In 1982, Jane's Fighting Ships recorded: "Estimated cost of fourth submarine £175 million including equipment and weapon system when fitted."

[8] The submarines of the class have seen service in a wide range of locations, most notably firing Tomahawk land-attack cruise missiles in anger at targets during conflicts in Afghanistan, Iraq and Libya.

[9] During April 2003, HMS Turbulent returned home flying the Jolly Roger after having launched thirty Tomahawk cruise missiles during the invasion of Iraq.

[15] Triumph returned to Devonport on 3 April 2011 flying a Jolly Roger adorned with six small Tomahawk axes to indicate the missiles fired by the submarine in the operation.

In 2000 a leak in the PWR1 reactor primary cooling circuit was discovered on Tireless, forcing her to proceed to Gibraltar on diesel power.

[18] In 2013 the Defence Nuclear Safety Regulator reported that the reactor systems were suffering increasing technical problems due to ageing, requiring effective management.

However some improvements over the Swiftsure class include its reduced acoustic signature, which is due to the hull being covered in anechoic tiles which are designed to absorb sound rather than reflect it, making the boats quieter and more difficult to detect with active sonar.

[2] Like all Royal Navy submarines, the Trafalgar class have strengthened fins and retractable hydroplanes, allowing them to surface through thick ice.

[2] The Trafalgar class is equipped with five 21-inch (533 mm) torpedo tubes with accommodation for a mixture of up to 30 weapons:[2] The Tomahawk missiles are capable of hitting a target to within a few metres, to a range of 1,000 miles (1,600 km).