Cannon Ringing Noise Upon Firing

[mwarnick1]

Hi,

I was having a discussion with a friend about the pinging noise that is heard when firing some cannons and mortars.  What causes this?  Does it impart any information about the safety or other functioning characteristics of the cannon, powder charges, projectile weights, etc?

Thanks,

Matt

"My first mortar (old size beer-can caliber) has 1/2 thick walls and rings with a high pitch 'ping' when shot."

[GGaskill]

Measure the diameter before and after shots to see if you are getting any permanent expansion.  If you are, it is a bad thing and I would stop firing that mortar.

Everything deflects when loaded so you should expect any artillery piece to expand slightly when fired, then shrink to its original size when the pressure has abated.  You hear ringing because the resonant frequency of the piece is in the audible range.  If the frequency of the ringing changes, I would interpret that as a clue that the barrel is expanding (bad.)

Wrap some tape around it to suppress the ringing if you don't like to hear it ringing.

[jeeper1]

A few years ago the "American Shooter" tv series did an episode on the NSSA cannon shoots. All the bronze cannons rang like a bell when fired. They said it was normal.

[Kansas Boomer]

I shoot a mortar and a cannon. I have never heard either of them ring. Of course, I have ear plugs and ear covers on, while firing either one of them.   Boomer

[guardsgunner]

think of your mortar off the bed suspended by the trunnions and you have a bell. Even my steel 24 pdr. rings pretty good when you get over a couple hundred yards.

[Cat Whisperer]

Of all the mortars I've been around I've only one or two that ring.  My first, beer-can caliber (real beer cans when they were made of steel) has walls of about 3/8" with the bore being one beer can + 1/4" bore depth and a powder chamber.  You can take your finger and thumb and thump it and it rings at the same note.  Built in in 1973-74 firing it for the first time on the 4th of July of '74 not too many miles down the road from the bridge at Lexington-Concord.  It's been ringing ever since.

Most of my other mortars have super thick walls and don't ring.

So what note is your's tuned to?

[kappullen]

Matt,

That's a good thing (ringing)!

In the machinist trade we tap grinding wheels to test for cracks.
If she don't ring, she's cracked, and in the dumpster.

The Liberty bell stopped ringing when she cracked too!

Kap

[mwarnick1]

Thanks to all for the help.  I also saw the shooting show on TV about the bronze cannons and remember the ring comment.

The cannon in question (I didn't hear it ring) was a bowling ball mortar with a welded seam up the side of the tube.  The mortar did have a seriously reinforced firing chamber but the weld made us a little nervous.

My soup can mortar doesn't ring at all.....

Thanks,

Matt

[jeeper1]

I suspect that you need thin walls to make it ring.