Trains in the desert
On the flip side, freezing is a foreign word for the people in Saudi Arabia.
However engines still have to deal with special conditions: across the sandy desert - from the port city of Dammam on the Persian Gulf to the capital Riyadh in the interior - mtu engines power ten Powerheads, which integrate the whole propulsion system, produced by the Spanish manufacturer CAF. The conditions for trains in the desert are difficult: desert sand is so fine that no seal can withstand it - not even that of the engine compartment.
Each of the ten diesel-electric power cars is equipped with two 1,800-kilowatt mtu twelve-cylinder engines of the 4000 series. These are part of complete power modules consisting of a rail engine, a traction generator and the mtu automation system Powerline. "Integrating two mtu motors into one powerhead is unique and the result of customised development work," says mtu project manager Frank Scheider. The requirement, he says, was due to the fact that the motors had to incorporate redundancy , as their operation was vital. "If the engines fail in the middle of the desert, not even the air conditioning would work, that would be life-threatening for the passengers," says Scheider, who also explicitly praises the cooperation with the manufacturer CAF.
The air filter of the powerheads is also designed for the sandy conditions. Special cyclone coarse filters separate 90 percent of the sand grains before the air enters the engine room through the roof of the powerhead. However, before the air is compressed by the turbocharger and enters the combustion chamber, it is cleaned again by two large cyclone air filters, each with an integrated paper filter. What still gets into the engine now no longer harms it.