Des Moines-class cruiser

The Des Moines-class cruisers were a group of U.S. Navy heavy cruisers, commissioned in 1948–1949. They were the last of the all-gun heavy cruisers, exceeded in size in the American navy only by the s.

Description
Derived from the heavy cruisers, they were larger, had an improved machinery layout, and carried a new design of auto-loading, rapid-fire 8"/55 gun (the Mk16).    The improved Mk16 guns of the main battery were the first auto-loading 8" guns fielded by the US Navy, and allowed a much higher rate of fire than earlier designs, capable of sustaining 12 shots per minute per barrel, or about twice that of the Mk12s found on the Baltimore class. The auto-loading mechanism could function at any elevation, giving even these large-caliber guns some anti-aircraft ability. While the secondary battery of six twin 5"/38 Mk12 DP guns was essentially unchanged from the preceding and Baltimore-class cruisers, the Des Moines class carried a stronger battery of small-caliber anti-aircraft guns, including 12 twin 3-inch/50 Mk27 and later Mk33 guns, that were considered superior to the earlier ships' quad-mounted 40mm Bofors against then current airborne threats.

History
Twelve ships of the class were programmed, but only three ships were completed: USS Des Moines (CA-134), USS Salem (CA-139), and USS Newport News (CA-148), with the USS Dallas (CA-140) cancelled when she was approximately 28 percent complete. The first two were decommissioned in 1959 and 1961, respectively, but Newport News remained in commission until 1975, serving for a long period (1962-1968 as Second Fleet flagship, and then providing gunfire support off Viet Nam 1969-1973. She had the distinction of being the last active all-gun cruiser (serving 25.5 years continuously) and the first completely air-conditioned surface ship in the U.S. Navy.  Salem is a museum ship in Quincy, Massachusetts. Newport News was scrapped in 1993, and Des Moines was scrapped in 2006–2007.  Dallas (CA-140) and eight other ships (CA-141 through CA-143 and CA-149 through CA-153) were canceled at the end of World War II.

Ships in class

 * USS Des Moines (CA-134)
 * USS Salem (CA-139)
 * USS Dallas (CA-140) canceled 1946.
 * USS Newport News (CA-148)