Mortars

[major bill]

The mortar is the fat ugly half-brother of the cannon. They were useful in the Civil War and were especially useful during sieges. Mortars ranged in size from a 6 pounder (3.67 inches) to the massive 13 inch mortar.

 

[major bill]

"The Dictator" a 13 inch mortar used by the Union during the siege of Petersburg.

 

[Legion Para]

 

[John Winn]

And don't forget the coehorn mortars or, my and E.P. Alexander's favorite, the twelve pounder howitzer used with a reduced powder charge and the trail lowered into a ditch. The most bang for the buck !

 

[Irishtom29]

During a proper siege ( I don't consider Petersburg to have been a siege) as saps approached the covered way mortars were used to suppress defensive fire from guns exposed on fortification terrepleins. When the British captured El Morro at Havana in 1762 British mortar fire was so severe the Spanish were unable to man their guns on the threatened front, thus allowing the Brits to descend the ditch and mine a bastion. The bastion was blown and breached and British infantry stormed the breach and captured the fort.

 

[44 Henry]

I believe the largest Civil War mortar was a 13 inch.

 

[44 Henry]

Expired Image Removed
Mini Abe on the front lines. LOL

 

[major bill]

You are probably right that the largest Civil War mortar was the 13 inch so I changed my post. The 16 inch mortar was a stone mortar that was omitted from the Ordnance Manual in 1861 an probably never seen action during the Civil War. This weapon was a stone mortar which fired stones. The concept being that once a breach was made in a wall, this weapon would fire 120 pound of stones placed in a bucket into the breach to clear the breach of enemy. It could also fire 15 six-pounder shell set with 15 second fuses which would ten explode in the wall breach, thus killing all the defenders. Conversely the defenders could use the same weapon to defend a breach in the wall. The 16 pound stone mortar was strictly anti-personnel weapons.

 

[AUG]

During a proper siege ( I don't consider Petersburg to have been a siege) as saps approached the covered way mortars were used to suppress defensive fire from guns exposed on fortification terrepleins. When the British captured El Morro at Havana in 1762 British mortar fire was so severe the Spanish were unable to man their guns on the threatened front, thus allowing the Brits to descend the ditch and mine a bastion. The bastion was blown and breached and British infantry stormed the breach and captured the fort.

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At Vicksburg the besieging Federal troops made good use of improvised wooden mortars constructed by hand by boring out sweet-gum logs and wrapping iron bands around them. They were designed to fire 6 or 12-pound shells and were said to be quite effective in suppressing the defenders while the saps were dug ever so closer to the foot of the works. The Confederate troops defending the 3rd Louisiana Redan claimed that they were under constant fire from these mortars near the end of the siege; those manning the works had almost no way to protect themselves from them.

 

[major bill]

Did the 13 inch mortar really need to be that thick, or did the company making the mortar get paid by the weight of the mortar and fudge a bit on how heavy the mortar really needed to be?

 

[Irishtom29]

Did the 13 inch mortar really need to be that thick, or did the company making the mortar get paid by the weight of the mortar and fudge a bit on how heavy the mortar really needed to be?

I wonder myself. At the Castillo de San Marcos (where I'm an NPS volunteer) there's a Spanish bronze 15" mortar with a much thinner wall. Bronze guns were more reliable than iron ones, iron guns often bursting under heavy use, perhaps the iron mortar in question had such a heavy wall to compensate for the material and expected heavy use. Maybe?

 

[Irishtom29]

Dedicated stone firing mortars were called perriers and were effective at harassing covered ways and terrepleins, Vauban favored them; the fist sized stones used could penetrate several inches into the ground so imagine if a soldier were struck in the noggin. Carnot favored up close fortress defense by means of mortars firing great masses of small bullet like projectiles but this was never used and many engineers were doubtful that bullets fired from mortars would fall with sufficient velocity to do much harm.