A distinctive yellow VW Beetle is making its way over Bristol’s Suspension Bridge when suddenly disaster unfolds. A huge explosion can be seen in the distance with billowing plumes of smoke, and the doctors at Holby City Hospital must prepare for the worst. This is the opening scene of Casualty’s two-part 40th Anniversary special, and it mirrors the very first episode of the show on September 6, 1986 when the driver of the Beetle was Charlie Fairhead, who went on to become the hospital drama’s longest-serving character.The people on the ground may have changed over the past 40 years and the camerawork is a little more sophisticated.But as the world’s longest-running medical show celebrates its landmark birthday, the special double bill serves as a reminder of why it has been so beloved for so long.Before George Clooney and ER, and more recently the critically acclaimed The Pitt, there was Casualty. It followed the stories of both those coming into the emergency department and those who treated them. Back in 1986 this was ground-breaking and immediately controversial because it dared to show, in all its gory detail, the chaos of an NHS emergency department. Casualty at 40 …It’s a blast! The beloved history of the BBC hit as the world’s longest-running medical show celebrates landmark birthday (pictured Kate Winslet in 1999) But as the world’s longest-running medical show celebrates its landmark birthday, the special double bill serves as a reminder of why it has been so beloved for so long’You watch The Pitt and it’s set in one of those few hospitals in America that’s publicly financed,’ says William Beck, who stars as Dr Dylan Keogh. ‘It films in the same aesthetic, has the same metronome as our show. It’s brilliant, but it’s there because of the people who came up with Casualty.’Those people were script editor Jeremy Brock and theatre director Paul Unwin – two politically driven 25-year-olds who met at the University of Bristol. Both had spent time in hospitals – Unwin after a serious car crash, Brock with ulcerative colitis – and wanted to write something that was both a love letter to the NHS and a warning about what was happening in the service.Inspired by American multi-strand dramas such as M*A*S*H and Hill Street Blues, their original pitch opened with the line: ‘In 1948 a dream was born. In 1985-1986 that dream is in tatters.’ They framed the A&E department – at that time known as the Casualty department – as ‘the frontline in the battle for the soul of the NHS’.It was immediately commissioned for a primetime Saturday-night slot and, to prepare, they spent time shadowing staff at Bristol Royal Infirmary. The hospital’s real-life Charge Nurse Peter Salt became the main inspiration for Charlie Fairhead (played by Derek Thompson), who drove that Beetle in the first episode which saw the hospital dealing with a gas explosion.That first episode sparked controversy though. Some scenes showed the staff drinking and smoking while on duty – no longer the angels depicted on TV previously – and the NHS itself was portrayed as a flawed institution struggling to cope. It was as if no one had pointed this out before. Edwina Currie, then a junior health minister, attacked the show in the House of Commons, calling it ‘anti-NHS propaganda’ and ‘left-wing rubbish’.But the public lapped it up and still do. ‘We’ve all been to A&E so there’s a sense of recognition,’ says series producer Liza Mellody. Back in 1986 this was ground-breaking and immediately controversial because it dared to show, in all its gory detail, the chaos of an NHS emergency department Other big names who appeared early in their careers include Martin Freeman (pictured), Nicholas Hoult, Tom Hiddleston, Minnie Driver, Ray Winstone and Orlando Bloom That first episode sparked controversy though. Some scenes showed the staff drinking and smoking while on duty (pictured Minnie Driver) ‘You don’t go there for a day out. You go at your worst time, because somebody is ill. You need help. You’re seeing humans at their worst, and hopefully meeting people who are heroes – doctors and nurses – but also just normal people.’Plus everyone loves a bit of gore, and a bit of medicine. Then we have our serial within that. The backdrop is that we’ve got to know these doctors and nurses so we are connected to them, while every week you get some great stories played by guest actors.’In some ways that hasn’t changed in 40 years but, just as the NHS has