The United States Navy reclassified many of its surface vessels in 1975, changing terminology and hull classification symbols for aircraft carriers, cruisers, frigates, and ocean escorts. The United States Navy (USN) is the branch of the United States armed forces responsible for conducting naval operations. ... The United States Navy uses hull classification symbols (sometimes called hull codes) to identify the types of its ships. ... An aircraft carrier is a warship designed to deploy and recover aircraft—in effect acting as a sea-going airbase. ... USS Port Royal (CG-73), a Ticonderoga-class guided missile cruiser, launched in 1992. ... Frigate is a name which has been used for several distinct types of warships at different times. ... Ocean escort was a United States Navy warship. ...

From the 1950s to 1975, the Navy had three types of fast task force escorts and one type of convoy escort. The task force escorts were cruisers (CL/CLG/CG), frigates or destroyer-leaders (DL/DLG), and destroyers (DD/DDG); the convoy escorts were ocean escorts (DE/DEG), often known as destroyer escorts. Added in the early 1970s was a new ocean escort called the patrol frigate (PF). In 1975, these classifications were simplified to cruiser (CG), destroyer (DD/DDG) and frigate (FF/FFG). USS Lassen, an Arleigh Burke-class destroyer In naval terminology, a destroyer (French: contre-torpilleur, German: Zerstörer, Spanish: destructor, Italian: cacciatorpediniere) is a fast and maneuverable yet long-endurance warship intended to escort larger vessels in a fleet or battle group and defend them against smaller, short-range attackers...

Under the pre-1975 classification, cruisers were large vessels, the size of WWII gun cruisers, intended as the primary surface combatants. All but one (USS Long Beach (CGN-9)) were converted WWII gun cruisers (CL/CLG or CA/CAG). They were to carry the long-range Talos missile, and, in many cases, strategic weapons such as Regulus or Polaris (but these were not fitted). One cruiser was to be assigned to each carrier group. There were relatively few of these ships, due to their cost and because the frigates could carry almost as many weapons as a cruiser. German soldiers at the Battle of Stalingrad World War II was the most extensive and costly armed conflict in the history of the world, involving the great majority of the worlds nations, being fought simultaneously in several major theatres, and costing tens of millions of lives. ... USS Long Beach (CGN-160/CLGN-160/CGN-9) was the first all-new cruiser designed and constructed after World War II (all others were completions or conversions of cruisers begun or completed during the war). ... Regulus missile The SSM-N-8A Regulus cruise missile was the nuclear deterrent weapon employed by the United States Navy from 1955 to 1964. ... Polaris A-1 on launch pad in Cape Canaveral Polaris A-3 on launch pad in Cape Canaveral The Polaris missile was a submarine-launched, nuclear-tipped ballistic missile (SLBM) built during the Cold War by the United States Navy. ...

From 1950 to 1975, frigates were a new type, midway between cruiser and destroyer sizes, intended as major task force escorts. The first ship of the type was a redesignated ASW cruiser; the next four were very large AAW (gun) destroyers, and the remainder were essentially oversize guided missile destroyers. They carried the mid-range Terrier missile, but no offensive (strategic) weapons. Anti-submarine warfare is a term referring to warfare directed against submarines. ... American troops man an anti-aircraft gun near the Algerian coastline in 1943 Anti-aircraft warfare, or air defense, is any method of engaging military aircraft in combat from the ground. ... Guided Missile is a London based independent record label set up by Paul Kearney in 1994. ... The RIM-2 Terrier was one of the earliest surface to air missiles to equip United States Navy ships. ...

Destroyers were developed from the WWII designs as the smallest fast task force escorts. DDs were fast ASW ships; DDGs were AAW ships carrying the short-range Tartar missile. ...

Ocean escorts were an evolution of the WWII destroyer escort types. They were intended as convoy escorts and were designed for mobilization production in wartime or low-cost mass production in peacetime. DEs were ASW vessels; DEGs were AAW vessels with the Tartar.

The US frigate classification was not used by any other navy; similar vessels were either cruisers or destroyers in foreign service. The ocean escort type corresponded to foreign frigates (convoy escorts).

The Soviets defined "cruiser" differently, considering ships equivalent to U.S. frigates to be "cruisers". By 1974, there were only six ships in U.S. service classified as cruisers, but the Soviets had 19 ships classified as cruisers in service with seven more building. (All totals exclude gun-only cruisers.) All but two of the Soviet ships were relatively small vessels, roughly equivalent to U.S. frigates and far smaller than U.S. cruisers. The Soviet Naval ensign The Soviet Naval jack The Soviet Navy (Russian: Военно-морской флот СССР, Voyenno-morskoy flot SSSR, literally Naval military forces of the USSR) was the naval arm of the Soviet armed forces. ...

The differing U.S. and Soviet definitions of "cruiser" caused political problems when comparisons were made between U.S. and Soviet naval forces. A table comparing U.S. and Soviet cruiser forces showed six U.S. ships vs. 19 Soviet ships, despite the existence of 21 US "frigates" equal or superior to the Soviet "cruisers". This led to the perception of a non-existent "cruiser gap."

To close this "gap," the U.S. frigate (DL/DLG) classification was eliminated on 30 June 1975. All the gun Frigates (DL) had already been stricken. Most of the DLGs became cruisers (CG), but the smaller Farraguts became destroyers (DDG). The change from DLG to CG redefined "cruiser" as smaller ships, more like large destroyers. Cruiser classifications were also simplified, with the Guided Missile Light cruisers (CLG) simply becoming CGs. Gun cruisers were provided the designation "CA" at this time, but there were no remaining gun cruisers in active service with the fleet, so the designation was and remains theoretical. Wikipedia does not yet have an article with this exact name. ...

The ocean escorts (DE/DEG) and patrol frigates (PF) became frigates (FF/FFG).

Finally, the attack carriers (CVA/CVAN) became multimission carriers (CV/CVN). These changes brought U.S. Navy classifications into line with foreign classifications, and eliminated the perceived "cruiser gap".

A final change came on 1 January 1980, when the Ticonderoga-class destroyers (DDG) became cruisers (CG). January 1 is the first day of the calendar year in both the Julian and Gregorian calendars. ... 1980 (MCMLXXX) was a leap year starting on Tuesday. ... Ticonderoga class cruisers warships use phased-array radar; the increased combat capability offered by the Aegis combat system and the AN/SPY-1 radar system justified the changing of the classification of Ticonderoga and Yorktown from DDG (guided missile destroyer) to CG (guided missile cruiser). ...

Reference

• sci.military.naval FAQ, Part F Surface Combatants, Section F.8 - reprinted with permission