building a decline, page-18

Hi Minerjoe, Calcs came from the following scenario, I ran curves based on: Shaft vs. Decline vs. Vent m/s vs. Macinery kw/rating, added a conservative number of 150k Tonnes/yr. Basically the curves start to cross at about 800 vertical metres at a 3.5 x 3.5 Decline, basically the haulage fleet will need to be doubled to sustain tonnes or the Shaft will need to be stripped to accomadate bigger skips and intake for the Mine at depth. Its just indicating to me that a fleet of say 8x15T Trucks to maintain tonnes and we will probably choke from lack of air flow vs. 2x5oT Trucks that fit in the 4x4.5 Decline that would sustain adequate air flow at depth, also the TKM,s on the 15Tonners are huge up against the 50Tonners, anyway there are a mirage of other factors to put in and I dont have the detail as such of the MCO Mine.
I agree with your 3.5x3.5 Decline here, I would still probable opt for an extra .5 on the height though, as your aware hand held bolting just adds another factor into the cycle, at a cost, agree with the split feed, take a longer round then replace with 3mtr bolting steel for 2.4mtr split sets for support, at least with a 4mtr back height you will be able to complete the cycle with the one set up.