47481 crosses St Pinnock Viaduct (between Liskeard and Bodmin) on 18 April 1979 with the 1B24 07:30 Paddington to Penzance service. At 151 feet high, this is the tallest viaduct in Cornwall. The iron decking replaced Brunel's original timber decking in 1882, and in order to ease the stresses on the structure, the line was singled in 1964.