Author Topic: Building the Paixhans Monster Mortar & Water Cooler Jug w/Concrete Projos (Read 8141 times)

Double D · « **Reply #60 on:** January 29, 2009, 05:53:40 AM »

On threads...use acme not V.

seacoastartillery · « **Reply #61 on:** January 30, 2009, 04:30:38 PM »

When I discussed the very large threads on the Chamber Piece with Mike, he was not thrilled, so we decided to think on it for a bit and go down to the yard and get our piece of 12" OD Hot forged seamless. It was gone! Who the heck bought our 3' 9" piece of 12"? Who knows, but since we are back to square one, why not order a real nice piece of 3/4" seamless tube, 11" ID and 12.5" OD X 28" long, (to give us a one and a half caliber long bore) and be confident in the quality of metal. It also gives us an excuse to use a round of 4150 resulfurized that was heat treated to 30 Rc. It was squirreled away for some special purpose someday. It is 11.007" OD X 12.259" so we can cut off a 1.2" disk to get to the new Chamber Piece length of 11.0". A redesign was once again necessary, of course, so it is open for review in the photo below.

Regards,

Mike and Tracy

Rickk · « **Reply #62 on:** January 30, 2009, 04:47:30 PM »

it wasn't me... it was to ()&()(^* cold to rumage aound during my short visit.

I have snow... you have cold!!!

Rick

Double D · « **Reply #63 on:** January 30, 2009, 06:33:01 PM »

Quote from: Rickk on January 30, 2009, 04:47:30 PM

it wasn't me... it was to ()&()(^* cold to rumage aound during my short visit.

I have snow... you have cold!!!

Rick

Yeah, but it's a dry cold.

Victor3 · « **Reply #64 on:** January 31, 2009, 01:53:34 AM »

That looks much more simple.

On your Delrin obturation ring...

Years ago I worked on developing a 10" lathe-turned seal for a bottling machine spindle. The OD/ID had to be held within +/- .003. We tried three types of acetal (one being Delrin), Nylon 6/6, UHMW-PE (run and hide from this awful stuff), and teflon.

We wanted to use acetal for the application (low cost/machinability), but we found that the part would "grow" a bit after parting off and would not fit the groove it needed to go into. Over time, the diameter would change. We couldn't have that; the part could sit in stock for months.

When we contacted our acetal supplier, he came out and said that our "abusive machining process" (cutting dry with high speeds & feeds) was responsible for the diameter variations we were seeing.

We did some experiments and found that the part would indeed hold dimension reliably if we machined it slower and flooded it with water-based coolant per the supplier's recommendations.

As an alternate, you could machine a reverse angle (opposite of a chamfer) step in the OD of the end of the chamber piece and fill it with a fast-curing RTV silicone after you assemble it.

dominick · « **Reply #65 on:** January 31, 2009, 08:03:45 AM »

Mike and Tracy,

You are probably aware of this already but if you order a piece of 12.5" x .750" wall tubing, it will more than likely be cold drawn seamless. You may want to ask to measure the id of the tube prior to purchasing as C.D.S. is notorious for being non-concentric. I have run into more than one oval shaped or flat spotted bore with the stuff. It may not pose a problem, depending on the plug clearance that you are planning to use. Just a suggestion.

Dom

seacoastartillery · « **Reply #66 on:** January 31, 2009, 02:05:13 PM »

Rickk, I believe when you were here it was about 12 deg. F with a pretty consistent 25 mph wind. The windy and overcast conditions make it COLD. But we still have more than 300 sunny days per year. DD is right; it's a dry cold, not at all that moist, penetrating cold you get on the New England coast in February.

Thanks, Victor3, we will run some tests on some SS-69 by Silicone Solutions when we get some. It sounds like a no-fuss way to stop flame and gas intrusion between parts.

