The images were unveiled at the Defence Security and Equipment International exhibition in London’s Docklands by BAE Systems, as it announced the first contracts had been placed for some of the key equipment aboard.

Work will begin on the first – as yet unnamed – ship in the class in just three years’ time, with that same vessel due to be in service as soon as possible after 2020.

As things stand at present there will be 13 of these warships – anti-submarine warfare, air defence and general purpose duties such as hunting down pirates, pummelling enemy positions with its main gun, or providing humanitarian aid in the wake of disaster – replacing the 13 Type 23s currently in the service around the world with the RN.

A combined RN-MOD-BAE 550-strong team has been working on the design of the ships since the spring of 2010 and those efforts have reached the stage where BAE are ready to issue the first contracts.

The ships will be powered by a combined diesel electric or gas turbine system – meaning they’ll be capable of high speeds, but also cruise along extremely quietly.

Rolls-Royce have been selected to design the 26’s gas turbines; MTU will provide the diesel generator sets and David Brown Gear Systems have been asked to develop the gearbox.

The fourth contract has been placed with Rohde & Schwarz to work on the vessels’ communications system.

The Type 26 will be slightly longer than the Duke-class they replace (148m to 133m) and slightly heavier (5,400 tonnes to 4,900).

It incorporates many of the features of the similarly futuristic-looking Type 45 destroyers – chiefly angled sides and an enclosed upper deck for increased stealth.

Sea ceptor missiles will fend off incoming air attack, there’ll be a medium calibre gun on the forecastle, vertical missile silos for other weapons.

As with the Type 45 destroyers the new vessels are being designed with the future in mind so it will be easier to adapt them to new technology introduced to the Fleet during the course of their lifespans.

As for their predecessors, the oldest Type 23, HMS Argyll, is expected to serve until around 2023, while the youngest, St Albans, will be on duty until around 2036.