Scrapheap Challenge: Drag Sled

Woof Justice, police dog handlers from Newcastle-upon-Tyne, take on West Country cabbies the Turbo Taxis in the second semi-final. The teams have to create drag sleds - single-axle vehicles that can tow a rider on a sled or skis - using only what they find in the scrapyard. Robert Llewellyn and Lisa Rogers present