Dominick, You are correct, that was what we were thinking of, but after quite a bit of reading on this topic, it seems like D.O.M. 1020 has superior strength and very much improved dimensional qualities. In fact we had a piece of 1.00" ID Mechanical Tube D.O.M. here and it checked 1.0012" at one end and 1.0008" at the other 22" away. Not Bad. We will keep looking for a local supplier, but are NOT holding out much hope. Thanks for the cautionary note; we are paying attention. You will be happy to know, that despite eliminating all welding from the mortar, we will still present our local welder with an interesting shell hoist building project like the one beside the 13" Seacoast Mortar, Model 1861 in Hartford, Connecticut. Originally made from wrought iron, this will be a thick wall, steel tube construction in 2009. Already got the Wooden, 6" block and tackle off a Gun Broker auction.

Regards,

Tracy and Mike

Victor3 · « **Reply #67 on:** January 31, 2009, 10:13:36 PM »

Another option might be to use round silicone foam cord stock. You could press it into the step after assembly. McMaster-Carr carries various types of rubber cord stock, but I can't get to their website right now for some reason.

You could probably get away with neoprene, but silicone would handle the heat better.

Does the bottom plate still need to be 1" thick in your new design?

seacoastartillery · « **Reply #68 on:** February 01, 2009, 12:22:49 PM »

Thanks Victor3, Good hint; actually Mike asked me about 'O" Rings which are almost 100% neoprene rubber I found and then when I researched thermal resistance I found all the info sources agree with you that neoprene is a poor choice stacked up against silicone. That RTV material, SS-69 was rated at 330 deg. C, for goodness sakes! That's over 600 deg. F! That's plenty good for an exposure time of one one-hundredth of a second. Given that the probable muzzle vel. SWAG is 300 fps., the ave. vel. of the projectile in the bore is ROUGHLY 150 fps. and that the bore length is 1.5 feet, then the exposure time is computed thusly: 1.5 ft./150 fps. = .01 second approx. (one one-hundredth of a second).

Yes, we do need a 23" dia., 1" thick, steel bottom plate and boiler plate will do just fine. The purpose is "Weight on the Bottom" for balance, that's all. Remember, no trunnions or trunnion yokes on the Henri-Joseph Paixhans Mortier Monstre, nor any supporting elevation gear either. It's just an extra 117 lbs, the second lightest component of this Brute. We are up to 599 pounds or 700 pounds with the bed now. OOPS, forgot the lifting handles, another 20 lbs for 720 total. Thanks again Victor!

Regards,

Mike and Tracy

Victor3 · « **Reply #69 on:** February 01, 2009, 09:59:52 PM »

You're still huring my back with those weights

I don't know what your bed requires, but you might look into closed cell, medium-high density polyurethane structural foam stock. Light and strong, cuts like a dream, and can be glued and painted.

Double D · « **Reply #70 on:** April 06, 2012, 03:24:28 AM »

I found out what Mike and Tracy were up to building this.

BoomLover · « **Reply #71 on:** April 06, 2012, 08:32:35 AM »

That is AWESOME!

Sign me up for at least 3 of these baby's! BoomLover

dominick · « **Reply #72 on:** April 06, 2012, 10:42:20 AM »

Well, this company can't say they are the first to build a water cooler jug launcher.

seacoastartillery · « **Reply #73 on:** April 06, 2012, 12:24:46 PM »

Thanks for posting that, Double D. When we first saw that about 7 months ago, after Cat Whisperer sent it in an email, we were just as surprised as you fellows seem to be. A startling little video! When we made the 2/5 scale French Monster Mortar we had no visions at all of breaking down cinder block walls or putting holes in vans.

Those visions came later after we read the book, Siege Train, the story about Manigault's, CSA Artillery which was part of CSA Gen. Pierre Gustave Toutant Beauregard's defenses of Charleston, SC during the War Between the States. One of the fights with Federal Naval forces in and around John's Island south of Fort Sumter resulted in the loss of two 2,600 pound 8" Howitzers, M1840 when the fire of the Federal ship Pawnee became unbearable. The photo of one of these Army howitzers on that ship on a make-shift naval carriage is well known and inspired Mike and I to think about an 11" version based on the functional core of the Paixhans Mortar. We will show pics of both and I think that you gentlemen will get the idea.

