Dan, Glad you like it so far. We think that we can do a pretty good job of comparing modern scale results to original BIG GUN results, BUT nobody should take this as a scientific study, because it is not that. There are too many unknowns, too many things where we are forced to use quess-work and SWAGS. You may not have that abbreviation in Sweden. It means Scientific Wild Assed Guesses. HEY, what do you know; we DO HAVE some scientific stuff here after all! Sorry Dan, no peanut butter testing will occur. It all was a big joke.
gulfcoastblackpowder, We sure will do a few fun tests in between serious ones. We have always wondered if those lexan sheets are bullet-proof. Ballistic gel? These big non-deforming bolts will blow through 20 feet of that stuff without slowing down; besides it's expensive in large quantities. Kevlar, maybe, we'll see. We will get plenty of data on the carefully prepared shots, don't worry.
Lance, The next step is making an authentic iron armor target as close to CSN Commander Brooke's that he used in the winter of '63 just south of Richmond on the south-west bank of the James River. If you want a good book on this experiment and many others conducted by this talented ordnance designer, order a copy of George M. Brooke, Jr's.
Ironclads and Big Guns of the Confederacy, the Journal and letters of John Mercer Brooke". Let your imagination run wild; that ironclad target sounds like a good one. Better make it a Union Monitor or maybe a New Ironsides since we will have the 7" Brooke there this year. Mike says, "Tell him it better have a stack belching black smoke or I won't let him play with my toys this year."
I think he is getting psyched already!
Mike/Tracy -
Good thinking. You've outlined the starting premises and drawn your expectations of parallels to full scale. The results will either duplicate or not the observed results of what was achieved at full scale many moons ago. From that comparison you can draw conclusions to the accuracy of your 'design of experiment'.
In addition, you can compare the effects (in small scale) of different velocities on a give target/angle of incidence.
These observations, obviously, would lend some insight to the effects on similar steels with similarly shaped projectiles of what-ever scales - by comparison of your results with known results published in yester-year.
Thanks for your taking the time and effort for this research!
Tim, Thank you for that statement, "The results will either duplicate or not the observed results of what was achieved at full scale many moons ago." This is the very essence of what this project is all about. We must be careful to report and photograph exactly what happens and not presume to know or report what should have happened.
As we must approximate some of the materials used in these tests, we must likewise expect only approximate results. I hope we will clearly see some parallels with the 1860s results, but we cannot honestly expect anything specific. We expect it will take about 3 weeks or so to build the targets and make the bolts. What do you think will more accurately approximate forged wrought iron bolts, 12L14 Ledloy or fully annealed 1018?? We need some help with this question. Do we have any metallurgists out there?
When we do the smooth bore 42 pdr., 8" and 11" and 100 Pdr. Parrott testing we will have an opportunity to do the CSS Virginia type 35 deg. angled casemate testing at various different ranges. We will have to buy some stout lexan barriers to protect ourselves during those round shot tests. They will be thicker than what those boys on Mythbusters use, for sure!! Thanks for those well reasoned comments, Tim. Tell Lance he better make that Monitor half scale so we can hit it when it's underway.
Double D, We want you to promise us that you will drive really carefully. Traveling cross country like you are leaves you WAY TOO MUCH TIME to think about things for US TO ACCOMPLISH!! WE want you to arrive at the new homestead and have plenty to do.
Seriously though, we certainly appreciate your comments and all the others which are extremely helpful.
I saw the replies I know that I may not have stated my logic correctly. So let me say the same thing again differently. What I meant was if your projectile is 1/6 scale your target must be 1/6 scale. No I don't mean if the original target was 6 foot by 6 foot you target must 1 foot by 1 foot. I mean if the original target was 6 inches thick, your scaled target must be 1 inch thick. It can still be 6 foot by 6 foot as that axis is not relevant. Following the same logic the range should 47.5 yards.
