Production years: pre-production 1971–1972, series production from 1973 – still in production in updated form as the T-150K-09 In 1972, even before official series production began, T-150K tractors built at the Kharkiv Tractor Plant first worked on Estonian collective and state farms; they remained widespread farm machines here practically until the turn of the century, and in places somewhat longer. It is a general-purpose four-wheel-drive agricultural wheeled tractor of the 3 t (30 kN) drawbar class, designed for various farm work with mounted, semi-mounted and towed implements (ploughing, cultivating, harrowing, stubble cultivation, sowing, harvesting various crops), and also for transport with trailers and semi-trailers with a total payload of up to 20 t at speeds of up to 30 km/h. The letter "K" in the name comes from the Russian word "колёсный" (wheeled), meaning it is the wheeled version of the T-150 crawler tractor. The tractor has a four-stroke six-cylinder V-type liquid-cooled turbocharged SMD-62 diesel engine with 121.5 kW (165 hp). The engine is started from the driver's seat by means of a pony engine with an electric starter. It is a variant of the SMD-60 engine used on the T-150 crawler, differing in fuel pump setting, crankshaft speed, power, the presence of a compressor and the design of the clutch shaft. The tractor's chassis consists of front and rear half-frames joined by vertical and horizontal articulations. The vertical joint allows the tractor to turn, and the horizontal joint lets the wheels follow the contours of the ground. The T-150K gearbox is a three-range mechanical unit with constant-mesh gears, hydraulic clutches and a creeper, and together with the transfer case gives 12 forward and 4 reverse speeds. Within a range, gears are changed under load using the hydraulic clutches, without interrupting power. The rear axle of the T-150K is permanently engaged, while the front axle can be disengaged when needed, for example for transport work. The front axle is attached to the frame by two semi-elliptic leaf springs, the rear axle rigidly. The track width can be changed by repositioning the wheels and can be either 1680 or 1860 mm. For most work the wheels are set to 1860 mm. The tractor has an independent PTO, which can turn at either 540 or 1000 rpm. The pneumatic system operates the brakes of the tractor and trailer, the wipers and the main clutch release mechanism, and is also used to inflate tyres. The tractor is steered hydraulically by turning the front and rear half-frames relative to each other around the vertical joint. The tractor has a split hydraulic system, a rear 2- and 3-point linkage, a hitch and a hydraulic tow hook. The tractor has a sealed, heat- and sound-insulated, ventilated and heated two-seat all-metal cab. On early T-150Ks both seats were adjustable, with parallelogram suspension and hydraulic dampers; on later ones only the driver's seat is adjustable. The cab has a rear-view mirror, a drinking water flask, a case for a first-aid kit and hooks for hanging clothes. To warm the engine for starting at ambient temperatures below -5 degrees, the tractor has a PZhB-300 pre-heater. From 1984 the plant made dual-wheel kits for the T-150K, consisting of four complete wheels with rims and tyres and the necessary connecting parts. According to some sources, dual wheels on the T-150K reduce both static and dynamic ground pressure by about half and also improve off-road ability.