building a decline, page-5

You are probably referring to a machine called a road header they tend to be used in softer rock than what you would find at Morningstar which I think is some type of granite,(dolerite) a road-header was used to do the decline for BMA's mine (ASX BMO ) about three years ago.
Road headers have a rotating head with hardened teeth that grind out the ore, its a continuous process with no blasting needed
I am guessing at MCO they would drill, charge and blast with some type of two masted machine, probably what miners call a jumbo, then muck out the gangue with a LHD then bolt the ceiling.
Road headers and jumbos are a dime a dozen several companies rent them.
Mels metrics seem about right I was thinking a 1 in 10 grade though but I have no professional experience so take what I say with a grain of salt, probably best to direct your question to Minerjoe who posts on here.