Projects and prototypes based bridgelayer MTU
Bridgelayer MTU served «testing ground» for new bridge means. But first it is to talk about two projects carried out in the OKB SV IR led AF Kravtseva at the initial stage of work on the K-67 launched bridges (in accordance with the TTT approved P. Marshal Rybalko in October 1946).
In May 1948 OKB IR SW version proposed bridge kit K-67, providing installation (installation) on the barrier rut bridge 15 m long with two retrofit T-34 tanks. The bridge is equipped with built-in wheels can be transported on a trailer at the tanks, trucks and cars. Bridge and assembly elements kit mounted on the T-34 in the source area. According to the draft tanks equipped trosoblochnoy system providing laying open the bridge (after a stop at the tank obstacles) for 0.3-0.5 min. Carrying capacity of the bridge is 75 m, width of the carriageway — 3,1 m, height — 0.93 m, mezhkoleyny clearance — 0.98 m. The bridge was installed without logging crews of the tanks.
In November of the same year, the Design Bureau IR ST completed the project of the bridge tank (mostonostsa) K-67 from three-section retractable bridge. As a base used modified chassis of the T-54. By design, the machine weighed 37.5 tonnes and provided installation of the bridge carrying capacity of 75 t without leaving the crew. The width of the roadway of the bridge is 4 meters, length — 15 m, height — 0.95 m, mezhkoleyny clearance — 1 m. According to the project, the bridge can be moved apart to the width of the vehicle position (3 meters) in operation (4 m) back. Disclosure (folding) end sections provided with special arrangements. Estimated time of installation of the bridge was 1-2 min. The crew — two people. As the weapons were provided anti-aircraft gun and two machine guns DSK DTM. Subsequently, the bridge circuit with the opening end sections embodied in the design of serial bridge layer MTU-20.
In 1952, EDO IV were transferred to the new staffing as a result of which it was purely a design organization. Accordingly, the changes and the nature of his work. Earlier OKB been developing prototypes of engineer armament, as the customer acted Scientific and Technical Committee. This initiative belonged to the performances is the design office. Further, after the production of prototypes to OZIV, positive test results and their acceptance into service, OKB convey these products to industry for mass production. Now, under the new staffing design team began to design the only experimental samples by category NIII them. DM Karbysheva.
In 1954-1955. EDO BPI SA as part of the research theme UPS to prepare a technical proposal for the complex based on the K-67 bridge layer (MTU), which provides multi-span bridge assembly. As part of the theme to the UPS OZIV (n. Nakhabino) produced an experimental vehicle launched bridge PMU (probably «Pull bridgelayer universal»). Installation of the bridge was carried out using the method of sliding, earned while working on K-67 launched bridges (MTU).
V1956-1957 years. NIII in them. DM Karbysheva (December 30, 1960 — TSNIII them. DM, Karbysheva) together with EDO IV, work on the research topic «Movable bridges support» (PMC). One of the main objectives is to provide an agent that provides the installation of a bridge with a length substantially exceeding the length of the bridge layer MTU. In particular, the subject was carried out on the basis of a draft bridge layer tank T-54 with the installation of a bridge-type MTU and collapsible mechanized large span bridge.
The vehicle launched bridges at the base of the tank T-54 with the installation of a bridge-type MTU (later received the name «Heavy Assault Bridge» or TSHM) increase in the length of the bridge was supposed to implement by introducing special (front) support in the forward part of the car (outrigger), accommodation opening mechanism end sections of the bridge and a fundamental change in the hydraulic system. At the top of the tank’s hull was provided (similar to MTU) installation of four brackets, which was based installation mechanism of the bridge and the bridge itself.
Inside the housing units were placed mostoukladochnoy machines and mechanisms for the installation of the bridge. The bridge was a double track, single-span structure with elastic connections between the tracks. Its length was 20 m, capacity — 60 tons, the width of the roadway — 3.3 m, mezhkoleyny clearance — 0.8 m. To reduce the size of the bridge in the transport position of its end sections are formed on the roadway. Under the project, the length of the bridge in the folded position is 12 meters. The folding bridge endings and closure of the lower tier were to be made a special mechanism with hydraulic drive without leaving the crew out of the car.
