I think it moved!

[KABAR2]

Thanks for the update, things gotta give soon I doubt that anything else but rust is holding it closed.

I am sure you'll have it open soon.


Allen <><

[GGaskill]

If you can rig the barrel so that you can leave the 2" round resting on the surface you are trying to move when you have finished the day's activities, its study pressure may help get things moving.

[cannonmn]

Thanks.  This one is stuck very solidly, as if it was welded, as I can tell from the ring when the rod strikes the anvil, which is in contact with the breech door.  It is always hard for me to believe that only rust is acting like a weld, but I'm sure that's the case here, there's nothing in the design of this thing that would allow the breech plug to hang up mechanically and not want to pivot back and down on the breech door hinge.

I wasn't sure before I started that this one was made to take metallic cartridge cases, but so far it seems that it does.  The chamber area is noticeably larger than the bore.  Also the bore isn't sealed by the breech door, since penetrant leaks through pretty freely from the bore to the outside in the area of the hinged breech door.   Morratt's first b/l cannon, the one shown in his oriiginal patent, did not take cartridges, and all three times he took his gun for testing at the Navy Yard, there were gas leakage problems.  I'm sure that's why he decided to go with metallic cartridges in his three subsequent guns, namely the two howitzers (3.4 in. rifle and 12 pdr. smoothbore) and his Army 6" rifled howitzer.

[KABAR2]

Is it possible to position the rod so that it is in the upper area of the breech?

you will be doubling your force at the end of the fulcrum,  one other Idea if you

had a hammer drill or air hammer that could be attached  to the rod the sudden

rapping motion of these tools could upset some of the rust freeing the breech.

[cannonmn]

position the rod so that it is in the upper area of the breech?

Yes, given the fixture we have on the inside of the breech, there's about an inch of range up or down for the rod to strike and we try to get it to strike at the upper end most of the time.  The desired resut of the impact at this stage is vibration which works the penetrant into small spaces where it would take "forever" to go without the vibration.  That's also why we're not putting much arm into the rod to make it hit the breech harder, at this stage-don't want to really heave it until it starts to move a little, this way we get a little assurance that we're not just stressing the hinge in case that's the only thing stuck fast. 

If the two bolts holding the hinge on under the breech will come out, I may detach the hinge under the barrel to remove any resistance that may be coming from there, which will also remove the chance that too much pounding could break the hinge.  Then I wouldn't have a problem with giving the rod a good heave.  The hammer-rod weighs 100 lbs. and even a halfhearted push of the rod causes the whole 900 lb. (?) cannon to move about a half-inch backward on its pallet each time the rod strikes the aluminum anvil, so there's a fair amount of momentum transfer occurring.  Today we have a fresh tank of propane so the heating, cooling, and penetrant application will continue also.

[Double D]

John,

Have you tried that ATF-Acetone penetring solution yet?

[Cannoneer]

Cannonmn,

Do you think that the Moffatt 12-pdr howitzer that you're working on now, has an almost identical hinged breech-plate configuration as the earlier Moffatt patent drawing that you posted? The part I'm really curious about is the truncated cone that fits into the machined, correspondingly shaped, recessed area of the breech.

[cannonmn]

Today we arrived at the shop and tried the rod-hammer and the breech immediately began to open, like an inch each hammer blow.  The penetrant we had put on and worked in yesterday musta eaten the rust overnight, because yesterday the hammer blows made everything ring, and nothing moved.  Today we got a "thunk" sound as the breech opened rather quickly.  The following slideshow will answer questions about how this gun is arranged.  It is clearly made for metallic cartridges, a type I've never seen a single example of and don't expect to find full boxes of anywhere, either.

This gun may have used separate-loadiing ammo, charge in cartridge case, and projectile loaded separately ahead of the charge.  The reason I think that is because the chamber area is so short.  There's only 4.5 inches from the sharp shoulder where the case rim seats, to the start of the forcing cone, which is about another one inch long.  Diameter of the cartridge case rim would be about 5.25 inches, base of case next to rim would be about 4.95 inches, and of course bore is 4.62 inches.  Dia. of the small end of the conical plug is 5.14 inches, at large end is 5.89 inches.  This conical structure is 2.64 in. high, not including the breech door is is mounted on.

