Ann: Quarterly Cashflow Report, page-23

The single drum winder is not a constraint as only one compartment is available for both men and ore/mullock haulage and is generally able to provide sufficient material to keep the mill operating at capacity given its propensity for maintenance outages and such.
A double drum winder and an additional haulage compartment would offer no real advantage because the narrow vein nature of the deposit will never allow sufficient tonnages to be mined on a continuous basis.
The payable shoots are of low volume, narrow, flat lying and only amenable to airleg mining techniques. The broken rock generally needs to be scraped to the draw points necessitating multiple handling and further restricting mill feed.