The Longhai Railway is a 1,759 km (1,093 miles) line between Lianyungang and Lanzhou. Between 1935 and 1937, they received 15 Pacifics for long-distance passenger service from manufacturers of Belgium and the Netherlands. Four came from Cockerill, four from Haine-Saint-Pierre, four from Tubize and three from Werkspoor. They had relatively low drivers of 1,750 mm and cylinders of 500 by 710 mm. They originally carried the numbers 501 to 515 and were taken over by China Railway after World War II. There they were classed as PX13 for a short time, but got the designation SL13 in 1959. Some were still seen in service in the eighties.