Summary Statement: December 31, 1862 – Wisconsin’s Batteries

The last state with entries in the fourth quarter, 1862 summary statements was Wisconsin.  During the war, the Badger State provided thirteen light batteries.  One of those, the 13th Battery, would not be organized until December 1863 and thus falls outside scope for this post.  But the other twelve should be accounted for.  The summary carries six returns for those batteries on hand at the end of 1862, plus an additional line for weapons assigned to the 3rd Wisconsin Cavalry.


With a few gaps to fill in, here are the Wisconsin batteries:

  • 1st Battery:  Reporting at New Orleans with six 20-pdr Parrotts.  The location was valid for August 1864, when the return was received in Washington.  As of the end of 1862, Captain Jacob T. Foster’s battery was employed with Sherman’s forces in the action at Chickasaw Bayou (Third Division, Right Wing, Thirteenth Corps).  Foster’s men fired 2,380 rounds in three days there.  Foster reported his men were very fatigued after the battle, “…the guns were handled as rapidly as light artillery, whereas they are in fact siege pieces, and should have at least 175 men to maneuver there.”  Foster’s gunners would be in action again less than two weeks later at Arkansas Post.
  • 2nd Battery:  No return.  Captain Ernst F. Herzberg commanded this battery at the end of 1862, but was replaced by  Charles Beger within the first week of the new year. The battery served at Camp Hamilton, outside Fortress Monroe, Virginia, at this time of the war.
  • 3rd Battery: No return.  Lieutenant Cortland Livingston took this battery into action at Stones River, as part of Third Division, Left Wing, Fourteenth Corps (Army of the Cumberland).  The battery fired 358 rounds in the battle.
  • 4th Battery: No return.  Was also at Camp Hamilton, Virginia.  Captain  John F. Vallee commanded this battery.
  • 5th Battery: No return.  Captain Oscar F. Pinney was mortally wounded on the first day at Stones River.  Lieutenant Charles B. Humphrey assumed command.  The battery was in First Division, Right Wing, Fourteenth Corps. The battery fired 726 rounds and lost one gun in the battle.
  • 6th Battery: At Cartersville, Georgia with two 6-pdr field guns, two 12-pdr field howitzers, and two 3.80-inch James Rifles.  Another case of a location derived from a later reporting date.  In this case the battery was at Cartersville in October 1864.  In December 1862, the “Buena Vista Battery” was operating in northern Mississippi as part of Seventh Division, Thirteenth Corps.  Captain Henry Dillon commanded.
  • 7th Battery: At Jackson, Tennessee with two 6-pdr field guns and one 12-pdr field howitzer.  Lieutenant Galen E. Green commanded this battery, which was assigned to the District of Jackson, Thirteenth Corps.  A somewhat sedate assignment at the time for the “Badger State Flying Artillery.”
  • 8th Battery: No return. “Lyons’ Pinery Battery” also supported First Division, Right Wing, Fourteenth Corps at Stones River. Captain Stephen J. Carpenter, in command, was killed on the first day of the battle.  Lieutenant Henry E. Stiles assumed command. The 8th fired 375 rounds in the battle.  It lost a 6-pdr and a 10-pdr Parrott.  At the end of the first day, Stiles reported two guns serviceable (type not specified).
  • 9th Battery: Fort Lyon, Colorado with four 6-pdr field guns and two 12-pdr field howitzers. Captain Cyrus H. Johnson commanded this battery posted in the District of Colorado (alongside McLain’s Colorado Battery, I might add)
  • 10th Battery: At Nashville, Tennessee with six 6-pdr field guns.  Assigned to the Fourth Division, Center Wing, Fourteenth Corps.  Captain Yates V. Beebe’s battery did not see action at Stones River.
  • 11th Battery: No return. An interesting back story to cover this blank line.  Formed in February 1862 as the 11th, this battery was transferred out as Battery L, 1st Illinois Light Artillery.  So we’ve covered them in a previous post.
  • 12th Battery: At Germantown, Tennessee with four 10-pdr Parrotts.  Sort of the reverse happened with this battery. It was formed in Missouri, but under authority of the Wisconsin governor.  Captain William Zickerick commanded the 12th at the end of 1862.  It was part of the Seventh Division, Thirteenth Corps at the time.

