Internal combustion engine traction - Overall architecture

For over a century, train traction was powered by steam, generated by a fuel – coal in general, or fuel oil – carried on board either the locomotive or a vehicle coupled to the locomotive: the "tender". This type of traction was called "autonomous" in comparison with "electric" traction, which developed from 1879 onwards thanks to an electricity distribution infrastructure along the line.

It wasn't until 1912 that the first locomotive used a "Diesel" engine, named after its inventor who patented the internal combustion engine in 1892. From then on, "self-propelled steam traction" was gradually replaced by "self-propelled internal combustion traction", which was far more energy-efficient and produced incomparably less pollution.

The purpose of this article is to deal with combustion engine traction. It is one of the main components of the term "autonomous". In the first part, we define it and analyze its advantages and constraints. The main development criteria worldwide are then given.

The second part presents the different types of heat engine used, their specific features and main applications.

The third section analyzes the sizing criteria in terms of installed power, taking into account mass and overall dimensions. The consequences for the architecture of the motor vehicle are deduced.

The torque delivered by the internal combustion engine is incompatible with the force to be transmitted by the axles to the track; an intermediary, called a "transmission", is required. We list the three possible types in Part 4. Specific articles will deal with these transmissions in greater detail.

The use of internal combustion engines calls for very specific motor vehicle architecture solutions for the implementation of all functions: fuel reserve, power supply, cooling and auxiliaries. This is the subject of Part 5.

The study of the main environmental impacts is presented in the sixth section, where the specific features of maintenance are also analyzed.