The engineering of the TG&BR was of the more substantial nature on the two lines; including three major bridges at the crossing of the Humber River, the Grand River, and the Saugeen River at Mount Forest; and the ascent of the Niagara Escarpment (Caledon Mountain) between Mono Road and Charleston (now Caledon village) which involved a "horseshoe" reverse curve of 500 feet radius and a gradient of 2% or 1:50.