What is the purpose of the locomotive’s speedometer?

The purpose of the locomotive's speedometer is to provide the engineer with the train's speed. This is crucial for safe train operation, as it allows the engineer to maintain compliance with speed limits, adjust speed for track conditions, and ensure safe stopping distances. The speedometer gives real-time feedback on how fast the train is traveling, which is essential for making informed operational decisions.

While engine temperature, fuel efficiency, and train length are important aspects of train operation, they are not functions of the speedometer. The engineer relies on various other instruments to monitor engine performance and efficiency, as well as train length, which are typically assessed through other gauges or onboard systems. The speedometer specifically focuses on conveying the current speed of the locomotive to ensure that safe operational standards are met.