Most viewed in two versions — made of aluminum and steel 30KhGSA. Driving mechanism for installation in principle remained similar scheme mechanism bridgelayer MTU. Attaching the front support in the working position and back again was done with a hydraulic drive mechanism. The mechanism of the bridge is provided with a hydraulic drive cylinder arrangement on the bridge (four-cylinder) or to the machine. It was assumed that the additional mission will include PTO, guitar, transfer case, three chain drives, two drive shafts, final drive and drives two hydraulic pumps.
Installing the bridge an obstacle was to be made in the following order:
— when approaching obstacles include transmission bridgelayer;
— after a stop at the bridge Unlock obstacles, the front support into the operating position, opens and closes the end of the bridge locks the lower zones of power;
— nominated Axle;
— etching of a cable winch the front end of the bridge fell on the beach obstacles;
— front support translated into transport position;
— mostoukladochnaya machine pulls back, the second pair of rollers guiding conclusion from the bridge.
Collapsible mechanized bridge large span bridge was designed for devices up to 40 m span and ensure the crossing of military equipment and military fronts.
It is considering several options for basic decisions collapsible mechanized large span bridge, including:
— laying a bridge with mounting beam;
— leveling the bridge by a cable stretched across an obstacle;
— aiming to help bridge avanbeka and balances;
— assembly and laying of the bridge with the help of special machines based on mostosborochnoy MTU using avanbeka nakatochnoy and intermediate supports.
The most effective was recognized as the last option, which took to the further development and brought to the stage of conceptual design.
K1959, in EDO IV jointly with them NIII DM Karbysheva completed work on the design documentation mostosborochnuyu machine, which received the name «bridgelayer RMB.» It was intended to be mounted on a collapsible barrier bridge RMB (movable span bridge) with a span of 40 m and a bridge TSHM (Heavy Assault Bridge) with a span of 21 m. Development of design documentation for the project led by Chief Engineer I. Bourenkov. In 1960, at the pilot plant engineering equipment (p. Nakhabino) produced an experimental model bridgelayer RMB.
In accordance with the order of the Chief NIII DM Karbysheva №472 from 30 November 1960 under the chairmanship of Lt. Col. Commission GV Shevchenko from 15 December 1960 to 15 January 1961 he held on campus tested experimental sample bridgelayer RMB. From EDO IV participated in tests IA Bourenkov.
To build bridges used folding blocks (section) collapsible bridge RMB riding across the bottom (under the bridge with «riding across the bottom» means the type of superstructure, which is located between the roadway carrying trusses (beams) at their lower security zone). They were offered DM NIII Karbysheva designed GUI «Project-Stalkonstruktsiya» and fabricated metal structures plant in Chelyabinsk.
Bridgelayer RMB equipped with a lifting device (jib crane), outriggers; it also placed abutments, section avanbeka and other installation equipment.
Disclosure and storage blocks of the bridge was carried out by another RMB assembly and transport machines with special end frames and winches. These operations can be performed in parallel with other operations to assemble the bridge. Opened unit fixed and supplied lifting device bridgelayer the assembly frame, located on the aft part of the bridge layer of the roof and provide precise orientation of the axis block assembled bridge, after which it attaches to the unit installed earlier.
According to test results, the Commission noted:
«1. Adopted in the project kinematics assembly and pickup collapsible large span bridge (40 m) of the individual folding sections is workable. All major assembly operations, and a tip of the bridge is completed and do not cause trouble, used to carry them out mechanization and techniques provide quite (after finishing) a fairly high rate of assembly of the bridge (no more than 1.5 hours) … «
Following the successful testing of the experimental sample, by the decision of the Council of Ministers of 30 May 1960, research materials and design documentation for RMB launched bridges were transferred to the Design Bureau of Transport Machinery (KBTM, Omsk), which in 1960 began corresponding ROC . The result was a pre-production vehicle launched bridge, bridge TSHM provides installation, with additional equipment that allows gather bridges block RMB. This product has received the name «Collapsible mechanized bridge» RMB «.
In the act of test collapsible mechanized bridge RMB held from May 7 to July 30, 1964 in the area of Energo, noted: «Collapsible mechanized bridge» RMB «is an original solution of the superstructure in the form of folding sections, the most prepared for the assembly. Each section represents a portion of the finished bridge length of 4.5 m.
