USS Cairo - Armament

Armament

Like many of the Mississippi theatre ironclads, Cairo had her armament changed over the life of the vessel. To expedite the entrance of Cairo into service, she and the other City-class ships were fitted with whatever weapons were available; then had their weapons upgraded as new pieces became available. Though the 8 in (200 mm) Dahlgren smoothbore cannons were fairly modern most of the other original armaments were antiquated; such as the 32-pounders, or modified; such as the 42-pounder "rifles" which were in fact, old smoothbores that had been gouged out to give them rifling. These 42-pounder weapons were of particular concern to military commanders because they were structurally weaker and more prone to exploding than purpose-built rifled cannons. Additionally, the close confines of riverine combat greatly increased the threat of boarding parties. The 12-pounder howitzer was equipped to address that concern and was not used in regular combat.