The new navigational lights are being installed at Portsmouth Harbour as part of infrastructure work for the Queen Elizabeth class carriers.

Work to install the top sections of 14 navigation light towers is now nearing completion.

The final construction stage will involve lifting the superstructures onto the pile foundations, which were driven earlier in the year.

Each of the towers will rise 30 metres from the seabed and weigh 22 tonnes.

A 350-tonne crane barge will be used to lift them into place.

The lights are powered by a combination of solar panels and batteries and will only be lit when the aircraft carriers are either approaching or leaving their berths at Portsmouth Harbour.

An infographic HMNB Portsmouth Navigation Lights Arrangement shows where the light will be placed.

The navigation light towers are being installed as part of a £34 million package of infrastructure work being delivered on behalf of the Defence Infrastructure Organisation (DIO) by VolkerStevin to support the new carriers.

DIO’s principal project manager,Philip Wise, said: “The navigation lights are essential to ensure the safe passage of the carriers into the naval base at Portsmouth.”

He added: “The work to install them represents a significant step forward in our preparations for the arrival of the two new ships which will be the largest ever constructed for the Royal Navy.”

The project manager for VolkerStevin, Gerrit Smit, said the work isn’t without its challenges.

“The installation of the navigational aids is another key milestone on this exciting project. The works are associated with challenges such as working in a busy harbour environment,” he explained.

“Due to close collaboration with the Queens Harbour Master, the ferry operators and other stakeholders, we are ensuring safe passage as well as a safe delivery of the construction works,” continued Smit.

In total, around £100 million is being spent by the Ministry of Defence to ready Portsmouth for the carriers – the biggest and most powerful ships in the Royal Navy’s history.

At 280 metres, the HMS Queen Elizabeth is longer than the Houses of Parliament (265 metres). And its length is greater than the height of the Spinnaker Tower in Portsmouth (170 metres).

Under its contract, VolkerStevin is also working to rebuild the Middle Slip jetty to accommodate the ships and providing a dedicated high voltage electrical supply to power the carriers.

DIO also awarded a contract to Boskalis Westminster Ltd to dredge the harbour to make it wide and deep enough for the ships.

The first of the new aircraft carriers will arrive at Portsmouth’s naval base in spring 2017.