First of all, I think we are ready to get to the semi-serious experiments. Remember these are not scientific tests, because the exact values of the original external ballistics are generally not known. What we know for sure, like Brooke's test of the Treble-Banded 7" being 285 yards from gun to target and the target being 8" thick and made of wrought iron and backed by a mound of clay dirt, we will use. For conditions that are unknown, we will use the most logical methods, ranges and materials that we can. The original was 8" thk. and composed of four, 2" thk. plates. Until we can get the correct, wrought iron material, we will use pieces of structural steel, such as 6" and 8" to make our 1/6 scale thk. plates, (.333")(4)=1.333" The range, we are pretty sure must be adjusted to make sure that the velocity of the original bolt at 285 yards is the same as ours is at some calculated lesser range. Maybe 47.5 yds., maybe 71.25 yds. If anyone knows of an exterior ballistics program that will allow input of the original 120 lb. projectile data, please let us know. We need to know what the big bolt's velocity was at 285 yards given a muzzle velocity of 1,300 fps. The ballistic coefficient would help too.
Now to the physics. I'm not sure you can actually duplicate the impact physics in scale. Can you achieve 1/6 of sectional density, ballistic coefficient, velocity, and gyroscoptic stablility impact values of the original at impact?
At first we didn't think we could do these, but now we believe they are possible. Our bolt's material, length and dia., ogive and base, (milled base groove forming the skirt) will all be in EXACT proportion so the SD,and the BC should be to scale. Velocity will be authentic and measured with a protected chronograph at the muzzle and maybe at the mid-range targets if we can place landscape timbers and heavy steel plates a few feet in front of it. Gyroscopic stability has been achieved based on full power accuracy loads which we have already developed. Rifling twist is 1/6 scale of the original and works fine.
What you want to do is find the range in which your gun gives the same results as the original test.
This is a key and very important goal of all of these experiments! We are as sure as we are about any of these factors, that having the same velocities at the targets of both original and scale bolts and the resulting proportional energies, is very critical to achieving a proportional impact result on the scale target.
Here's how I would address the issue. First compute the original 285 yard impact values for the original gun. Then compute the range at which your 1/6 scale gun will achieve 1/6 of those same values. Also compute the range at which your 1/6 scale gun will give the same impact velocity as the original. Impact velocity will be the only original impact value you might be able duplicate with your gun.
The first part can be a description of the effect of the 120 lb. bolt on the target, (i.e., how many plates holed, how many broken or cracked, extent of cracks, etc.) The second two items are related by the velocity factor and can be done. The last point will not be known until this experiment is actually finished.
Fire two tests shots at each of three ranges on two targets one on a 1/6 thick target and and an original thickness target.
Fire one shot on the 1/6 scale thick target and one shot on the the original thickness target at the 1/6 scale range or 47.5 yards.
Fire a second test with the same two targets at the range you computed that would give the 1/6 scale projectile the same impact velocity as the original.
Fire a third test a 285 yards.
Should make for some interesting results. I say that the longer the range the deeper the pentration.
By the way doesn't SAM's Club or COSTCO sell peanut butter in bulk containers. Say two 55 gallon drums of peanut butter laid end to end...
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The first two need to be simplified and why the original thickness target? 8" thick?? 12" x12" x 8" thk. Whoah Nelly!! Are you going to come down here are help us hoist this Young Giant up the hill? New rules on National Grassland in Colorado expressly prohibit ANY vehicle from going off marked roads more than just to park the vehicle safely out of the roadway. We will haul scale targets and other light weight equipment only out to the farther ranges. We can do the second test with a scale target and the third would be no problem. No comments on peanut butter; I may have said too much already, but you know how he dislikes those Smilie faces, so I relied on his obvious intelligence to realize all that stuff about the peanut butter torpedo target was merely a joke. Hope so.
Terry C. Peanut Butter Armor and Ballistic Jelly! I must be getting punchy because it's getting late or too darn serious for my own good. I had to read that four times before I got it. Now how bad is that? I better turn in now. Good one, Terry!
Regards,
Tracy and Mike
