mining methods, page-3

Longwall extraction methods are commonly applied to higher $ value metallurgical coal seams but thermal coal can and is also be exploited this way if a buck can be made. As Profess says, the deeper the pits get, the easier it to justify installation of a longwall miner.
What gets me is that CPL often refers to the multiple kilometres of very shallow, gently dipping seams on the Vista property - a scenario that lends itself to a walking dragline/truck shovel op and very low costs. It almost implies that they won't need to develop deep pits. They can just continue exposing seams along strike, thereby maintaing low strip ratios and costs. That's why I'm confused that Vista is being promoted as being receptive to two forms of mining that are really at the opposite ends of the spectrum in terms of costs, safety and technical challenges. Longwalls carry a lot of upfront capital costs in regards to manufacture and installation.
I'm sure Gene and Co have good reason to think parts of the Vista project are longwall amenable so maybe someone can identify the info in reserves and resources figures that indicates the deeper seams are worth going after?