Daily Archives: 19 September 2010

20-pdr, or 3.67-inch, Navy Parrott Rifle

Yesterday I mentioned a 20-pdr Navy Parrott Rifle on display in Cumberland Gap National Historical Park.   Having discussed the Army’s version of this caliber in an earlier post, perhaps it is time to properly introduce the Navy model.

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20-pdr or 3.67-inch Navy Parrott Rifle

The Navy received 336 of the 20-pdrs from West Point Foundry during the Civil War.  The main difference between the Army and Navy model was the breeching jaws in place of the Army’s knob.  Here’s what the Army’s looked like:

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Breech of 20-pdr Army - Evergreen Cemetery, Gettysburg

Compare to the profile on the Navy Parrott in the same caliber:

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Breeching Jaws of 20-pdr Navy Parrott

A set of jaws, with a block spanning the opening, forms a “loop” through which passed a breeching tackle rope to restrain the gun when fired.  A pin held the block in place.  You can see the join between the block and jaws, which I would assume is welded in place today.  Also note the rear sight socket on the right side of the breech band.  Normally the socket, which is the same used on Army models, was set with the hole oriented vertically.  I would guess during repairs or other work, the sight socket was twisted, and is out of alignment today.

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Muzzle Profile - 20-pdr Navy Parrott

The gun displayed at Cumberland Gap has a slight muzzle swell.  At present, I cannot confirm if this was a “Navy” standard, or (as with other model Parrotts) this was simply a feature of early production batches.

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Muzzle and Bore of 20-pdr Navy

Hard to make out the rifling, but just enough to count five lands and grooves.  Unlike the Army, the Navy did not mark the muzzles of the guns.  Instead the particulars were stamped on the trunnions and top of breech.

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Right Trunnion - 20-pdr Navy

On the right trunnion was the date of manufacture, projectile size, and diameter of bore.  In this case – 1861 // 20 pdr // 3.67.  I failed to get a good photo of the left side trunnion, but regulations required a “P.” stamp indicating successful proofing, along with the initials of the inspector.   In this case “R.B.H.” for Robert B. Hitchcock.

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Breech Stampings - 20-pdr Navy Parrott

Over the breech band were the initials of the manufacturer, registry number, and weight.  Here those appear as “R.P.P   No. 83  1695 lbs.”  These stand out crisp even after nearly 150 years, even better than marks of some later day “inspectors” who attempted to leave a mark.

The Navy normally placed an anchor over the barrel between the trunnions.  But that mark is not visible today.

Other than markings and the breeching jaws, the Army and Navy models were interchangeable.  Tallies from West Point production show on occasion production batches were reallocated to meet service requirements.  While the breeching jaws caused little impact on the Army’s use, when the Navy received an Army model a wrought iron shackle or clevis was attached over the knob.

While the story of this particular piece is undocumented, 20-pdrs of this sort saw service in both the blue- and brown-water fleets.  The Navy often provisioned lighter gunboats with 20-pdrs, where heavier rifles could not go.

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

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.