The British Rail Class 76 , also known as Class EM1 , is a class of 1.5 kV DC , Bo-Bo electric locomotive designed for use on the now-closed Woodhead Line in Northern England . The British Rail Class 76 , also known as Class EM1 ( Electric Mixed-Traffic 1 ) , is a class of 1.5 kV DC , Bo-Bo electric locomotive designed for use on the now-closed Woodhead Line in Northern England .