8-inch Siege Howitzers – Model 1841

I featured this type while discussing the 1863 Christmas action outside Charleston but it is time for a more formal introduction.

8-inch Siege Howitzer Model 1841

American use of 8-inch howitzers dated back to the Revolution, with examples figuring into the siege operations at Yorktown.  However, by 1812 the Army discontinued the use of the 8-inch howitzer for land use, opting for the 24-pdr caliber.  Ordinance regulations posted in 1816 re-established the caliber for a siege & garrison howitzer type, but with no recorded contracts, this appears to be more an administrative move (perhaps legitimizing the use of Revolutionary War-era equipment from stocks).  Regulation revisions through the 1830s continued to list 8-inch siege howitzers, still with no evidence of designs, prototypes or production.  (Please see pages 278-82 of The Historical Sketch of the Organization, Administration, Material, and Tactics of the Artillery, published in 1884, for a more detailed discussion of these regulations.)

Contracts issued in August 1841 finally matched the regulations to a weapon for issue.  Secondary sources identify this as both Model 1840 and 1841.  Arguably either is correct, but I will use the year 1841, referencing the contract date and the nomenclature used in the Ordnance Manual of 1862.   The line drawing below appeared in the 1862 Instructions for Heavy Artillery, as part of Plate VII, likely copied from the earlier regulations:

8-in Siege Howitzer Model 1841

The specifications called for cast iron construction.  The external form followed the Model 1841 Siege Howitzer followed that year’s standard form.  The breech was a flattened cone with knob attached to the center.  The base ring measured 18.25 inches in diameter.  Instead of a first reinforce, the howitzer had a recess over the chamber (much like the 24-pdr field howitzers).  The second reinforce served as the attachment point for cylindrical rimbases, mounting the trunnions.  The chase was without ring and terminated with a muzzle ring, measuring 16.5-inches in diameter.  Not seen on the diagram was a “lock piece” moulding at the top of the breech.  The lockpiece protected the vent.

Bore and Chamber of 8-inch Howitzer - Shiloh

The Ordnance Manual of 1862 listed the overall length of the howitzer as 61.5 inches.  The bore was 38.5 inches plus the 8 inch deep chamber, for a total of 46.5 inches.  The chamber itself conformed to the convention of the time, cylindrical shape 4.62 inches in diameter, necked down from the bore.  The diameter mapped the chamber to 12-pdr size, as was used for the 24-pdr Flank Howitzer as well as both the 24- and 32-pdr Field Howitzers.  But the 8-in howitzer was deeper than the others.  The chamber volume for the 8-inch Model 1841 was 134 cubic inches (compared to 76.5 cu. in. for the 24-pdr Flank Howitzer, 117 cu. in. for the 32-pdr Field Howitzer, and 79.5 cu. in. for the 24-pdr Field Howitzer).  The shape of the chamber required the use of a sabot in order to properly seat the charge and round.

Comparison of Heavy Field, Siege, and Garrison Howitzers

The trunnions, at 5.82 inches in diameter, 5 inches in length, and rimbase spacing of 18 inches, matched the specifications for the 24-pdr Siege & Garrison Gun.  There was nearly a sixty inch length difference between the gun and the howitzer, so when mounted, the howitzer did not reach the carriage’s elevating screw.  Thus the crew used a quoin, or elevating wedge.  (See the Ordinance Manual of 1850, p 44 for details about the carriage).  The limber and carriage together weighed 3,915 pounds.  All told, when ready to move, with carriage and limber, the 8-inch Siege Howitzer Model 1841 weighed about 6,529 pounds – requiring eight horses.   In action, the 8-inch howitzer required a crew of five.

The 8-inch howitzer fired a 45-pound shell, propelled by a four pound charge at 12 degree 30 second elevation, to a range of 2,280 yards.  Ammunition types included shell, spherical case, grape-shot, and canister.  As mentioned, the shell weighed around 45 pounds, with case slightly less.  A stand of grape-shot for an 8-inch howitzer weighed 74.5 pounds, and included nine 3.36-inch shot.  Canister for for this caliber weighed 53.5 pounds and contained 48 pieces of shot.  Some sources mention the option to mount the howitzer in reverse on the carriage, to allow high angle fire akin to a mortar.  But no ranges tables are cited.

