The latest operating data released by the port showed an overall decrease in operations compared to April, as well as a slight decrease from May 2012.
Total exports for the month were 6% lower than May last year.
The amount of coal railed to RBCT dropped 45.7% month-on-month to 3.22Mt in May but was just slightly lower than the May 2012 data.
At the end of the month, RBCT counted 39 vessels and 405 trains and end-of-month stocks of 2.47Mt at the port, down from levels both last month and last year.
For the year to date the port has received 27.9Mt of coal and shipped 27.7Mt.