Here’s why Polk needed that Gun

Why did General Leonidas Polk need an 8-inch rifled gun?

Maybe due to rumors of this “turtle.”

USS Essex

Starting in the summer of 1861, rumors floated down river of ironclad gunboats under construction in the shipyards of the Mississippi and Ohio Rivers.  Just as similar rumors about Confederate river ironclads caused concerns on the Union side, the southern commanders had to fear a Federal gunboat fleet descending the Mississippi (as it eventually did).   Regardless of the validity of rumors, the Confederates recognized the strategic importance of the Mississippi and the need to strongly fortify key points on the river.

When Polk first violated Kentucky’s neutrality on September 3, he moved straight for the high bluffs at Columbus which overlooked a bend in the Mississippi.  Compared, with no small exaggeration, to the straits of Gibraltar, the combination of high bluffs and sweeping river bend made the position formidable.  Naturally the Federals probed this new Confederate stronghold.  Just days before Tredegar sent the 8-inch Rifle west, on October 7 the gunboat USS Tyler under Commander Henry Walke tested the Columbus defenses.

Thus with the Confederacy threatened at points all along the coast, the largest rifled gun available went west to a rust-colored bluff overlooking the Mississippi.

The gun itself was bored and rifled from either an 8- or  10-inch Columbiad casting block.  Externally, the 8-inch rifle may have resembled this gun presently on display at Fort Donelson, Tennessee.

Fort Donelson 360
Tredegar 10-inch Columbiad at Fort Donelson

Tredegar cast this 10-inch Columbiad in January 1863.   At first glance this gun appears to be a Rodman gun.  But subtle differences give away it’s Confederate origin.  The rough exterior is due to Tredegar’s reluctance to perform additional (arguably superfluous) machining.  The long trunnions (emphasized against the cast iron carriage) fit wooden carriages often used by the Confederates.  And the reinforce of the gun is not a blended “bottle” curve, but rather a cylinder.

The most prominent “Rodman” feature is the mushroom knob.  But unlike most Federal Rodmans, the Confederate Columbiads used ratchets instead of sockets to engage the elevating gear.  Some early war Confederate Columbiads featured standard round knobs.

At the time of casting, the 8-inch gun was the largest rifled weapon available to the Confederates.  Some accounts reference the gun’s projectile weight as a 128-pdr gun (two times the 64-pdr of an 8-inch smoothbore).  But this particular gun received its own name in honor of the commander’s wife  – “Lady Polk.”