And as mentioned, one additional line:

  • 3rd Cavalry:  Reporting at Fort Scott, Kansas with two 12-pdr mountain howitzers.  The company designation appears to be “E.” The 3rd Cavalry had a section of mountain howitzers at the battle of Prairie Grove.  So we might arbitrate the location given in the summary.

So we see the Wisconsin batteries were posted to the Western and Trans-Mississippi theaters and involved with (probably, counting the 3rd Cavalry detachment) three different battles in December 1862.

Moving down to the ammunition pages, here are the smoothbore quantities on hand:


And we have some entries to plant question marks next to:

  • 1st Battery: Seventy-one 6-pdr canister.  Now recall that 6-pdr caliber was 3.67-inch diameter, as was 20-pdr Parrott.  So this might be a case of “it fits in the bore, so we must be able to use it….”  to put things simply.  Plant a question mark there.
  • 6th Battery: 131 shot, 238 case, and 146 canister for 6-pdr field gun; 81 shell and 68 case  for 12-pdr field howitzer; 144 cainster for 12-pdr mountain howitzer.  Now 6th Battery was mixed with smoothbore guns, rifled guns, and field howitzers.  But were they using mountain howitzer canister in field howitzers? Or is that last entry a data entry error?  Again, we have a question mark.
  • 7th Battery: 60 shot, 80 case, and 45 canister for 6-pdr field gun; 15 case and 15 canister for 12-pdr field howitzer.  Small quantities might be explained by the battery having only three tubes on hand.
  • 9th Battery: 400 shot, 320 case, and 80 canister for 6-pdr field gun; 150 shell, 190 case, and 62 canister for 12-pdr howitzer.
  • 10th Battery:  598 shot and 550(?) case for 6-pdr field gun.
  • 3rd Cavalry: 69 shell and 7 canister for 12-pdr mountain howitzer.

While the smoothbore section leaves us some questions to ponder, the rifled projectile sections are noticeably empty…. starting with the Hotchkiss columns:


Hotchkiss was unknown, apparently, to the Wisconsin men.  Furthermore, Parrott and Schenkl were only a little more familiar:


Well… we can zoom in there…:


Two batteries with quantities to mention:

  • 1st Battery: 124 shell, 415 case, and 51 canister of Parrott-patent for 20-pdr Parrott.
  • 12th Battery: 502 shell, 149 case, and 119 canister of Parrott-patent for 10pdr Parrott; also 28 Schenkl shot for 10-pdr Parrott rifle.

But nothing further on the Schenkl columns on the next page:


So we are left to speculate about what projectiles were on hand for the James rifles.

On to the small arms:


For the four batteries reporting quantities:

  • 1st Battery: Sixteen Army revolvers and six horse artillery sabers.
  • 6th Battery: Sixty-six cavalry sabers.
  • 9th Battery: 135 Navy revolvers and twenty-three horse artillery sabers.
  • 10th Battery: Eighteen horse artillery sabers.

Closing this post, we come to the end of the fourth quarter, 1862 summaries. I’m going to take a short break on these posts before starting the first quarter, 1863.  There will be a few “administrative” notes to make as the column headers changed a bit with the new year.  But we’ll continue working through all these rows and columns in a somewhat orderly fashion.




“I feel desirous to do something…”: Foster looking for action along the James

On this day (October 8) in 1863, Major-General John G. Foster, commanding  the Department of Virginia and North Carolina, wrote to Major-General Henry Halleck in Washington to propose a series of operations in his sector.  Foster’s command included everything from the Virginia Peninsula down to the northern border of South Carolina.  Earlier in the summer, he’d forwarded reinforcements to the Department of the South when operations on Morris Island evolved into an extended siege.  Such limited Foster’s activity through the summer. Not one to be idle, he looked to create an opening that fall to break the quiet James River sector.  From his headquarters at Fort Monroe, he addressed Halleck:

General: I feel desirous to do something, and although my force is very small, I hope, by substituting the defense of citadels for that of the long lines, as Williamsburg, Yorktown, Gloucester, and Getty’s line, outside of Portsmouth, to obtain a small but effective movable column. The sickness which has prevailed at Williamsburg, Gloucester, Yorktown, and throughout the whole of North Carolina, has very much enfeebled the troops and made them for a time incapable of long marches. They are, however, available for expeditions by water, and what marches I may be forced to make can be borne by the negro troops. This is the case in the expedition now out scouring Matthews-County, of which the infantry is wholly composed of negro troops. To come to the point, I propose (now that I am obliged to understand that the troops sent to the Department of the South cannot be replaced so as to give me force enough to go to Weldon or to take Fort Caswell) to undertake little operations in succession, calculated to attract the attention of the enemy and draw off his force, which can be made very safe by means of the aid of the navy and the army gunboats.