Build a bridge using a crane (lifting device) is not difficult.
Successfully resolved the issue zashtyrivaniya lower zones of the bridge with the help of hydraulic jacks … «
However, despite the above advantages, the tests generally have not given positive results.
Finally, the Commission stated: «Collapsible mechanized bridge» RMB «does not meet the tactical and technical requirements for the bridge pickup time and can not be recommended for service up to working out better ways of sliding and install the assembled bridge an obstacle …».
The disadvantages were the need to bridge the RMB (except for the disclosure of blocks RMB) performing strongly consistent «chain» of repeated cyclic operations and assembly avanbeka bridge with lifting device, which increases the assembly of the bridge up to 6-7 hours. To assemble the required elements of the bridge carefully aligned playground on the banks of the initial minimum size 25×30 m. A very high load on the intermediate turned nakatochnuyu support the original shore during sliding bridge maximum span; Thus, the specific pressure on the ground at the site of her bearing approached the 3 kg / sq. cm. In addition, the speed of the wheel assembly and transport vehicles and tracked chassis bridgelayer vary significantly.
Unfortunately, a situation exacerbated structural and operational deficiencies of the prototype mechanized bridge RMB.
It must be stressed that the RMB was actually launched bridge mostosborochnoy a special machine, which together with the installation and transport vehicles with folding block RMB is, in fact, the bridge mechanized complex (IMC).
Mostosborochnaya machine — wheeled or tracked vehicle, which transports the material in part of the bridge, fitted with a mounting device and accessories.
MMK (Mechanized bridge complex) — a set of machines (fleet) comprising mostosborochnuyu machine and assembly and transport (transport) of the machine with the elements of the superstructure, providing rapid installation (dismantling) the obstacles bridges of varying lengths.
Despite the setback befell, domestic experts were on the verge of creating a new class of overhead funds, but because of the problems, exposed to the landfill, military trials and the subsequent withdrawal of demountable bridges nomenclature Army Corps of Engineers, and their further development ceased.
It should be noted that these complexes appeared abroad only in the 1990s.
These include the FFB (Germany), ABLE (United Kingdom), FB-48 (Sweden), HDSB (USA) and others. Ironically, only by 2007, after 43 years after the creation bridgelayer RMB, the same KBTM (after the transfer of research results from 15 TSNIII Ministry of Defense, in the past — they NIII. Karbysheva DM) came home MMK.
As part of the research conducted OKB BPI SA, together with their DM NIII Karbysheva already mentioned the topic of «Movable bridges support» (PMC), was offered the option of upgrading bridgelayer MTU to increase the length of the bridge. Under the leadership of chief engineer of the project, IA Burenkova were performed appropriate conceptual and technical design drawings for the bridge length 16 m lifting capacity of 52 tons. The basic elements of the bridge layer MTU remained unchanged.
Working design documentation for the product, received the name of «Farm AFM» (probably stands for «aluminum truss-bridge»), passed Feodosia shipbuilding plant for the manufacture of prototypes. Provides two variants of construction of the bridge — a roadway steel SKHL-4 and a light alloy AMg6. To increase the bridge length of 16 m was used end portion pivotally connected to the track and arranged on them. In nominating the bridge end of the disclosed and notices automatically. Installing the bridge was provided without departing from the calculation of the car. Installation time varied between 2-3 minutes.
Finally, the act of acceptance of works factory test stated:
«1. Prototypes farms AFM Routine factory tests survived.
2. After removing the defects noted in the act of testing, and repair of farm AFM can be submitted in control tests. «
No information about you held control tests recommended by the Commission, could not be found yet. However, it is known that, in connection with the already mentioned decision of the Council of Ministers on May 30, 1960 the design documentation for prototypes bridgelayer bridges with AFM (as well as vehicle launched bridges TSHM, simultaneous passage on PMC), was transferred to the KBTM. As a result of R & D carried out in the 1960-1964 biennium. on the basis of these materials, in Omsk was created on the basis of vehicle-launched bridge TSHM medium tank T-55 (factory index «Object 602») with an aluminum bridge, equipped with elongated end sections. After their opening with the integrated hydraulic length of the bridge is 20 m. In 1964, the results of tests and improvements, this machine have adopted under the name of «armored vehicle launched bridges MTU-20.»
