▁along ▁with ▁numerous ▁rot ary - wing ▁aircraft . ▁Their ▁primary ▁purpose ▁though , ▁is ▁usually ▁to ▁serve ▁as ▁the ▁center pie ce ▁and ▁flags hip ▁for ▁an ▁Ex ped ition ary ▁St rike ▁Group ▁or ▁Am ph ib ious ▁Re ady ▁Group , ▁carrying ▁US ▁Marine ▁Corps ▁Ex ped ition ary ▁Units ▁and ▁their ▁equipment ▁close ▁to ▁shore ▁for ▁am ph ib ious ▁land ings ▁and ▁depart ures . ▁The ▁following ▁are ▁ships ▁and ▁classes ▁of ▁US ▁Navy ▁am ph ib ious ▁assault ▁ships ; ▁▁▁▁ ▁Active ▁ ▁( L HD ) ▁( 8 4 3 ft , ▁ 4 0 , 5 0 0 ▁tons ) ▁▁▁ ▁( L HA ) ▁( 8 4 4 ft , ▁ 4 5 , 0 0 0 ▁tons ) ▁ ▁Under ▁construction ▁ ▁Ret ired ▁ ▁( L HA ) ▁ ▁– ▁( On ▁don ation ▁hold ) ▁▁▁▁▁ ▁– ▁( On ▁don ation ▁hold ) ▁ ▁– ▁( In ▁Reserve ) ▁▁ ▁( LP H ) ▁▁▁▁▁▁▁▁▁ ▁– ▁( Convert ed ▁to ▁miss ile ▁trial ▁platform ▁with ▁the ▁National ▁Def ense ▁Reserve ▁Fle et ▁in ▁ 2 0 0 6 , ▁scra pped ▁in ▁ 2 0 1 8 ) ▁▁▁▁▁▁ ▁Stand - alone ▁am ph ib ious ▁assault ▁ships ▁( all ▁L PH , ▁number ed ▁in ▁with ▁the ▁I wo ▁J ima ▁class ); ▁ ▁– ▁( convert ed ▁Com men cement ▁Bay - class ▁esc ort ▁car rier ) ▁ ▁– ▁( convert ed ▁Es sex - class ▁aircraft ▁car