Royal Navy aircraft carrier HMS Queen Elizabeth got underway from her Portsmouth homeport on April 1 to head for Rosyth where she is scheduled to undergo her first dry-docking maintenance since entering service.

The lead ship of a new class of Royal Navy aircraft carriers is starting the overhaul following a busy 2018 in which the ship concluded first-of-class flight trials with the F-35B off the US East Coast.

As was the case with her departure from Rosyth, the 65,000-ton, 280-meter long ship will have only inches to spare on her way into the harbor where she will undergo maintenance.

Her height of 63 meters (206ft) above the waterline is an additional challenge and the first of Rosyth’s three bridges HMS Queen Elizabeth will pass under is too low. As a solution, engineers have placed her mast on a steel cartridge which houses two hydraulic cylinders and a hydraulic system which lower the structure to an angle of 77˚, before raising it back in place once through.

The overhaul will be completed by defense contractor Babcock who received a £5 million contract for the dry-dock maintenance of HMS Queen Elizabeth in January 2019.

The routine, planned hull survey and maintenance of her underwater systems will take place over a six-week period and will sustain 100 jobs at its peak.

Once she completes the maintenance, HMS Queen Elizabeth will carry out the third and final stage of aviation trials later this year with British-owned F-35s. She is expected to enter operational service in 2020, prior to her first deployment in 2021.