The Ordnance Manual of 1862 cited some interesting estimates for penetration against different defensive materials, mostly based on French experiments.  An 8-inch howitzer would penetrate 30 inches of compact earth at range of 650 yards.  And 13 inches of wood, perhaps a ship target, at the same range.  Regarding masonry, the manual cited the shell’s tendency to break up on impact, negating any penetration.

The Artillerist’s Manual of 1860 (written by John Gibbon) provided a rather detailed discussion of siege operations, offering suggestions for employment of the howitzers in both attack and defense.  Given the limited penetration of shells, officers preferred to use howitzers for enfilading or ricochet fire.  The later required a projectile fired at an angle to the enemy works to bound or skip along the terreplein inside the works.  Because of the angles of elevation and ballistics, the howitzers were considered useful in such role.  However, for good effect, the instructions called for ricochet batteries placed no further than 600 yards from the enemy works, preferably less.  Gibbon elaborated the desired effect of the howitzers was “…to sweep the covered ways and ditches, to destroy palisadings, and injure the traverses by exploding shells in them.” (p. 453 of the Manual)  In the defense, Gibbon called for the use of howitzers firing over the capitals, or apexes of the friendly works to best sweep the ground in front of those vulnerable points.   The gunner’s objectives of course were the workers in the parallels and boyau.

Production of the 8-inch Siege Howitzer Model 1841 began at Columbia Foundry, in Washington, D.C. with the aforementioned August 1841 contract for a single howitzer.  West Point Foundry produced thirty-two between 1846 and 1853.  Tredegar, in Richmond, Virginia, cast seven examples, delivering six in 1853 and the final in 1856.  And lastly, Fort Pitt Foundry in Pittsburgh, Pennsylvania delivered ten of the Model 1841 during 1861. Thus, Federal deliveries totaled 50.

At the start of the war, the Confederates asked for fifty 8-inch howitzers from Tredegar (at the cost of $425 each, mind you!).  The Model 1841 being a familiar pattern, most likely Tredegar continued with the Federal design.  Tredegar delivered only twenty as siege howitzers.  A logical conclusion is the two examples at the Navy Yard (one pictured above) are from this batch, as they lack any Federal markings.  Three additional castings from Tredegar were bored out as 4.62-inch rifles.   When performance was found lacking, two were re-bored to howitzers.

These howitzers saw service in the “garrison” role as part of the armament of fortifications on both sides.  Returns are not specific with regard to model numbers, but 8-inch howitzers were common within the Washington defenses.  And as mentioned on the Christmas Day post, the Confederates used such weapons around Charleston.   Photographic evidence indicates the Army of the Potomac used the 8-inch Howitzers during the operations around Richmond.

Howitzer at Seven Pines Battlefield

Often identified as a “32-pdr Howitzer,” the weapon here is clearly an 8-inch Model 1841.  The Library of Congress metadata tags cite this as an 1862 photograph taken on the Seven Pines battlefield near the “Twin Houses.”  Since the weapon identification is suspect, I’ll take the time of the photo with a grain of salt.   When the Army of the Potomac invested Petersburg, included in the siege train was a dozen 8-inch howitzers, although by that time period it is likely the weapons used were Model 1861 types.

Out west, the Confederates used one 8-inch Howitzer in the defenses of Fort Donelson (Report of Lt. Col. Milton A. Haynes, OR, Series I, Volume 7, Serial 7, p. 388).  Registry number 7 from the West Point production lot stands on the battlefield today representing the landward Confederate defenses.

8-inch Siege Howitzer - Fort Donelson

Note rather accurate siege carriage, perhaps only missing the quoin in this view.

