US Navy 8-Inch Chambered Shell Gun Number 348 on USS Cairo

Aug 28

US Navy 8-Inch Chambered Shell Gun of 63 Hundredweight Number 348 is displayed aboard USS Cairo at Vicksburg National Military Park. Number 348 is one of three of the 8-Inch shell guns aboard. Number 348 was cast at the Fort Pitt Foundry in 1845. It is marked as weighed in hundredweight "64-0-8" (7,176 pounds).

The cannon was designed to fire an approximately 50-pound explosive shell. The threat of shell guns would spur the development of ironclads as an explosive shell which embedded itself in a wooden ship's side near the waterline might explode and tear a ship-sinking hole in the wood. On some ships it supplemented larger numbers of shot-firing 32-Pounders. On USS Constellation, the 8-Inch of 63cwt formed the majority of the battery. On the Merrimack-class steam frigates, the 8-inch of 63cwt formed the spar deck battery.

Post-war, the type does not seem to have been retained in US Navy inventories. The Dahlgren-inspired 8-Inch of 6,500 pounds had been produced in relatively large numbers near the end of the war. The older 8-inch model was not available to be donated to communities requesting cannons as monuments in the 1890s and 1900s. This is in contrast to the 32-Pounder of 57cwt of the same era which was donated in large numbers - over 100 still surviving.

The three recovered with USS Cairo are among seven known survivors of the type. Three others are at Mare Island and were carried aboard USS Independence. One is at Port Hudson.

All together, USS Cairo was recovered with thirteen cannons - most of which are relatively rare types.