Train horn problem

[thunderbeam63]

Lst night at around 10:35 A train horn started to blow for at least 10 minutes.At around three minutes into it I heard this fast high pitched squeel coming from the horn then went back to normal.Anybody know or thinks what happened?

[SirenMadness]

Well, if you've heard a diaphragm type of horn, you probably heard the high-pitch squeal at the end of each activation interval because of the rapidly decreasing air pressure causing the diaphragm inside the back of the horn to vibrate less vigorously, thus creating a much higher pitch, because of its lower vibrational profile.

[Robert Gift]

Beam, did you ever find out what the problem was with the horn?
Since is was heard by the public, they have a right to ask.
Was it a stuck open electric valve?
New locomotives have an electric valve.
Unfortunately, these pushbutton horns do not allow partial valve opening which can lessen the volume.

[thunderbeam63]

I Asked people in my school if they heard it.

I think it must've been a broken valve or something.

[red04stanggt]

I am engineer for the BNSF. ALot of the old engines have half arse whistles and really dont make much noise and provide no warning at crossings. THe newer locomotives are REAL loud

[Robert Gift]

Red, do all new locomotives have a push button horn button which actuates an electric valve?
It is either off or completely open.
At grade crossings I have sounded an Amtrak horn where you could partially open the mechanical valve allowing many degrees of volume.
When we approached grade crossings protected by lights, bells and gates and no traffic, I slightly opened the valve. It would not disturb as many residents near grade crossings, yet still provided required audible notification.
But if needed, the valve could be opened completely for full volume.
At crossings protected by lights, bells and gates, I oppose even sounding the horn.
Likewise, with a mechanical siren, you can rev it up to only a lower rpm for less volume.
But our electronic siren is always full volume.
To sound a quieter warning, such as near a hospital, I have hummed like a descending Q siren into the electronic siren's P.A. microphone! sounded like a real siren but much less volume!

[red04stanggt]

Red, do all new locomotives have a push button horn button which actuates an electric valve?
It is either off or completely open.
At grade crossings I have sounded an Amtrak horn where you could partially open the mechanical valve allowing many degrees of volume.
When we approached grade crossings protected by lights, bells and gates and no traffic, I slightly opened the valve. It would not disturb as many residents near grade crossings, yet still provided required audible notification.
But if needed, the valve could be opened completely for full volume.
At crossings protected by lights, bells and gates, I oppose even sounding the horn.
Likewise, with a mechanical siren, you can rev it up to only a lower rpm for less volume.
But our electronic siren is always full volume.
To sound a quieter warning, such as near a hospital, I have hummed like a descending Q siren into the electronic siren's P.A. microphone! sounded like a real siren but much less volume!

The new electronic General Electric locomotives are push button. THe old locomotives have a lever/handle you pull on and it pushes into a nipple into the control stand which I belive would be the valve to sound the whistle. The new EMD locmotives if your familure with engines they are the SD70Ace's they have a little lever but they are electronic also. All the new bells on the newer locomotives are electronic with a speaker down by the front steps

[Robert Gift]

The new ... SD70Ace's they have a little lever but they are electronic also. All the new bells on the newer locomotives are electronic with a speaker down by the front steps

That is unfortunate. Does not allow varying horn volume output.
Electronic bells? Yuck.
But with a speaker bell, at least it can be aimed straight ahead.
Or does it face downwards to accomadate both directions?
Would be nice it the horns could be aimed in the direction the locomotive was heading instead of three forward and two backwards.

[SirenMadness]

I hear "bell" speakers from our VIA trains, and they sound pretty decent, less annoying than a real bell.

[Robert Gift]

I hear "bell" speakers from our VIA trains, and they sound pretty decent, less annoying than a real bell.

I'd much rather hear a real bell. Much more overtones and sounds better and clearer.