Cornelia Colliery is situated on the Orange Free State side of the Vaal River. The output of this Colliery in tons is:
1911 262,076 1915 508,428 1919 595,580
1912 296,706 1916 538,363 1920 645,412
1913 338,321 1917 592,413
1914 445,496 1918 581,296
The present output is at the rate of 55,000 sales tons per month. The consumption by local industries at Vereeniging, such as the Victoria Falls & Transvaal Power Company Limited, the Union Steel Corporation, the Vereeniging Brick & Tile Company, the Vereeniging Milling Company, the Lime Works, and the Muncipality is steadily increasing. In addition, a substantial trade is being done with the Witwatersrand Gold Mines and with Merchants and other industries in Johannesburg and other towns of the Transvaal and Orange Free State.
The Colliery employs 130 white employees and 1,800 natives.
Camp Colliery (below) is on the Transvaal side of the Vaal River and was sunk during the years 1912 and 1913. A tunnel was driven under the river to connect with the Orange Free State Coalfield. Owing to the unsettled conditions caused by the War, operations at this Colliery were temporarily suspended in 1914. The Colliery is equipped with headgear, permanent winding engine, compressed air and rock drilling and boiler plant, with native quarters, etc.
The coal formation underlying the Estates, according to the report of Dr F H Hatch, F.G.S., M.Inst.C.E., dated 15th April, 1903, extends over 151 square miles of the total area of the Estates property. There are two Colliery pits open at present.