Guardian: The Caterpillar 797B heavy hauler is the world’s biggest truck. It’s taller than a four-storey house, as wide as a tennis court and it removes nearly 35,000 tonnes of oily sand a day from a deep open cast mine in northern Alberta in western Canada. Truck number 108 is driven by Norman Johnson, 63, a long-time Shell man who is planning to spend his retirement fishing, camping and “hunting the critters” in the vast boreal forests and bogs that stretch across the region. …