The term 'locomotive undercarriage' refers to the wheeled frame that supports a locomotive. The most common type of undercarriage is known as a BOGIE, which is a five-letter word. A BOGIE is a two-axle truck that is connected to the locomotive and carries the weight of the engine. It also helps to keep the locomotive stable while it is in motion. The BOGIE is an essential part of the locomotive undercarriage, as it helps to ensure that the locomotive can move safely and efficiently.