How many whistle blows are required to move the train forward slowly?

• A. 1
• B. 2
• C. 3
• D. 4

Answer: (C)

In mine signaling, the whistle code uses the number of blasts to tell the crew what action to take. Three short blasts are the signal to move the train forward slowly. This gives a controlled, cautious pace that lets the operator and crew watch for obstacles, track conditions, or other workers in confined underground space. The distinction of three blasts helps prevent confusion with other commands, such as starting, stopping, or changing speed, which are conveyed by different blast patterns. So three blasts are used specifically to indicate slow forward movement, balancing clear communication with safety in the mine environment.