Entering service in the 1980s, the Royal Navy's Invincible-class aircraft carriers served diligently until 2014
The Invincible class was designed in 1966
Initially, the ships were designed as a helicopter cruiser, but later, due to the complex requirements of the world situation
the Royal Navy had to redesign, turning Invincible into an aircraft carrier class
The vessels were built as aviation-capable anti-submarine warfare platforms to counter the Cold War North Atlantic Soviet submarine threat
and initially embarked Sea Harrier aircraft and Sea King HAS.1 anti-submarine helicopters
When completed, the Invincible had a displacement of about 22,000 tons, a length of 209 m, a beam of 36 m, and a draft of 8 m
The Propulsion system was a Combined gas and gas configuration consisting of four Rolls-Royce Olympus TM3B gas turbines and eight Paxman Valenta diesel generators
with a combined output of 100,000 hp
The ship's maximum speed was 28 knots, the range was 7,000 nautical miles
During building both the Invincible and the Illustious were fitted with 7° ski-jump ramps, while the Ark Royal has a 15° ramp
In February 1982 it was announced that the Invincible was to be sold to Australia as a helicopter carrier to replace HMAS Melbourne
leaving only two carriers in British service
However, the deal was cancelled after the Falklands campaign
as it was realised by the government that three carriers ought to be available to ensure two in service at any one time
The standard air arm constituted eight Sea Harrier VTOL aircraft and nine Sea King naval helicopters
This total was later increased for improved operational capability
The helicopters were equipped for Anti-Submarine Warfare or Anti-Ship role depending on mission need
The Invincible class carriers were eventually decommissioned due to their age and replaced by the new
much larger and much more capable Queen Elizabeth class aircraft carriers