Parts of a Train – Locomotive and Car Parts With Scheme

As a railroad worker and a train enthusiast I remember how strongly I wanted to know what the parts of a train are and how they are all interconnected, to serve as a great transportation solution for both freight and passengers.

In the this article I will go in-depth on the following sub-topics:

Parts of a Train
  • Parts of a Locomotive

    Diesel-Electric Locomotive Parts

  • Parts of a Car

    Passenger Car Parts
    Freight Car Parts

  • Let’s start get started!

    Parts of a Train - How do trains operate?

    Today a train is a combination of locomotives and cars, in the past there was a third car called caboose, attached at the end of a freight train, which stopped being used once the radio communications began to be implemented.

    So what are the parts of a train? Simple, Locomotives and Cars.

    Parts of a Train Locomotive - How do locomotives operate?

    As mentioned above I will go in depth on locomotive components, and I will analyze both diesel-electric locomotive parts as well as the steam locomotive parts.

    parts of a train

    Let’s start with the Parts of a Diesel-Electric Locomotive.

    The Diesel-Electric Locomotive has over 27 major parts that contribute in harmony to its operation.

    I also recommend you to read what is a locomotive consist to understand things better.

    Please check the scheme created below for a general idea of where the parts are situated, note: this is for a general purpose only.

    Main Alternator

    The alternator generates AC electricity, used to power the traction motors. The Main Alternator is powered by the Diesel Engine. That’s why the locomotive it’s called Diesel-Electric Locomotive.

    Diesel Engine

    This type of locomotive it’s powered by the diesel engine, which powers the AC alternator. The diesel engine cylinders might be arranged in V or inline, where the engine engages the drive shaft for various tasks, including the most important, powering the alternator which produces the electrical energy to power the train.

    Auxiliary Alternator

    - it’s mainly used to power auxiliary electrical sources, like the interior car lights, outlets, air conditioning, dining appliances. The majority of passenger train locomotives are equipped with this extra alternator, where the freight locomotive doesn’t need it.

    Air Intakes

    - This part is used for cooling the locomotive, the air is drawn inside the locomotive through these intakes, reaching the engine and other parts that need cooling, after passing through various filters and temperature regulators.

    Motor Blower

    As the name states, the motor blower, blows air over the traction motors, keeping them cool. The cooling system is way more complex, especially for the newer locomotives.

    Rectifiers/ Inverters

    Rectifiers are used to convert the electricity from the main alternator from DC to AC.

    Control Station

    The area from which the locomotive engineer operates the locomotive/train. In the United States, it is positioned in an angle on the left side.


    Most of the locomotives in the United States have just one cab, at one end.


    This train part is needed for the diesel engine to start, exactly as an automobile.

    Fuel Tank

    Usually two tanks, on each side of the locomotive. The total capacity is around 5,000 gallons of fuel.


    The gear has a reduction of 3 to 1 for freight and 4 to 1 for passenger trains, engaged by the traction motor.

    Turbo Charging

    Used to increase the capacity of pushing air into the cylinders faster, delivering up to 50% more power. Works like any other turbo charging system.

    Sand Box

    Always carried by the locomotives to provide assistance with adhesion on bad rail conditions.

    Electronic Controls

    In most of the cases it is situated in the cab, for easy access. It provides few types of electronic control and data management access for different devices.

    Air Reservoirs

    Required for brakes and other systems around the train, the reservoir contains compressed air.

    Radiator and Radiator Fan

    The diesel engine is liquid cooled, the radiator works as any other vehicle radiator. The liquid passes through the engine to cool it down, reaching the radiator and the fan, cooling the liquid and moving back to the engine, into a continuous cycle.

    Drive Shaft

    Used to transmit the power from the diesel engine to the alternator, air compressor and radiator fans.

    Gear Box

    This locomotive part is used to change the direction to the drive shaft, upwards toward the radiator fan.

    Air Compressor

    This train part provides a continuous supply of compressed air for the train brakes, being powered by the diesel engine.

    Traction Motors

    As the name states, the diesel-electric locomotives use electricity to power the train. The alternator is powered by the diesel engine, and the traction motors are powered by the alternator.

    Safety Rail
    Water Tank
    Coupler Head
    Safe Footboard

    These are all the diesel-electric locomotive parts that I was able to list, please let me know in the comments if you have more knowledge and I’ll update it.

    Parts of a Train Car - Passenger

    Passenger cars are broadly used throughout the world, while there are few differences between the passenger cars (bullet speed trains vs. regular passenger trains), we will evaluate the regular passenger cars we see hauled by AmTrak.

    I was able to list over 20 parts of a train car, let’s take a closer look.

    Air Conditioning Condenser
    Auxilary Inverter
    Brake Frame
    Toilet Retention Tank
    Suspension Air Bag
    More information is coming.