Characteristics for an American attack transport (APA) in March 1961

Dimensions 563 x 76 x 24 feet. Speed 15 (cruising)-17 (maximum) knots. Troop capacity 1,500. Cargo capacity 500 tons. Landing craft 4 LCM6; 20 LCVP. Cargo booms 1-30 ton; 2-60 ton.

Source

Army forces in amphibious operations (the Army Landing Force). Department of the Army Field Manual FM 31-12. March 1961.