What do the different train whistles mean?

July 6, 2007

Although train whistles can be annoying if you live or work near a railway track, they are an important safety device essential for warning of potential dangers.

Four “toots” is the most common train whistle you’ll hear. The four “toots” consists of two longs, a short and a long whistle. This whistle sequence is the one used when a train is crossing a road where cars or people might be present.

“Whistle boards”, commonly an “X” on a small plate on a post, indicate where the engineer is to begin to sound this signal. The law (rule) is that this signal is to be commenced a quarter mile in advance, or 20 seconds in advance of occupying the crossing or other structure.

As well as being a warning device, whistles also serve as a communication tool between train staff. Various combinations of whistles are used by the engineer to tell the conductor or brakeman of various conditions.

The train whistle is also used as a protection device when approaching tunnels and bridges. The engineer is required to sound the whistle where there are impaired side clearances.

A succession of short “toots” is sounded in an emergency such as people, vehicles or livestock on the track. Other trains hearing this signal must stop until it is safe to proceed.

The way the train engineer sounds the wistle has different meanings:

When stopped, air brakes applied and pressure equalized – one long blast.
Release brakes, proceed – Two long blasts.
Acknowledgment of any signal not other wise provided for – Two short whistles.
When stopped, back up, answer to signal to back up – Three short whistles.
Request for signal to be given or repeated if not understood – Four short whistles.
Flagman protect rear of train – One long and three short whistles.
Flagman protect front of train – Three short and one long whistle.
Flagman may return from west or south – Four long whistles.
Flagman may return from east or north – Five long whistles.
Inspect brake system for leaks or sticking brakes – One short one long whistle.