I will now have to email my "advanced artillery cartridge collector" buddies to see if they have or have ever seen a Moffatt cartridge case of any kind.  Moffatt had a patent for these which I've seen, but not sure it is for the version this gun would use, will have to check it again.

Doug, did not get to try the Acetone/ATF yet, am reluctant to switch penetrants on same job for fear that one will cause other one to coagulate or something bad.   Will try on next project.

http://s17.photobucket.com/albums/b62/cannonmn/miscforumsetc/forums44/?action=view&current=b22f5fff.pbw

[KABAR2]

That's fantastic news! I'm glad you have one opened up, now comes the fun of finding a modern case that can be machined down and
modified to fit the cannon, what about seeing if Moffatt had any cartridge patents? you've hit pay dirt before on this fellow you might
do it again.

[cannonmn]

Here's one I just found.  Looks like the guy was ahead of his time-combustible cartridge with metallic base as a gas check.  That's what the 120MM Abrams tank gun uses now.

http://www.google.com/patents?id=giNeAAAAEBAJ&pg=PA1&dq=moffatt+cartridge&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20cartridge&f=false

[KABAR2]

That was quick! great find.

You know if you substitute a brass winding for the paper winding you have what was being used
to produce artillery cartridges of the day, now was he responsible for that or was someone else?

[cannonmn]

if you substitute a brass winding for the paper winding

I haven't found any of his patents that dealt with wrapped metal cartridge cases.

I "lost" one R.R. Moffatt or Richard R. Moffatt patent I had bookmarked, somehow, a cartridge that looked like a juice can, had many holes around the edge of the cartridge head (c. collector word for base.)  It had an internal valve so you could ignite with friction primer and not get a lot of back-blast.  If anyone finds that one pls give me link to it.  I don't recall seeing any projectile attached to it, so it might be the one I'm looking for, hard to tell.

[cannonmn]

I found the items I had lost.  This brief report describes the cartridge cases Moffatt was using during that period of time.  Even though the report deals with his Army 6" howitzer, I'm sure he used the same thing, different size, in his two smaller guns.

http://books.google.com/books?id=hOigAAAAMAAJ&dq=ordnance%20june%2018%2C%201877&pg=RA7-PA649#v=onepage&q=ordnance%20june%2018,%201877&f=false

[KABAR2]

Very simple case if you can find a modern case that can be cut down an and modified to chamber in the piece the
tappet for blocking gas is very simple it is just a strip riveted in to the base, this is doable.

[cannonmn]

if you can find a modern case that can be cut down

Tx Allen.  I'm getting the impression since the cartridge case was surrounded by so much metal in the Moffatt guns, it didn't have to be very strong, on its own.  There had to be some metal at the rear for obturation but since the report talks about tin cartridge cases, I'm thinking one of exactly the right shape made from soldered or welded sheet metal might be the best thing.  Modern artillery cases would be overkill I think.  Also I measured several common sizes already and nothing is close enough to make a rework possible, although I haven't run out of cases to try yet.  It seems to me like the cartridge would work well if it could easily reform itself to the exact chamber profile when fired at black powder pressures.  The modern steel and brass artillery cases won't do that.

[Double D]

How was this thing primed & fired? 

[KABAR2]

How was this thing primed & fired? 

It was fired by a friction primer a metal plate with two holes allowed the flame to transmit to the powder charge
back pressure from the charge forced the metal plate down over the hole in the base of the cartridge sealinging it,

this was a much simpler system than used in the Hotchkiss and other shells with a tappet design, but the principle is the same.

[Double D]

I asked because the patent drawing shows a primered fixed shell and the gun does not appear to have a striker mechanism to impact a primer.

If this gun uses a base plate shell it should fairly easy to to turn one out from brass or aluminum on the lathe.   The base plate shell could be fired with shotgun or 50 BMG primers.

