Usually at the start of a load-and-fire operation, the rotating drum already has a compliment of ready service ammunition. If not, the magazine crew immediately
Figure 6-15.-Filling of the loader drum through the lower hoist. 6-14
begins hand-feeding powder cases and projectiles into the loading system at the lower hoist (fig. 6-15). The lower hoist then raises the rounds to the upper loading station, where the ejector transfers the rounds into the rotating drum.
With a load-and-fire order in effect, the rotating drum indexes until a loaded cell reaches the transfer station. At the transfer station, a positioning mechanism aligns the round to the fuze setter mounted overhead. If the projectile has an MT fuze, the fuze setter extends (fig. 6-16), sets the fuze, and retracts. An ejector then transfers the round into the upper hoist (fig. 6-17).
With the first round in the upper hoist and the hoist raising, the rotating drum indexes clockwise to bring the next loaded cell into place. The upper hoist raises the first round into the cradle (fig. 6-18), which is latched at the HOIST position. The cradle pawl holds the round while the hoist pawl lowers for the second round. When the hoist pawl is clear of the cradle, the
Figure 6-17.-First round in the upper hoist.
Figure 6-16.-A round at the transfer station with fuze setter in place setting fuze.
Figure 6-18.-First round raised into the cradle.
cradle unlatches and pivots upward (raises) to align with the gun bore (fig. 6-19).
The cradle completes the raise cycle and latches to the slide (fig. 6-20). The rammer extends, driving the round into the breech. At this time, the breechblock partially lowers (closes) to hold the round in the breech, while the cradle lowers to receive another round.
While the cradle is still raised and after the round has been rammed, the rammer retracts, and another round is ejected into the upper hoist (fig. 6-21).
With the rammer retracted, the cradle lowers, the breechblock closes completely, and the empty case tray lowers to the FIRE position (fig. 6-22).
With the loading system latched in the FIRE position, the gun fires and recoils (fig. 6-23). The breechblock opens, the empty case is ejected into the empty case tray, and another round is raised into the cradle by the upper hoist (fig. 6-24).
As the cradle raises to ram the second round, the empty case tray raises to align with the case ejector (fig. 6-25). The empty case is ejected out onto the deck at the same time the second round is rammed for tiring.
Figure 6-20.-Cradle completely up and rammer extending.
Figure 6-19.-The cradle raises.
Figure 6-21.-Rammer retracting and loader indexing.
Figure 6-22.-Cradle lowers and empty case tray lowers to the FIRE position.
Figure 6-24.-The breech opens and the empty case is ejected.
Figure 6-25.-The cradle and empty case tray raise to ram the second round and eject the empty case.
Figure 6-23.-The gun fires and recoils.
This completes one firing cycle. The loading system continuously keeps each station full as rounds are fired.