The first point is Fort Powhatan, now deserted, which I propose to seize and turn into a small but strong work for us, from which I can commence a system of cavalry raids. Then, as soon as this has attracted the attention of the enemy so as to accumulate force enough to stop the operations of the cavalry, to seize a point on the other shore of the James, higher up, say, at Wilcox’s or Swynyard’s Wharves, or Harrison’s Landing, and pursue the same game. Then, with a small increase of force, City Point may be seized and fortified, and a dash be made toward Petersburg. To make sure of taking it will require quite an increase of force, say, 20,000 men; but this force can be sent, if you judge expedient, at any time. All that I can do now is to annoy the enemy, and from time to time to accumulate a force to meet an apprehended attack. If this meets with your approval, I will at once enter upon the necessary preparations.

I have the honor to be, general, your obedient servant,
J. G. Foster, Major General.

With hindsight we know this proposal was dead on arrival.  After September 21, the weight of the Federal armies shifted towards Chattanooga, Tennessee.  Sickness and the need to hold the purchase gained at Morris Island prevented Gillmore from releasing troops.  And within a day the Army of Northern Virginia would take up the march once again, threatening to take back any gains of the summer’s fighting in the east.

Take Petersburg to cut off connections to the deep South?  Foster was about a year ahead things.

(Foster’s letter appears in OR, Series I, Volume 29, Part II, Serial 49, page 267.)

From ’63 to ’66: The later batches of 3-inch Ordnance Rifles

In earlier posts I’ve discussed the 3-inch Ordnance Rifles produced by Phoenix Iron Company through 1862.  Early guns had “side sights” and lacked a stamp for Samuel Reeves’ patent.  Although some sources indicate the patent stamp appeared with registry number 236 in the series, I have offered a rebuttal on that point.  Regardless of the stamps, around registry number 284 the guns received an auxiliary sight between the trunnions.  Now let me turn to guns produced after March 1863.

…. Oh, and before going too far, conceded a point to a reader who wishes to remain anonymous – the Phoenix guns are properly identified as “wrought iron ordnance rifles” to set them apart from other weapons made to the ordnance pattern.  But I hope you will allow me to use the short name to reduce the word count!

As alluded to in the earlier post, the later batches of guns from Phoenix simplified the sights to a single set – pendulum hausse and muzzle blade sights.  Among the first guns to conform to that new standard is registry number 597, credited in the last week of March 1863.

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3-inch Ordnance Rifle #597 at Fort Monroe

The gun is a bit pitted, and … well… the better collection of ordnance rifles is up at Gettysburg.   So let me introduce you to registry number 616 over near the Gettysburg maintenance facility.

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Muzzle of #616

Fairly typical muzzle markings indicate Theodore Thadeus Sobieski Laidley (a name like that inspires a post!) inspected this gun in 1863. He called the weight at 816 pounds – like so many ordnance rifles.  The right trunnion stamp reiterates the vendor’s name.

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Right Trunnion of 3-inch #616

The left trunnion displays the patent date for the manufacturing process.

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Left Trunnion of 3-inch #616

But between the trunnions, only the “U.S.” acceptance mark.  No hole for the auxiliary sight.

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Trunnions of 3-inch rifle #616

This gun only retains the pendulum hausse seat and muzzle sight.

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3-inch Ordnance Rifle #616

The front sight originally stood taller than what we see today.  Handling has left them just a stub. Number 616 actually has a substantial base to the sight.  Most survivors simply have the remainder or “nubbin.” Some surviving 3-inch rifles have more substantial muzzle sights, such as the base left on 616.  Others have only the threaded hole for the sight.