[Cannoneer]

The cannon that Cannonmn is now working on has a copper bouched angled vent for a friction primer, but some of R.R. Moffatt's other designs included both vent, and firing pin options on them.
Below is the description of Moffat's friction primer ignited cartridge taken from the text that Cannonmn posted ( Annual report of the chief of ordnance...., U. S. Ordnance dept.).

[Double D]

Are there any drawings of the "cup of tin"?  It sounds fairly simple.

[cannonmn]

Are there any drawings of the "cup of tin"?  It sounds fairly simple.

I don't know that any Moffatt artillery cartridge cases survive, but I haven't checked around yet.  I'll probably post something on the IAA forum to see if anyone knows.  But as you mentiioned, it sounds pretty simple.  What I'd thought of doing was first determining by trial and error exactly what thickness of rim will fit in the gun with breech closed, then cut a circular plate appropriately for the base and rim, so the extractor will work correctly. 

Then build the cup part ,screw that to base with several screws, put hole(s) in middle, etc.  Then worry about joining on some kind of wrapped sheet metal body  Something along those lines.

[moose53]

Cannonmn , Look at    Breach Loaders « Reply #11 on: July 01, 2006, 05:01:16 PM »  cases are fairly simple to make if you have access to a machine shop. I can post a how to if you are interested . You can try   http://www.gboreloaded.com/forums/index.php/topic,93883.0.html moose53

[cannonmn]

deleted by author

[moose53]

Cannonmn, Looks like I am a little ahead of you , on the off chance you didn't find it here it is again . http://www.gboreloaded.com/forums/index.php/topic,93883.0.html  I don't know why it posted a dead link.  moose53

[cannonmn]

Thanks.  I looked that over and was not sure it applied to what I'm doing, since what the Moffatt gun was designed to take is a solid-tin base, sheet tin (or other sheet metal) bodied cartridge case.  What I saw in the other thread was a combustible aluminum foil bag, which doesn't have obturating capability.  Let me know if I misread it.

[GGaskill]

Maybe he was referring to the rubber case head for obturation.

[Cannoneer]

I saved these from when I was searching for Moffatt patents; I think most, if not all of these have been posted before, but the second from last is interesting in that he was trying to remedy the fact that the cartridge base rim was too thin to withstand the normal wear and tear of handling and/or packaging. 



R.R. Moffatt inventions

http://www.google.com/patents?id=OUNeAAAAEBAJ&pg=PA1&dq=moffatt+cartridge&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20cartridge&f=false


http://www.google.com/patents?id=giNeAAAAEBAJ&printsec=abstract&zoom=4&source=gbs_overview_r&cad=0#v=onepage&q=&f=false



http://www.google.com/patents?id=GFhwAAAAEBAJ&pg=PP1&dq=moffatt+cartridge&source=gbs_selected_pages&cad=2#v=onepage&q=moffatt%20cartridge&f=false



http://www.google.com/patents?id=hCNeAAAAEBAJ&pg=PA1&dq=moffatt+cartridge&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20cartridge&f=false



http://www.google.com/patents?id=gyNeAAAAEBAJ&pg=PA1&dq=moffatt+cartridge&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20cartridge&f=false



http://www.google.com/patents?id=1BtfAAAAEBAJ&pg=PA1&dq=moffatt+brooklyn+new+york&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20brooklyn%20new%20york&f=false




http://www.google.com/patents?id=Fu4_AAAAEBAJ&pg=PA1&dq=moffatt+brooklyn+new+york&source=gbs_selected_pages&cad=1#v=onepage&q=moffatt%20brooklyn%20new%20york&f=false

[moose53]

Cannonmn, Yup you misread it , read reply #11. moose53

[cannonmn]

Thanks.  No. 11 has this photo and another one of same item.

[moose53]

Cannonmn, Yes it is surprisingly easy to make cases after you make a few mandrels. You can use copper ,brass ,or tin if you can find a good source. I think I got down to 3/4 hr per case. moose53