Improving armored vehicle launched bridges continued. In 1974, based on the design of MTU-20 KBTM on the modified chassis of T-72 tank created bridgelayer «Object 631» adopted later adopted under the name of «armored vehicle launched bridges MTU-72.»
In MTU 20 and 72 protect the MTU interchangeable bridges, i.e. These vehicle launched bridges may be transported and carry out the installation of bridges to each other. But, despite the almost doubling of the length of the bridge (20 m), roadway bridges new vehicle launched bridges, unfortunately, remained a rut, with mezhkoleynym spacing of 0.8 m and a width of 3.3 m. In this case, the roadway disappear drain holes water with mud and wooden checkers, provides improved traction with propulsion machinery running. Now crests passing trucks tanks interacted with weld on the roadway aluminum strips 8.7 mm thick. When Yuzhen tracked vehicles on the bridge slid metal on metal, and the presence of dirt only aggravates the situation. At the same time the right to call the bridge has become much more difficult. The allowable deviation angle from the longitudinal axis of the bridge fell almost 2-fold. As a consequence — toll bridge has become more difficult.
Returning to the bridge layer MTU (MTU-12), it should be noted that this machine had a chance to participate in many wars and armed conflicts. She actively used and providing fighting Soviet troop contingent in Afghanistan.
In the mountains, the motion of streamers launched bridges, cornices and other rugged areas, often there were cases of collisions with rocks. While in MTU blow fell on the end (entrance) of the bridge, the MTU-20 — in the joints of the end sections of the bridge. In this case, usually deformed lugs articulations end sections. Load is borne by including external vertical aluminum cheek fork lugs (280 mm long and 17×194 mm section). When deformed lug fully disclose and fix the end sections of the bridge MTU-20 becomes impossible.
As a result, even minor damage to the articulations of the end sections of the bridge MTU-20 (as well as the bridge MTU-72, used with the machine mostoukladochnoy MTU-20) is disabled it. Repair of the bridge made of aluminum alloy in the field often was impossible, and bridge the farm or were without use, or sent back to the Soviet Union.
Do not be amiss to note that it is now widely advertised vehicle launched bridges are made of steel. However, bridges these machines apply a special, high-strength, hardened steel. Repair of such material structures using electric welding requires special conditions and establishment of a special cooling mode that whole maintainability gives them considerable advantages over aluminum bridges.
The deformation of the end portions of the bridge MTU did not significantly reduce the possibility of using the bridge; if necessary, he repaired on the spot. There are cases where mechanized bridges TMM (TMM-3) because of its low applicability in the mountains are excluded from state units operating in Afghanistan and replaced by armored vehicle launched bridges MTU.
After the withdrawal of Soviet troops from Afghanistan much of the military equipment has left the army DRA … Years have passed, but on the mountain roads of the country and now there are bridges and MTV launched bridges, developed on its basis (MTU-20, MTU-72).
Instead of conclusion
Let out massively armored vehicle launched bridge MTU (K-67) became the first Soviet engineering vehicles, provide a solution to the problem of overcoming obstacles in stride the narrow (small rivers, ravines, anti-tank ditches, scarps, counterscarp, etc.) fighting the Soviet Army. The bridge layer has a high rate of installation of the bridge (this option is not surpassed by far), simplicity of design, reliability, high maintainability, but the length and width of the bridge were insufficient. Overall, however, the car proved to be very successful.
In addition to the Soviet Army, MTU supplied in large quantities abroad (according to available data, in 43 countries) and operated by the many states. In some countries, these machines are still in service. In our country, MTU has served 43 years.
The car in practice marked the emergence of a new class of domestic crossing equipment, referred to as «armored vehicle launched bridges.» Image MTU was used and is still used as one of the main symbols of Army Corps of Engineers.
Unfortunately, the author and initiator of armored vehicle launched bridges MTU Anatoly Kravtsov, who made a major contribution to the creation of the machine, and OKB BPI SA are hardly mentioned in modern publications.