I thought of (and saw this) in another post, and I think it has merit.
Tanks are going to be maneuvering in situations where they are in proximity to friendly vehicles at times, right? Wouldn’t it be rather necessary for a tank or other armored combat vehicle to be equipped with a horn?
And if tanks do have horns, what do they sound like? I’d imagine it would have to be pretty loud to be heard over the noise of the tank’s engine.
The tanks I’ve been around (Danish Leopard 1A5s) had not-particularly-loud electrical horns that sounded like a run-of-the-mill car horn to my untrained ears - they were mostly used to warn bystanders when the tank started moving (obviously, not under tactical conditions). Boring, no ?
One would think that you’d would be very alert when standing around 50 tons of steel that can crush you like a fly, but soldiers are notoriously overtired.
I am sure I remember hearing somebody reflecting on British casulaties in the recent gulf war. He said that the British army suffered an average of 11 casualties a year from accidents with AFVs during training. I don’t recall how many of those were fatal accidents. If British tanks don’t have horns, perhaps they should.
Russian T-72s do. It’s a really cute, wimpy sounding horn that just doesn’t really quite fit in with the image of a tank. Not that loud at all.
I’m just having trouble imagining a huge tank having a little “meep meep excuse me meep” horn suitable for a small Subaru.
With all the mechanisms and whatnots, there isn’t an air compressor somewhere that a locomotive “WHONNNK! WHONNNNK!” horn could be connected to?
And here, I always thought that a tank’s horn sounded like KABOOM!. I mean, that certainly gets across the message of “Get out of my way”, doesn’t it? 
Whichs prompts the question, do tanks go BEEP-BEEP-BEEP-BEEP when they back up?
Yo momma so fat, when her pager goes off, folks behind her scatter.
Sorry. As you were. 
They don’t need horns. THey just fire a shot or two from the machine gun. That tends to get people’s attention.
Does it play “La Chucaracha”?
“Gimn Sovetskogo soyuza” 
hijack/
I biked up the coast of CA once, and may path took me through this huge Marine base, Camp Pendleton.
I was quite astonished to see yellow diamond traffic signs with tank silhouettes. They were warnings posted at tank crossings.
/hijack
Yeah, for other tanks. Of the opposite gender. Especially after a few drinks.
Ex-grunt here. Yes, AFAIK all armored vehicles in the US Army have horns and they are used to warn people that the vehicle is about to do “something.” For example, vehicles with ramps like the M-2/3 Bradley or any of the M113 series, we were required to sound the horn before we dropped the ramp in training situations or in the motorpool.
You usually did not sound the horn if you were backing up because most units required the 2 ground guides when backing up.
The sound? They always reminded me of a loud car horn, rather like on a full sized truck (think Ford 250).
I once saw a Cadillac with horns…
Really cute, wimpy… just doesn’t really quite fit in with the image of a tank - yep, that’s the T-72