Ann: Operation Update, page-23

Hey mate, it is truck weighbridge to measure and pay the road haul contractor. Nothing to do with barges. So yes it will be infinitely more efficient to load when 1,000 t/hour conveyor is operational but IMO customer won't wait that long.
So I did this in Australia for many decades and 8 years in Indonesia. The weightometer on conveyor is used to control feed rate onto the conveyor and thus the barge. So the accumulator shows how many tonnes that has been loaded onto the barge. So that is nothing to do with payment. The only method used for payment is Draft Survey.
So during loading the conveyor weigher helps with the loading process but the tug/barge Captain and the CKA Port Captain monitor the loading by eye ensuring the barge is evenly loaded for the entire length and width. by moving the barge under conveyor discharge chute.
The tug skipper will pull it up when the safe draft is achieved. The Port Captain may pull it up when the desired tonnage has been loaded.
So none of that has anything to do with payment.
The exact dimensions of the barge are known (Survey Certificate). Before the barge loads the draft is surveyed. After loading it is surveyed again. The density of water is measured, nominally 1. The volume of water displaced is the weight of coal loaded.
Long story but this is the way it is done!