This could be the construction of the steep and straight(ish) road from the Errwood dam wall which was from 1831 to 1892 the 1:7 Bunsall Incline of the Cromford and High Peak Railway where railway waggons were hauled up to the top by a fixed steam engine before continuing their journey with a locomotive. The railway line connected the Peak Forest Canal's terminus at Whaley Bridge with the Cromford Canal south of Matlock, Derbyshire.