New Mercedes-Benz SLT heavy haulage tractors offer ultimate power and control
By Steev Hayes
PHOTOGRAPHY Steev Hayes / Mercedes-Benz
The all-new heavy-duty SLT tractor line-up from German truck manufacturer Mercedes-Benz was revealed earlier this year. Designed for use at weights of up to 250 tonnes, three variants of Actros SLT are available: two 6x4s, an 8×4, and six Arocs SLTs which include two 6x4s, one 6×6, one 8×4, one 8×6, and one 8×8.
SLT trucks are designed to work solo at gross weights of up to 250 tonnes, in tandem, or three linked together – although one truck would need reinforcement –
for ultra-heavy load movements.
Power is supplied by the Mercedes-Benz tough OM473 engine, which comes in three power outputs (see page 28). The OM473 engines are of an ultra-tough design, made from strong alloy, and ribbed for extra rigidity.
A one-piece cylinder head made from vermicular graphite cast iron can cope with very high ignition pressures, while one-piece pistons with wet cylinder liners help with engine cooling. Common-rail fuel injection with X-Pulse pressure booster gives a maximum pressure of 900 bar in the system, which rises to 2100 bar in individual injectors.
The engines use turbo-compounding. This uses a second turbine downstream of the exhaust gas turbocharger, utilising the energy still available in the exhaust gasses after they’ve passed through the turbocharger, and achieving a further increase in engine efficiency. Power is transmitted to the engine’s gear drive and directly to the crankshaft via a shaft and hydrodynamic clutch.
Read the rest of this feature in the Summer 2014 issue of Trucking. Buy the magazine here