The Dictator siege morter's barrel

[bluez]

I have noticed that the Dictator siege morter has an unusal thick barrel wall.  I am speculating why, was it done to protect the operators if the shell should detonate? Or did they perhaps use unusual hard loads? As i understand the monitor doesn't have a sub chamber?

[Cat Whisperer]

Hmmmmm.  Good question.  It burned something like 20 lbs of powder to chuck the 13incher some 5 miles, IIFC.  Big Bang in my book. 

Cast Iron.  Not a bad idea to overbuild it.

[Double D]

I thought I had a drawing of that mortar or at least the dimensions.

AOP  has plans for a 13 inch but they call it a 13 inch Seacoast mortar.   My planset for the 10 inch Seacoast Mortar Model 1844 does have  dimension chart that includes the 13 in seacoast mortar.  I don't know if they are the same dimensions as a 13 inch siege mortar.  

The 13 inch Seacoast mortar had a Gomer chamber that was smaller than the bore.  The 8 inch Siege mortar Model 1861 had a ellipsoidal chamber. The mouth of that chamber was bore diameter.  The chamber of the  Model 1841 Siege mortar is a Gomer with the mouth same diameter as the bore.

The dimensions show the wall thickness at the muzzle of the 13 inch Seacoast as 11.25 inches.
 
I don't think the thick walls were to protect from bore detonation so much as to hold the pressure of the massive loads used to launch the shell.

  

[Cannoneer]

bluez,

That is a photograph of the "Dictator" that you posted, the "Monitor" was the name of the first U.S. Navy ironclad ship that carried an armament of two XI-inch Dahlgren guns fired from inside an armored revolving turret.

What you're referring to as a siege mortar and Double D is calling a seacoast mortar are in fact the same model 13-inch mortar, it's just that some were issued to the Federal Army and others to the U.S. Navy.

[Cat Whisperer]

Is there a record of where each SN seacoast mortar served?
Just curious, SN 1 is now in Des Moines, IA.

[bluez]

bluez,

That is a photograph of the "Dictator" that you posted, the "Monitor" was the name of the first U.S. Navy ironclad ship that carried an armament of two XI-inch Dahlgren guns fired from inside an armored revolving turret.

What you're referring to as a siege mortar and Double D is calling a seacoast mortar are in fact the same model 13-inch mortar, it's just that some were issued to the Federal Army and others to the U.S. Navy.

Thanks, i have edited the thread

[subdjoe]

I was reading through one of the artillery manuals that is online just last night and came across that.  Naturally, I cleared my history and didn't bookmark it.  But, as near as I can recall, the reason the walls are so thick on the big mortars is because of the greater pressures caused by the greater elevations of the pieces. 

I'll try to find which manual it was.  I think it was 1866 or 1867, US Ord. Dept, but I forget the author. 

[dominick]

If you were to saw through the barrel near the breech on any large bore [9" dia.+] Iron cannons of that era, they would also be that thick or very close to it. The iron from that time period is only about 15,000 to 20,000 PSI. 

[Artilleryman]

This is what it looks like when you fire a 200 lbs shell with 6 lbs of powder.  This was enough to move the 10 tons of barrel and mortar bed on the platform. 

[gulfcoastblackpowder]

Sweet googly-moogly!  That's an awesome picture Artilleryman!

I imagine that was only shot on a rare occurance.  Where was this, and more importantly, do you have any video?

[Double D]

We have had this before.

Been a while since I saw this one.

[Cat Whisperer]

would that be at Range #10 at Ft. McCoy?

[Artilleryman]

I don't remember the range designation, but the guns were mounted on Observation Point One.  The target area is one mile from the gun position.

[Cat Whisperer]

Thanks, I remember seeing TOW's  and Dragon's fired from there from there in '81 - '82.  Could see hits out to 4000 meters or so, past that too much smoke.

[bluez]

I don't remember the range designation, but the guns were mounted on Observation Point One.  The target area is one mile from the gun position.

Very spectacular.

The shells are loaded with flash powder?

Also the noise before and after the impact in the first clip, is that from the shell going through the air?

[Artilleryman]

As I remember it the shells were loaded with 7 lbs of BP.  Down range the incoming shell sounds like a jet plane approaching.  I haven't heard that type of audio after the shell exploded in other clips that I have listened to.  The whistling sound I believe is the sound made by the fuse hole as the shell rotates through the air. 

[gulfcoastblackpowder]

Thanks for the videos.  I have seen them, but didn't make the connection between them and the picture.

[Cannoneer]

CW,
As I understand it, the U.S. Navy did keep accurate records on the service of their 13-inch mortars while the U.S. Army either didn't keep records of this type, or the records have yet to be discovered, and to make tracing the service history of these mortars even more difficult the two military branches sometimes shared this ordnance.



God bless the Paulson Bros.; thanks for posting the pic Norm, that's a fine shot.




These two quotes are on a marker that's placed next to a 13-inch Seacoast Mortar at Fort Hamilton in Brooklyn, NY.

"‘These mortar shells were the most disgusting, low-lived things imaginable,"
W.W. Blackford, a Confederate Engineer.

“Old veterans never forget the noise those missiles made as they went up and down like an excited bird, their shrieks becoming shriller and shriller, as the time to explode approached.”
Unknown Georgia infantryman

Talk about being ungrateful; well there's no accounting for tastes, I guess these two gentlemen just didn't care for the 200+ pound gifts being presented to them via airmail. Now, you Southern fellows don't get nasty, this was only a jest.

[subdjoe]

Check the description in Hardtack and Coffee

Hardtack and Coffee