Mind the gap!Credit:PA HMS Queen Elizabeth starting to exit the dock, Rosyth, Scotland, 26 June 2017Credit:PA Sailors and engineers have worked round the clock getting the vessel ready. A total of 1,000 sailors and contractors will be onboard for the first six weeks of testing.Crew have spent hours each day carrying out safety drills for fires, flooding and personnel overboard. More than 650 doors and hatches have been checked to ensure they are watertight and fire safe. The warship under steam off the coast of ScotlandCredit:BEN SHREAD/Ministry of Defence Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. After trials begin this summer, the ship will move to its new home in Portsmouth this autumn. Trials for planes and helicopters will take place next summer.The flight deck is more than four acres in size and the ship can carry up to 36 F-35B stealth jump jets. Ian Booth, managing director of the defence industry alliance behind the ships, said: “The incident with the fire in London really brings it home to you, you don’t take chances with any incident on the ship, whether it be flooding or fire.” The Royal Navy has not had an aircraft carrier since the defence cuts of 2010. The arrival of the new carrier comes as the Navy is facing a budget black hole of around £500m each year and the demands of manning the new ships have been accused of causing shortages elsewhere.Critics of the carriers have also claimed they are expensive white elephants that are too vulnerable to new high speed missiles. HMS Queen Elizabeth on the Firth of ForthCredit: Andrew Milligan/PA The first steel was cut on the carrier eight years ago but it will not be sent on operations until 2021. Early deployments are expected to see US Marines F-35B jets embarked alongside British planes, to make up for early shortages of UK jets. Cdr Mark Deller, commander air, said the ship would be accompanied by a frigate or destroyer.He said: “We will go where it’s best to go and not where it’s best for a Soviet nuclear to go, so the reality is we can probably look after ourselves as long as our escort is in the right place at the right time. You don’t have to hang around and endure it, you can move away and go somewhere else.” “If XP is for operational use, it is extremely risky,” Alan Woodward, professor of computing at the University of Surrey told The Times. “Why would you put an obsolete system in a new vessel that has a lifetime of decades?” Sir Michael Fallon insisted the security around the computer software on the aircraft carrier is “properly protected”. Capt Jerry Kyd, commanding officer, said: “There is nothing on the globe that is invulnerable, whether that’s a city, a car, an individual, or a ship. We are not shy in the military to understanding the risks and how we mitigate that in the theatre of war.“If you look at all the premier nations around the world, why is it that every nation in the top tier is investing billions of dollars in aircraft carriers? Is it just us, or has everyone got it wrong? The reason being is that they provide the government, very simply, with an incredibly flexible tool. It’s not just about war-fighting. This is about deterrence, coercion, signalling, proving a huge sea base for disaster relief, humanitarian assistance, defence engagement.” Fears have been raised that Britain’s largest ever warship could be vulnerable to cyber attacks after it emerged it appears to be running the outdated Microsoft Windows XP.As HMS Queen Elizabeth left its dockyard for the first time to begin sea trials, it was revealed the £3.5billion aircraft carrier is apparently using the same software that left the NHS exposed.Screens inside a control room on the ship, which is the largest vessel ever built for the Royal Navy, reportedly displayed Microsoft Windows XP – copyright 1985 to 2001.But Michael Fallon, the Defence Secretary, insisted the ship’s systems were safe because security around the computer software on the aircraft carrier is “properly protected”. Captain Jerry Kyd, Commanding Officer, onboard the HMS Queen ElizabethCredit:Jeff J Mitchell/Getty The aircraft carrier squeezes out of dock to begin sea trialsCredit:Jeff J Mitchell/Getty Europe A screen in the operations room on board HMS Queen Elizabeth (right) appears to be running Windows XPCredit:Jeff J Mitchell/Getty It came after the 65,000 ton HMS Queen Elizabeth slipped out of Rosyth dockyard and into open water on Monday through an exit with only 14in clearance on either side and 20in of water under the keel.The aircraft carrier then edged along the Forth under three bridges, including the landmark rail bridge, with a little over six feet to spare. Cdr Fiona Percival, head of logistics on the ship said: “[The Russians] will come and look, but they look at everything.”It came as the Defence Secretary taunted the Kremlin over fears it will attempt to spy on HMS Queen Elizabeth during its sea trials, saying Russia will envy Britain’s new flagship. He told BBC Radio 4’s Today programme: “It’s not the system itself, of course, that’s vulnerable, it’s the security that surrounds it.”I want to reassure you about Queen Elizabeth, the security around its computer system is properly protected and we don’t have any vulnerability on that particular score.” The radio mast has been lowered to allow the vessel to pass under a bridgeCredit:Andrew Milligan/PA He said 2021 “will be the first time we will deploy this ship in anger”. Cdr Mark Deller, commander air on the Queen Elizabeth, told The Guardian: “The ship is well designed and there has been a very, very stringent procurement train that has ensured we are less susceptible to cyber than most.”He added: “We are a very sanitised procurement train. I would say, compared to the NHS buying computers off the shelf, we are probably better than that. If you think more Nasa and less NHS you are probably in the right place.” Bosuns mate Scott Campbell guards the Navy’s new warshipCredit:Getty A defence source told the newspaper that some of the on-boar hardware and software “would have been good in 2004” when the carrier was designed, “but now seems rather antiquated”.However, he added that HMS Queen Elizabeth is due to be given a computer refit within a decade.And senior officers said they will have cyber specialists on board to defend the carrier from such attacks. Sir Michael Fallon contrasted the carrier with what he called the “dilapidated” Russian carrier Admiral Kuznetsov, which sailed through the Channel late last year. The carrier’s flight deck is more than four acres in size He told BBC Radio 4’s Today programme: “It’s not the system itself, of course, that’s vulnerable, it’s the security that surrounds it.”I want to reassure you about Queen Elizabeth, the security around its computer system is properly protected and we don’t have any vulnerability on that particular score.”The operating system was that which left the NHS and other organisations around the world vulnerable to a major WannaCry ransomware attack last month. It affected 300,000 computers in 150 countries.Windows XP is no longer supported by Microsoft, meaning it does not receive updates to protect users from new types of cyber hacks. A computer expert warned that Windows XP could leave HMS Queen Elizabeth vulnerable to cyber attack. The trials mark the latest milestone in the nearly decade-long building of the Royal Navy’s two carriers, at a cost of more than £6bn.The Navy is also preparing for the warship’s first appearance to attract a concerted Russian spying effort, with submarines, ships and planes try to get a good look at the UK’s new flagship.