What are the main components of a railcar?

The main components of a railcar include wheels, axles, couplers, and a frame. These elements are crucial for the operation and functionality of a railcar.

Wheels and axles are integral for movement, allowing the railcar to roll along the tracks, while couplers facilitate the connection between multiple railcars, ensuring they can be linked together for transport. The frame provides structural support, maintaining the integrity of the railcar while supporting the weight of the cargo it carries.

Each of these components plays a vital role in ensuring the railcar can operate safely and effectively on the rail network. While the other options mention important aspects of railcars, they do not encompass the foundational components that define a railcar's structure and functionality.