Heavy Artillery in the Civil War

This entry is part 3 of 3 in the series Artillery
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Heavy artillery in the Civil War can be divided into two classes:

  • Siege and garrison artillery;
  • Seacoast artillery.

Mortars were used in both classes but will be covered in a separate section below.

Siege and Garrison Artillery 

These types of artillery were mounted on gun carriages and moved with the armies as part of the siege train. Most of these types of artillery were rifled guns. They had a greater muzzle velocity and greater penetrating because of the rifling. Fort Pulaski, at the mouth of the Savannah River, wasDamage to Fort Pulaski considered impregnable by no less an authority as the U.S. Chief of Engineers. It surrendered after a 2-day bombardment of heavy rifled artillery.

Both sides attempted to convert their heavy smoothbore guns into rifled artillery. The cast iron was not strong enough by itself so reinforcing hoops of wrought irons were used. Many cast iron guns, however, burst because of the extreme pressure of firing a rifled shell.

Major Thomas Jackson Rodman was able to perfect a casting technique for large smoothbore guns. His guns were used as field, siege and garrison artillery by the Federal army. Rodman also experimented with a different type of gunpowder that was slower to explode than black powder which made a violent explosion. It was a better alternative until the introduction of nitrocellulose and nitro-glycerin based propellants later in the 19th century.

Here are the 6 different types of siege and garrison artillery with their projectile weight and range in yards at a 5 degree elevation:

  • 4 1/2″ muzzle-loading rifle…………………….33…2,078
  • 30 pounder Parrott muzzle-loading rifle…29…2,200
  • 24 pounder smoothbore gun………………….24…1,900
  • 18 pounder smoothbore gun………………….18.5…1,592
  • 12 pounder smoothbore gun………………….12.3…1,834
  • 8″ smoothbore howitzer………………………..50.5…1,241

The ammunition that was used in these types of guns was similar to field artillery ordnance with the addition of red-hot shot that was used to fire buildings and ships.

Seacoast Artillery

The other type of heavy artillery was classified as seacoast artillery. This type of artillery weighed between 6,903 lbs. at the lightest end, up to the 117,000 lb. 20″ Rodman smoothbore. Seacoast artillery was generally in fixed positions of defense at permanent forts. However, the Federal siege train at Petersburg used a mix of rifles, howitzers and mortars against the Confederate defenses.

Here are the different types of seacoast artillery with their projectile weight, range in yards and elevation in degrees:

  • 32 pounder smoothbore gun…32.6…1,922…5
  • 42 pounder smoothbore gun…42.7…1,955…5
  • 100 pounder Parrott Gun at Fort Totten, D.C.18″ smoothbore columbiad……65……1,813…5
  • 10″ smoothbore columbiad……128….1,814…5
  • 15″ smoothbore columbiad……350…5,730…28.35
  • 20″ smoothbore Rodman………1,080…3.5 miles…25 This gun weighed 117,000 lbs.
  • 100 pounder Parrott muzzle-loading rifle………70-100…2,370…5
  • 200 pounder Parrott muzzle-loading rifle……..132-175…2,000…5
  • 300 pounder Parrott muzzle-loading rifle……..230-250…2,500…10
  • 80 pounder Whitworth muzzle-loading rifle…..80….13,665…10
  • 70 pounder Armstrong breech-loading rifle….79.8…2,183…5.9
  • 8″ Blakely muzzle-loading rifle…………………….200
  • 150 pounder Armstrong muzzle-loading rifle…150
  • 12 3/4″ Blakely muzzle-loading rifle………………700

Mortars

Mortars were classified as either siege or seacoast artillery. Mortars were used to lob shells over enemy defenses and into their communication trenches and rear areas. The Coehorn type mortars at 296 pounds were light enough to be carried by four men. The other mortars were brought to battle on specially-built  mortar wagons. At Petersburg, the Federals used a 13″ seacoast mortar nicknamed “The Dictator”. It was mounted on a The Dictator Mortar at Petersburgflatbed rail car and run on the military railroad that was directly behind their siege line.

Mortars had a variety of ordnance that was similar to the other types of artillery:

  • Most mortar shells were spherical balls, rather like bowling balls with two lifting holes.
  • In 1863 the Federal army invented a spherical shell that contained canister shot and bursting powder with a fuse that was timed to explode over the target area. Ten-inch shells of this type were used at the siege of Petersburg.

Here are the types of siege and garrison mortars with a description, weight of the projectile and range at a 45 degree elevation:

  • 8″ mortar…..44.5…1,200
  • 10″ mortar…87.5…2,100
  • 24 pounder Coehorn…17.0…1,200
  • 10″ seacoast mortar…87.0…4,250
  • 13″ seacoast mortar…220…4,325

 

 

Series Navigation<< Field Artillery in the Civil War (Part 2)

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