A Train Whistle Mystery.

Travel by train around the United States and, if you’re paying attention, you’ll soon notice that Amtrak engineers blow the whistle quite a lot. And if you’re really paying attention, you’ll notice that there are several different whistle patterns—for example, two short toots when the train is about to move forward; three toots when it’s about to back up.
 
By far the most common whistle signal is the one you hear every time the train approaches a grade crossing, which is where motor vehicles drive across the tracks. It’s long-long-short-long. There will be minor variations—sometimes it’s brisk, sometimes long and drawn out—depending on how fast the train is approaching a crossing. And sometimes you can detect a slight difference in the signal after a new engineer with a slightly different “touch” has come aboard in a crew change. But the signal itself is always the same: long-long-short-long. Furthermore, that’s the way it’s actually specified in railroad manuals.

There are several versions of trackside signs telling engineers to blow the whistle, but this one specifically asks for long-long-short-long.

 
But here’s what I find so curious: no one seems to know where long-long-short-long came from. Over the years, I’ve asked many Amtrak people, including conductors and engineers, and no one knows.
 
Then, the other day, I got an email from a reader who said it’s actually Morse Code for the letter “Q”. (And indeed it is: dah-dah-dit-dah.) He went on to say he was told that British ships in the late 1800s blew long-long-short-long on the ship’s horn—the letter “Q”—as a way of letting other maritime traffic know that Queen Victoria was on board and to yield the right of way. Certainly an interesting explanation … and, I thought, plausible, too.
 
To corroborate that explanation, I contacted Mark Smith, founder and the person behind The Man in Seat 61, the best and most complete web site devoted to rail travel anywhere in the world. As an expert on passenger rail and as a Brit, I could think of no one better to ask. Here is his response:
 

“The Queen story sounds apocryphal to me – though Queen Vic’s reign up to 1901 would be the right time for railroading in the US to be starting and expanding, so Q … makes (some) sense.”

 
So it’s only POSSIBLE that the long-long-short-long whistle signal is actually “Q” for Queen. But somewhere … some time ago … someone made the decision that trains in North America—both passenger and freight— would blow long-long-short-long when approaching grade crossings. But who? And why that specific pattern? Does anyone know?