Main Types and Classification of Railway Bogies

The bogie is an independent component of a railway vehicle, with the number of connections between the bogie and the car body minimized as much as possible. The parameters of the bogie directly determine the vehicle’s running stability and ride comfort.

The use of bogies in railway vehicles aims to increase load capacity, vehicle length and volume, and operating speed, in order to meet the development demands of railway transportation.

Main Classification Methods of Bogies

I. Classification by Number of Axles

Two-axle bogie:

Suitable for most freight cars and some locomotives. It features a relatively simple structure and low manufacturing cost.

Three-axle bogie:

Typically used for heavy-duty locomotives or special vehicles, such as diesel locomotives and some electric locomotives. Three-axle bogies provide improved stability and higher traction capability.

Multi-axle bogie:

Mainly used for long and heavy freight vehicles or heavy-haul trains, such as D38 heavy-duty Schnabel cars, to accommodate high loads and complex track conditions.

II. Classification by Application

Freight car bogie:

Examples include Z8A, Z8G, and ZK3 types, primarily used for freight transportation. These bogies emphasize load-carrying capacity and running stability.

Passenger car bogie:

Examples include 209T, PW-200, and CW-200 types. Higher requirements are placed on running smoothness and ride comfort. Passenger car bogies typically feature enhanced suspension performance and allow higher operating speeds.

Locomotive bogie:

Including electric locomotive bogies (e.g., SS8 type) and diesel locomotive bogies, which mainly undertake traction tasks and require high traction and braking performance.

EMU bogie:

Divided into motor bogies and trailer bogies. EMU bogies must simultaneously meet the requirements of traction, braking, and high-speed operation.

III. Classification by Structural Characteristics

Bolster bogie:

A traditional bogie design in which a bolster connects the wheelsets and the car body, providing a certain level of vibration damping.

Bolsterless bogie:

Examples include CW-200 and SW-200K bogies. The bolsterless design reduces weight and structural complexity while improving running quality.

Radial bogie:

The leading and trailing axles are aligned radially with the curve radius, resulting in a zero angle of attack. This reduces wheel flange wear and lateral wheel–rail forces, making it suitable for lines with numerous curves.

IV. Special Types of Bogies

Urban rail transit bogie:

Examples include Shanghai Metro bogies and Paris Metro rubber-tyred bogies. These are designed to meet the specific requirements of urban rail transit, featuring smaller wheel diameters and superior curve negotiation capability.

Heavy-duty vehicle bogie groups:

Composed of multiple bogies to meet the transportation requirements of oversized and overweight cargo.