Users of the Northern Rail Trail may have noticed concrete posts, about five feet tall, with the letter W near the top. These are whistle posts. They order the locomotive engineer to blow his whistle in warning as the train approaches a grade crossing.

These posts were positioned a quarter mile before the crossings, and on the right side of the track so as to be visible to the engineer from his position on the right side of the locomotive cab. At a typical speed of 30 miles per hour, a train would take 30 seconds to travel that distance.

The warning signal for a crossing was a series of four whistle blasts: long-long-short-long. The engineer was required to extend the fourth blast until the locomotive had occupied the intersection.

Some 16 of these posts remain along the Northern Rail Trail. They have recently been repainted to return them to their original appearance.

There is an interesting story (whether true or not, I don’t know) about the origin of this crossing signal.

In Morse code, this sequence of long-long-short-long is the letter Q. The story states that using the letter Q as a warning signal dates back to the days of Queen Victoria of England. When she would return to harbor aboard a ship, that ship would blast the letter Q in Morse code with their horn to let everyone know that the Queen of England was aboard and that other vessels should yield the right of way.