Britain's Royal Navy is revamping part of its Portsmouth Naval Base so it can accommodate the country's newest aircraft carriers.

The 18-month project involves the 90-year-old Middle Ship Jetty. The base's Victory Jetty will be improved later so that both HMS Queen Elizabeth and HMS Prince of Wales can be in port simultaneously.

The ships are 920 feet long and displace more than 77,000 tons.

"This is a huge project -- and a very exciting one, refurbishing and rebuilding jetties, bringing in new power facilities, installing navigation beacons, dredging millions of tonnes of mud," said Capt. Iain Greenlees, the base's head of infrastructure.

"This program confirms the future of Portsmouth Naval Base for the next 50 to 80 years. It will be the only port which can fully support HMS Queen Elizabeth and Prince of Wales and meet all their needs."

HMS Queen Elizabeth is being fitted out at a dockyard in Scotland and is scheduled to arrive in Portsmouth in 2017.

The task of rebuilding the Middle Ship Jetty is worth nearly $53 million and is being conducted by construction firm VolkerStevin. In December, eight months of dredging begins on the main shipping channel to widen it by about 3.2 feet.