BRONZE CANON BARREL CASTING

[Tom O]

I am new here, but just a couple of thoughts

It is a small point, but Joules are a unit of energy. The force that is exerted on the metal is proportional to the time over which that energy is dissipated - the power. That power will be unevenly distributed across the section and length of the barrel. The most likely time for a failure of this type of gun is during its first firing. The metal becomes strain hardened with further use. This is especially important because explosion is an impulse load, and casting, unlike rolling or forging, does not introduce strain in the grain structure of the blank.

That's all without the need for unseen voids which obviously make the situation much worse. Ultra sound and x-ray equipment can detect those, but I have never seen that attempted outside of the aviation industry as it is _very_ expensive

All that being said, it is very cool and I wish I had one!

True but most powder tests I have heard of use at least a double load and are tied to a tree or are clamped down.

 

[historicalarms]

I am new here, but just a couple of thoughts

It is a small point, but Joules are a unit of energy. The force that is exerted on the metal is proportional to the time over which that energy is dissipated - the power. That power will be unevenly distributed across the section and length of the barrel. The most likely time for a failure of this type of gun is during its first firing. The metal becomes strain hardened with further use. This is especially important because explosion is an impulse load, and casting, unlike rolling or forging, does not introduce strain in the grain structure of the blank.

That's all without the need for unseen voids which obviously make the situation much worse. Ultra sound and x-ray equipment can detect those, but I have never seen that attempted outside of the aviation industry as it is _very_ expensive

All that being said, it is very cool and I wish I had one!

the "joules" energy I mentioned is not burst energy, it is energy that is imparted to the projectile by the powder gas expansion...basically it is how hard the slug hits what your shooting at. The BP pressure I mentioned is the "burst pressure". You are right the first firing can be the "test" but it can also be just the beginning of a catastrophic failure. Pressure stress on steel is accumulative and a small little bit of over stress at each firing can creep closer to a failure. Bp pressures are easily controlled to a safe level with knowledge & discipline....HOWEVER....the notion that it is "absolutely" safe is a folly not to be ventured into. "Safe pressures" are very subjective to the tube you are using it in . Common sense use of very heavy wall seamless pipe with a tensile strength of 80-100 psi will control BP pressures in the 20-28,000 psi range. For many many years, that range was thought to be the upper limit BP could attain but with modern testing equipment used after they blew a 16 inch 3 gun turret off one of their battle ships, the US Navy proved BP can easily reach 100,000 psi under certain conditions.
I thought I had a pretty good handle on BP shooting muzzleloaders but when I started researching cannon shooting....those big charges of powder are a whole different ball of wax. About 15 or 20 years ago the US govt & parks service got tired of cleaning up the 15 or so folks that were being killed a year from cannon demonstrations so they and the North-South Skirmish assn got together and made a safty manual for cannoneering....search a copy of that....and follow it.

 

[Tmyatt]

Thanks for all the comments and input. The casting has been sold. One less thing on my "going to get around to it list".

 

[mbond]

Yes, the only sensible way to quote the energy of any kind of gun, it to quote the energy imparted to the projectile. Some of that energy will be in the form of heat, but most will be kinetic energy.

The failure of the barrel has nothing to do with the level of energy in the projectile per se - though they are hardly independent. Failure of the barrel happens when the power (energy over time) is sufficient to spall the crystals. Strain hardened crystalline structures are much more resilient against this type of load, but fatigued structures are not.

As I say, I can discuss the theory all day long, but I have very limited practical experience. I am hoping to learn from those on this form with experience, and I hope to contribute in some way too

 

[Susquatch]

As I say, I can discuss the theory all day long, but I have very limited practical experience. I am hoping to learn from those on this form with experience, and I hope to contribute in some way too

Some of us on here take great delight in both the theory and the practical application. Just discuss or ask about whatever you want and you can be pretty sure that someone will chime in. Might even initiate some good debates.

 

[Ironman]

I've made a couple of golf ball cannons in my time and would not hesitate to make another. . so yeah, cannons-R-us, but Sched 120 high tensile steel is better.

 

[Dan Dubeau]

I've made a couple of golf ball cannons in my time and would not hesitate to make another. . so yeah, cannons-R-us, but Sched 120 high tensile steel is better.

I've always wanted to make a golf ball cannon for some of the charity golf scramble tournaments I participate in. Your team can pay $20 to the cause to have your drive blasted 300+yards straight down the middle of the fairway. I think it would be a lot of fun. I'm sure it would get you in hot water from some people in uniform though.....

 

[DPittman]

I've always wanted to make a golf ball cannon for some of the charity golf scramble tournaments I participate in. Your team can pay $20 to the cause to have your drive blasted 300+yards straight down the middle of the fairway. I think it would be a lot of fun. I'm sure it would get you in hot water from some people in uniform though.....

A golf ball Canon on a golf course might be handy(or at least fun) for clearing some of the Canada geese that overpopulate many golf courses.

 

[Dan Dubeau]

Shotgun works well for that, but I've already got 14 clubs in the bag, so that's out .

 

[Susquatch]

A golf ball Canon on a golf course might be handy(or at least fun) for clearing some of the Canada geese that overpopulate many golf courses.

My BIL told me that they have this cool system now. It's a drone with a scary face on it. They chase the geese with it and then put out signs with the scary face on it. The geese disappear.

 

[Tom O]

Well that is different!
Makes ya wonder who modeled for it.

 

[Susquatch]

Well that is different!
Makes ya wonder who modeled for it.

Seriously, it looks like this:

The website is:

Goose Control | Denver, CO | The Goosinator

Are you trying to get rid of the geese on your property? Call Randy at 303-916-1676 now to buy your very own Goosinator.

www.goosinator.com

 

[Tom O]

Hmmm looks like a ripoff of the Flying Tigers after flying through the barn door! Or possibly the idea was hatched after Indiana Jones, scaring the birds and getting the wings ripped off in the tunnel.

 

[6.5 Fan]

Why scare the geese off, they be tasty. Shoot 8 holes and stop for roast goose.

 

[Dan Dubeau]

Why scare the geese off, they be tasty. Shoot 8 holes and stop for roast goose.

They make great jerky too.

 

[historicalarms]

I have used my big cannon to scare geese of our crops... curiously, a couple of them didnt leave with the rest of them.

That drone idea is genius, geese will always scatter in terror from a plane flying over them, they associate them with birds of prey that hassle them 24/7.