Attack transport Attack Transport is a United States Navy ship classification . History . In the early 1940s , as the United States Navy expanded in response to the threat of involvement in World War II , a number of civilian passenger ships and some freighter s were acquired , converted to transports and given hull numbers in the AP series . Some of these were outfitted with heavy boat davits and other arrangements to enable them to handle landing craft for amphibious assault operations . In 1942 , when the AP number series had already extended beyond 100 , it was decided that these amphibious warfare ships really constituted a separate category of warship from conventional transports . Therefore , the new classification of attack transport ( APA ) was created and numbers assigned to fifty - eight APs ( AP # s 2 , 8 - 12 , 14 - 18 , 25 - 27 , 30 , 34 - 35 , 37 - 40 , 48 - 52 , 55 - 60 , 64 - 65 and 78 - 101 ) then in commission or under construction . The actual reclassification of these ships was not implemented until February 1943 , by which time two ships that had APA numbers assigned ( USS " Joseph Hewes " and USS " Edward Rutledge " ) had been lost . Another two transports sunk in 1942 , USS " George F . Elliott " and USS " Leedstown " , were also configured as attack transports but did not survive to be reclassified as such . Despite an impressive assembly of forces , the Aleutian campaign and the Northern Pacific Theater ranked as Admiral Nimitz ' s third priority in the overall Pacific Theater for receiving materiel and support . As a result , only attack transport ( APA ) ships were assigned for the assault , without support from any companion attack cargo ( AKA ) ships . This created extreme logistics burdens for the invasion force because it resulted in considerable overloading of the transports with both men and equipment . To compound problems , these forces were not able to assemble or train together before executing the Aleutian invasion on 11 May 1943 . Lack of equipment and training subsequently resulted in confusion during the landings on Attu . As World War II went on , dozens of new construction merchant ships of the United States Maritime Commission ' s S4 , C2 , C3 and VC2 ( " Victory " ) types were converted to attack transports , taking the list of APA numbers to 247 , though fourteen ships ( APAs 181 - 186 and APAs 240 - 247 ) were cancelled before completion . In addition , as part of the 1950s modernization of the Navy ' s amphibious force with faster ships , two more attack transports ( APA - 248 and APA - 249 ) were converted from new " Mariner " class freighters . The 1956 feature " Away All Boats " portrayed the fictitious Attack Transport PA - 22 , USS ' Belinda ' . Demise . By the end of the 1950s , it was clear that boats would soon be superseded by amphibious tractors ( LVTs ) and helicopters for landing combat assault troops . These could not be supported by attack transports in the numbers required , and new categories of amphibious ships began to replace APAs throughout the 1960s . By 1969 , when the surviving attack transports were redesignated LPA ( retaining their previous numbers ) , only a few remained in commissioned service . The last of these were decommissioned in 1980 and sold abroad , leaving only a few thoroughly obsolete World War II era hulls still laid up in the Maritime Administration ' s reserve fleet . The APA / LPA designation may , therefore , now be safely considered extinct .