The P7 locomotive was first used in 1911, on the line running from Trieste to Parenzo in Istria. This route’s rails were very narrow (760 mm Austrian reduced gauge), and it was so winding, with inclines so extreme, that it took seven hours to traverse. The new locomotive decreased travel times for the 123 km journey by two hours. The line was closed in the 1930s due to difficulty of maintenance and lack of use.