Flash boom thump?

[Hank Trent]

Got to puzzling about this while watching the artillery fire at AHT.

Let's say a typical artillery piece is firing shells at a typical distance. You're approximately where the shell would land. What happens in what order?

Do you see the muzzle flash, hear the boom of the firing, and then the explosion of the shell? Or some other order?

I was "shelled" with ground charges at a battle last year, which they detonated a second after I heard the boom, so I still found myself bracing after hearing the boom of enemy artillery, waiting for the "shell" to hit nearby.

But then I wondered, due to the speed of sound and the velocity of a projectile, if that was right, or if there would be little or no gap between the sound of the firing in the distance and the explosion nearby.

Hank Trent
hanktrent@voyager.net

[Slouch]

Re: Flash boom thump?

really depends on the distance, type of gun, type of projectile, etc.

I was just reading "Four Years in the Confederate Horse Artillery", where at one battle he notes seeing the smoke from the muzzle, then the scream of the shell, followed shortly by the boom from the cannon. This was from a federal Parrot.

[LibertyHallVols]

Re: Flash boom thump?

1) Flash - Travels at the speed of light.
2) Boom - Travels at the speed of sound (I don't think CW projectiles were supersonic, but perhaps I'm wrong).
3) Thump? Maybe not! What if the projectile made some sort of noise as it travelled through the air? Those who've been to an N-SSA event can attest to the zipping, buzzing, or whistling of minie balls. I've never heard live artillery fire... anyone else?
4) Thump... or maybe "Boom", or whatever sound(s) you'd hear as it exploded/impacted.

Just a thought...

[Hank Trent]

Re: Flash boom thump?

really depends on the distance, type of gun, type of projectile, etc.

I was afraid "typical" would be too vague. Let's say, I dunno, a 12-lb Napoleon firing a shell against infantry at 800 yards. Does that sound reasonably common at a battle that might be reenacted? Or pick something similar that would be typical. I don't really know that much about artillery types.

Good point about the sound the projectile might make in the air as well. I've been shot at by modern small-arms fire, and the zipping/whining sound is noticeable, but never heard any kind of live artillery fire.

Hank Trent
hanktrent@voyager.net

[Tom Craig]

Re: Flash boom thump?

I don't have much expertice myself, but I do know that numerous period accounts talk about the sound of shells whizzing or screaming through the air depending on the type of shell that it was.

From annectdotal reenacting experience I can say that at any sort of distance you definitely see the flash of the cannon (or rifle for that matter) muzzle well before you hear the sound of the explosion.

Take care,
Tom Craig
1st Maine Cavalry

[Michael Comer]

Re: Flash boom thump?

Some years ago I was at Stone's River and happened to be directly across a field from a gun crew doing a demo at the visitor center. The distance would have been about 500-600 yards I suppose. I'm not a real good judge of distance but my perception of the size of the gun and crew would put it in that range.

Anyway, I didn't know they were going to do a demo and just happened to be standing in the woodline where some Confederate forces had been when they fired. Since I was looking directly at the gun I saw and heard very well what happened. I saw the flash and smoke and 2-3 seconds passed until I could hear the report. No thump nearby or whistling over head though, thankfully.:)

It was a pretty neat experience all in all and was done at more historically accurate ranges than what we see at a lot of events. If they had known I was there, they may not have done the demo as safety conscious as the NPR is.

[Rear Rank 2]

Re: Flash boom thump?

It was modern artillery, self propelled 175mm (since replaced by the 8 in.) and towed M-198 155mm that I called in. the rounds hit target before the sound of the guns from behind. Prior to impact the rounds could be heard going over.
Just my 2 cents worth.

[Jefferson Guards]

Re: Flash boom thump?

Some great video footage of live firing of period artillery at service ranges. I believe it answers some of the questions posed here:

http://www.youtube.com/profile_videos?user=pbocorp&p=r

[BrianHicks]

Re: Flash boom thump?

As previously stated, the Flash travels at the speed of light.

You'll see the gun flash first.

The speed of the sound from the muzzle blast?

Speed of sound equals: 1129 feet per second. Depends on how far away you are. If you are 800 yards, (2400 feet) you'll hear the muzzle blast in just over 2 seconds after you see the flash.

The boom of the round exploding? Depends on the range to impact, and the weapon firing.

