Dalrymple's existing 60 million ton a year capacity has been stretched to capacity in a market where global demand for exported coal from Queensland has boomed. The recent increase in output from Rio Tinto’s Hail Creek coking coal mine to 5.5Mtpa has placed additional pressure on the facility.

Owner of the key coal exporting terminal, Prime Infrastructure Group, said it had commenced the engineering and design work required to boost capacity.

Any effect is only expected in 2006 with the design program not expected to be finalized until the end of 2005.

Further expansion is on the cards and Prime is in the initial stages of securing necessary regulatory approvals to increase beyond 91 million tons.