Pivotmounted 11inch 280mm Dahlgren Smoothbore

Perhaps the most responsible task to befall a naval officer was the oversight of a gun and its crew. Many different types of gun entered service with the U.S. Navy, but the larger rifles and smoothbores such as this Dahlgren 11-inch were the most likely to be found aboard sea-going sloops and cruisers.

This gun weighed some 16,0001b (8 US tons [7,258kg]) and could hurl a 1301b (59kg) shell nearly a mile. The rate of fire varied from rapid (two minutes per shot) to sustained (three minutes per shot), the gun being aimed by means of a sight-bar positioned on the breech and a front sight located between the trunnions.

The name "pivot" arose from the ingenious arrangement which enabled the gun to fire on either beam (since warships were very rarely engaged on both sides, simultaneously) using iron-shod wheels (trucks) by moving the carriage along overlapping iron bands, which were fixed to the deck planking, thus allowing movement over a full 360 degrees. The guncrew, under command of a lieutenant, used rope and tackle to pull the gun out for firing and back for loading, or to rotate it, either by small amounts for aiming or by large amounts to move the whole device to the other beam. When not in action, the gun was held firmly in position on the pivot mount by screw-clamp compressors located on both sides.

The most effective arrangement for such guns was for a ship to carry a minimum of three, preferably four, with one forwards, one aft, and either one or two amidships.

Gun drills were practiced endlessly, but for most gun-crews in the Civil War that was as much action as they ever saw, since few vessels saw much combat, and many sailors never fired a hostile shot during the war at all.

Trunnion plates

Civil War Naval Pivot Cannon Carriages

Screw compressor Carnage rollers and lournal plates Transoms Huner

Trunnion plates

Screw compressor Carnage rollers and lournal plates Transoms Huner

280mm Dahlgren Gun

Above: A gun-crew aboard the USS Unadilla fires the "evening gun."

Above: A gun-crew aboard the USS Unadilla fires the "evening gun."

Dahlgren Gun Image

Eye for shilling tackle

Dahlgren Gun Crew

Breeching Shifting trucks

Racers

Right: Apart from sea-going warships, and river monitors, such as the USS Monitor herself, designed by John Ericcson, Dahlgren guns were also mounted to provide protection for forts and harbors

Breeching Shifting trucks

Eye for shilling tackle

Racers

Civil War Dahlgren Gun Images

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  • cora
    Who invented the 280mm rifles in the civil war?
    8 years ago

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