JOHANNESBURG - South Africa’s Transnet said it will shut down its coal export line over a 10-day period for annual maintenance but this would not affect tonnages delivered as the halt was factored into its schedule. The state-owned logistics firm said in a statement seen by Reuters on Tuesday that the shut-down is meant to help it catch up on a maintenance backlog and upgrade its railway network. Companies such as Exxaro, BHP Billiton , Glencore and Optimum Coal Holdings use the export line to transport the commodity. A Richards Bay Coal Terminal (RBCT) spokeswoman said the company would also carry out its own extensive maintenance work but that exports were continuing from stock piles despite not receiving coal in the period. RBCT only gets coal from Transnet rails. Last year the terminal exported 71.3 million tonnes of coal, the highest amount ever and is set to expand its capacity to over 100 million tonnes in 2015.