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Hole for muzzle sight on #674

Again, the variations seen here (markings and sights) had no substantial effect on the use of the guns.  Or at least not that I’ve found in the veteran’s accounts.  So something must have worked!   With a few possible and minor exceptions, all remaining 3-inch Ordnance Rifles confirmed to those particulars.

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3-inch Ordnance Rifle #931

That includes registry number 931 delivered in 1866, more than a year after the last Confederate surrender.

So in conclusion, the long line of 3-inch Ordnance Rifles – over 950 of them – conformed in all practical details to the pattern set by the Ordnance Board in 1861.  There are no major variations that would affect performance of the weapon.  However for modern-day visitors, there are some subtle differences with the markings and sight arrangements.  These are in some cases clues to the story of the otherwise silent guns.

Oh, and don’t think I’m done with the Ordnance Rifles.  I fully intend to bore you readers with more minutia about these guns!

The Big Rodmans: 20-inch Rodmans, Part 2

In yesterday’s post on the 20-inch Rodman Gun, I’d mentioned the gun pictured below arrived at Fort Hamilton, New York for testing in the fall of 1864.

20-inch Rodman #1

Compared to the trials of the 15-inch gun, the 20-inch gun received a bit more fanfare – and full coverage in Harper’s Weekly. When first fired on October 26, 1864, those in attendance included the gun’s inventor Major Thomas J. Rodman; Army Chief of Ordnance, Brigadier General Alexander B. Dyer; Captain Henry Augustus Wise, Chief of the Navy’s Bureau of Ordnance; and General W. F. Smith. If illustrations accompanying the Harper’s article are any indication, a rather large crowd of onlookers joined the dignitaries.

“Large” was the word for every aspect of the gun. The gun rested upon a specially built 18 ton carriage from the Watertown Arsenal, which was also designed by Rodman. As a measure of the size of the gun, prior to firing, a man lowered himself into the bore of the gun and wormed down to the vent in order to clear an obstruction. 1

The objective of the test was only to verify the gun could fire the heavy projectiles. Unfortunately I’ve never come across any first hand account or report of the gun’s trials. Most secondary sources point to a caption in Francis Miller’s Photographic History of the Civil War. Although Miller incorrectly identified the photo of the 15-inch prototype as the 20-inch gun, he stated the big gun fired four shots in 1864. Firing a 1,080 pound solid shot, the gun used charges increasing through 50, 75, 100, and finally 125 pounds of powder. According to Miller, tests resumed in March 1867 with four more shots. This time charges of 125, 150, 175, and then 200 pounds, fired at a 25° elevation, propelled shot to a maximum range of 8,000 yards.2

Certainly impressive figures, but with the war winding down that massive iron gun was too much for peacetime budgets. Fort Pitt delivered one more 20-inch gun in 1869. This gun also survives today, on display at Fort Hancock, New Jersey. (And again let me thank Bill Coughlin for the photo.)

20-inch Rodman #2 at Fort Hancock

This gun bears the registry number 2 along with its weight marks of 115,100 pounds. John Alexander Kress inspected this monster gun. Once accepted, #2 went to Fort Monroe. In 1876 the gun went to Philadelphia for the Centennial Exposition.3

20-inch Rodman at Centennial Exposition

From there the gun eventually ended up at Fort Hancock among other heavy guns also undergoing trials in the later decades of the 19th century. Thankfully it was preserved to “guard” the post instead of being discarded.

Although the Army received only two 20-inch Rodmans, the guns significantly influenced post-war planning. Plans considered these largest of guns for the critical locations along the seacoast. Over the years, schemes for the 20-inch guns included more advanced carriages, muzzle loading rifled variants, and even breechloading conversions. None of these progressed far. Army acquisition at the time focused on refinement of weapons which could be mass produced in the event of war (since everyone felt there’d be ample warning before any future war). As such, the 1864 testimony of William Wade, part owner of the Fort Pitt Foundry, is worth note. When asked by the Joint Committee on the Conduct of the War, Wade indicated his foundry’s capacity was, “two 10-inch or 8-inch guns per day, three 15-inch guns per week, and two 20-inch guns per month.4

Perhaps we could end the story there, simply saying the two 20-inch Rodmans were great guns that were never called to action. But that’s not the case. In the late 1870’s Peru came shopping for weapons due to heated tensions with Bolivia and Chile. In addition to some of the 15-inch Rodmans, the Peruvians acquired at least on 20-inch Rodman (sometimes noted as a 1000-pdr gun), presumably a surplus weapon at the foundry. During the War of the Pacific, this Rodman, paired with a 20-inch Dahlgren gun also cast by Fort Pitt, was used in defense of the port of Callao. 5 The guns presumably wound up in the hands of the Chileans at that point. Perhaps the big Rodman guns did fire more than a few “test shots” after all.

