Tatra 815

Tatra 815 at a glance

Tatra, founded in Moravia and one of the oldest vehicle makers in the world, has used the backbone-tube concept since the 1920s. The 815 brought it into the age of tilting forward-control cabs and turbocharged diesels. It was built for construction, mining, oil and gas work, forestry, municipal services, rallies and military use, and was exported across Europe and to the Americas, Asia, Africa and Australia. The company's story is in the history of Tatra.

Development and timeline

Work on the 815 began in the early 1970s. A first prototype was running by 1974 at the latest, with further prototypes in 1976 and 1977. A pre-series of four to five trucks a month started in 1981, and full series production followed when the Tatra 148 and 813 ended. Updates kept the truck current for more than four decades.

The backbone chassis and swinging half-axles

Instead of a ladder frame, the Tatra 815 uses a central tube that carries the drivetrain inside it. The gearbox, transfer case and differentials are bolted together into this backbone, and each wheel hangs on a swinging half-axle. The differentials use two opposing spiral bevel gears, which lets Tatra build trucks with any number of axles from the same modules.

The result is a chassis that is very stiff in torsion, keeps all wheels in contact with uneven ground and protects the driveshafts inside the tube. Front axles use torsion bars; rear axles have leaf springs or air suspension. Axle load capacity runs from 8 tonnes per axle with torsion bars up to 16.5 tonnes with the heaviest suspension. Steering is mechanical with hydraulic assistance, and trucks with two front axles steer both. The brakes are dual-circuit pneumatic with drums and ABS, which is now standard.

Air-cooled V8, V10 and V12 engines

The classic 815 engines are Tatra's own air-cooled diesels of the T3 series, all with a bore of 120 mm and a stroke of 140 mm. Air cooling removes the radiator and coolant, which helps in extreme heat and cold.

Later V8 engines with turbocharging and charge-air cooling cover 230–325 kW and 1,400–2,100 Nm. For buyers who preferred water-cooled engines, Tatra offered Deutz and Cummins units, among others, from 260 to 440 kW with 1,550–2,750 Nm. The engine is mated to a single-plate dry clutch and a five-speed gearbox with a range group; heavy tractors and special trucks add a two-speed transfer case for 20 forward gears. Most versions are all-wheel drive, some with a front axle that can be disconnected, and the rear and transfer differentials can be locked.

Cabs and body types

The 815 introduced Tatra's tilting forward-control cab, offered in short, medium and double-cab versions. In 1997 the TerrNo1 family brought a new cab and a modernised design, and the cab was facelifted again in July 2010. The old 1cars text describes cold-climate trucks with an extra cab heater, engine and oil pre-heaters, an air-sprung driver's seat and air conditioning on some versions.

Body types include three-way tippers, rear tippers, flatbeds, semi-trailer tractors, tractors with a flatbed, truck cranes on five-axle and longer chassis, and special bodies. According to the old 1cars text, a typical tipper version has a cargo platform about 2,400 mm wide and 4,310 mm long, carries close to 17 tonnes and has a gross weight of 28,500 kg, with up to 44 tonnes as a road train.

Racing: six Dakar wins

The Tatra 815 made its name far beyond building sites. Czech driver Karel Loprais won the Dakar Rally six times in the truck class with a T815, which made the backbone chassis famous among rally fans. Its ability to keep all wheels on the ground at speed over rough terrain suited desert racing well.

Tatra 815 compared with other heavy trucks

The Tatra has the widest spread of axle layouts and power of the three, and its chassis concept is unique among series trucks. On paved roads a European road truck such as the MAN or the Volvo FH is more comfortable and economical; off road and in heavy mining work, the Tatra's independent wheel travel is its advantage. The most powerful trucks ranking shows where its strongest engines sit, and the KamAZ-4310 versus Ural-4320 comparison covers two conventional 6x6 rivals.