HMS Berwick was a Rothesay or Type 12I class anti-submarine frigate of the British Royal Navy. She was built by Harland & Wolff and launched on 15 December 1959. The Rothesay class was an improved version of the Whitby-class anti-submarine frigate, with nine Rothesays ordered in the 1954–55 shipbuilding programme for the Royal Navy to supplement the six Whitbys. Berwick was 370 feet 0 inches (112.78 m) long overall and 360 feet 0 inches (109.73 m) between perpendiculars, with a beam of 41 feet 0 inches (12.50 m) and a draught of 13 feet 6 inches (4.11 m). The Rothesays were powered by the same Y-100 machinery used by the Whitby-class. Two Babcock & Wilcox water-tube boilers fed steam at 550 pounds per square inch (3,800 kPa) and 850 °F (454 °C) to two sets of geared steam turbines which drove two propeller shafts, fitted with large (2 feet (0.61 m) diameter) slow-turning propellers. The machinery was rated at 30,000 shaft horsepower (22,000 kW), giving a speed of 29.5 knots (33.9 mph; 54.6 km/h). Crew was about 212 officers and men.