The legacy of the 20-inch Rodman was to American seacoast defenses in the last decades of the 19th century. While the days of muzzleloading, black powder, smoothbores waned after the Civil War, the range of the 20-inch guns influenced plans. With these larger guns, defenders could control larger expanses of waterways. Instead of just defending the harbor entrances, the Coast Artillery could think about covering likely approaches to the coast. The real change would wait until modern breechloading, rifled, steel guns arrived.


  1. Harper’s Weekly, Volume VIII, No. 412, November 19, 1864, page 749.
  2. Miller, Francis Trevelyan, The Photographic History of the Civil War: Volume 5 – Forts and Artillery (New York: Review of Reviews, 1911), page 137.
  3. Ingram, J.S., The Centennial Exposition Described and Illustrated (Philadelphia: Hubbard Brothers, 1876), page 146.
  4. Testimony of William Wade, “Heavy Ordnance,” Report of the Joint Committee on the Conduct of the War at the Second Session, Thirty-Eighth Congress (Washington: Government Printing Office, 1865), page 86.
  5. Markham, Sir Clements R., The War Between Peru and Chile, 1879-1882 (London: Sampson Low, Marston, and Company, 1882) page 186.

Walk Around the Lincoln Gun: 15-inch Rodman Prototype

The last several artillery posts have focused on the gun in this wartime photo:

15-inch Rodman Prototype at Fort Monroe

The 15-inch prototype remained at Fort Monroe after trials ended, very successfully, in early 1861.  Worth noting, the gun received its first nickname around that time – “The Floyd Gun” – after Secretary of War John B. Floyd, who’d been a supporter of the project.  By April 1861 the Fort Monroe garrison mounted the big gun on a barbette carriage near the Old Point Comfort lighthouse.   I’d speculate the carriage was either the same or a similar outfit to that used during the proofing in 1860.  However, the gun didn’t sit there very long.  In July 1861 the new 12-inch Rodman Rifle arrived for testing.  Jumping the gun, so to speak, General Benjamin Butler ordered the untested rifle onto the 15-inch smoothbore mount.

After the USS Monitor-CSS Virginia duel, General John Wool ordered the 15-inch gun placed back in a barbette carriage into the fort’s defenses.   The circular traces used by one of these two guns remains today, ironically, in Jefferson Davis Park on the fort’s wall.

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Traces for Center Pivot Barbette Carrige in Jeff Davis Park

On April 15, 1862, both the 12-inch rifle and the 15-inch prototype gun fired in the direction of Sewell’s Point, more so to gain the range than against any particular target.  But with this activity one can say the prototype “fired in anger.”

It was also around this time the gun received a new nickname.  With Mr. Floyd’s resignation and subsequent commission as a Confederate general, the old name was just bad for public relations.  So Secretary of War Edwin Stanton ordered the gun’s name changed to “The Lincoln Gun” and it remains so today.

If the wartime photo’s listing data from the National Archives is correct, the 15-inch prototype remained in place through 1864.  We know it is indeed the prototype from the muzzle markings.

Close Up of Muzzle

At the top appears the registry number  “1” and at the bottom are the initials “T.J.R.” for Thomas J. Rodman.

The right side trunnion, although at an angle in the photo, clearly shows the foundry stamps.

Right Trunnion in Photo

The stamps read “F.P.F.” and “K.R. & Co.”  These stand for “Fort Pitt Foundry”
and “Knap, Rudd and Company” respectively.   That particular stamping set appeared only in 1860.

Today the Lincoln Gun rests only a few hundred yards from its wartime post, at the edge of Fort Monroe’s parade ground.

