Watch Scrapheap Challenge online: Episode 4 Off Road Rescue

The Challenge This week's challenge is to build off-road rescue machines capable of lifting a hampered hatchback from a water hazard before carrying it cross-country to the safety of stable ground. With steep slopes to get up and down, sticky bogs to get stuck in and soft, slippery sand to sink into, our teams will operating at the limit of their bodging capabilities. Rough Riders Ozzie Senior, Barry Eastaugh (Bazza) and Jason Lord are three Yorkshiremen who spend half of their lives 20 miles off the coast of Hull on a gas storage platform in the North Sea. Between them, they oversee and run the safety, maintenance and mechanical upkeep of the platform. They have a wealth of mechanical engineering experience ranging from heavy plant machinery to bike and car engines. Barry is a 'guru' of a welder and there's not a lot these boys have not had a go at. The Riders have big characters and enthusiasm to match. Ozzie is a karaoke king and has won many an Elvis impersonator competition (and he is also likely to burst into a song at any given moment). Barry is known for his year-round tan and Lycra shorts. The Rough Riders are guaranteed to rise to any challenge – and they'll probably do it singing! The Rough Riders' expert is Tim Dray. He started out as an agricultural engineer and soon fell in love with off-roading. He has built many an off-road vehicle and has spent a lot of time organising the Camel trophy. Since this period, he has been a consultant to Land Rover, building and designing their 4x4 courses. Bakewell Puddings Nick Marriott, Mark Elliott (Smell) and his nephew Andrew Charlesworth (Charlie) are from the Derbyshire town of Bakewell. All are into bikes and racing (Motor Cross and Enduro). Mark and Nick have been friends for 20 years and have been in the same Motor Cross team as well as in a punk band together. Mark started to teach Charlie to ride at the age of nine, so it's fair to say bikes are this team's thing. Mark Elliott is an engineer, Nick Marriott is an architect and Andrew Charlesworth is a Rolls Royce engine inspector. These guys are also outdoorsy, sporty, rugby-loving, mountain-climbing kind of people who participate in the annual Bakewell raft race and the odd cross-town wheelbarrow race. They thrive on a challenge with plenty of ingenuity and humour to keep us all entertained! The Bakewell Puddings' expert is Steve Matthews and he's been building commercial recovery vehicles for the past 20 years – mostly out of scrap! In the past, he's also renovated tanks. He doesn't like beer, so what does he do to relax? Well, he likes nothing better than a cup of tea and ... building more cars! The judge This week's judge is Simon Buck, the only British winner of the most hardcore of all 4x4 events – the Malaysian Rainforest Challenge. His motto is 'it's better to be a spectacular failure than a dismal success.' He's a gung-ho guy – enough to drive at 70mph through the Malaysian rainforest ... in the monsoon season ... at night. As you can imagine he spends a lot of time getting vehicles out of a tight spot!

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