Hvy.Arty Why were Civil War mortars small, yet so massive?

Smaller mortars such as the Coehorn (12 & 24#ers) had thinner walls because they didn't fire the large powder charges needed for heavy rounds or longer distances. At Vicksburg, Union forces hollowed out tree trunks, iron hoops were placed around them and these were used to fire small rounds (6 & 12# ers)short distances. A member of this forum, Duffy Neubauer (Starkville Civil War Arsenal) has made a replica of one of these "treetrunk" mortars and has successfully fired it.
 
Last edited:
Mortars had been in use for several hundred years, notably providing the "bombs bursting in air" for The Star-Spangled Banner, so I expect they had worked out suitable designs and dimensions. I doubt they would make them as massive as the Dictator if experience had not shown it to be necessary.
 
Mortars had been in use for several hundred years, notably providing the "bombs bursting in air" for The Star-Spangled Banner, so I expect they had worked out suitable designs and dimensions. I doubt they would make them as massive as the Dictator if experience had not shown it to be necessary.

As a student of Renaissance military history, I can tell you the history of mortar (and mortar type gun) development is a long one, covering considerable differences in powder quality, projectile type, casting advancements and metallurgical experiences. I do believe the design used in the ACW represented an accumulation of that knowledge and hard experience.

What's interesting is how little the conceptual USE of mortars changed over the centuries. While the employment of field guns changed radically throughout military history, mortars (being largely static siege weapons) have a surprisingly straight-line development in ters of their USE.
 
Some Civil War mortars were short but very massive. Was it truly necessary to have tubes that thick? Did the Army study just how thick a mortar needed to be?
The 13" siege mortars like the "Dictator" had to be thick to handle the 200 lb projectile and the 20 lb powder charge .
Most of the stress on them is because of their high trajectory, in comparison to the relatively flat trajectory of most regular guns.
 
I have read somewhere that some of the 13" seacoast mortars had cracks running from top to bottom on muzzle face.
 
Tangential question: were mortars, of any size, actually worthwhile in the ACW? Every fort bombardment I've read about seems to consider them almost worthless. Even at Petersburg, which probably saw their greatest use in quantity, they seem more like a psychological weapon than a real destroyer. Did Coehorn mortars ever make a difference in any engagement?

Mortars don't seem to have gotten really useful until the world wars.
 
Tangential question: were mortars, of any size, actually worthwhile in the ACW? Every fort bombardment I've read about seems to consider them almost worthless. Even at Petersburg, which probably saw their greatest use in quantity, they seem more like a psychological weapon than a real destroyer. Did Coehorn mortars ever make a difference in any engagement?

Mortars don't seem to have gotten really useful until the world wars.

Mortars were useful for sieges throughout the age of gunpowder, because they did what normal trajectory guns could not. Here's a wiki article on siege artillery:

https://military.wikia.org/wiki/Siege_artillery_in_the_American_Civil_War
 
Tangential question: were mortars, of any size, actually worthwhile in the ACW? Every fort bombardment I've read about seems to consider them almost worthless. Even at Petersburg, which probably saw their greatest use in quantity, they seem more like a psychological weapon than a real destroyer. Did Coehorn mortars ever make a difference in any engagement?

Mortars don't seem to have gotten really useful until the world wars.
I don't know if they made a big difference , but Coehorns were used effectively by Confederate forces at The Crater .
 
Smoothbore artillery was divided into three categories. Each type of gun fulfilled a distinct tactical niche. Cannon were flat trajectory line of sight weapons. Howitzers fired a high trajectory exploding rround. Mortars lobbed a shell in an arching 45 degree arc to drop vertically into works, forts or cities. Anyone who has attended a fireworks show has seen mortar fire at work.
Mortars were cast in the characteristic squat shape because of the large charge needed to lob a heavy shell onto a target from a range beyond return fire. Waterborne mortars were very effective during the river war. At Vicksburg, improvised mortars were cobbled together by soldiers on both sides. Shells lobbed to fall vertically over the walls caused Confederates to abandon some forward positions.
The range & accuracy of rifled cannon made mortars largely obsolete. Counter battery fire was effective at ranges far beyond a mortar's reach. For example, Fort Pukask's wall was breached by 30 pound Parrott rifles at a 2 mile range. The traditional shell lobbing mortars were not necessary to force the garrison to surrender.
 
Waterborne mortars were very effective during the river war.

Against what fortifications? I was under the impression they were found to be inaccurate and ineffective against the forts guarding New Orleans and also Fort Pulaski. If they were effective elsewhere I'm curious what made the difference.
 
Back
Top