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15-inch Rodman Prototype

My photo of the muzzle markings didn’t turn out right (for which I’ve kicked myself several times).  So trust me that the “No. 1” and “T.J.R.” remain on the muzzle.  The right trunnion also still shows the manufacturer’s stamps.

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Right Trunnion of Prototype Rodman

And the left trunnion provides the year of manufacture.

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Left Trunnion of Prototype Rodman

Notice the trunnions are shorter than those of earlier Columbiads.  Rodman designed the 15-inch gun to fit iron, not wooden, carriages.  However the prototype’s trunnions are about a half-inch longer than those of production Rodmans.

The breech displays the weight, just as recorded by Rodman in May 1860.

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Weight Stamp on Breech

Compare the ratchets in the breech face to the sockets on the 15-inch guns at Fort Foote, Maryland.

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Breech Face of Production 15-inch Rodman

Less easily determined by the naked eye is the shift of the trunnion location.  Production 15-inch guns had the trunnions just 1.25 inches to the rear, eliminating preponderance.

Rarely can we trace the story of a Civil War era gun with any degree of certainty.  However in the case of the Lincoln Gun, we know every place the gun was from foundry to field site.  We even have reasonably accurate records of every time the gun fired!

The Lincoln Gun – an artifact preserved in Fort Monroe National Monument with a story to tell!

15-inch Rodman Prototype: Trials of the New Gun

Discussing the prototype 15-inch Rodman gun, I left off with the 25-ton iron form arriving at Fort Monroe for trials.  Now it’s time to talk about shootin’ that big gun.

Thus far in the discussion of Rodman guns, my articles focused on “experiments” within the scientific sense.  But prototyping takes on a different focus.  To pass trials, a prototype undergoes tests to ensure it meets requirements and expectations.  Beyond that, prototype testing ensures the system is a practical fit in the desired role.  The focus extends more to “will it work the way we intend to use it?”

Instead of placing the gun on very restrained test mount, Captain Alexander B. Dyer had a wrought iron carriage built at Fort Monroe Arsenal for the prototype.  Generally, the carriage matched that of the Columbiad barbette center pintle design – just bigger all around to fit the bigger gun.  Recall too the prototype 15-inch Rodman retained a 1200 pound preponderance at the breech along with the ratchet elevating system.

For trials in 1860, the crew at Fort Monroe placed the gun on a concrete and cut stone platform along the beach.  As with the standard service mounting in a fort, the trials mount had concentric rings to allow the carriage to traverse.  The mount allowed just over 28° elevation.

Normally any new gun undergoes proofing to verify it could withstand service charges.  However, since the 15-inch was an entirely new design proofing involved testing to see just how much load the gun could reasonably withstand.  Proofing with 0.6-inch grained powder started with 25 pound charges propelling a 330 pound shell.  After five shots this increased to 30 pounds with a 310 pound shell, which the gun fired five times.  At subsequent intervals, the powder charge increased by five pounds until reaching 40 pounds.  Rodman also fabricated several “perforated cake” charges for these tests (and those deserve treatment in a separate post). During these proofs, the greatest range was with a 40 pound charge at 28° elevation reaching 5730 yards.

After forty fires during the proof, a board of officers, representing the engineers, ordnance corps, and artillery, determined the gun was ready for evaluation.  Just to drop names, the board included General Joseph Totten, Major John Barnard, Captain Horatio Wright, Major John Symington, Captain Dyer, Captain Josiah Gorgas,  Colonel Justin Dimick, Major Robert Anderson, Captain J. H. Carlisle, and Lieutenant G. Tallmadge.   For the board, the gun fired forty-nine more times at an elevation of 6°, with a 35 pound charge and a 317 pound shell.  Ranges varied between 1873 and 2017 yards.  During these fires, the upper carriage recoiled between 68 and 77 inches.

Rodman attempted to measure muzzle velocity with a Navez device, but results were erratic.  Instead, the crew fired a few rounds at a short range target (885 feet, because “short range” is relative) and estimated velocity from the time of flight. With 35 pounds of powder, observers figured velocity at 1328 feet/second.  Using 50 pounds of perforated cake, velocity dropped to 1282 feet/second.  Interestingly, these tests used rope grommets instead of sabots.

