A railway bogie is a critical undercarriage structure that supports a locomotive's weight and houses essential components like the drive system, brakes, and suspension. Each locomotive typically has two bogies, which can be equipped with two or three axles, each fitted with wheels and bearings. Powered bogies contain traction motors and gearboxes to drive the wheels, while unpowered bogies are pulled by locomotives. Bogies are complex subsystems with various design elements, including frames, braking systems, and sophisticated suspension and damping mechanisms. Wheelset arrangement classifications, like the UIC system, categorize locomotives based on their bogie and axle configurations.