Iron Awe - how and why HIO could 100X, page-698

The study investigated production of 10mtpa of Hawsons Supergrade® concentrate production for a mine of 20 years production for 201Mtpa. The ore is to be mined and processed on site, with the final mineral concentrate being transported via slurry pipeline to a rail head site near Broken Hill.

Concentrate will then be dewatered and transported on the existing rail to Port Pirie, where a port upgrade including storage sheds, pipe conveyor and new ship loaders is proposed. Ore would then be transported via barge to capesize ocean going vessels for delivery to export markets to customers in the Middle East and East Asia.

Straight from the PFS. And what Tran says is correct. Currently 12Mtpa spare capacity on that rail line. And this rail line is already used for mining products. The section your refer to seems to be specific for the rail line to port Whyalla not the one to Port Pirie.
You appear to using arguments against the company you hold against HIO. That isn't only lazy, it's also incorrect.