Scrapheap Challenge: Railroad Racer links, from Channel 4


		The Bluebell Railway www.bluebell-railway.co.uk Website of the railway that hosted the challenge and provided the expert. Railway Technology www.railway-technology.com/contractors/infrastructure/rexquote/index.html State of the art Railroad excavators. Train Web www.trainweb.org Railroad-related information and photographs. School for Champions: Rolling Friction and Automobile Tyres www.school-for-champions.com/science/frictionrolling2.htm A good summary of the science of wheels including a comparison between car and train wheels. How Stuff Works: Car Tyres www.howstuffworks.com/tire4.htm More about rolling resistance and how car tyres work.