Diesel locomotives of the TEM2 and TEP70 series are striking examples of machines with their own traction, which are actively used on the railways of the post-Soviet space. Unlike electric locomotives, which depend on the contact network, these units of rolling stock are equipped with a power unit located directly in the body, which allows them to operate autonomously in any area. Diesel engine internal combustion drives a generator that transmits energy to the traction electric motors of the wheel sets, providing high cross-country ability and independence from external infrastructure.
The concept of “self-propelled vehicle” covers a wide range of technical means where the on-board unit serves as the source of energy for movement. The key factor here is autonomy: The vehicle does not require constant connection to external sources such as conductive rails or trolley wire, although some hybrid models may combine different power sources. Ability to generate traction force using internal resources makes such vehicles indispensable for shunting work, driving freight trains in non-electrified areas and performing emergency recovery operations.
The basis of the design of such machines is the power frame on which all units are mounted. Main generator converts the mechanical energy of rotation of the diesel shaft into electrical energy, which is then transmitted to the traction motors. This scheme, called diesel-electric, is considered one of the most reliable in heavy engineering, as it allows efficient use of engine torque at various speed conditions of train movement.
⚠️ Attention: The operation of vehicles with their own traction requires strict adherence to maintenance regulations, since the failure of the on-board power supply system leads to a complete stop of the train far from the stations.
Classification of autonomous locomotives
All self-propelled vehicles are divided into several main classes depending on the type of engine used and purpose. The first and largest group consists of diesel locomotives, which use the energy of combustion of liquid fuel. Within this class there is a division into mainline locomotives, designed for driving long-haul trains over long distances, and shunting locomotives, operating within stations and industrial tracks.
The second important class is represented by gas turbine locomotives, where a gas turbine is used instead of a piston diesel engine. Such machines are distinguished by high power with a lighter weight of the power plant, but their mass use is limited by high fuel consumption and difficulty of maintenance. Third class is railcars and motor locomotives, lightweight vehicles often built on truck bodies or special chassis for track maintenance and delivery of work crews.
- 🚂 Mainline diesel locomotives: powerful locomotives for freight and passenger transportation on non-electrified areas.
- 🚜 Shunting locomotives: compact machines with high traction force at low speeds for forming trains.
- 🛠️ Special equipment: snow plows, track layers and cranes that have their own engine for movement and operation of mechanisms.
The division according to the type of energy transfer deserves special attention. In addition to electric, there is hydraulic transmission, where torque is transmitted through fluid couplings and torque converters. Such machines can often be found in industrial transport and on narrow-gauge railways, where simplicity of design and reliability in extreme conditions are important.
Diesel locomotive power plant design
The heart of any self-propelled machine is diesel engine. Modern mainline diesel locomotives use powerful 16-cylinder V-shaped engines capable of developing thousands of horsepower. The engine design includes a supercharging system, which allows you to burn more fuel and increase operating efficiency. Turbocharger uses the energy of exhaust gases to force air into the cylinders, ensuring stable operation at high altitudes above sea level.
The cooling system plays a critical role in the functioning of the power plant. Since the motors operate continuously under high load, heat is dissipated through powerful radiators with forced ventilation. Fans are often driven by hydraulic motors, which allows flexible adjustment of airflow intensity depending on temperature conditions.
Operating principle of a diesel generator
Inside the locomotive casing, a diesel engine rotates the main generator shaft. The generator generates electric current, which is rectified and supplied to traction motors installed on the axles of the wheel sets. This avoids the use of a complex mechanical transmission.
The fuel system includes tanks, high-pressure pumps and fine filters. Fuel quality directly affects the resource injectors and plunger pairs. Any ingress of water or mechanical impurities can lead to water hammer and serious damage to the cylinder-piston group, so monitoring the cleanliness of the fuel is a priority task for the driver and repair crews.
Electric transmission and traction motors
The conversion of mechanical energy into electrical energy and vice versa is a key process for most modern self-propelled machines. Main generator generates alternating current, which then passes through a rectifier unit. The resulting direct current (or alternating current of a certain frequency in modern systems) is supplied to traction electric motors (TED) located directly on the axles of the wheel pairs.
The use of electric transmission allows several important advantages to be realized. Firstly, the diesel engine can operate at optimal speed, regardless of the speed of the locomotive. Secondly, the electrical circuit makes it easy to implement reversal of the direction of movement and electrical braking when the traction motors switch to generator mode, extinguishing the speed of the train.
| Parameter | Electric transmission | Hydraulic transmission |
|---|---|---|
| System efficiency | High (up to 85-90%) | Average (75-80%) |
| Equipment weight | Large (generators, motors) | Smaller (torque converters) |
| Service | Requires electrician qualifications | Requires oil and seal monitoring |
| Application | Mainline and shunting diesel locomotives | Railcar, narrow gauge equipment |
Modern control systems use microprocessor complexes to regulate traction force. Thyristor converters allow you to smoothly change the parameters of the current supplied to the engines, ensuring smooth acceleration without jerking or slipping of the wheelsets. This significantly reduces wear on the track and the rolling stock itself.
Shunting locomotives and industrial traction
In the category of machines with their own traction, shunting locomotives occupy a special place. Their main task is not the development of high speed, but the creation of maximum traction force at low speeds to move heavy freight trains within the station. These machines are often designed with a short wheelbase and an axle formula that provides excellent fit into tight, small radius curves.
Industrial traction places its own demands on technology. Machines operating in factories, ports and mines are often equipped with reinforced buffers, falling object protection and dual control systems. Diesel-hydraulic transmissions are more common here than on main lines, due to their compactness and ability to operate under conditions of frequent reverses.
- 🏭 Factory diesel locomotives: work in dusty conditions and possible chemical emissions.
- 🌲 Timber narrow gauge railways: require increased cross-country ability and often have several driving axles.
- 🚛 Mining trucks: giant cars with electric wheel drive, which are also technically self-propelled cars.
An important aspect is the environmental friendliness of industrial machines. Modern standards require the installation of exhaust gas neutralization systems and the use of filters soot particles, especially if work is carried out indoors or near residential areas.
Railcars and track machines
Railcars are a lightweight version of vehicles with their own traction, designed for transporting people or goods, as well as for performing specialized work. They are often created on the basis of truck components, which simplifies their repair and supply of spare parts. Engine Such machines can transmit torque both to the wheels through a manual gearbox and to the generator.
There are many modifications of track machines: snow blowers, crushed stone clearing machines, cranes and even laboratories for track diagnostics. All of them are united by the presence of their own power plant, which allows them to travel to the place of work under their own power, without the need to be placed on a train. Motor locomotives are an even lighter class, often used on secondary tracks.
☑️ Check before departure of the track vehicle
A peculiarity of the operation of railcars is the frequent change of operating modes: from idling while waiting for a command to sudden jerks during maneuvers. Therefore, the requirements for frame strength and reliability coupling device are especially high here. The driver's cabin is often combined with a crew compartment, which dictates special requirements for sound insulation and ventilation.
⚠️ Attention: When driving railcars on a stretch, it is necessary to strictly follow traffic rules, since their low weight and dimensions make them less noticeable to drivers of suitable trains.
Prospects for the development of autonomous traction
The future of self-propelled vehicles involves finding alternative energy sources and increasing efficiency. Hybrid circuitswhere is the diesel