An insight into the lives of construction workers building turbines at one of America's biggest wind farms in Montana. The 200-strong crew have 8 weeks to erect 70 structures and must learn the site's strict safety regime as they deal with massive machinery and terrifying heights. Crane operator Keith Miles lifts a section that weighs as much as 7 double-decker buses, and new staff member Oscar Scott faces a test of nerves as he works 260ft in the air, where strong winds make it difficult to stand.