If you live near train tracks, then the sound of a locomotive horn is fairly commonplace. It fades into the background like wind or cars driving down the road. However, as all drivers know if you are about to cross over train tracks, but suddenly the cross rails go down you better listen up for that locomotive horn warning you to stop. As you wait for the train to pass and hear the sound grow closer, you may wonder exactly how loud it is.
The maximum level volume a locomotive horn can be is 110 decibels. The lowest level volume a locomotive horn can be is 96 decibels. In terms of comparison, this would place the volume level somewhere between a shouted conversation and the noise of a chainsaw.
Locomotive horns are very loud and for good reason, and while it can be irritating, they are that loud because everyone must know they are coming. There are a couple of reasons why a locomotive horn needs to be that loud, so let’s take a look at them, as well as the patterns you may hear that indicate that a train is coming to where you are.
Why Are Locomotive Horns So Loud?
At its very simplest and most basic, the reason that train horns are so loud is for safety. Because they are moving so quickly, they have to give a warning far enough in advance that cars have the chance to stop at grade crossings. By law, train engineers must sound their horns anywhere between 15-20 seconds, or ¼ of a mile before they reach the grade crossing. In certain cases, they can sound the horn 25 seconds before they reach the grade crossing.
Because the train is still fairly far away, the volume needs to be high enough that pedestrians and vehicle drivers at grade crossings can clearly hear it, and either quickly get across the tracks or come to a stop until the train has passed. Additionally, if there are barriers such as trees or buildings in the way, the volume must be higher, as well, to get around them.
In addition to being required to blow the horn a certain amount of time before arrival, the Federal Railroad Administration included another aspect of the Train Horn Rule. This is the fact that the horn is sounded in a pattern. If you listen closely, you will notice the following: First there are two long blasts, then one short blast, followed by another long blast.
The timing, volume, and pattern, all work together to help give people the heads up they need to get out of the way as soon as possible.
What are Quiet Zones?
In the past, many states prohibited trains from sounding their horns at grade crossings due to the high volume and the disruption, irritation, and inconvenience it caused people as they were going about their daily lives. These were known as quiet zones. However, as time went by it became clear that the lack of horns increased the number of collisions at grade crossings, significantly.
In response, the compromise was made to make this warning horn sound over less time than it had in the past. Thus, the limit of 15-20 seconds in advance of arrival at a grade crossing, with some exceptions made at 25 seconds when the engineer is not sure how far they are. Though there are still a few places in the United States that still have quiet zones, they are required to have other safety measures in place.
Conclusion
Locomotive horns are distinctive and loud. The lowest volume they can be is 96 decibels, and the highest volume they can be is 110 decibels. This means the sound can be as loud as a shouted conversation or as loud as a chainsaw. While the loudness is annoying and, in the past, there were quiet zones that prohibited trains from sounding their horns, it was discovered that without train horns, the number of collisions went up significantly at grade crossings.
In response, the Federal Railroad Administration put in place the rule that while the horn would be sounded the engineer had to wait 15-20 seconds, or ¼ of a mile, before reaching the station or crossing. Additionally, the horn had to be sounded in a pattern of two long blows, one short, and another long. The distinctive sound, volume, and timing were enough to give people warning of the locomotive’s approach and cross safely or stop.
