The "A-A Wheel Arrangement" refers to a specific configuration of wheels on a vehicle, particularly in the context of locomotives. In this arrangement, the wheels are positioned in pairs, with each pair mounted on a common axle. This design helps distribute the weight of the locomotive evenly, improving stability and traction on the tracks. This wheel arrangement is commonly found in various types of trains, including those used in freight and passenger services. The A-A configuration allows for better maneuverability and can enhance the overall performance of the locomotive, making it suitable for different rail conditions.