Lack of an adequate transportation network has hindered the country's development. Altogether, rail trackage totals 1,086 km (675 mi). The state-owned, meter-gauge, single-track railroad from Conakry to Kankan (663 km/412 mi) was built between 1900 and 1914; it is in disrepair and no longer able to carry heavy traffic. As of 1991, the railway was being rehabilitated with French assistance. A standard-gauge track of about 112 km (70 mi) along this line, between Conakry and Debélé, near Kindia, links the port and the OBK bauxite mine. The Friguia Mining Co. built and maintains 144 km (89 mi) of railway between the Fria mines and alumina works and the port of Conakry; the Boké mining operation constructed a 135-km (84-mi) railroad linking its deposits at Sangarédi with the port of Kamsar.