Cannon Walk Around: The Keokuk XI-inch Dahlgren

Since we are now well acquainted with this gun’s story, time for a “walk around.”

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Keokuk Gun in Charleston’s White Point Garden

The gun is one of fourteen surviving XI-inch Dahlgrens, including two from the USS Monitor, in their original form (another nine survivors were altered to 8-inch rifles) out of a production run of 465.  As mentioned in the earlier post on XI-inch Dahlgrens, the Keokuk gun has an altered muzzle.

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Muzzle of Keokuk Gun

I’ve not found a primary source to confirm this, but most accounts indicate the sides of the muzzle swell were shaved down to permit easier passage through the Keokuk’s gun ports.  Mounting the gun on an open barbette, the Confederates certainly had no need to reduce the muzzle.

The chase of the Dahlgren tapers evenly and proportionally back to the “shoulders” of the gun.  Just before the trunnions, the gun diameter begins to increase much more rapidly to meet the cylindrical reinforce. The trunnions are 9 inches long and 10 inches in diameter.  The rimbases are just under 13 inches in diameter, with a face separation of 32-inches.

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Trunnions, rimbases and “shoulder” of Keokuk Gun

Notice the front sight block on top, between the trunnions.  That front sight matched to the rear slide sight on the back of the breech, seen here between two lockpiece blocks.

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Reinforce, lockpiece blocks, and rear sight

This view accentuates the cylindrical reinforce.  The rear sight is between, and to the rear of, two lockpiece blocks.  Notice only one is cut for mounting the lockpiece.  In a closer view, you can see the vent hole in front of that block.

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Upper breech of Keokuk Gun

Recall the USS Keokuk fired but three times on April 7, 1863.  After recovery, the Confederates likely, with a mind to conserve powder, fired the gun only when necessary.  So no surprise the second vent and lock piece were never mounted.

The breech profile confirms to Dahlgren’s hemispherical design.  The blade cascabel features a set of “jaws” to which the block is not permanently fixed (either by welding or corrosion).  So the breeching loop is a complete circle.

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Breech profile of Keokuk gun

The cascabel sticks out 12.5 inches from the breech.  Visible on the bottom of the blade is the piercing for the elevating screw.

Just behind the trunnions is the cylindrical reinforce, roughly 32 inches in diameter.  This view from underneath the breech also shows the profile of the rear sight block.

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From underneath the Breech

You may have noticed, looking at the trunnions and the post under the breech, the carriage for the Keokuk gun does not exactly fit the gun.

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Post on carriage for Keokuk gun

The carriage is not the type used for the gun during the Civil War.  Photographs taken in 1865 show the Dahlgren on a wooden carriage.  Instead this is a wrought iron carraige used for Rodman guns.  The stamps on the carriage announce its manufacturer – Union Iron Works of Buffalo, New York.

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Union Iron Works stamp

The works were one of the rolling mills built during the war.  A photograph from the turn of the last century shows the Dahlgren, along with a 10-inch Confederate columbiad, on similar (if not the same) wrought iron carriages not far from where they stand today.

There’s no mistaking the “shaved” muzzle of the Dahlgren.

A historic gun along the seawall, with a rich story to tell.  If you pause for a moment, you might catch a salty breeze coming in from the sea.

Published by Craig Swain

"Historical marker hunter" and Civil War enthusiast.

5 thoughts on “Cannon Walk Around: The Keokuk XI-inch Dahlgren

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