DOK-M heavy Dozer (1967)
Military Bulldozer (1967-78), unknown numbers.
The DOK-M Heavy Army Dozer was a massive military bullzdozer, optionally armoured, and weighting 28 tons when fully loaded. It is used for earth moving, building trenches or removing snow. It also have a powerful winch to act as recovery vehicle. With its distinctive articulated frame, it has been in service with the Czechoslovakian Army since 1967, and still is.
Design
The CZK DOK and its improved variant DOK-M (dozer otočný kolový) is a two-axle military bulldozer with a universal shovel, winch and snow attachment designed for earthmoving operations, remove snow or sinkholes from roads, as well as hauling and load vaste amounts of materials aside dirt. In a purely military scheme it was designed to quickly build trenches and shelters and pull trailers if needed to the battlefield's rear lines.
Its rapid trench digging ability was allowed by its trench plow ZP 60/90, paring the troops a long and potentially dangerous job with their small hand shovel. It was useful notably to create a new defensive line in a rapidly moving battlefield. It was usable as ARV as well with its winch, albeit up to a certain weight excluding main battle tanks, heavy trucks and wheeled or lighter tracked armoured vehicles, with a pulling power up to 65 tonnes on road.
The design at CKD started in the early 1960s and perhaps as early as 1959 for a dedicated, articulated military bulldozer with a partially armored cabin from frontline or rear lines work. But detail is not known. CZK seems to have been a civilian work vehicles manufacturer, now extinct. It was however developed in cooperation with VVTÚ and Stavostroj n.p. Nové Město nad Metují. The army called the program the "universal engineer machine" abbreviated "UŽAS". After prototype phase, tests and trials, it was accepted for service with the Czechoslovak People's Army in 1967 and delivered to the genie and other specialized units.
Chassis and specifics
The DOK Weighted 27,5 tonnes light and 28,5 tones fully loaded. It was not a small machine at 10,53 meters or even 12,17 meters when the blade was fully extended forward, for a width of 3,15 meters and height of 3,15 meters with the blade low and 3,56 meters with the blade high. Ground clearance was 51 cm. One of the interesting feature of the design was its articulated chassis. The powerplant was located at the rear, along with the main driving chassis, the generator and pump drive, and there was an articulated transmission nut at the link (and massive hinge) for the front section that comprised an hydraulic drive for the dozer blad earms and a small cab above the front axle, both directional and driving.
The two hydraulic arms driving the blade's frame were located either side of the cabin. The latter was for two seats close together, with a driver and an operator. The cab could use extra armoured glass panels but it had unprotected sides or front. It had however air conditioning due to the glasshouse effect of the sun with a filter (NBC proof) and a heater. It had a warning beacon on the roof.
Powerplant
The DOK was powered by a 17,63 Liters T930/42 diesel, 12-cylinder, four-stroke with fork-ignition and direct fuel injection as well as two turbochargers for an output of 190 kW (254 hp) at 1,800 rpm. Top speed on road is 46 km/h and off-road on average 10 km/h. There is a fuel tank of 480 liters, and engine oil tank of 40 liters and hydraulic fluid tank of 500 liters.
Fuel consumption on road is 30 l/hr and when working of road up to 80 l/hr for an off-rang of 250 km and perhaps 300 on road. Its universal shovel capacity is 2,6 m3 for a max lifting force of 100 kN and max winch cable force of 180 kN. Its hydraulic operating pressure is 19 MPa and wading range 1,250 mm.
In addition to the main engine, it had electric motors thanks to a TD-803, 160 kW generator at the rear, a winch and the loading pulley, large earthwork standard tyres (unsprung) with air-pressure lines. The winch traction power is 32 kW with the steel cable measuring 88 m. The dize blade could be used with scarifying blades, or scoop material. For snow work, it could be equipped with an optional snow plough mounted on the shovel completed by a skid steer, two fixing tugs and two tug holders.
Production & Variants
Production in unknown globally but the vehicle was also produced for Germany.
1967: Service introduction of the first Czech army variant DOK.
1969: DOK-L Introduced in the East German Army.
1973: Aceptance of the upgraded DOK-M in the Czech and East German Army. The DOK-M (DO zér K oles M odernized) has a civilian grade injection system excalibur.
1978: Production is stopped, the DOK is gradually replaced by the more modern KN-251 dozer.
DOK-M specifications |
| Dimensions | 10,53 x 3,15 x 3,15 meters |
| Weight | 27.5 - 28.5 tons FL |
| Crew | 2: Driver, operator |
| Propulsion | T 930-42 diesel engine 17 Liters 250 hp, biturbo. |
| Top speed | 46 km/h Road, 10kph off road |
| Fuel consumption | 30-80 liters road/off road (480 liters total) |
| Suspension | Unsprung (large tyres) |
| Maximum range (on/off road) | 250 km ( mi) |
| Armament | None |
| Production | Unknown |