Improved performance by Gina Rinehart's Roy Hill has the iron ore miner pushing closer to its long-held export goal, but evidence suggests it is yet to export at its target annualised rate of 55 million tonnes for three consecutive months.

Roy Hill, which is 70 per cent owned by Mrs Rinehart's flagship company Hancock Prospecting, does not publish export numbers, but its performance can be deduced through a combination of port data, shipping data and export figures published by the ASX listed miners that share Port Hedland with Roy Hill.