Eshmun,You are partly right and I am partly right. While the...

Eshmun,

You are partly right and I am partly right. While the stope height is indeed 13m, you have forgotten the 4x4m development drive on every level so the floor to floor height is 17m. I think you have overcomplicated a simple calculation...I'll explain -

Beresford:
Stated planned mined depth below surface = 430m
On the graphics, especially the long section (not oblique and with 100m tick marks) the top of development starts at ~100m depth and the FS document says the development is designed to 430m below surface. So 330m vertical development - I'm pretty confident of that number and the cross-check is 20 levels at 17m =340m vertical which agrees.
So, 331,000oz divided by 330m vertical = (conveniently) 1,000ozpvm and 2 declines means 500ozpvm per decline.

Allanson
Stated planned mined depth below surface = 540m
On the graphics, especially the long section (not oblique and with 100m tick marks) the top of development starts at ~150m depth and the FS document says the development is designed to 540m below surface. So again 390m vertical development - I'm pretty confident of that number and the cross-check is 24 levels at 17m =408m vertical which agrees.
So, 162,000oz divided by 390m vertical = 415ozpvm

So both still 50% below a 'healthy' payback for the required vertical development - and that is not addressing the extreme challenge of mining 1.2mtkpa from - as you suggest - an orebody with an average width of 2.2m.

DYOR
Electra