As designed, the ship had a full load displacement of 3,605 tons, a length overall of , a beam of , and a draught of . Starting in February 1989, "Sydney" was modified from the "Oliver Hazard Perry" FLIGHT II design to FLIGHT III, requiring a lengthening of the helicopter deck for the RAST helicopter recovery system, which increased displacement to 4,100 tons and pushing the overall length to . Propulsion machinery consisted of two General Electric LM2500 gas turbines, which provided a combined to the single propeller shaft. Top speed was , with a range of at . Two electric auxiliary propulsors were used for close manoeuvring, with a top speed of . Standard ship's company was 184, including 15 officers, but excluding the flight crew for the embarked helicopters. "Sydney" was the first ship of her class to carry female sailors and officers, requiring the installation of partitioning to some mess decks.