successfully combined with the cross-country ability of the profile (the ability to overcome irregularities, obstacles and fit "into the track"). Pavezi's combat vehicles did not work out very well, but the tractors served in the Italian army. They even became trophies of the Soviet troops during the Great Patriotic War. The British used their version of the Pavesi tractor, produced under license and improved by Armstrong-Siddeli.
Snow and swamp-going vehicle 2906 of the Blue Bird complex. The speed of the transporter on the road is up to 80 km / h, while afloat - up to 9 km / h.
Interest in such machines revived in the 1960s in connection with the experience of local wars in difficult-to-pass areas. In the United States, for example, they adopted a whole program for the creation of military articulated vehicles. Within its framework, a two-link cargo M520 "Gower" was created with the rotation of the links only in the horizontal plane, the M561 "Gama Gout" with a turn in several planes, followed by the "Flax Frame", a kind of designer of several active (drive) uniaxial sections, "Dragon -Wagon "and" Twister "with biaxial links, folded in two planes. In "Twister" (8x8) by "Lockheed", each link had its own engine and four-wheel drive, and for greater agility, both pairs of wheels of the front section were made steerable. However, wheeled articulated vehicles were then more useful in the civilian sphere - an example of this is the Soviet high-wheeled universal tractor K-700 "Kirovets" or the Swedish "Volvo" VM DR860. Although the development of "Kirovtsa" in the early 1960s at the Leningrad Kirov plant assumed the possibility of military use.
Articulated circuits were also useful for tracked chassis. These schemes can be divided into two types: trailed, with a sequential arrangement of links, and saddle, when individual active links are connected by a cargo platform.
In the 1950s, engineer Nodwell in Canada proposed an articulated system of two track units connected to each other through a pivot and hydraulic power cylinder. The Swedish company "Volvo Bolinder-Muktell" in 1961 produced the Bandvagn (Bv) 202 conveyor of a trailed scheme of two articulated links with rubber-metal tracks, a specific ground pressure of 0.1 kilogram per square centimeter and a travel speed of up to 40 kilometers per hour. The Bv-206, which replaced it in 1981 (already represented by the Hegglunds company) with a carrying capacity of up to 2 tons, gained wide popularity in foreign armies - it was purchased by Great Britain, Italy, Canada, Norway, USA, Finland, Germany - and served as the basis for a rather extensive family transport and special vehicles, including armored Bv-206S and Bv-210. The power plant is mounted in the front link, the transmission transmits rotation to the caterpillar tracks of the front and rear links. The same company created the TL-4 transporter with a carrying capacity of 4 tons and its armored version BVS-10 - here the carrying capacity decreased to 2.84 tons.
Floating two-link transporter DT-30P "Vityaz", USSR. Machine weight - 29 tons, carrying capacity - 30 tons, number of seats in the cab - 5, engine - diesel, 710 liters. sec., speed on land - up to 37 km / h, afloat - 4 km / h, cruising range for fuel - 500 km.
An example of a very successful family of tracked two-link transporters, built according to this scheme, is the Soviet Vityaz family, developed under the leadership of K. V. Oskolkov (later he was replaced by V. I. Rozhin). Prototypes, created with the participation of the 21st Research Institute, were built in 1971 at the Rubtsovsk Machine-Building Plant, and since 1982 the machines have been serially produced by the Ishimbay Transport Machine-Building Plant. The family includes floating transporters DT-10P with a carrying capacity of 10 tons, DT-20P (20 tons) and DT-30P (30 tons) and non-floating DT-20 and DT-30. Two caterpillar links of the floating "two-link" are connected by an articulated hitch, and a pivoting device with four hydraulic cylinders provides forced folding of the machine in the horizontal and longitudinal-vertical planes and mutual rotation in the transverse plane. Diesel engines have a multi-fuel diesel engine and a hydromechanical transmission that transmits rotation to the drive wheels of the tracked course of both links. Even in the DT-30P with a maximum weight of 59 tons, thanks to four rubber-fabric caterpillar tracks with a width of 1.1 meters with a length of the supporting surface of 4.5 meters and track rollers with sponge chambers, the specific ground pressure does not exceed 0.3 kilograms per square centimeter (for comparison, for MT-LBu - 0, 5). Folding swing reduces braking losses and ground damage. The active second link allows you to overcome a vertical obstacle by lifting and "pushing" the front link onto it. The displacement of the pontoon hull and skating rinks ensures overcoming water obstacles without preparation, and folding the links in a vertical plane facilitates access to an unprepared shore or such a complex operation as an independent return from the water to board a landing craft. Locking center and link differentials allow the machine to move while maintaining only two tracks. The DT-30P can carry a motorized rifle company with light weapons, while it itself is placed in the cargo compartment of an Il-76 medium military transport aircraft. Non-floating diesel fuel are designed for bulky cargo up to 13 meters long (versus 6 for a floating one) and are made according to a saddle scheme - with a single platform for both links. In addition to cargo transporters, combat platforms can also be carried.
"Knights" are intended for the transportation, supply and maintenance of troops in swampy areas, in Siberia, in the north, the Far East, and have worked in Antarctic expeditions.
