Variations on Two Themes: Tredegar’s 3-inch Iron Field Guns

Months ago I mentioned the connections between 6-pdr smoothbore field gun development and the early rifled field guns on the Federal side.  Similar connections appear on the Confederate side, particularly with the guns from Tredegar Foundry.  Just as the bronze 6-pdr smoothbore served as a baseline pattern for a 3-inch bronze rifle, the iron 6-pdr smoothbore offered a pattern for a 3-inch cast iron rifled gun.

Two 3-inch iron rifles sit today on Marye’s Heights behind the Sunken Road at Fredericksburg.

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Two Iron 3-inch Guns on Marye's Heights

The exterior form and dimensions resembled the 6-pdr smoothbores mentioned in last week’s post.  In particular these match the guns with muzzle swells and round knob cascabels.

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3-inch Rifle on the Right

And notice the relatively smooth exterior indicating at least some machine work was completed at the foundry.

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3-inch Rifle on the Left

The trunnions display the marks for Tredegar.

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Right Trunnion with Tredegar Marks

And production during 1861.

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Left Trunnion Showing Year of Manufacture

As with the 6-pdr smoothbores, the external form of these guns tapered sharply between the reinforce and trunnions.

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Front Perspective View of 3-inch Rifle

The muzzle swell matches the form used on both the 6-pdr smoothbore and the early 10-pdr Parrott rifles.

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Muzzle Swell

The rifling pattern, however, matched that of the bronze 3-inch rifle and the 3-inch Tredegar Parrott rifles.  The 12 groove rifling stands out distinctly, indicating perhaps a minimal amount of use.

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12-groove Rifling of 3-inch Iron Rifle

Although the “shell” in the bore is not authentic.

Examination of the breech confirms the similarity to parent, or at least sibling, 6-pdrs with the same general dimensions of the reinforce – 9 inches long and 12-inches in diameter by my non-calibrated measuring tape.

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Breech of 3-inch Iron Rifle

But notice the small “cut out” at the base of the cascabel neck.  That cut was made to provide clearance for the breech sight.  Two dimples on the top of the breech provide the other mounting points.  Those points conform in general arrangement to the sights mounted on the breech of 3-inch bronze guns at Fort Monroe.

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Breech of 3-inch Bronze Rifle at Fort Monroe

Neither Fredericksburg gun offer muzzle markings, where Tredegar placed the foundry numbers.  That is a shame since the year on the left trunnion puts these among the first batches of the 3-inch type produced by the foundry.  In addition to the two at Fredericksburg, four other surviving iron 3-inch rifles bear marks from 1861.  Probably less than a half-dozen were produced in the early months of the war.  Details are lacking on those early guns, and likely some used different rifling schemes.

Production began in earnest in December 1861, with three produced. The problem tracking these against the Tredegar books is compounded by inconsistent nomenclature.  In some cases the guns are “6-pdr rifles” and in others “3-inch rifles”.  Such opens the production tallies for speculation.  Tredegar produced between 60 and 90 cast iron 3-inch rifles, not counting Parrott types.

Like the 6-pdr smoothbores, the 3-inch rifled guns underwent an exterior design change during the war.  A 3-inch rifle produced in March 1862 currently on display at Gettysburg lacks the muzzle swell of the guns displayed at Fredericksburg.

Gettysburg 275
3-inch Tredegar Gun at Gettysburg

I will turn to discuss that gun next.  Its foundry number traces back to an invoice.  Furthermore a battlefield incident at Gettysburg helps explain why the type fell into disfavor.

Published by Craig Swain

"Historical marker hunter" and Civil War enthusiast.

2 thoughts on “Variations on Two Themes: Tredegar’s 3-inch Iron Field Guns

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