The EKJV at Kundna (NST, TBR/RND JV) mines the narrow veined Hornet/Rubicon/Pegusus/Pode lodes which have a combined strike length of a little over 2km from one decline at the based of the Rubicon pit (see image below). Historically these have been higher grade than Westralia but more recently the grade has been falling and tonnage increasing to maintian production. In the Dec 2018 quarter Rubicon/Hornet had a grade of 6.14g/t (for 121,131 tonnes mined) and Pegusus had a grade of 5.96 g/t (for 114,734 tonness mined), ie total tonnes 235,865t for 48,705oz all from only one decline.
The Beresford - Allason lodes at Westralia have a combined strike lenght very similar to the Hornet/Rubicon/Pegusus/Pode lodes at Kundana near Kalgoorlie of about 2km and in the Dec 2018 quarter produced 195,000t of stope and development ore at a grade of 4.2g/t for 25,925ozs of gold.
So Beresford/Allason produced (195,000t/235,865t)x100 =73.34% of the tonnage of the Hornet/Rubicon/Pegusus/Pode lodes from 3 declines (at Westralia) verses 1 decline (at Kundana) over roughly the same strike length for each group of deposits and the Kundana lodes are also now being mined from deeper levels than at Westralia. Clearly by comparison the current number of declines at Beresford/Allason are sufficient because the Kundana mines are hoisting about 21% more ore from only one decline (and deeper depths) and by my estimates the ore bodies are on average of equivalent widths. If anything the Kundana vien deposits are narrower than the Westralia BIFs.
The Dec quarterly also said, as I've mentioned before, that the development to stope ratio was running a little behind feasibilty in Dec 2018 quarter with an actual ratio of 33.3/66.6=0.5 vs 42/58=0.72 (for the feasibilty).
Based on the Dec 2018 quarter figures at Westralia development ore vs stope ore mined was 82,000t vs 113,000t which gives a ratio of 82/113=0.72 which coincidentally is in line with the overall development vs stope feasibilty ratio. If the overall development vs stope ratio had have reached feasibilty in the Dec quarter we might have expected to see an improvement in ore ore production of about 44% which could have given ore production of 280,800t at 4.2g/t for 37,921 oz which at a recovery of 93% would yield 35,266ozs from Westralia. Adding the 15,304*0.93 = 14,232ozs produced from the open pit mining in the Dec quarter gives 49,498oz around the top of the old guidance level.
There is little reason that I can see why this mine shouldn't be able to produce at feasibilty levels should enough equipment be thrown at it. The number of declines seem more than adequate based on the Kundana comparison. This is not to say costs might not be higher if more machinery and personal are involved but the production tonnages seem very doable IMO. Esh
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