Articulated snow and swamp vehicle SBH-2 "Attack", Russia. Carrying capacity - 0.5 tons, engine - diesel, 52.6 liters. sec., speed - up to 45 km / h. Rice. Mikhail Dmitriev
In terms of carrying capacity, the Canadian Husky-8 (36.3 tons) is close to the DT-30, but it is a commercial vehicle with a speed of up to 14.5 kilometers per hour. As you can see, two-link tracked vehicles are quite naturally created in countries with a harsh northern climate. However, Southeast Asia also entered the business - the Singaporean company Singapore Technology Kinetic, using American and Canadian units, created a two-link ATTS transporter with a carrying capacity of 4.7 tons and a speed of up to 60 kilometers per hour. And it is no coincidence that the "two-link workers" have already gone beyond the "snowy northern latitudes." The same British have already brought Swedish transporters with them to Iraq and are using them there, not without success. And the Russian DT-10P has found application in Chechnya. Based on the experience of military operations in the North Caucasus, the development of means of reducing acoustic and thermal signature and local protection, which were presented already in a new family of "two-link" (under the motto "Omnipresent") with a more powerful engine, continued.
Canadian "Husky-8"
The demand for machines of this type, apparently, will expand, and the greatest interest is now caused by machines with a carrying capacity of up to 4 tons, with the ability to move afloat, the presence of protective equipment while maintaining speed. So, according to the requirements developed by the 21st Research Institute of the Russian Ministry of Defense, the DT-4P "Ice ax" with a carrying capacity of 4 tons and an armored DT-3PB for 3 tons were developed at the Rubtsovsk Machine-Building Plant.
But the articulated wheel chassis continues to attract attention. The Yekaterinburg company "Iset" presented two-link snow and swamp-going vehicles "Attack" of 4x4 wheel arrangement with low-pressure tires and the carrying capacity of an army jeep.
Spherical exotic
The creators of all-terrain vehicles periodically return to such outwardly exotic schemes as spherical or hemispherical wheels - they are attracted by the "automatic" adjustment of the bearing surface area depending on the soil - wheels with "active" segments around the circumference, a combination of a wheel propeller with a walking, caterpillar with "Roller" and so on. True, such machines have not yet appeared in the military service.
They have been experimenting with such combinations of wheeled and caterpillar tracks for a long time, when one of them is made lifting. Many of these prototype chassis were built in the 1920s and 1930s. An example of a later return to the idea is the chassis of the "object 19" of the Design Bureau of the Altai Tractor Plant, tested in the mid-1960s, or the "high-speed all-terrain" vehicle BVSM-80 R. N. Ulanova 1983. Both chassis, which remained experimental, were 4x4 vehicles with a small tracked propeller, lowered to the ground to increase cross-country ability.
Floating two-link transporter DT-10PM "Omnipresent", Russia. Carrying capacity - 10 tons, engine - diesel, 810 liters. sec., speed on land - up to 40 km / h, afloat - 5-6 km / h.
We go on the screw
The idea that the auger - the famous screw of Archimedes - can serve not only to supply water, minced meat and the like, but also serve as a mover, did not arise yesterday either. So, in 1920 in the United States, engineer F. R. Bar built a "snow motor" for driving on snow and ice by installing four auger drums instead of wheels or tracks on the tractor. Soon a similar propulsion device was tested on a Fordson tractor and an Armstead car. The diameter of the drums provided a low specific pressure, and the rotation of the endless screw propelled the machine even on the most viscous soil. Then the augers (rotors) began to play the role of floats: the resulting amphibians felt great on shallow swampy bodies of water, rivers with muddy or sandy shores. The idea of the auger was returned several times. During the Second World War, the American army tested several augers in Alaska. In 1960, in the same USA, the Marsh Skru Amphbien and RUC augers were tested, as well as the Twilighter with two augers and a wheel drive that was retracted when moving to soft ground.
In the USSR, at the Gorky Polytechnic Institute in the 1970s, a rotary-screw "ice-milling" machine was built on the basis of GAZ-66 units, and a ski-screw snowmobile "Laika" was also developed there. But the search and rescue complex of machines that appeared in the same years, developed at SKB ZIL for the space search and rescue service, turned out to be much more interesting, and there is no need to prove the military importance of space services. Note that the complex was developed under the leadership of V. A. Grachev - an outstanding designer, who is called "Korolev of the automotive industry". The "complex 490", or "Blue Bird", adopted in 1975, included machines of different types: two wheeled amphibious all-terrain vehicles (passenger 49061 with a carrying capacity of 2.02 tons and transport 4906 for 3.4 tons) and a rotary auger-type snow and swamp-going vehicle 2906 (later - 29061). The transporters have an all-wheel drive three-axle chassis (6x6) with an independent torsion bar suspension of the wheels and a uniform axle arrangement, a displacement body, and steered front and rear wheels. Their equipment included a radio navigation system and a direction finder. But such cars will not pass everywhere either. Therefore, a snow and swamp-going vehicle with a carrying capacity of 0, 375 tons is transported on a cargo conveyor equipped with a crane boom. He can swim, but his main purpose is to move through swampy swamps and virgin snow of any depth. The entire complex is transported entirely by an Il-76 aircraft, each vehicle individually - by an Mi-6 or Mi-26 helicopter. Well, "all-terrain" is really a complex concept.