After a few more ranged shots, the trials got down to some fun trials – ricochets on the water!  The board wanted to know the behavior of the large projectile when used in one of the favored anti-ship techniques of the time.  With elevations ranging between horizontal and 5°, using 40 pound charges and 318 pound shells, five shots fired over the open waters around Fort Monroe.  However due to rough waters, these tests were far from conclusive.  Yet the conclusion was higher elevations yielded better ricochet patterns.

At the end of all these fires, the board examined the bore of the gun.  Using a star gauge, the officers found no enlargements in the bore.  For all practical purposes, the gun stood up well to use.  However, the carriage had sustained some damage.  The original traversing wheels cracked under the strain of firing, and were replaced by a stronger set.

The trials also considered how the crew operated the gun.  Obviously with a larger projectile than any weapon then in service, handling was a consideration.  Rodman’s report noted that three men could load the gun – two carrying the projectile and one pushing it into the muzzle with the rammer.  However, a team of five was preferred.  Running the gun into battery required seven men, and an eighth used to ease the work.  Although two men could traverse the gun, the preferred number was four.

For a shot at horizontal, time required for servicing and loading the piece fell to just over a minute after practice.  Running the piece out at maximum elevation required between three and four minutes.  The crew could traverse the gun at a rate of roughly 45° per minute.  Not bad for the “first run” of the gun.  Even in the 1890s with crews intimately familiar with the carriage and gun, officers planned for one shot every four or five minutes in combat.

At the end of these trials the board gave the gun positive marks.  The gun survived the trials and performed well.  Despite the size, the gun was just as well handled as the contemporary Columbiads.  The officers believed, “… the introduction of guns of much larger caliber than any now in the service, is desirable and practical.”  They went on to say, “the efficiency of our present armament for harbor defense would be improved by the addition of a judicious portion of guns of this class.”  However, the board did express caution about the endurance of the gun, asking for additional fires.

Starting in December 1860, Dyer supervised additional tests on the 15-inch prototype.  All told, he exceeded 500 fires.  At the end of which, he reported no measurable wear in the bore.  Vent erosion was less than normal for a gun at that endurance.

While Dyer fired this big cannon, the country was falling apart.  I find interesting how members of the board were soon swept up in events.  Anderson, of course, would move from this trial to his next post at Fort Sumter.  Within a few months, Gorgas resigned his commission and became the Confederate chief of ordnance.  But Rodman left the trials and returned to Pittsburgh.  There he worked on a 12-inch rifled gun constructed in the same manner as the 15-inch gun.

One final note, perhaps bringing this story from one about “cannons” to one about people – describing the gun crew at one point, Rodman indicated the composition to be “one sergeant and six negroes.”  Such raises several questions.  Why wasn’t a detail of artillerymen used?  Were these freedmen or slaves?  Were these men trained in artillery handling before these trials?  Regardless, I find an interesting thread here.  On the eve of the Civil War the Army used African-American labor to test its most important new weapon.  And that very gun later acquired the nickname “The Lincoln Gun.”


Thomas J. Rodman’s report of the 1860 prototype trials appears in Reports of Experiments on the Properties of Metals for Cannon, and the Qualities of Cannon Powder; with an Account of the Fabrication and Trial of a 15-inch Gun (Boston: Charles H. Crosby, 1861), pages  281-293.

15-inch Rodman Prototype: The Result of All Those Experiments

Having discussed the early casting experiments by Thomas J. Rodman to refine his casting technique and subsequent gunpowder tests, it is time I turned to the prototypes of the Rodman Guns.  Instead of constraining the next tests to just 10-inch weapons, the first prototype of the improved pattern increased to 15-inch.  The result was this gun – with registry number 1 – the prototype of a long line of Rodman guns.

The Lincoln Gun - Fort Pitt Foundry #1

Concurrent with the gunpowder experiments, Rodman “ran the numbers” to determine the optimum thickness of metal for a 15-inch gun.  I’m reluctant to walk through the reasoning here, due to space and my “physics for poets” background.  The short version, for those of us willing to neglect the particulars of square roots and other higher forms of math, is the gun needed a thickness of around 16 inches around the seat of the charge.  The thickness increased to 25 inches from the bore bottom to the exterior breech face.