We agree BoomLover! They might not have been the first, but you have to admit, the results on the targets are quite spectacular, Dom. Inspiration for the howitzer build came from one of those old videos from the Hernando Sportsman's Club shoot, (thanks Intoodeep), where a vehicle was used as a target.

Mike and Tracy

Both of the captured guns on the Pawnee ended up at the Washington Navy Yard; they are still there.

The functional tube on right would be the basis for a water jug firing, 11" Howitzer. Need more weight in the tube or carriage, probably both, to handle the recoil of 137 pounds of concrete! Maybe this would not be allowed on that Florida range. Need to find out before building.

RocklockI · « **Reply #74 on:** April 06, 2012, 01:20:06 PM »

yikes

That will put the fire out ! Next thing you know they'll be using Depleated Bowling Balls as ammo .

Double D · « **Reply #75 on:** April 06, 2012, 04:03:36 PM »

Sabotted bowling balls in the Monstre...You may be on to something there Gary.

KABAR2 · « **Reply #76 on:** April 06, 2012, 05:50:35 PM »

Quote from: Double D on April 06, 2012, 04:03:36 PM

Sabotted bowling balls in the Monstre...You may be on to something there Gary.

YES! just what the world needs a bowling ball traveling at 3700 ft per sec...........

GGaskill · « **Reply #77 on:** April 06, 2012, 06:02:41 PM »

... a bowling ball traveling at 3700 ft per sec.

It wouldn't do that for very long; they have terrible sectional density and, consequently, ballistic coefficients.

intoodeep · « **Reply #78 on:** April 06, 2012, 06:35:36 PM »

Quote from: GGaskill on April 06, 2012, 06:02:41 PM

... a bowling ball traveling at 3700 ft per sec.

It wouldn't do that for very long; they have terrible sectional density and, consequently, ballistic coefficients.

GGaskill is correct. We have used candle pin balls in the Mt. Howitzer and found the same type of results. They may roll straight but, they do not always fly straight....

Double D · « **Reply #79 on:** April 07, 2012, 04:02:54 AM »

...and Bowling balls have weighted centers so they hook when they roll.

jamesfrom180 · « **Reply #80 on:** April 09, 2012, 07:32:13 AM »

The candle pin ball was fun to watch. I have wondered if some of those loose projectiles could have reached the gulf. I believe with some minor effort a shot from the line could indeed make the water. To google earth to check!

Approximately 5.55 mi. as the water jug flies. Pretty long shot, don't think it would make it.

seacoastartillery · « **Reply #81 on:** April 09, 2012, 11:18:02 AM »

James, Maybe I am slow today, but I don't see any reference to "Candle pin balls" or "loose projectiles" or "the Gulf", so could you explain what you are getting at in other words? Thanks.

Tracy

GGaskill · « **Reply #82 on:** April 09, 2012, 01:45:38 PM »

See reply #78 above.

seacoastartillery · « **Reply #83 on:** April 09, 2012, 03:51:10 PM »

Thank you Mr. Gaskill. You pointed me in the right direction. James' obtuse comments all became clear due to my knowledge of the Intoodeep/ Florida connection, the size and type of projected orb the cannon fires and where he fires it while in Florida. One simple word would have clued me in saving brain cells for more significant stuff. That word is "Hernando".

One question for you smart ballisticians and engineers. Would a water jug with 137 Lbs. of concrete in it have a chance of lifting one side up a bit, if a 3,000 Lb. sedan, with it's far-side wheels anchored and minus it's engine, if the impact velocity of the jug was 250 fps and a solid, center-post, non-penetrating hit was achieved above the center line?

