What must railroad radio emergency calls begin with?

Railroad radio emergency calls must begin with "Emergency, Emergency, Emergency" to clearly convey the seriousness of the situation. This standardized phrasing is intended to capture the immediate attention of all parties listening on the radio frequency. By repeating the word "Emergency" three times, it emphasizes the urgency and ensures that all personnel understand it is a critical situation that requires immediate action or response.

The use of this specific format is crucial in the rail industry, as it helps prevent misunderstandings during emergencies when clear and decisive communication is essential. The protocol aids dispatchers, engineers, and other railroad staff to prioritize and respond appropriately to the emergency being reported.

Other phrases like "Alert" or "Urgent Request" do not carry the same level of urgency or standardization in emergency situations, which can lead to confusion or a delayed response. "Distress call acknowledged" is not a recognized starter for calls that initiate an emergency response, as it indicates that a distress call has been received rather than that a new emergency situation is being reported.