From the 1860s large deposits in the Don Basin ("Donbas") in southern Russia supplied 87% of Russia's coal. It was used by railways and the iron and steel industry. After 1900 smaller deposits near Dombrovo, Zabaikal and Cheremkhovo in Siberia were opened. Small older mines south of Moscow also operated. Coal production was controlled by inefficient Russo-British syndicates, and there were shortages of workers, so the companies set up welfare systems for them. Their smallish output and the weak Russian railway system centered on the Ekaterininskaia (Krivoi Rog) Railway held back the growth of Russian heavy industry.