The 15 mighty navigational aids, which stand up to 30m tall, clearly mark the deep water channel specially created to enable the carrier to safely navigate her way back to Portsmouth Naval Base.
To make sure the solar and battery-powered lights on top of the navigational aids are shining brightly whenever HMS Queen Elizabeth enters or leaves the harbour, regular maintenance is critical.
And that’s where the BAE Systems’ divers come in.
More used to working up to 50 metres below water, seven members of the 14-strong diving team have qualified as climbers so they can safely scale the giant towers and make sure they’re in tip top condition.
“We were asked if we could assist in the maintenance of the navigation aids and we were only too happy to help,” said Diving and Maritime Co-ordinator Jim Lynch.
“The team check the condition of the solar panels and batteries, ensuring they’re clean, free from guano and salt build up, and that the battery terminals are operating effectively.
“We carry out planned maintenance on a six-monthly basis as well as regular checks to ensure they’re fully operational.”
Diver Ed Ellis said he and his colleagues’ day jobs are usually spent inspecting and maintaining almost five miles of sea walls around the historic naval base, including jetties, quay walls and berthing facilities as well as centuries-old culvert systems and service tunnels, so maintaining the navigational aids is quite a change of direction – literally.
“It’s one extreme to the other but we all enjoy a challenge – although it can be a bit nerve-wracking as the platforms at the top of the aids can sway by up to a metre so we can only work on them at winds up to 17 miles an hour,” he added.
This will be HMS Queen Elizabeth’s fifth entry into Portsmouth Harbour in the safe hands of expert pilot Tony Bannister, who will be standing alongside new Captain Nick Cooke-Priest on the ship’s bridge to help make sure the carrier, the largest ever operated by the Royal Navy, stays on course.
Tony explained that the lights act as a kind of runway, shining red, white and green to clearly show when the carrier is on the right heading, particularly entering and leaving the centuries-old narrow harbour entrance.
“The navigable channel is just 100 metres wide and, as the beam of the ship is 48 metres wide, these lights are absolutely critical to the carrier’s safe passage both into and out of the harbour,” he said.Radio-operated from Semaphore Tower in the naval base, the lights are switched on as soon as it’s confirmed that the carrier will be entering or leaving the harbour. The rest of the time they flash at low level to avoid other vessels colliding with them.