had to modernise, so have we. ‘We can’t be political, we are the BBC and we have to be fair. We want to be real about what’s happening in hospitals but we also have to let the audience make up their own minds.’The series has not only spawned two spin-offs – Holby City (about the wider hospital, which lasted for 23 years) and the short-lived police procedural Holby Blue – it’s also provided a springboard for some of Britain’s biggest talents.Kate Winslet, who played a teenager dealing with an abusive boyfriend in a 1993 episode, said: ‘In England it almost seems to be part of a jobbing actor’s training. Appearing in the show taught me a big lesson in how to be natural in front of the camera.’Other big names who appeared early in their careers include Martin Freeman, Nicholas Hoult, Tom Hiddleston, Minnie Driver, Ray Winstone and Orlando Bloom, while Brenda Fricker, who won a Best Supporting Actress Oscar in 1990 for her role in My Left Foot, played staff nurse Megan Roach.The show has tackled huge subjects from murder and train crashes to riots, sexual assault, mental health issues and motorway pile-ups. Four times a year, before they start work on a new series, the show’s writers meet with experienced NHS frontline medics. ‘We have guest days and our writers will sit in a room with doctors, nurses and paramedics,’ explains Liza. ‘We’ll say, ‘We’re thinking about doing this’ and they’ll share their experiences. The key is to be entertaining but absolutely authentic.’The 40th anniversary episodes start with heart-throb doctor Flynn Byron, played by former Call The Midwife star Olly Rix, jogging across the bridge when there’s an enormous explosion, thought to be a terrorist attack, so he quickly heads towards it. Flynn is an ex-special forces doctor who arrived in Holby last year and now he’s the clinical lead, bringing a military-style drive for change and efficiency.First he helps the wounded at the scene and then gets into trouble when he’s involved in an accident that leads to his ambulance being submerged in water. Olly reveals he spent two weeks filming these scenes on the underwater stage at Pinewood Studios, where James Bond is filmed.’I did a lot of training with this extraordinary dive team,’ he recalls. ‘We didn’t have to use much imagination as we really were in the water, but thankfully it was safe enough that I could do all the underwater stunts myself. It was a bit nerve-wracking at times.’ Incidentally, Olly has found love on the show, recently revealing his engagement to co-star Anna Chell (who plays paramedic Jodie Whyte).We also follow what’s happening at the wider Holby City Hospital, where the team is struggling with the wounded and trying to find out if more danger is imminent. For Dr Dylan Keogh, who’s in charge, it’s a particularly difficult situation as he personally knows one of the seriously wounded. ‘He has a huge amount to deal with and a bit of a bomb goes off for him,’ says William Beck.The producers are hoping the specials will be not just a boon for the show’s three million devoted fans (from a height of over 15 million in the 1990s) but also a showcase for those who may not have seen the series for years. ‘Casualty fans are so loyal,’ says Melanie Hill, who plays clinical nurse manager Siobhan McKenzie. ‘A lot of them have watched every episode. And the fact that it’s the 40th anniversary, I’d like to think of it as a way a new audience can latch on.’Long-running fans of the show will be satisfied by a series of nods to the past over the two episodes, while producers also see it as a showcase for the future, because it’s all change for Casualty. From the next series the show will be set in Cardiff (with mostly the same cast), where it has been filmed since 2011, rather than fictional Holby.’We’ll be moving our fictional world to Cardiff,’ says Liza. ‘Practically, there is a lot to be said for not having to pretend we’re somewhere else. We can really be in Wales and it will allow us to show its beauty, plus we have a new set, a new hospital.’So it truly has been a time both to look back and also to the future. ‘We want to remind people that Casualty is warm and funny, but also filled with entertainment and adrenaline,’ says Liza. ‘People might be talking about the US series, but they should remember that we’re here and covering what’s real to us in the UK with just as much drama.’Casualty 40th Anniversary special episodes, Saturday, from 8pm, BBC1 and BBC iPlayer.