Here are some basic muzzle velocities:

M1857 12-pounder "Napoleon" = 1,440 ft/s

12-pounder Howitzer 1,054

10-pounder Parrott rifle 1,230

3-inch Ordnance Rifle 1,215

12-pounder Whitworth breechloading rifle 1,500

As you can see, the round will fly at just faster than the speed of sound (except for the 12 pounder howitzer), so the sound of the muzzle flash at 800 yards, will be just a fraction after the sound of the impact with most artillery fire.

[Johnny Lloyd]

Re: Flash boom thump?

Hank-

It takes some time for the sound of an explosion to reach the distance you are at. It depends how far away you are from the impact area how quickly you hear it.

Depending on the shape of the projectile, you can also hear the sonic whizz as it flies through the air above your head.

I have some practical experience in this. :wink_smil

All the best -Johnny Lloyd

[lukegilly13]

Re: Flash boom thump?

I remember reading, I think in "Company Aytch" where the soldiers were experiencing sniper fire and they kept saying "up goes smoke". It seems they were teasing a young private who was clinging to the ground hiding behind his hat. They were seeing the smoke, then hearing the round/impact, then hearing the shot. I'm guessing artillery would be the same only closer together.

[Carolann Schmitt]

Re: Flash boom thump?

In addition to the video Brian posted, a few years ago the History Channel did a show on the long-range artillery matches at Grayling, MI. The show had cameras and microphones on the firing line and at the target area. The sound and visual images are very impressive. The show also features some good examples of the effect of various artillery shells on their targets, and some very good shooting by John Wells and the 3rd US Artillery.

Anyone who has attended a N-SSA national skirmish knows there is a distinct difference in the sounds of a blank round and a live round.

And bronze mortars ring like a bell when they're fired...:)

Regards,
Carolann
Knaps Battery E, N-SSA

[Hank Trent]

Re: Flash boom thump?

This is great information! So long story short, it looks like ground charges that fire after a short delay from the sound of the artillery are not actually the way it would happen, but probably have something to do with hand-eye coordination of the operator and/or other reasons.

So typically (with lots of exceptions and variations, of course) it would be:

Flash
Whistle
Boom from the muzzle and explosion of the shell about the same time.

In other words, there would probably not be a flinch reaction to the sound of an enemy cannon, but there might be to the whistle or the flash/smoke if it could be seen.

Good information.

Hank Trent
hanktrent@voyager.net

[Minieball577]

Re: Flash boom thump?

In addition to the video Brian posted, a few years ago the History Channel did a show on the long-range artillery matches at Grayling, MI. The show had cameras and microphones on the firing line and at the target area. The sound and visual images are very impressive. The show also features some good examples of the effect of various artillery shells on their targets, and some very good shooting by John Wells and the 3rd US Artillery.

Anyone who has attended a N-SSA national skirmish knows there is a distinct difference in the sounds of a blank round and a live round.

And bronze mortars ring like a bell when they're fired...:)

Regards,
Carolann
Knaps Battery E, N-SSA

Carolann touched on another aspect that I have been thinking about, and that is the distinct "Ring" of the bronze guns. Not only do the bronze Coehorns ring like a bell, but so does the Light Model 1857 Napoleon 12 Pndr Field gun, the closest in the attached image, we shoot regularly. This is something I have never heard when we have fired it with blanks.

Speaking of the Grayling MI long range match, that is coming up at the end of this month, and is open to spectators. More information can be found at the following website, http://www.museumandcollector.com/grayling.html

[jrd28thmp]

Re: Flash boom thump?

I'm with Battery G, 1st Penna Lt Art'y, and we are fortunate enough to crew an M1857 Napoleon, and from the research we have done, stumbled upon, and observed at events, my guess is you would see the flash and smoke before you met your maker, as far as i know, the projectiles fired from a napoleon did not make the characteristic whistling sound, they did not go fast enough, in fact, after one or two bounces of the solid shot projectile, it was going slow enough that, if you were far enough away, you would be able to witness the projectile skipping toward you, obviously, not that you could stop it...as far as the spherical case shot fired from the same weapon, again, there would be the smoke and flash, but the ideal explosion would be 50 feet above the head of the enemy, to rain shrapnel down, so at that close of a distance, i don't think the explosion would be audible unless you survive...hope this helps