This gun truck tackle block was likely used to move and secure one of the CSS Alabama's large pivot guns.
Gun Truck Tackle
This particular single-sheave block was hooked to a large eye bolt in the deck. This was coupled with a double-sheave block hooked to the cannon truck to provide mechanical advantage to pivot the cannon. One of the upper double-sheave blocks was recovered from the site in 1991 and this single-sheave block was recovered in 2000. It is made entirely of brass and both the hook and eye are designed to swivel. One such block is visible in the photo of Capt. Raphael Semmes leaning against the aft pivot gun.