Rodman also took the time to determine, based on his complied data, the best profile for the gun’s chamber (or bore bottom as he called it).  The preceding experiments indicated the traditional flat-bottomed bore tended to crack at the corners.  In the course of experiments Rodman found the sub-caliber chambers of the old Columbiads detrimental to performance.  He wrote, “There should be no angles, either salient or re-entrant, in the termination of the bore, but he surfaces of the bore and of its termination should be tangent along their lines of junction…. the semi-ellipsoid is believed to be the best and true termination.”  However, the casting plan diagram showed that of a hemisphere.

Casting Diagram and Plan of 15-inch Prototype

The diagram indicates the use of the Rodman neck vice the traditional cascabels.  The thin lines around the finished gun’s form indicate Rodman planned for a large amount of excess metal.  On surface examination, this resembles the casting technique developed by John Dahlgren for his naval guns.

Another point of similarity, which Dahlgren would later cite, is the exterior form.  Yes, the exteriors of Rodman and Dahlgren guns feature blended curves, lacking external fixtures.  But Dahlgren’s pre-war shell guns show the use of a pure cylinder over the chamber, traditionally the location of the first reinforce on the gun.  Rodman guns, as seen on the prototype plan, featured a near continuous curve expanding from the breech face to a maximum thickness over the seat of the charge, thence gradually tapering down to the muzzle.

The exterior form matched that called the “ordnance shape” and offered few right angles where stress would accumulate.  Rodman guns offered no “flats” save that of the muzzle face, rimbases, and trunnions.  If this form borrowed from Dahlgren, the paper trail has yet to be established.  On the other hand, simple examination of Army ordnance from 1841 through 1861, considering the columbiad trials and even the shape of the 1857 “Napoleon,” demonstrate the evolution to such blended curves.

In the fall of 1859, Rodman tested and selected the best iron from supplies available at Fort Pitt Foundry.   The foundry lit furnaces on December 23 to start the casting process.  As with previous hollow core castings, after pouring the molten iron, the foundrymen  poured water into the insert.  According to Rodman’s notes, water entered the insert at 36° and exited at 58°.  Rather low temperatures considering the last 10-inch casting initially had water entering at 80° and exiting at 102°, but in the warm month of August.  Notice the difference between entry and exit temperatures remained 22°, summer or winter.

After twenty-one hours, the water temperature exiting the insert dropped to 47°, and the workers removed the insert.  As with the earlier castings, water then poured directly into the interior bore.  Exit temperatures jumped to 86°.  Cooling continued for over 140 more hours.  All told the gun sat in the pit for 168 hours, far less than the time taken to cool a solid cast gun of half the size.

The finished gun weighed 49,099 pounds, with a 1200 pound preponderance at the breech.  It measured 190 inches long with a maximum diameter of 48.1 inches.  The gun measured 25 inches in diameter at the muzzle.  The 15 inch bore ran 156 inches deep.  Regardless of the metric, this was a large gun – indeed the largest produced up to that time in the United States.

In May 1860, the gun went to Fort Monroe for trials.  And how was a 25 ton cannon moved from Pittsburgh to Old Point Comfort?

For this purpose two strong trussed beams, 50 feet long, were prepared.  These beams were placed parallel to each other, and about 36 inches apart, their ends resting upon two bolsters placed transversely across the middle points of two 8-wheeled platform cars.  The gun was suspended under the two trussed beams, and between the cars; so that its weight was equally distributed over the 16 wheels of the two cars.

Thus packed, the gun moved on the Pennsylvania Central Railroad, Northern Central, and finally the Washington Branch.  In Washington, D.C. the gun, still on the cars rolled onto a heavy cargo vessel, which took the setup to Fort Monroe.

Once at Fort Monroe, Army personnel prepared the gun for proofing.  It was time to fire some large projectiles from one of the world’s largest guns.  I’ll discuss the testing and proofing of the 15-inch prototype next.


Thomas J. Rodman’s report of the 1859 experiments appears in Reports of Experiments on the Properties of Metals for Cannon, and the Qualities of Cannon Powder; with an Account of the Fabrication and Trial of a 15-inch Gun (Boston: Charles H. Crosby, 1861), pages 192-274, 281-282.