RAN Wessex 31B over HMAS Melbourne (ll)

The Westland Wessex 31A and the later B model was a carrier-borne anti-submarine and rescue helicopter manufactured by Westland Aircraft Ltd Yeovil, England. The Wessex was developed under licence from the Sikorsky S58 which was designed for the US Navy as an Anti-submarine warfare and transport helicopter by the great American designer, Igor Sikorsky. It was powered by a Wright Cyclone radial engine of 1525 hp and the first flight took place in 1954.

The S58 soon became ubiquitous throughout the US Army, the US Marines and the US Navy–known variously as the HUS-1 Seahorse and the H-34 Chocktaw. The rugged machine could carry a variety of anti-submarine warfare weapons, and the transport versions could accommodate 16 people or 5,000lb of cargo. In all, over 2,700 variants of the S58 were constructed by American, British and French manufacturers.

Westland’s in England, building under licence, improved the design by installing a powerful Napier Gazelle gas turbine engine. An automatic flight control system was also installed. Westland named its helicopter “Wessex”, and it first came into service with the Royal Navy in 1961.

The RAN introduced the helicopter in 1962 as the Wessex 31A. The 31A’s first publicly recognised action was during the night of the Voyager incident in 1964. Many Wessex sorties were flown from HMAS Albatross at Nowra, NSW to locate survivors after the collision of the destroyer HMAS Voyager, with the aircraft carrier HMAS Melbourne. On-board operations with HMAS Melbourne began in 1963.

The Wessex 31B version shown in the painting was one of 22 that were fitted with a more powerful engine, resulting in greater load-carrying; there was also an update of ASW systems. They were operated by a crew of four, cruised at just over 100mph (160km/h), had a range of about 250 miles (400km) and could carry bombs or two torpedoes. As well as operating from the aircraft carrier Melbourne they were embarked on HMAS Sydney, then a troop carrier, HMAS Tobruk and HMAS Stalwart. The Wessex was used extensively in the Bass Strait Counter Terrorism Plan in the 1980s–an excellent and detailed account of Wessex operations appears in, “Flying Stations”, a story of Australian Naval Aviation published in 1998 by Allen and Unwin.

Finally, a yet more powerful Westland Wessex HU5, shown in Marshall’s painting below, was operated by the Royal Navy. It was powered by two Rolls-Royce “Gnome” turboshaft engines. The HU5 cruised at 120 mph, could reach 14,000ft and the service range was 470 miles. They were often fitted with special external and internal mountings for 7.62mm calibre machine guns.