[5] Two oil-fired Babcock & Wilcox boilers fed steam at 550 pounds per square inch (3,800 kPa) and 850 °F (454 °C) to a pair of double reduction geared steam turbines that in turn drove two propeller shafts, with the machinery rated at 30,000 shaft horsepower (22,000 kW), giving a speed of 28 knots (52 km/h; 32 mph).

The anti-aircraft defence was provided by a quadruple Sea Cat surface-to-air missile launcher on the hangar roof and two Oerlikon 20 mm cannon.

An MRS3 fire control system was carried over the ship's bridge to direct the 4.5-inch guns, while a GWS22 director for Seacat was mounted on the hangar roof.

[11] Early in 1967, she interrupted her passage out to Singapore to carry out a deployment on the Beira Patrol, which was designed to prevent oil reaching landlocked Rhodesia via the then Portuguese colony of Mozambique.

In April 1970, Sirius again deployed to the West Indies, where she would perform the role of guard ship in that region, relieving Mohawk.

In 1973, Sirius became guard ship to the West Indies once more, performing a variety of duties while there, including counter-drug operations.

Later in the same year she appeared in an official government documentary during AAW and ASW exercises, along with RAS with RFA Grey Rover (A269) and a port visit to Madeira.

In 1988, Sirius, as part of the group deployment Exercise 'Outback 88', deployed to the Far East and Pacific, attended Exercise Starfish with New Zealand, Australian, Malaysian and Singaporean naval units, and visited Australia for the 1988 bicentennial naval Salute, visiting a variety of ports in the process.

In 1998, Sirius was finally sunk as a target in the Atlantic Ocean by the submarine Spartan and the Type 23 frigate, Monmouth.