Tracy

GGaskill · « **Reply #84 on:** April 09, 2012, 04:38:11 PM »

Would a water jug with 137 Lbs. of concrete in it have a chance of lifting one side up a bit, if a 3,000 Lb. sedan, with it's far-side wheels anchored and minus it's engine, if the impact velocity of the jug was 250 fps ...

Well, the math would be mv²/2 for the projectile's kinetic energy, so converting 137 lbs of force to mass is 137/32.2=4.25 slugs. 4.25 times 250 squared divided by 2 is 133000 ft lbs. The leverage of the impact would depend on how far above the center of mass the hit was; let's assume 1 ft for ease of calculation. You would also need the moment of inertia of the car about the far side and that would be hard to determine analytically.

The work of lifting the car is work equals force times distance (w=Fd) so figuring backwards, you would lift the car, at 3000 lbs, 133000=3000d; solving for d is 133000/3000=44 ft. So it might roll the car over even. However, a car is a complex body and determining, let alone hitting with a water cooler jug of cement, the center of gravity would be a challenge. Also, I think you would lose a lot of energy to deformation of the parts of the car which would lessen the energy available for lifting or rotating the car body as a whole.

So my opinion is there is enough energy to lift it or roll it but it is unlikely due to the inability of placing the energy in the right place.

Artilleryman · « **Reply #85 on:** April 10, 2012, 05:01:13 AM »

Sounds like a job for Mythbusters.

KABAR2 · « **Reply #86 on:** April 10, 2012, 05:25:58 AM »

Quote from: Artilleryman on April 10, 2012, 05:01:13 AM

Sounds like a job for Mythbusters.

No because they would miss the target and hit someone's house

seacoastartillery · « **Reply #87 on:** April 10, 2012, 06:00:25 AM »

Thanks very much for that interesting response, George. We thought that the energy would be enough, but were not sure why we felt that way. Appreciate your method and explanation. If we can understand it, anybody can. We can visualize what you are getting at by your statement:

" However, a car is a complex body and determining, let alone hitting with a water cooler jug of cement, the center of gravity would be a challenge. Also, I think you would lose a lot of energy to deformation of the parts of the car which would lessen the energy available for lifting or rotating the car body as a whole.

So my opinion is there is enough energy to lift it or roll it but it is unlikely due to the inability of placing the energy in the right place."

If we ever have the time to build the howitzer and test it out on a derelict vehicle, we will keep these items in mind. A greater chance of success would probably require the gun being closer to the car for more sure placement of the jug at the appropriate location and reinforcement of the location by augmenting the car's structure with an energy transfer plate which is heavily gusseted to a stout I-beam going to the car's far side where a similar plate would resist "push-through". U-channel, angular, cross bracing from both plates to welded anchor points opposite them located where the floor meets the vertical center-post would prevent the whole roof from being pushed back, wasting lots of precious energy. Sounds like too much work to prove a point. This will most likely remain in the theoretical realm.

Norm, We enjoy their show occasionally, but do not anticipate contacting the myth busters.

Tracy and Mike

jamesfrom180 · « **Reply #88 on:** April 10, 2012, 07:20:24 AM »

I do apologize for my obtuseness. I feel you would deform the van before it would rotate. I wouls like to see you build that howitzer.

seacoastartillery · « **Reply #89 on:** April 10, 2012, 02:20:04 PM »

James, I would rather stand between Tiger Woods and his former wife, and she with a golf club in her hand, than would I want to Seriously call you obtuse. In fact, it was my own blindness which made reply # 78 impossible to find! If we do get around to making that howitzer, you will be the first to know. The problem is that the tube and carriage will have to weigh 5,480 pounds if we are to maintain a 1:40, bullet to tube&carriage weight ratio. This is the smallest ratio which naval artillery shooters we know consider reasonable with respect to longevity of the carriage during multiple firings.

Tracy