chinese t/o & bfs, page-46

I actually don't think the viability of the Surat assets is questionable at current prices. There are existing mines in the Surat and Clarence Moreton (basically the same basin) and they are smaller mines which are either exporting small quantities through Brisbane (Acland, Wilkie Creek) or even selling into the domestic market at a huge discount to the export thermal price (Kogan Creek, Commodore).

New Hope even re-opened two of their Clarence Moreton mines that were shut prior to the boom.

And Acland began operations in the early 2000s when export thermal coal prices were $50/t for NEWC grade.

The COK deposits might have slightly worse strip ratios than some of these mines but not by much, and the increased tonnage and more efficient rail/port system should compensate.