ZIL » 137
Miliatary wheeled train ZIL-137 with hydrostatic drive of the semitrailer was the most advanced achievement of the Soviet automotive industry in the field of active wheeled trains. According to the general design, it represented the development of the first experimental vehicle ZIL-157V made in 1960, but was made on a chassis of all-wheel drive truck ZIL-131. During test period it was called 2E131, while two main types of semi-trailers called 3E131 and 4E131. Later it got its own index ZIL-137. The combination consisted of a special AWD tractor ZIL-137T based on a 150-hp ZIL-131V, and one of two types of two-axle 7.2-tonne semi-trailer chassis - standard ZIL-137A and ZIL-137b with an extended by half a meter the rear overhang flatbed truck platform.
ZIL-137T distinqueshed from a standard model ZIL-131 by a dual-clutch transmission and the installation of the hydraulic pump driven by a take-off gearbox. It transmitted high-pressure (up to 150 kgf/cm2) fluid to the semi-trailer using a flexible pipeline. The oil was applied to a hydraulic engine and than using a torque converter and propeller shafts transmitted to the semi-trailer axles. Thanks to the electro-hydraulic system rear wheels of the trailer was activated automaticly during acceleration and operating in bad road conditions. The all-wheel drive train had a single track of 1820 mm and equipped with a combined braking system and internal air pressure control in all tires.
The curb weight of the tractor is 7000 kg, semitrailer chassis - 3800 kg, the combination without a load - 10.8 tonnes, with a special equipment - up to 19.5 tonnes. Its overall length with a short semitrailer is 14,080 mm. Maximum speed of the empty combination - 80 kph, fully loaded - 60 kph, with the activated semi-trailer drive - 7.0 kph. Maximum turning radius is 10.2 m. Fuel consumption - 52 l/100 km.
The first protoype of ZIL-137 was built in Moscow in 1963. In 1964, it was successfully passed the state tests with mileage of 18,000 km and was recommended for production and use in the army. In 1966 first ZIL-137s were sent to use in the army, and since 1970 producing of the active trailers was started on Bryansk Automobile Plant (BAZ). By the mid-1970s, the monthly output of the trucks reached 30 units. 1972 trucks and trailers were assembled in Bryansk by 1978.
The most widely the trains were used with the extened trailers 137B to delivery new missile systems and roomy vans with a special equipment. During their operation period a lot of shortcomings were appeared, mainly refers to a complex and highly capricious hydraulic high pressure system. In the first half of the 1970s BAZ developed its own model similar to the ZIL-137M, which was subsequently renamed to a BAZ-3405-9366.