Another 8-inch Siege Howitzer, West Point registry number 28, stands guard in Shiloh’s National Cemetery.

8-inch Siege Howitzer at Shiloh

One last note on surviving pieces.  Reader Todd Johnston passed along a link discussing three 8-inch Model 1841 Howitzers at St. Augustine’s Castillo de San Marcos.

8-inch Siege Howitzers - St Augustine

The pieces mentioned are the three closest to the camera (including one in the foreground).  The three are identified by registry number as weapons present in the siege train commanded by then Captain Benjamin Huger in the Mexican War.  Perhaps these pieces are actually “two war veterans?”  And the piece pictured above at Fort Donelson was with these three howitzers in Mexico, based on its registry number.

In summary the 8-inch Siege Howitzer Model 1841, produced in limited quantities, filled a specific role within the American artillery parks at the time of the Civil War.  Seldom called upon to perform in the intended role, these weapons mainly served in defensive works.  But a handful saw service in the great battles of the war.

Next I’ll look at the 8-inch Model 1861 which replaced the Model 1841.


Aside from on site notes and links provided above, sources consulted for this post were:

Hazlett, James C., Edwin Olmstead, and M. Hume Parks. Field Artillery Weapons of the Civil War, Revised Edition. Urbana and Chicago: University of Illinois Press, 2004.

Muller, John.  A Treatise of Artillery.  Reprint of the 1780 edition.  Alexandria Bay, NY: Museum Restoration Service, 1977.

Olmstead, Edwin, Wayne E. Stark, and Spencer C. Tucker. The Big Guns: Civil War Siege, Seacoast and Naval Cannon. Alexandria Bay, NY: Museum Restoration Service, 1997.

Ripley, Warren. Artillery and Ammunition of the Civil War, 4th Edition. Charleston, S.C.: The Battery Press, 1984.

Published by Craig Swain

"Historical marker hunter" and Civil War enthusiast.

8 thoughts on “8-inch Siege Howitzers – Model 1841

  1. Craig,
    For a former active duty redleg and Civil War artillery enthusiast, thank you for this amazing blog. This is truly an invaluable resource you have here. As I am pondering the question of attending grad school in the field, I have to ask whether or not you have done so and if you have any advise in that area. Given your knowledge, any advise in that regard would be helpful. Thanks, and I hope this is not out of line.

    1. Tim, I completed a semester and a half of graduate school, and would encourage anyone with post-graduate studies in mind. However, based on my experience I say shop around a bit for the right fit. You want the best return on investment. Consider the end state you desire, and how the program will help toward that. Or in other words, how will the graduate degree help you in a chosen career field. Keep in mind that not all grad schools are the same. And don’t be afraid to visit and interview with professors, to get a feel for the environment. After all it is your money (or benefits) being spent!


  2. Hello Craig –

    Great article and pics! I was curious if you had ever seen reference to the diameter of the shot used in an 8-inch canister?

    Rick Burton

    1. According to the Ordnance manual the 8-inch and 24-pdrs used the same diameter shot for canister – 1.84- to 1.87-inch. And the shot was cast iron, not lead as stated in some secondary sources.

  3. George C. Jenkins of Battery B, 2nd Illinois Light Artillery describes the use of an 8″ siege howitzer used as a field piece on April 7, 1862, the second day at Shiloh. “We took our sixty four pdr, out on the Field, and had it out all day and we made, it talk pretty lively.”

    During the Battle of Corinth, Oct. 3 & 4, 1862, Jenkins describes the use of the 8″ siege howitzers in teo forts, Battery Williams and battery Madison. His unit was in Battery Madison, named for their commander, Capt. Relly Madison. In both descriptions he notes the weight of the projectile as being 64 pounds. It is unknown if they were using Model 1841 or 1861 guns.

    Recently a deactivated shell was discovered in Corinth which weighs 53 pounds without powder or shot.All of this makes me wonder about the weight of case and shell for these weapons.

    Also, do you have any information on the type of fuse used by the weapon?

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